Book of Abstracts - Chalmers · 2015-09-09 · Corresponding author: [email protected] . 7...

Book of Abstracts

Department of Earth and Space Sciences

Chalmers University of Technology

2

Session1

Instruments:

past, current and future missions

3

Measurement of upper atmospheric wind from sub-millimeter limb sounding:

Results from JEM/SMILES and simulation study for SMILES-2

Philippe Baron1, Naohiro Manago2, Hiroyuki Ozeki3, Yoshinori Uzawa1, Donal Murtagh4,

Satoshi Ochiai1, Makoto Suzuki5

1. NICT

2. Chiba University

3. Toho University

4. Chalmers Technical University

5. JAXA/ISAS

Sub-millimeter limb sounding is a mature and efficient technique to measure trace gases

in the middle and upper atmosphere. It has been demonstrated with the AURA/MLS and

JEM/SMILES missions that horizontal winds can also be inferred from the Doppler shift of

the strong spectral lines. The project SMILES-2 is under study in Japan and the objective is

to extend the SMILES capabilities to the mesosphere. The use of sub-millimeter and THz

channels with mixers cooled at 4 K is investigated. Upper atmospheric dynamics is one of

the topics that SMILES-2 wants to address. This presentation will summarize the wind

results obtained from SMILES . The study for optimizing the spectral setting of SMILES-2 for

wind measurement will also be presented. It will be shown that with few modifications of the

current definition of the spectral bands, SMILES-2 could have the potential to measure winds

from 25 km to 110 km with a precision better than 5 m/s and a vertical resolution better than

5 km through most of the vertical range.

Presentation style: Oral

Corresponding author: [email protected]

4

The Canadian Atmospheric Tomography System (CATS) – Possibilities and

Potential Missions

Doug Degenstein1, Adam Bourassa1, Chris McLinden2, Craig Haley3

1. University of Saskatchewan

2. Environment Canada

3. COM DEV International

The design of the Canadian Atmospheric Tomography System (CATS) is based on the

highly successful Optical Spectrograph and InfraRed Imaging System (OSIRIS) with

modifications to provide measurements with significantly higher spatial resolution. CATS has

been studied by the Canadian Space Agency for the past ten years and as such has been a

candidate instrument on a variety of different national and international missions. The focus

of these missions has varied from the study of processes that govern the complicated upper

troposphere – lower stratosphere region to the prediction of air quality at ground level.

However, foremost amongst the rationale to fly CATS is the continuation of the excellent

OSIRIS nitrogen dioxide, ozone and stratospheric aerosol data records. This presentation

will detail: the scientific goals associated with the CATS instrument regardless of its

designated mission; recent work, done using OSIRIS data and through simulation studies, to

help achieve these scientific goals and the current CATS mission status. Included is a

discussion of the high spatial resolution retrievals that are facilitated by CATS data

collection.



5

ALTIUS instrument model, in-flight calibration methods and ozone product

Emmanuel Dekemper, Didier Fussen, Didier Pieroux, Filip Vanhellemont, Nina Mateshvili,

Christine Bingen, Charles Robert, Ghislain Franssens

IASB-BIRA

ALTIUS (atmospheric limb tracker for the investigation of the upcoming stratosphere), is a

3-channel hyperspectral imager aiming at measuring trace species concentration profiles at

high vertical resolution. It is a passive instrument on a sunsynchronous polar orbit nominally

operating in two modes: collecting the Earth atmospheric limb radiance in the dayside, and

observing the occultation of the Sun, bright stars and planets during terminator and eclipse.

Both platform and payload are now sufficiently developed to allow for realistic mission

performance assessment. Based on the current design, we present the expected error

budget for L2 ozone profiles from bright limb and occultation measurements. We also

describe the baseline in-flight strategies for the radiometric calibration, and the pointing and

spectral registration. Using the instrument and platform models, these calibration

approaches have been worked out to estimate their expected performance channel per

channel.



6

OMPS Limb Profiler Data Products

Matthew DeLand1, P. K. Bhartia2, Glen Jaross2, Natalya Kramarova1, Ghassan Taha3, Zhong

Chen1, Nick Gorkavyi1, Philippe Xu4

1. Science Systems and Applications Inc. (SSAI)

2. NASA

3. USRA

4. SAIC

The Ozone Mapping and Profiler Suite (OMPS) Limb Profiler (LP) instrument is currently

flying on the Suomi NPP satellite, and has collected almost 3.5 years of regular data since

its launch in October 2011. LP hyperspectral measurements simultaneously cover a spectral

range between 290 nm and 1015 nm with variable spectral resolution (0.8-30 nm), and an

altitude range between 0 km and 80 km with 1 km sampling. The OMPS LP radiance data

provide the basis for numerous scientific products. Ozone profiles covering the altitude range

10-60 km with ~1.8 km vertical resolution are created by combining UV retrievals and visible

retrievals. The LP Version 2 ozone product (released in summer 2014) generally agrees with

MLS data to within ±5% in the stratosphere. Localized regions with larger biases may reflect

uncorrected altitude registration errors and 2nd order aerosol effects in LP data, as well as

mesospheric geopotential height errors in MLS data. We are implementing a Version 3

aerosol product (675 nm only), based on Chahine’s non-linear relaxation retrieval method, to

create extinction coefficient profiles from cloud top to 30-35 km. We have developed a cloud

height product, based on the spectral dependence of vertical gradients in radiance at visible

and near-IR wavelengths, that compares well with CALIOP observations. OMPS LP

measurements are very sensitive to the presence of polar mesospheric clouds (PMCs) in the

line of sight. While this situation does affect UV ozone retrievals in high latitude summertime

conditions, LP PMC measurements also provide the opportunity for 2-D tomographic

analysis and coordinated studies with collocated OMPS Nadir Profiler PMC measurements.



7

The Canadian Atmospheric Tomography System (CATS)

Craig Haley1, Doug Degenstein2, Ryan Cooney3

1. COM DEV International

2. University of Saskatchewan

3. Canadian Space Agency

The Canadian Atmospheric Tomography System (CATS) is a UV/visible/near-IR

spectrometer designed to measure limb-scattered sunlight to derive vertically-resolved

concentrations of O3, NO2, and BrO and aerosol extinction from the Upper Troposphere

through the Stratosphere. CATS is a follow-on to the OSIRIS instrument currently in

operation on the Odin satellite. In addition to monitoring the stratosphere and extending the

long time-series provided by OSIRIS, CATS will focus on the study of fine scale phenomena

in the Upper Troposphere/Lower Stratosphere (UTLS) region. To accomplish this new goal,

the current CATS design incorporates the following modifications over OSIRIS: 1) Increased

spectral range, focussed on an improved aerosol product. 2) Better spectral resolution,

aimed at improved NO2 and BrO data products. 3) Improved vertical resolution and

sampling, important for measurements in the UTLS region. 4) Better horizontal (along-track)

sampling, to allow a tomographic retrieval approach to be used. The current status of the

CATS instrument design and development will be reviewed, highlighting the changes from

the OSIRIS instrument design, the main outstanding technical risks, and the current

development activities.



8

Tangent height and stray light performance of the SNPP OMPS Limb sensor

Glen Jaross1, Leslie Moy2, PK Bhartia1, Grace Chen2, Zhong Chen2

1. NASA Goddard Space Flight Center

2. Science Systems and Applications, Inc.

Two major challenges that are common to all solar backscatter Earth limb measurements

are internally scattered stray light and tangent height registration. Stray light poses a

particular problem for OMPS because it images 100km of the Earth limb simultaneously at

the focal plane. A pre-launch characterization of point spread functions is used to predict the

stray light content of every Earth limb image, and subsequently used in the data correction

algorithm. A comparison of the corrected radiances with radiative transfer model predictions

revealed uncorrected errors in excess of 1% above 60 km in the UV and above 40 km in the

VIS and IR. We believe we have identified the sources of this additional stray light and show

it is easily accommodated in the existing correction methodology. Two scene-based

methods were previously developed to verify the tangent height registration obtained through

spacecraft pointing information. Both the RSAS Method and the Peak Method rely upon the

ability to accurately model the transition from altitudes where single Rayleigh scattering

dominates to where the atmosphere is optically opaque. The results of these two methods

applied to OMPS are in good agreement and indicate TH errors in excess of 1 km in the

pointing provided by the SNPP spacecraft. A third method, which relies on UV radiances

above 55 km, has been developed to monitor changes in pointing. While it lacks the overall

accuracy of the other two methods, it has a precision approaching 100 m when averaging at

least one day of data.

Presentation style: Poster


9

Microwave Limb Sounding of upper troposphere and lower stratosphere

composition: Prospects for future space-based and airborne observations

Nathaniel Livesey1, Michelle Santee1, Robert Jarnot1, Robert Stachnik1, Paul Stek1, Goutam

Chattopadhyay1, Jacob Kooi1, Jonathon Kocz1

1. Jet Propulsion Laboratory, California Institute of Technology

Observations from the Microwave Limb Sounder (MLS) instrument on NASA's Aura

satellite have been central to many studies of the upper troposphere and lower stratosphere

(UTLS) including polar ozone loss and associated phenomena, processes affecting the

budgets of UTLS water vapor, the impact of pollution on clouds, and long range transport of

pollution. We review potential future instruments utilizing the MLS technique that could

extend and augment the 10+ year MLS record. Specifically, we describe work underway to

develop follow on MLS-like instruments, including a simplified "continuity" instrument to

extend the MLS record (and add further species), and a more ambitious "Scanning

Microwave Limb Sounder" (SMLS) that scans the limb with 50x50 km horizontal sampling.

Depending on the choice of orbit, SMLS can make multiple (as many as eight)

measurements per day over selected regions. The SMLS temporal and spatial resolution

would enable valuable new insights into the impact of fast processes, such as deep

convection, on UTLS composition. We also introduce the "Airborne Scanning Microwave

Limb Sounder" (A-SMLS) that, using SMLS technology, makes the same observations as

Aura MLS over a ~300 km-wide swath in the upper troposphere when flown on a high-

altitude aircraft such as the NASA ER-2, WB-57 or Global Hawk. Results from past A-SMLS

test flights are discussed, and the potential utility of A-SMLS measurements to future

airborne campaigns is described.



10

The MATS satellite mission - Tomographic perspectives on the mesosphere

Linda Megner1, Jörg Gumbel1, Donal P. Murtagh2, Nickolay Ivchenko3, and the MATS Team

1. Department of Meteorology, Stockholm University, Sweden

2. Department of Earth and Space Sciences, Chalmers University of Technology,

Göteborg, Sweden

3. School of Electrical Engineering, Royal Institute of Technology, Stockholm, Sweden

Space-borne limb imaging in combination with tomography and spectroscopy opens

exciting new ways of probing atmospheric structures. MATS (Mesospheric Airglow/Aerosol

Tomography and Spectroscopy) is a new Swedish satellite mission that applies these ideas

to the mesosphere. MATS science questions focus on mesospheric wave activity and

noctilucent clouds. Primary measurement targets are O2 Atmospheric band dayglow and

nightglow in the near infrared (759-767 nm) and sunlight scattered from noctilucent clouds in

the ultraviolet (270-300 nm). While tomography provides horizontally and vertically resolved

data, spectroscopy allows analysis in terms of mesospheric composition, temperature and

cloud properties. Based on a two year mission, the scientific analysis will address

atmospheric structure and variability, wave interactions, and noctilucent cloud microphysics.

MATS is currently being prepared for a launch in 2018. This presentation summarizes

instrument and analysis ideas, and discusses scientific perspectives and relationships to

other missions.

Invited speaker


11

The STEAMR (Stratosphere-Troposphere Exchange And climate Monitor

Radiometer) instrument

Donal Murtagh1, Patrick Ericsson1, Urban Frisk2, Fredrik von Scheele2, Anders Emrich2

1. Department of Earth and Space Sciences, Chalmers University of Technology

2. Omnisys Instrument AB

3. OHB Sweden

The STEAM instrument has been under development in Sweden as part of the ESA

PREMIER project that finally not selected in the final competition for the seventh Earth Explorer mission. STEAM is a multi-beam sub-mm limb viewing operating in the 340 GHz region. The main target region is the upper troposphere lower stratosphere where changes in composition have the greatest impact on surface climate. The original STEAM-R instrument had 14 beams covering the region 4-28 km in a fixed staring pattern, however to be able to accommodate the instrument on a smaller national platform the number of beams has been reduced to 4 with a larger separation in order to cover the same altitude range. The addition of scanning using the platform will allow the intervening altitudes to be filled in. Simulations show that that using this strategy with passive cooling of the detectors allows the original PREMIER/STEAM mission requirements to be fulfilled. To further enhance the science of the reduced mission an extra channel at around 630 GHz has been added to allow for monitoring of the stratospheric chlorine content. The presence of clouds will be indicated by a nadir scanning channel at one of the higher frequencies chosen for the ICI instrument and will provide useful pathfinder data.



12

Submillimeter limb sounder for measurement of upper atmosphere

Satoshi Ochiai1, Yoshinori Uzawa1, Yoshihisa Irimajiri1, Philippe Baron1, Toshiyuki Nishibori2,

Makoto Suzuki2, Masato Shiotani3

1. National Institute of Information and Communications Technology (NICT)

2. JAXA

3. Kyoto University

The paper discusses a future mission of submillimeter-wave limb sounding to measure

stratospheric and mesospheric temperature, wind, and chemical species. The SMILES-2

project is an advanced version of JEM/SMILES, being proposed by our group for JAXA's

small satellite program. The improvement upon the preceded SMILES will be the extension

of measurement vertical range of temperature and wind up to the lower thermosphere by

using GHz and THz channels. Our plan to overcome the technical issues toward the realistic

design of SMILES-2 will be presented. The paper will also discuss a smaller mission, which

does not use superconducting devices. Such mission may have higher opportunity for

launching. It can measure the stratospheric and mesospheric wind with limited precision.



13

SMILES-2: I Proposal overview

Makoto Suzuki1, Toshiyuki Nishibori1, Satoshi Ochiai2, Philippe Baron2, Yoshinori Uzawa2,

Naohiro Manago3, Hiroyuki Ozeki4, Masato Shiotani5

1. JAXA/ISAS

2. National Institute of Information and Communications Technology

3. Chiba U./Center of Environmental Remote Sensing

4. Toho U./Faculty of Science

5. Kyoto U/RISHKyoto University

Superconducting Submillimeter-Wave Limb-emission Sounder (SMILES) was the first

instrument to use 4K cooled SIS (Superconductor-Insulator-Superconductor) detection

system for the observation of the atmosphere in the frequency regions 625 GHz (Bands A

and B) and 650 GHz (Band C). It has demonstrated its high sensitivity for measuring

stratospheric and mesospheric species, O3, HCl, ClO, HO2, HOCl, BrO, and O3 isotopes

from Oct. 12, 2009 to Apr. 21, 2010. Since SMILES operation has terminated after only 6

months operation due to failure of sub-mm local oscillator (and later 4K cooler system), there

exist strong scientific demand to develop successor of SMILES, the SMILES-2, which has

optimized and enhanced frequency coverage to observe: (a) BrO and HOCl without

interferences of stronger emission lines, (b) N2O, H2O, NO2, and CH3Cl not covered by the

SMILES frequency regions, and (c) O2 line to measure temperature. This paper discusses

possible SMILES-2 band selection considering limited instrument resources (number of SIS

mixers and sub-mm local oscillator) and scientific requirements. The SMILES-2 satellite

should be 500 km (above) and 51° (or higher) to observe diurnal variation of atmosphere. It

is difficult to have lower orbit altitude due to the ISS interference and the atmospheric drag.

Inclination can be a bit higher, although it gives slower coverage of diurnal cycle. The

satellite should be 500-700 kg and power consumption should be 500-1000 kW. It is

assumed to use JAXA/ISAS small science satellite bus, which is identical to METI/ASNARO-

1 bus. OH and O-atom can be measured with very high sensitivity at the 1.8-2.0 THz

frequency region. Hot Electron Bolometer technology has been developed for the THz mixer,

and it was already applied to the space-borne astronomical observatory, Herschel. SMILES-

2 will try to measure OH, H2O, and O-atom at the 1.8-2.0 THz region, one of 3 lines at the

same time (sequential switching). Due to the limitation from 4K/20K stage design (number of

mixers at 4K stage, and pre-amplifiers at 20 K stage), 2 SIS mixers for the sub-mm bands

and 1 HEB micer for the THz bands are under consideration. Instrument Altitude range: 10-

120 (-150) km, 2.5 km vertical sampling. Frequency sampling: 4 GHz bandwidth, 500 kHz

sampling interval, 1.3 MHz Gaussian (FWHM). Tsys = 150 K, Integration time <0.48 (0.1667

or 0.25) s. 80 cm antenna diameter is considered in the Phase-A study. (Band 1LSB) 485-

489 GHz: T, Wind, O2, H2O, O3, HO2, HNO3 (Band 1 USB) 523-527 GHz: O3, 17OOO,

18OOO, O17OO, O18OO, BrO, NO2, H2CO, N2O, HO2 (Band 2 LSB) 623-627 GHz:

SMILES Bands A+B extended, O3, HCl, BrO, HNO3, HO2, N2O, HOCl, CH3CN, CH3Cl

(Band 2 USB) 648-652 GHz: SMILES Band C extended, O3, 17OOO, O17OO, 18OOO,

ClO, HO2, BrO, NO (Band 3, HEB) 1.8, 2.0 THz OH, H2O, O-atom (one of 3 can be

observed)

14



15

SMILES-2: II Band selection study

Makoto Suzuki1, Naohiro Manago2, Philippe Baron3, Satoshi Ochiai3, Hiroyuki Ozeki4

1. JAXA/ISAS

2. Chiba U./Center of Environmental Remote Sensing


4. Toho U./Faculty of Science

Superconducting Submillimeter-Wave Limb-emission Sounder (SMILES) was the first

instrument to use 4K cooled SIS (Superconductor-Insulator-Superconductor) detection

system for the observation of the atmosphere in the frequency regions 625 GHz (Bands A

and B) and 650 GHz (Band C). It has demonstrated its high sensitivity (System

Temperature, Tsys ̃250K) for measuring stratospheric and mesospheric species, O3, HCl,

ClO, HO2, HOCl, BrO, and O3 isotopes from Oct. 12, 2009 to Apr. 21, 2010. Since SMILES

operation has terminated after only 6 months operation due to failure of sub-mm local

oscillator (and later 4K cooler system), there exist strong scientific demand to develop

successor of SMILES, the SMILES-2, which has optimized and enhanced frequency

coverage to observe: (a) BrO and HOCl without interferences of stronger emission lines, (b)

N2O, H2O, NO2, and CH3Cl not covered by the SMILES frequency regions, and (c) O2 line

to measure temperature. This paper discusses possible SMILES-2 band selection

considering limited instrument resources (number of SIS mixers and sub-mm local oscillator)

and scientific requirements. SMILES L2 system used strong O3 and HCl lines to retrieve

temperature, which has sensitivity only up to 40-50 km. Temperature should be observed by

SMILES-2 itself up to (or above) 100 km with a sensitivity of 1% (2-3K), since the

temperature is the primary physical parameter to determine the dynamics and chemistry of

the atmosphere and there is no global meteorological data set which is reliable above 60 km.

SMILES-2 should have observation capability of H2O and N2O better than 5% precision,

which are not observed by SMILES and are important tracers in the upper atmosphere.

These are major sources of HOx and NOx. SMILES-2 should improve HOCl and BrO

sensitivity by properly selecting observation frequency. SMILES BrO and HOCl observations

have suffered severe interference from the near-by stronger lines. SMILES-2 should have

original SMILES frequency coverage, and if possible it should add observation of other

species retrieved in the Aura/MLS and Odin/SMR. (Band 1LSB) 485-489 GHz: T, Wind, O2,

H2O, O3, HO2, HNO3 (Band 1 USB) 523-527 GHz: O3, 17OOO, 18OOO, O17OO, O18OO,

BrO, NO2, H2CO, N2O, HO2 (Band 2 LSB) 623-627 GHz: SMILES Bands A+B extended,

O3, HCl, BrO, HNO3, HO2, N2O, HOCl, CH3CN, CH3Cl (Band 2 USB) 648-652 GHz:

SMILES Band C extended, O3, 17OOO, O17OO, 18OOO, ClO, HO2, BrO, NO (Band 3,

HEB) 1.8, 2.0 THz OH, H2O, O-atom (one of 3 can be observed)



16

100 kg class MTI satellite proposal for lower thermosphere dynamics

measurement

Makoto Suzuki1, Akinori Saito2, Philippe Baron3, Hidekatsu Jin3, Minoru Kubota3, Satoshi

Ochiai3, Yoshinori Uzawa3, Naohiro Manago4, Hiroyuki Ozeki5

1. JAXA/ISAS

2. Kyoto University


4. Chiba University

5. Toho University

100 kg class small satellite proposal is now under preparation among MTI (mesosphere,

thermosphere, ionosphere) research community, which is targeting lower-thermosphere

dynamics (90-130 km, temperature, line of sight wind, O-atom density). 2.06 THz O-atom

line can provide 10 m/s LOS wind (10 km vertical resolution), and temperature from 90-130

km. Sub-mm 487 GHz region is also considered to measure O2, H2O, and O3 lines.

Ambient temperature instrument is currently considered, but 100 K cooled instrument can

provide better vertical resolution. Orbit should be 50-70 degree inclination to acquire diurnal

variation of wind and temperature. Additional instruments are necessary to observe electron

density (GPS occultation) and airglow (airglow imager, and/or airglow imaging

spectrograph).



17

The what, how and why of ALTIUS occultation observations

Filip Vanhellemont, Emmanuel Dekemper, Quentin Errera, Nina Mateshvili, Didier Fussen,

Didier Pieroux, Ghislain Franssens, Philippe Demoulin, Christine Bingen, Charles Robert

BIRA-IASB

Satellite-based limb scatter observation with the purpose of acquiring information on

atmospheric composition is at present considered to be a well-proven technique. It suffers

from an obvious disadvantage: nighttime and polar winter observations are impossible. The

ALTIUS (Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere)

mission proposal was partly motivated by the need to tackle this shortcoming. ALTIUS will

be able to measure in limb scatter mode as well as solar/lunar and stellar/planetary

occultation mode, and therefore will have a coverage in sun-illuminated as well as dark

conditions. In this presentation, specifics on ALTIUS occultation measurements will be

discussed, together with retrieval strategies, and simulated retrieval results. Furthermore, it

will be shown that the combination of profiles from limb and occultation observations

provides sufficient information to constrain ozone in a data assimilation system in the polar

night, which is not the case if one of these two modes is missing.



18

Status and Results from the Atmospheric Chemistry Experiment (ACE)

Satellite Mission

Kaley Walker1, Patrick E. Sheese1, Chris Boone2, Peter F. Bernath3, C. Thomas McElroy4

1. Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario,

Canada M5S 1A7

2. Department of Chemistry, University of Waterloo, 200 University Avenue West,

Waterloo, Ontario, Canada N2L 3G1

3. Department of Chemistry and Biochemistry, Old Dominion University, 4541 Hampton

Boulevard, Norfolk, Virginia, U.S.A. 23529-0126

4. Department of Earth and Space Science and Engineering, York University, 4700 Keele

Street, Toronto, Ontario, Canada M3J 1P3

On 13 August 2015, the Canadian-led Atmospheric Chemistry Experiment (ACE) will

complete its twelfth year in-orbit on board the SCISAT satellite. The long lifetime of ACE has

provided a valuable time series of composition measurements that contribute to our

understanding of ozone recovery, climate change and pollutant emissions. These profiles of

atmospheric trace gases and aerosols provide altitude-resolved data that are necessary for

understanding processes that occur at specific altitudes or over limited vertical length scales.

SCISAT/ACE is uses infrared and UV-visible spectroscopy to investigate the chemistry and

dynamics of the Earth's atmosphere. The primary instrument on-board, the ACE Fourier

Transform Spectrometer (ACE-FTS) is a high-resolution (0.02 cm-1) FTS operating between

750 and 4400 cm-1. The second instrument is a dual UV-visible-NIR spectrophotometer

called ACE-MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and

Troposphere Retrieved by Occultation) which was designed to extend the ACE wavelength

coverage to the 280-1030 nm spectral region. The ACE-FTS and ACE-MAESTRO

instruments have been making regular solar occultation measurements for nearly 12 years

and, from these measurements, altitude profiles of over 30 different atmospheric trace gas

species, temperature and pressure are obtained. The 650 km altitude, 74 degree circular

orbit provides global measurement coverage with a focus on the Arctic and Antarctic

regions. This presentation will give an overview of the mission status and will provide a

survey of the validation and scientific results obtained from ACE.



19

Session 2

Retrieval methods, radiative

transfer, tomography and

assimilation

20

An overview of OSIRIS tomographic observations and their potential for NLC

life cycle and satellite intercomparison studies

Susanne Benze, Jörg Gumbel, Ole Martin Christensen, Linda Megner, Kristoffer Hultgren

Stockholm University

Over the last five years, the OSIRIS instrument on the Odin satellite has been used

to make tomographic observations of NLCs and, to a lesser extent, temperature.

Tomographic observations enable us to study the vertical and horizontal variations of NLCs

with vertical resolution of 1 km and horizontal resolution of about 100 km. Retrieved

properties are NLC brightness at different UV wavelengths which is used to calculate particle

size, number density, and ice mass density. Ice mass density can be vertically integrated to

ice water content as retrieved for example from CIPS data. OSIRIS temperature is retrieved

from O2 atmospheric band dayglow observations at altitudes above the clouds. This

presentation will give an overview of the available OSIRIS tomographic NLC and

temperature data. For the first time we have a data set that resolves clouds and temperature

both vertically and horizontally. We will present the potential of this dataset in answering

important science questions about cloud formation, growth, and destruction of a cloud during

its lift cycle as well as dependence on properties of the surrounding atmosphere.

Furthermore, tomographic data helps us to clarify limitations that observation geometry

imposes on other satellite observations. Last but not least this data set was used to develop

a new Swedish satellite mission, MATS, that is planned for launch in 2018.



21

Version 4 Retrievals for the Atmospheric Chemistry Experiment (ACE)

Chris Boone1, Kaley Walker2

1. University of Waterloo

2. University of Toronto Peter Bernath, Old Dominion University

The Atmospheric Chemistry Experiment (ACE) is a satellite mission for remote

sensing of the Earth's atmosphere, launched August 2003 and continuing nominal

operations nearly twelve years after launch. The primary instrument on board is a high

resolution (25 cm maximum optical path difference) Fourier transform spectrometer (ACE-

FTS) operating in the infrared with broad spectral coverage (750-4400 cm-1). Details of the

upcoming processing version (version 4.0) for the ACE-FTS will be provided, including a

new in-depth analysis of the instrumental line shape for the spectrometer.



22

Towards unified error reporting

Thomas von Clarmann

KIT/IMK, Germany

Error estimates are essential to judge whether differences between estimates of the

atmospheric state can be explained or if they hint at unknown problems. While many recipes

exist to calculate the error budget of an observation, the data user is faced with the problem

that errors reported by various instrument groups are rarely consistent. In this talk, the

following problems will be tackled: (a) which error components should be included in the

error budget; (b) how should the content of prior information in the retrievals be dealt with;

(c) how can retrievals be characterized which were not produced via an optimal-estimation-

like formalism and thus do not provide the usual diagnostics; (d) how can error estimates

which were generated using different approaches be made comparable, and (e) what is to

be considered when comparing with direct (non-remote) measurements. An action plan

towards unified error reporting will be suggested.



23

Retrieving Stratospheric Aerosol Extinction from SCIAMACHY Measurements

in Limb Geometry

Steffen Dörner, Marloes Penning de Vries, Janis Pukite, Steffen Beirle, Thomas Wagner

Max Planck Institute for Chemistry

Techniques for retrieving height resolved information on stratospheric aerosol

improved significantly in the past decade with the availability of satellites measurements in

limb geometry. Instruments like OMPS, OSIRIS and SCIAMACHY provide height resolved

radiance spectra with global coverage. Long term data sets of stratospheric aerosol

extinction profiles are important for a detailed investigation of spatial and temporal variation

and formation processes (e.g. after volcanic eruptions or in polar stratospheric clouds).

Resulting data sets contain vital information for climate models (radiative effect) or chemistry

models (reaction surface for heterogeneous chemistry). This study focuses on the

SCIAMACHY instrument which measured scattered sunlight in the ultra violet, visible and

near infra red spectral range between 2002 and 2012. SCIAMACHY's unique method of

alternating measurements in limb and nadir geometry provides co-located profile and column

information respectively that can be used to characterize plumes with small horizontal

extents. The covered wavelength range potentially provides information on effective micro-

physical properties of the aerosol particles. However, scattering on background aerosol

constitutes only a small fraction of detected radiance and assumptions on particle

characteristics (e.g., size distribution) have to be made which results in potential

uncertainties especially for wavelengths below 700 nm and for measurements in backscatter

geometry. Methods to reduce these uncertainties are investigated and applied to our newly

developed retrieval algorithm. In addition, so called spatial straylight contamination of the

measured signal was identified as a significant error source and an empirical correction

scheme was developed. Comparisons with SAGE II measurement in occultation geometry

and balloon borne measurements with an optical particle counter confirm the viability of our

retrieval algorithm.



24

Polarized SASKTRAN for Limb Scatter Data Analysis

Seth Dueck, Daniel Zawada, Adam Bourassa, Doug Degenstein

University of Saskatchewan, Canada

The polarization state of limb-scattered sunlight displays vertical structure, and is

sensitive to aerosol loading. Furthermore, when used to simulate limb radiances, scalar

radiative transfer models (RTMs) can disagree with polarized RTMs by more than 5% due to

polarization’s effect on the multiple-scattered component. It remains common, nonetheless,

to ignore polarization in limb radiance data processing due to the overhead associated with

simulating polarized radiances with either a discrete RTM (large memory burden) or Monte

Carlo RTM (large computational burden). An approximate polarization calculation has been

built into the SASKTRAN High Resolution (HR) successive orders, discrete ordinates RTM.

With this approximation, HR agrees with the fully polarized SASKTRAN Monte Carlo module

to within 1% for many limb geometries, with relatively little increase in model runtime and

memory footprint. An overview of the pseudo-polarized model will be given, and the

implications for limb data processing will be discussed.



25

Temperature in the UTLS from Star Field Imaging

Larry Gordley, Tom Marshall, Kam Wan, Robert Stockwell

GATS, Inc

Probing the thermal structure of planetary atmospheres using observations of

occulting light sources is a well known process. By inferring profiles of index-of-refraction vs

altitude from bending angle measurements, the density structure is measured then inverted

to temperature and pressure structure. Modern detector focal plane array technology allows

this process to be implemented without requiring observer attitude information. This

approach is being used with solar imaging by the SOFIE instrument on the AIM satellite to

infer exceptional temperature profiles. We show how this approach can be applied to star

fields to achieve broad swaths of temperature fields using simple static imagers.



26

GOMOS and OSIRIS measurements of O3 and NO2 compared to model

simulations by the specified dynamics WACCM-model

Erkki Kyrölä1, M. Andersson1, S. Tukiainen1, V. Sofieva1, D. Marsh2, A. Smith2, D. A.

Degenstein3, A. E. Bourassa3

1. Finnish Meteorological Institute, Earth Observation Unit, Helsinki, Finland

2. National Center for Atmospheric Research, Boulder, Colorado, USA

3. Institute for Space and Atmospheric Studies, University of Saskatchewan, Saskatoon,

Saskatchewan, Canada

The GOMOS instrument on board the European Space Agency’s ENVISAT satellite

measured 880 000 stellar occultations during 2002–2012. From UV-Visible spectra (250-690

nm) of the horizontal transmission vertical profiles of O3, NO2, NO3, and aerosol extinction

can be retrieved. Atmospherically valid data are obtained generally in 15–100 km for ozone

and 20–50 km for other gases. The OSIRIS instrument on board the Odin satellite was

launched in 2001 and has measured continuously since. OSIRIS measures limb scattered

solar light in 280-800 nm and retrieves O3, NO2, and aerosol vertical profiles from 10 km to

60 km. GOMOS and OSIRIS ozone profiles have been successfully validated using ground-

based instruments. Ozone and other retrieved data have also been compared to other

satellite measurements. The best quality of GOMOS observations is achieved during

nighttime, when only few other measurements are available for validation and comparison.

OSIRIS observations are from daytime and have more possibilities for validation and

comparison. High-resolution atmospheric models provide an interesting additional possibility

for GOMOS and OSIRIS measurement comparisons. We use the Whole Atmosphere

Community Climate Model (WACCM) from the National Center for Atmospheric Research.

WACCM is a chemistry - climate model spanning the range of altitude from Earth’s surface

to the thermosphere (approximately 140 km) with 88 vertical levels of variable vertical

resolution of 1.1 km in the troposphere to 3.5 km above 65 km. Horizontal resolution is 1.9

latitude by 2.5 longitude and the model time step is 30 minutes. In the present analysis

version 4 of WACCM was run in ‘specified dynamics’ mode by constraining dynamical fields

to Modern-Era Retrospective Analysis for Research and Applications (MERRA)

meteorological re-analyses below 1hPa. Our WACCM simulations include ionisation rates

from SPE and medium energy electrons (MEE). In this work we show an inter-comparison of

GOMOS and OSIRIS O3 and NO2 profiles with the collocated WACCM profiles. The results

provide important new quality information about GOMOS and OSIRIS data products. They

also indicate probable development targets for the future WACCM evolution.



27

Improved Limb Cloud Detection Algorithm For SCIAMACHY

Patricia Liebing, A. Rozanov, F. Azam

IUP University of Bremen

A new approach for cloud detection in the SCIAMACHY Limb data set is presented.

The aim of this new approach is to distinguish between increased levels of upper

tropospheric and stratospheric aerosol concentration on the one hand and the presence of

water or ice clouds on the other hand, and to optimize filter thresholds with regard to criteria

such as efficiency or purity of the selected data samples. The ratio of measured reflectances

at around 1550 and 1670 nm is used to distinguish scenes dominated by clouds from those

dominated by aerosol, the threshold is defined with the help of another reflectance ratio

between 750 and 1050 nm. This strategy constitutes an advancement of the operational

Limb cloud flagging algorithm SCODA used for the current SCIAMACHY Level 2 data set. It

is motivated by simulation studies involving cloud optical depths over several orders of

magnitude and different cloud types. We will discuss the results of the simulation study,

explain the new algorithm and present preliminary results.



28

The OMPS Limb Profiler Stratospheric Aerosol Retrieval

Robert Loughman1, P.K. Bhartia2, Ghassan Taha3, Philippe Xu4, Ernest Nyaku1, Glen

Jaross2, Peter Colarco2, Valentina Aquila5

1. Department of Atmospheric and Planetary Sciences, Hampton University

2. Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center

3. Goddard Earth Sciences Technology and Research, Universities Space Research

Association

4. Science Applications International Corporation

5. Goddard Earth Sciences Technology and Research, Johns Hopkins University

The Ozone Mapping and Profiler Suite (OMPS) on board the Suomi National Polar-

orbiting Partnership (S-NPP) spacecraft was launched on October 28, 2011. The Limb

Profiler instrument on OMPS (OMPS LP) provides high vertical resolution ozone and aerosol

profiles from measurements of the scattered solar radiation in the 290 – 1000 nm spectral

range. OMPS LP collected its first Earth limb radiance measurements on January 10, 2012,

and continues to provide daily, global measurements that enable ozone profile retrieval from

cloud top to approximately 60 km and aerosol profile retrievals from cloud top to

approximately 40 km. Although the instrument was designed primarily for vertical ozone

profile measurement, it has a high sensitivity to stratospheric aerosols, cirrus clouds in the

upper troposphere, and stratospheric and mesospheric clouds. The relatively high vertical

and spatial sampling allow detection and tracking of periodic events when aerosol particles

are injected into the stratosphere, including volcanic eruptions and meteor explosions. We

will first present an assessment of the suitability of OMPS LP radiance data for stratospheric

aerosol detection based upon the aerosol scattering index (ASI). The ASI is defined as the

difference between the logarithm of the measured radiance and the logarithm of the

calculated radiance for the same scene (excluding aerosols from the atmosphere). Maps of

ASI derived from OMPS LP data indicate a clear aerosol signal, and allow an initial

assessment of the OMPS LP measurement quality. An initial estimate of the corresponding

aerosol extinction profiles derived from OMPS LP data will also be presented. The current

aerosol retrieval algorithm is based upon Chahine's non-linear relaxation method, and will be

shown to converge quickly and minimize radiance residuals effectively except for

observations that feature significant variation of the aerosol profile along the measured line

of sight. The aerosol extinction retrieval depends upon a-priori assumptions of the aerosol

phase function (as determined by aerosol size distribution, refractive index and shape).

Future work to refine these a-priori assumptions and assess the OMPS LP retrievals by

comparison to output of the NASA Goddard Earth Observing System (GEOS-5) chemistry-

climate model will be described.



29

Ozone retrieval from limb measurements using the Monte Carlo method as a

forward model

Nina Mateshvili1,2, Filip Vanhellemont1, Didier Fussen1, Iuri Mateshvili2, Christine Bingen1,

Tamar Paatashvili2, Emmanuel Dekemper1, Charles Robert1

1. Belgian Institute for Space Aeronomy

2. Abastumani Astrophysical Observatory

Monte Carlo simulations can accurately model multiple scattering in the difficult

spherical geometry of limb-viewing but are usually considered as too time-consuming to be

used for the retrieval of atmospheric constituents as a forward model. Here we propose a

single scattering code with a multiple scattering correction as a forward model for the

retrieval. The multiple scattering correction was calculated several times using a Monte

Carlo method. First, a multiple to single scattering ratio was calculated using ozone

climatological data. The ozone value was retrieved using a single scattering code with the

multiple scattering correction. The retrieved ozone values were used to calculate a new

multiple scattering correction and the ozone values were retrieved again. The procedure was

repeated 3- 4 times to achieve a convergence. The proposed retrieval scheme was tested at

different solar and viewing zenith angles. The Monte Carlo calculations were performed

using parallelization which also significantly improved the calculation speed.



30

Parameterization of non-linearity effects of absorption in scattered light

observations

Janis Pukite, Thomas Wagner


We address application of Differential Optical Absorption Spectroscopy (DOAS) for

scattered light observations for scenarios where the absorption optical depth has a non-

linear relation with trace gas concentrations in the presence of strong absorbers (in particular

ozone). This is the case, because Beer-Lambert law generally do not hold for scattered light

measurements due to many light paths contributing to the measurement. While in many

cases linear approximation can be made, for scenarios with strong absorption non-linear

effects cannot always be neglected. Especially this is the case for observation geometries

where the light contributing to the measurement is crossing the atmosphere under spatially

well separated paths differing strongly in length and location, like e.g. in limb geometry. In

these cases often full retrieval algorithms are involved to address the non-linearities

requiring iterative wavelength by wavelength forward modelling of absorption spectra

involving time consuming radiative transfer modelling. In this study we propose to describe

the non-linear effects by additional sensitivity parameters that can be used e.g. to build a

look up table. Together with widely used box air mass factors (effective light paths)

describing the linear response to the increase in the trace gas amount, the higher order

sensitivity parameters eliminate the need for repeating the radiative transfer modelling when

modifying the absorption scenario even in a presence of a strong absorption background.

While the higher order absorption structures can be described as separate fit parameters in

the DOAS fit, in practice their quantitative evaluation requires good measurement quality.

Therefore, we introduce an iterative retrieval algorithm correcting for the higher order

absorption structures not yet considered in the DOAS fit as well as the absorption

dependence on temperature and scattering processes.



31

Spectral tomography for scattered light limb measurements: retrieval in

multiple fit windows to improve the spatial resolution

Janis Pukite, Steffen Dörner, Thomas Wagner


The Scanning Imaging Absorption spectroMeter for Atmospheric CHartographY

(SCIAMACHY) on the ENVISAT satellite probed the atmosphere at the day side of Earth in

alternating sequences of nadir and limb measurements from August 2002 to April 2012.

Limb measurements allow the retrieval of stratospheric profiles of various trace gases on a

global scale. It has been shown that combining measurements of the same air volume from

different viewing positions along the orbit, 2D distribution fields of stratospheric trace gases

can be acquired in one inversion step. Since the atmospheric scattering and absorption

processes are wavelength dependent, the spatial sensitivity for limb observations also varies

with wavelength. In general, for longer wavelengths, photons from more remote areas along

the line of sight are contributing stronger to the measurement than for shorter wavelengths

because of the lower probability of Rayleigh scattering. In addition, the radiative transfer is

modified by the ozone absorption structures making longer light paths less probable within

strong ozone absorption bands. In this study, additional information on the spatial distribution

of NO2 is investigated by analysing results obtained by Differential Optical Absorption

Spectroscopy (DOAS) in various spectral fit windows. Combing the fit results in one profile

retrieval algorithm helps to improve the spatial sensitivity and resolution of the

measurements. The largest improvements for the spatial resolution and sensitivity are

expected for the upper troposphere/ lower stratosphere (UTLS) region where the variation of

the spatial sensitivity with wavelength is strongest.



32

An End-to-End GNSS Radio Occultation Simulator

Joel Rasch

Molflow, Sweden

GNSS radio occultation (RO) is a technique where one measures the refraction of

GNSS signals as they pass through the atmosphere using receivers on LEO satellites. From

the bending of the signals one can deduce atmospheric parameters such as pressure,

temperature, humidity, and electron content. The technique is very reliable and requires little

calibration, and holds the promise of being able to deliver important data for NWP. In order

to be able to simulate how the next generation of receivers for RO will perform, and what the

fundamental limitations of the technique are, it is necessary to be able to simulate the

microwave field propagation through the atmosphere and into LEO, as well as adding noise

and applying inversion methods to the signal. For this reason we have constructed a RO

simulator which uses the multiple phase screen technique to propagate the field in the

atmosphere, a diffractive integral to propagate it to LEO, and the phase matching technique

to invert the signal.



33

Application of the OSIRIS retrieval algorithms to the OMPS LP measurements

Landon Rieger1, Adam Bourassa1, Doug Degenstein1, Daniel Zawada1, Natalya Kramarova2,

Matt Deland2

1. University of Saskatchewan, Canada

2. NASA GSFC, USA

The Optical Spectrograph and InfraRed Imaging System (OSIRIS) on-board the Odin

satellite has now been operational for over 13 years, providing near-global coverage of

stratospheric aerosols, ozone and NO2. More recently, a NASA limb scatter instrument, the

Ozone Mapping and Profiler Suite (OMPS LP), was launched in 2011. Both instruments

measure from the UV to near IR and now have almost four years of overlap. To help provide

consistent ozone and aerosol products spanning across both instruments, as well as

improve understanding of both measurement sets, this work applies the OSIRIS ozone and

aerosol algorithms to the OMPS measurements. Presented here are initial results, including

investigation of the OMPS ozone and aerosols using the standard data products compared

to those performed using the OSIRIS algorithm. Also compared are the OSIRIS and OMPS

products using the same algorithm to help determine causes of biases in the retrievals.



34

Recent improvements in SCIAMACHY limb products

Alexei Rozanov, J. Jia, V. Rozanov, E. Malinina, J. P. Burrows

University of Bremen

The Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY

(SCIAMACHY) instrument is a UV-Visible-NearIR spectrometer operated on board the

European Environmental Satellite (ENVISAT) from August 2002 to April 2012. In its limb

viewing mode the instrument observed the Earth's atmosphere tangentially to the surface

measuring the scattered solar light. At the University of Bremen, limb-scatter measurements

from SCIAMACHY are currently used to retrieve stratospheric vertical distributions of several

trace gases (O3, NO2, BrO, H2O) and aerosol extinction coefficient as well as to detect

clouds. Although SCIAMACHY limb products are generally shown to be of a good quality,

some issues have been identified during the recent validation studies which raised a need

for some additional optimization. This presentation reports on recent developments and

quality improvements related to the SCIAMACHY limb products at the University of Bremen.

Invited speaker


35

Oxygen isotopic enrichment in the middle atmospheric ozone observed by

SMILES

Tomohiro Sato1, Hideo Sagawa2, Naohiro Yoshida3,4, Yasuko Kasai1,3

1. National Institute of Information and Communications Technology, Japan

2. Kyoto Sangyo University

3. Tokyo Institute of Technology

4. Earth-life Science Institute

Ozone plays a key and unique role in the earth atmosphere. The largest oxygen

isotopic enrichment in ozone of about 10-15% is a good historical tracer for chemical and

physical processes. Isotopic enrichments in ozone in the lower and middle stratosphere

were observed by in-situ measurements using mass spectroscopic and remote-sensing

spectroscopic techniques (e.g., Krankowsky et al., 2007, Irion et al., 1996). To use oxygen

isotopic enrichment as a strong tracer for material circulation, it is required to understand

distribution and behavior of ozone isotopic enrichment in global and long-time scale. Remote

sensing from space is essential for this purpose. In this presentation, we present isotopic

enrichment in asymmetric 18 ozone (delta-18OOO) derived from SMILES observation

spectra. SMILES (Superconducting Submillimeter-wave Limb-emission Sounder) observed

atmospheric radiation in the submillimeter-wave region from the International Space Station

(Kikuchi et al., 2010). The observation period is from 12 October 2009 to 21 April 2010.

SMILES observed limb-emission spectra of ozone isotopomers and isotopologues with high

S/N ratio using a new 4K-receiving system, which enables to observe delta-18OOO within

the order of a few percent error in the stratosphere and the mesosphere. We developed a

new retrieval algorithm optimized for ozone isotopic enrichment named TOROROS (Sato et

al., 2014). This algorithm is based on the least-squares method with a stringent a priori

constraint from knowledge of ozone isotopic enrichment. The spectral frequency region is

set for each ozone isotopomers and isotopologues to minimize interference from spectral

lines of other molecules. The altitude grid and input parameters are uniformed for all retrieval

processing. The vertical profile of the TOROROS delta-18OOO showed an increase and a

decrease (10~20%) with altitude in the stratosphere and mesosphere, respectively. The

delta-18OOO peak, of about 20%, was located at the stratopause. The values and behaviors

of the delta-18OOO are consistent with the past measurements and theoretical predictions in

the stratosphere. The total systematic error in delta-18OOO was estimated to be about 5%

and 7% in the stratosphere and the mesosphere, respectively. The largest error source is

uncertainty in the air-broadening parameter of the transition of asymmetric 18 ozone.

References Krankowsky D. et al., Stratospheric ozone isotope fractionations derived from

collected samples. J. Geophys. Res. Atmos., 112:8301, 2007. Irion F. W.,et al., Heavy

ozone enrichments from ATMOS infrared solar spectra. Geophys. Res. Lett., 23: 2377–

2380, 1996. Kikuchi K. et al., Overview and early results of the Superconducting

Submillimeter-Wave Limb-Emission Sounder (SMILES), J. Geophys. Res. Atmos.,

115(D14):D23306, 2010. Sato et al., Vertical profile of delta-18OOO from middle

stratosphere to lower mesosphere derived by retrieval algorithm developed for SMILES

spectra. Atmos. Meas. Tech., 7:941–958, 2014

36



37

Pseudo-retrievals for averaging kernel and total uncertainty characterization

for ACE-FTS level 2 (PRAKTICAL) data

Patrick Sheese1, Kaley A. Walker1,2, Chris Boone2

1. University of Toronto

2. University of Waterloo

For over the past decade, the ACE-FTS (Atmospheric Chemistry Experiment –

Fourier Transform Spectrometer) instrument on the Canadian SciSat satellite has been

observing the Earth’s limb via solar occultation in the 750-4400 cm-1 spectral region with

0.02 cm-1 spectral resolution. The most recent version of the level 2 data, version 3.5, which

starts in February of 2004 and is currently ongoing, is comprised of volume mixing ratio

profiles of over 30 atmospheric trace species and over 20 subsidiary isotopologues. This

study will use ACE-FTS level 1 spectra and the version 3.5 forward model in pseudo-

retrievals that use an optimal estimation technique in order to produce representative ACE-

FTS averaging kernels and to characterize the systematic and random uncertainties inherent

in the level 2 profiles. Preliminary results will be presented and discussed. The ACE-FTS

uncertainties will be compared to the reported uncertainties of data sets from other current

and past atmospheric limb sounders.



38

Improved OSIRIS NO2 retrieval algorithm

Chris Sioris, A. E. Bourassa, L. A. Reiger, N. D. Lloyd, D. A. Degenstein

University of Saskatchewan

A new NO2 retrieval algorithm has been developed for OSIRIS. It uses spectral fitting

in the 434-477 nm range and a new version of SaskTRAN as the forward model that is

capable of simulating realistic diurnal gradients of photochemically active constituents.

Ozone and aerosol profiles as well as surface albedo retrieved from OSIRIS are used as

forward model inputs. The MART (Multiplicative Algebraic Reconstruction Technique)

technique is used to invert the NO2 slant column densities. The retrieval range is variable,

determined by NO2 slant column density uncertainty at the upper limit and by the retrieved

cloud top height at the lower limit. Profiles between 7.5 and 46 km can be obtained with

retrieval uncertainty <100% although uncertainties at the NO2 number density peak are a

few percent on a 1 km grid. The algorithm has been compared with ~40 coincident balloon

profiles over the last ~13 years and shows improvements over the current operational

algorithm (v3.0), particularly in the lower stratosphere.



39

3-D tomographic processing of GLORIA limb measurements - challenges,

solutions, and an unprecedented 3-D view on filamentary structure in the UTLS

Joern Ungermann1, Peter Preusse1, Michael Höpfner2, Isabell Krisch1

1. Forschungszentrum Jülich GmbH

2. Karlsruhe Institue of Technology

The Gimballed Limb Radiance Imager of the Atmosphere (GLORIA) is a newly

developed unique instrument that combines for the first time a classical Fourier transform

spectrometer (FTS) with a 2-D detector array. Imaging allows the spatial sampling to be

improved by up to an order of magnitude when compared to a limb scanning instrument.

GLORIA is designed to operate on various high altitude research platforms. The instrument

is a joint development of the German Helmholtz Large Research Facilities Karlsruher Institut

fuer Technologie (KIT) and Forschungszentrum Juelich GmbH (FZJ). GLORIA builds upon

the heritage of KIT and FZJ in developing and operating infrared limb sounders (CRISTA,

MIPAS). In Summer 2012, GLORIA was an integral part of the first large HALO missions

dedicated to atmospheric research, TACTS and ESMVAL. The data span latitudes from

80°N to 65°S and include several tomographic flight patterns that allow the 3-D

reconstruction of observed air masses. We describe the tomographic retrieval and validation

of temperature and trace gas (H2O, O3, HNO3) volume mixing ratios for two hexagonal flight

patterns. One was taken during the ESMVAL campaign close to South Africa and one was

taken during the TACTS campaign over Scandinavia. Both hexagon exhibit 3-D filamentary

structure due to Rossby wave breaking at the sub-tropical jets. The presentation provides an

overview of the employed techniques required to process millions of aggregated radiances

to retrieved millions of state variables and associated errors such as measurement

contribution, precision, accuracy, or resolution. The Tikhonov-Phillips type regularisation

employed is based firmly upon a 3-D extension of the typical 1-D exponential covariance

assumption (that assumes exponential decrease of correlation) and can be thus interpreted

in an optimal estimation framework. The retrieved 3-D volumes are presented and validated

against in-situ measurements taken on board of the aircraft. After acquiring the tomographic

measurements, the HALO aircraft performed a dive into the measured volumes such that the

agreement can be evaluated not only along the outer upper rim of the volume, but also in the

centre.



40

Three Dimensional Radiative Transfer in SASKTRAN for Atmospheric

Tomography

Daniel Zawada, Seth Dueck, Doug Degenstein, Adam Bourassa


Limb measurements in the UV/visible spectral region have been successfully used to

retrieve vertically resolved profiles of trace gases in the atmosphere. Most limb retrieval

methods rely on the assumption that the atmosphere is horizontally homogeneous, i.e. that

atmospheric constituents vary only as a function of altitude. This assumption breaks down

when the line of sight spans a large horizontal gradient, for example, near the polar vortex or

when measuring a volcanic plume. Here we will present recent additions to the SASKTRAN

radiative transfer model allowing it to handle three dimensional atmospheres, breaking the

assumption of horizontal homogeneity. These modifications include an adaptive integration

technique to handle areas of high extinction (e.g. cirrus clouds) and the capability to

compute analytic weighting functions in one and two dimensions. By simulating

measurements in a fully three dimensional atmosphere and retrieving with a one

dimensional technique the effects of the horizontal homogeneity assumption are quantified.

Preliminary work on atmospheric tomography using limb scattered sunlight will also be

discussed.



41

Session 3

Mesosphere and above

42

The effects of energetic electron precipitation seen in mesospheric hydroxyl

and ozone over the solar cycle

Monika Andersson1, Pekka T. Verronen1, Craig J. Rodger2, Mark A. Clilverd3, Annika

Seppälä1, Shuhui Wang4, Bonar R. Carson2

1. Finnish Meteorological Institute, Helsinki, Finland

2. Department of Physics, University of Otago, Dunedin, New Zealand

3. British Antarctic Survey, NERC, Cambridge, UK

4. Jet Propulsion Laboratory, California Institute of Technology Pasadena, CA

The ion chemistry in the Mesosphere/Lower Thermosphere region is very important

because it influences neutral composition and dynamics of the atmosphere. Ionisation

caused by energetic particle precipitation (protons and electrons) leads to the production of

odd hydrogen (HOx) and odd nitrogen (NOx) species that have significant implications for

the ozone (O3) chemistry. By utilising measurements from three different instruments

(Microwave Limb Sounder (MLS/Aura), Global Ozone Monitoring by Occultation of Stars

(GOMOS/ENVISAT) and Sounding of the Atmosphere using Broadband Emission

Radiometry (SABER/TIMED)), we show that the direct, HOx-driven effect of energetic

electron precipitation (EEP) from the Earth’s outer radiation belt is causing significant,

previously unaccounted for, ozone variability in the mesosphere that is observable on solar

cycle time scales. Our analysis shows that between 2004-2009, the EEP affects

mesospheric HOx about 35% of the time. These changes are typically accompanied by

decreases in ozone at altitudes between 60-80 km. On a short time scales (days), EEP

leads to extremely large (up to 90%) ozone depletions in the atmosphere. The magnitude of

these short term effects is comparable to those caused by large but much less frequent solar

proton events. On solar cycle time scales, we find that EEP causes significant ozone

variations of up to 34% at 70-80 km. Since ozone is important to atmospheric heating and

cooling rates, such variation could play an important role in the EEP-driven modulation of

mesospheric temperature balance.

Invited speaker


43

Nitric monoxide (NO) retrieval from SCIAMACHY nominal mode limb scans

Stefan Bender1, M. Sinnhuber1, M. Langowski2, J. P. Burrows3

1. Karlsruhe Institute for Technology, Karlsruhe, Germany

2. Ernst Moritz Arndt University Greifswald, Greifswald, Germany

3. University of Bremen, Bremen, Germany

We present a retrieval method for nitric monoxide (NO) number densities from

SCIAMACHY nominal limb scans (0--93~km). We adapt the NO retrieval algorithm of the

SCIAMACHY mesosphere and lower thermosphere (MLT, 50--150~km) limb scans.

SCIAMACHY's nominal limb scans stop at around 93~km such that these scans do not

explicitly resolve the NO density maximum at around 105~km. Instead, this maximal density

is mapped to the uppermost tangent points and adversely affects the retrieved NO number

densities down to around 80~km. With an appropriately chosen a priori, we restore at least

part of the "true" number densities up to around 85~km. Combining the MLT data (50--150

km, one day every two weeks from 07/2008 until 04/2012) and the nominal data (0--93 km,

daily from 08/2002 until 04/2012), we obtain a ten-year daily global NO number density data

set from 60~km to 85~km. Different statistical methods can then be used to extract solar and

geomagnetic forcing parameters. The derived parameters constrain how solar and

geomagnetic activity influences the NO content in the mesosphere. Furthermore, we can

infer the impact of particle precipitation on the middle atmosphere by separating the solar

variability parameters.



44

Polar Mesospheric clouds and their background atmosphere as observed by

Odin

Ole Martin Christensen1, Susanne Benze2, Patrick Eriksson1, Jörg Gumbel2, Linda Megner2,

Donal Murtagh1

1. Chalmers University of Technology

2. Stockholm University

We compare a set of tomographic measurements performed with the two instruments

on board the Odin sattelite. Combined, they provide the first simultaneous high resolution

measurements of polar mesospheric cloud properties and background atmosphere capturing

both vertical and horizontal variations. We compare the ice mass density measured by Odin-

OSIRIS to the expected ice, assuming thermodynamic equilibrium calculated using the water

vapour and temperature measured by Odin-SMR. We find that assuming thermodynamic

equilibrium generally predicts to much ice, but manages to reproduce the large scale feature

of the cloud distribution such as altitude of maximum ice concentration, the latitudinal

distribution of ice, cloud frequency and the seasonal variation of these. Looking at single

clouds observed by OSIRIS we find that on average they are in a growing phase above

82.5\,km and 83\,km in mid and late season respectively while sublimating at altitudes below

this. Clouds are even observed far outside the region of supersaturation, using a simple

growth model we argue that this cannot be explained by sedimentation alone, but that

vertical winds are the most probable explanation for these observations.



45

Observation of 27-day solar cycles in the production and mesospheric descent

of EPP-produced NO

Koen Hendrickx1, Linda Megner1, Jörg Gumbel1, David E. Siskind2, Yvan J. Orsolini3, Hilde

Nesse Tyssøy4, Mark Hervig5

1. Stockholm University, Stockholm, Sweden

2. Navel Research Lab, New York, Washington D.C., USA

3. Norwegian Institute for Air Research, Kjeller, Norway

4. Birkeland Centre for Space Science, Department of Physics and Technology, University

of Bergen, Bergen, Norway

5. GATS Inc, Driggs, Idoha, USA

Nitric oxide (NO) is produced by energetic particle precipitation (EPP) in the

Mesophere-Lower Thermosphere region (MLT), and during the polar winter, NO can reach

down to stratospheric altitudes where it destroys ozone. Several case studies have shown a

deficit in models' abilities to correctly represent the transport of NO from the lower

thermosphere to the mesosphere and stratosphere, especially in connection with sudden

stratospheric warmings. We study by means of superposed epoch analyses the general

scenario, as opposed to a case study, of NO production due to energetic particles in the

auroral region. We focus on the downward transport from the lower thermosphere to

mesosphere, based on NO observations made by the Solar Occultation For Ice Experiment

(SOFIE) instrument onboard the Aeronomy of Ice in the Mesosphere (AIM) satellite. The

analysis clearly shows the effect of the 27 day solar cycle all the way down to 50 km during

polar winter. Initially a rapid downward transport is noted during the first 10 days after EPP

onset to an altitude of 82 km, which is then followed by a slower downward transport of

approximately 1-1.2 km/day to lower mesospheric altitudes in the order of 30 days.



46

What we learned from SMILES observation of atmospheric compositions in

middle atmosphere

Yasko Kasai1,2, Kota Kuribayashi1,2, Nao Suzuki1, Takayoshi Yamada1,2, Atsushi Hirakawa1,2,

Tomohiro Sato1, NICT-SMILES mission team

1. NICT


Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) is a

instrument with unprecedented sensitivity to observe atmospheric minor compositions. The

frequency region is around 600GHz. SMILES is the first global environment observation

instrument in the Japanese Experiment Module onboard the International Space Station

(ISS). We performed atmospheric limb observations between 12 October 2009 and 21 April

2010. Vertical profiles of O3 and its isotopic compositions, and of hydrochloric acid (HCl),

ClO, HOCl, HO2, hydrogen peroxide (H2O2), BrO, acetonitrile (CH3CN), nitric acid (HNO3),

water vapor, and ice clouds were retrieved from the spectra. The non-sun-synchronized orbit

of the ISS gives us the opportunity to observe the diurnal variation of these radical species.

Behavior of diurnal variations of active radical species were obtained for the first time. We

found SMILES is a powerful tool to investigate the region between mesosphere and lower

thermosphere (MLT).



47

Odin/SMR Nitric Oxide Observations and Its Contribution to a Better Understanding of Energetic Particle Precipitation Indirect Effect

Kristell Pérot1, Donal Murtagh1, Yvan Orsolini2,3

1. Chalmers University of Technology, Sweden 2. Norwegian Institute for Atmospheric Research, Kjeller, Norway 3. Birkeland Centre for Space Science, University of Bergen, Bergen, Norway

The Sub-Millimeter Radiometer (SMR) on board the Odin platform, launched in 2001, is a limb emission sounder measuring trace gases in the stratosphere, mesosphere, and lower thermosphere. Odin is a Swedish-led satellite project funded jointly by Sweden (SNSB), Canada (CSA), Finland (TEKES), and France (CNES), with support by the 3rd party mission programme of the European Space Agency (ESA). Energetic Particle Precipitation (EPP) refers to the process by which energetic protons and electrons affect the Earth’s middle atmosphere. The precipitation of magnetospheric electrons into the polar atmosphere during geomagnetic perturbations leads to nitric oxide (NO) formation in the polar upper mesosphere and lower thermosphere (UMLT). During polar winter, EPP-generated NO can be transported downward into the stratosphere by the meridional circulation, where it can affect the ozone concentration. This important solar-terrestrial coupling mechanism is called the EPP indirect effect (EPP IE). Odin/SMR supplies the scientific community with a 11 year NO data set, and measurements of several other related species. We will show how the analysis of these long term observations can contribute to a better understanding of the EPP indirect effect.



48

Polar Mesospheric Cloud Particle Size Retrieval from GOMOS / ENVISAT Observations

Kristell Pérot1, Alain Hauchecorne2, Franck Montmessin2, Jean-Loup Bertaux2

1. Chalmers University of Technology, Sweden

2. LATMOS, France

GOMOS (Global Ozone Monitoring by Occultation of Stars) is a stellar occultation instrument, combining four spectrometers and two fast photometers, that flew on board the European platform ENVISAT from 2002 to 2012. Polar mesospheric clouds (PMCs), that form during summer in the polar upper mesosphere, could be detected using the photometers' signals. Their main properties (occurrence frequency, peak altitude, radiance) have been retrieved from 2002 to 2010, leading to a 16-summer (in both hemispheres) database of more than 21000 clouds. PMCs are very sensitive to changes in their environment. That makes them important tracers for the complex mechanisms that control the summer mesopause region. A better understanding of the microphysical processes going on in this atmospheric region is essential to model of their growth, their transport mechanisms and their lifetime. To that purpose, the particle size distribution is an important parameter. This poster will be focused on PMC particle sizes retrieved from GOMOS spectral observations in the northern hemisphere. The retrieval method will be explained, and results based on the obtained 8-year dataset will be described and compared to PMC particle sizes derived from the measurements of other instruments.



49

Lunar tidal and solar cycle signatures in the mesosphere / lower thermosphere

region

Christian von Savigny1, Olexandr Lednytskyy1, Georg Teiser1, Matt DeLand2

1. Ernst-Moritz-Arndt-University of Greifswald, Greifswald, Germany

2. Science Systems and Applications Inc. (SSAI), Lanham, MD, U.S.A.

Characterizing variability in the middle atmosphere is an important task in terms of

understanding possible long-term changes related to anthropogenic activity. Two sources of

variability in the middle atmosphere and the mesosphere/lower thermosphere (MLT) region

that are not well understood are lunar gravitational effects and the sun’s differential rotational

cycle with a period of about 27 days. In this contribution we present latest results on lunar

semidiurnal tidal signatures in several MLT parameters, including temperature, OH and OI

airglow emissions, atomic oxygen as well as different NLC (noctilucent cloud) parameters.

The identified lunar semidiurnal tidal signatures are all highly significant, and for some

parameters present the first statistically significant identification of the lunar semidiurnal tide

in experimental data sets. The analyses are based on SCIAMACHY nightglow

measurements for the airglow parameters and the SBUV time series for NLCs. In addition,

we have also identified solar 27-day signatures in several MLT parameters – some of them

for the first time – and the presentation will provide an overview of the current status of our

understanding of 27-day solar cycle effects in the Earth’s MLT region.



50

MLT temperature observations by a frequency-tunable resonance scattering

lidar

Takuo Tsuda1, M. K. Ejiri2, T. Nishiyama2, M. Abo3, T. Kawahara4, T. Nakamura2

1. The University of Electro-Communications

2. National Institute of Polar Research

3. Tokyo Metropolitan University

4. Shinshu University

We are developing a new resonance scattering lidar system to be installed at Syowa

Station (69S, 39E) in Antarctica. For the new lidar system, we have employed a tunable

alexandrite laser covering the resonance scattering lines of two neutral species, which are

atomic potassium (K, 770 nm) and atomic iron (Fe, 386 nm), and two ion species, which are

calcium ion (Ca+, 393 nm) and aurorally excited nitrogen ion (N2+, 390 nm, 391 nm). Thus

the new lidar system will provide information on the mesosphere and lower thermosphere

(MLT) as well as the ionosphere. Using the new resonance scattering lidar together with

colocated other instruments, we will conduct a comprehensive ground-based observation of

the low, middle, and upper atmosphere above Syowa Station. This unique observation is

expected to make important contribution to studies on the atmospheric vertical coupling

process and the neutral and charged particle interaction. In this presentation, we will report

current status on test observations of Fe layers at National Institute of Polar Research

(NIPR) at Tachikawa, Japan (36N, 139E). In order to obtain the Fe resonance line at 386

nm, we operate the fundamental laser (i.e. the tuneable alexandrite laser) at 772 nm, which

is shifted by 2 nm from the K resonance line at 770 nm, and then obtain the pulsed 386 nm

laser using nonlinear crystal based on the second harmonic generation (SHG) technique. On

14 August 2013, we successfully detected first signals from Fe layers, with one-frequency

mode for Fe number density measurement. The observed iron number density would be

fairly comparable to that from the previous observations at mid-latitudes. After that, we have

prepared three-frequency mode for Doppler temperature measurements. Based on a

theoretical calculation, we have determined good combination of the three laser frequencies

to minimize the temperature error, and then performed operations of the three-frequency

mode on 5 and 18 Augsut 2014. The obtained MLT temperature data will be compared with

those from NRLMSISE-00 model and satellite observations, such as SABER/TIMED and

MLS/Aura. Furthermore, we will show a challenge of observing Ca+ temperature.



51

Na layer response to auroral activity in polar region

Takuo Tsuda1, S. Nozawa2, T. D. Kawahara3, T. Kawabata2, N. Saito4, S. Wada4, Y.

Ogawa5, S. Oyama2, C. M. Hall6, M. Tsutsumi5, M. K. Ejiri5, S. Suzuki7, T. Takahashi1, T.

Nishiyama5, T. Nakamura5

1. The University of Electro-Communications

2. Nagoya University

3. Shinshu University

4. RIKEN

5. National Institute of Polar Research

6. University of Tromsø

7. Aichi University

Sodium atom (Na) layer is generally distributed at 80-110 km. One of mysterious

subjects on high-latitude Na layers is relationship between auroral particle precipitation and

Na layer variation. A previous study suggested a Na column density decrease during a

geomagnetic active period due to that the particle precipitation accompanied by electron

density enhancement could induce ionization of Na through their ion-molecule chemistry.

Another study pointed a possibility of Na density increase. For this reason, it is suggested

that auroral precipitating particle bombardment on meteoric smoke particles can sputter Na

from the smoke particles. On the other hand, ionospheric electric field, which may become

more significant near auroral precipitating regions, could induce ion motions (i.e. can

generate sodium ion (Na+) convergence and/or divergence), and then also could affect

generation and/or loss processes of Na through their ion-molecule chemistry. Thus, for the

examination of the causality, it is vitally important to distinguish the effects of auroral particle

precipitation and ionospheric electric field. Using Na lidar (which was installed in early 2010)

and European incoherent scatter (EISCAT) radar at Tromsoe, Norway (69.6N, 19.2E), we

have investigated that the actual effect of the particle precipitation to the Na density

variations without electric filed injection. In the nighttime observation on 24-25 January 2012,

we detected a significant decrease of Na density coincided with electron density

enhancements (implying strong particle precipitations) and low ion temperatures (implying

no electric field injections). These results strongly suggested that auroral particle

precipitations induced Na density decrease. In the presentation, we will show these results,

and mention to a possibility for an extended study using Na data from limb-sounding

satellites, such as OSIRIS/Odin and SCIAMACHY/Envisat.



52

Survey of sprite events with SMILES atmospheric composition observations

Takayoshi Yamada1,2, Yasuko Kasai2, Toru Adachi3, Kota Kuribayashi1, Alfred Chen4, Rue-

Ron Hsu4, Han-Tzong Su4, Mitsuteru Sato5, Yukihiro Takahashi5

1. Department of Environmental Chemistry and Engineering, Tokyo Institute of

Technology, Japan

2. National Institute of Information and Communications Technology, Japan

3. Meteorological Research Institute, Japan

4. National Cheng Kung University (NCKU), Taiwan

5. Hokkaido University, Japan

Sprites are lightning-induced secondary discharges appearing in the middle

atmosphere. Both lateral and vertical scales are a few tens of kilometers, and 700 - 1000

events occur in a day in the global [Hsu et al., 2009 and Chen et al., 2008]. It has been

pointed out that sprite discharges may modulate atmospheric compositions in the middle

atmosphere [Enell et al., 2008; Sentman et al., 2008; Hiraki et al., 2008]. Hiraki et al., [2008]

suggested HO2 amount was estimated to enhance 1000-10,000 times more than the

background by sprite events at 40km. We survey the change of the amount of atmospheric

compositions using two satellite observations, superconducting Submillimeter-Wave Limb

Emission Sounder (SMILES) on International Space Station (ISS), and Imager of Sprites and

Upper Atmospheric Lightning (ISUAL) mounted in the FORMOSAT-2 satellite [J.L. Chern

2003]. The number of SMILES observation points and sprites detected by the ISUAL were

about 180,000 and 127 during SMILES observation period (12 October 2009 to 21 April

2010) , respectively. Coincidence was only three cases for the case which SMILES line of

sight passed through the ISUAL large sprite detection. HO2 spectrum was certainly

enhanced in all these cases. We estimated the amount of the HO2 enhancements.



53

Session 4

Stratosphere

54

Characterizing stratospheric aerosol from GOMOS: latest algorithm and

dataset development using AerGom

Christine Bingen, Charles Robert, Filip Vanhellemont, Ann Carine Vandaele, Nina

Mateshvili, Cédric Tétard, Didier Fussen, Emmanuel Dekemper, Aerosol_CCI team

BIRA-IASB

GOMOS, which flew on board Envisat, is a pioneering instrument posing many

exciting technical and scientific challenges. As a drawback with respect to the particularly

rich and abundant measurement dataset provided by stellar occultation, the weakness of the

signal and the diversity of stars used as light sources make the retrieval of gas and aerosol

quantities particularly complex. More than a decade of retrieval activities confirms that a key

aspect of the inversion problem is and remains the retrieval of the aerosol signature, of

which the slowly varying spectral response is often difficult to distinguish from contributions

of other species. Therefore, taking into account lessons learned from the ESA official GOPR

retrieval algorithm, a new algorithm called AerGom was recently developed, focussing more

particularly on the improvement of the aerosol retrieval. The performances obtained by

AerGom resulted in its selection as algorithm used for the stratospheric component in the

Aerosol_CCI project, part of the ESA Climate Change Initiative. In this communication, we

present the latest advances in terms of algorithm improvement and development of aerosol

time series from AerGom, as a single aerosol dataset or in association with the OSIRIS

dataset.



55

A combined Odin-OSIRIS and SAGE II Stratospheric Aerosol Data Record

Bourassa, A.E., L.A. Rieger and D.A. Degenstein


SAGE II has provided 20 years of high quality aerosol extinction measurements that

have been used in numerous studies. This work seeks to combine the SAGE II aerosol

record with that of OSIRIS, a limb scatter instrument with a now 13 year data set of its own

to produce a combined, altitude resolved aerosol extinction record of the past 30 years. In

the tropics to mid latitudes coincident OSIRIS and SAGE II measurements agree well over

the bulk of the layer with mean differences typically less than 10%. At higher latitudes and

outside the main aerosol layer larger differences are seen compared to SAGE II with a

general under-estimation of aerosol at high altitudes and over-estimation at low altitudes. For

most locations these difference are well corrected by scaling the OSIRIS data to match that

of SAGE II based on latitude and altitude, providing good agreement between the two

instruments for the three years of mission overlap. This produces a consistent merged

product over the majority of the stratosphere, although also highlights regions where

additional satellite data would be useful to improve the merged product.



56

Trends in stratospheric ozone derived from merged Odin-OSIRIS and SAGE II

satellite observations

Chris Roth, Adam Bourassa, Doug Degenstein

University of Saskatchewan

Stratospheric ozone profile measurements from the Optical Spectrograph and

InfraRed Imager System (OSIRIS) instrument on the Odin satellite (2001–Present) are

merged with those from the Stratospheric Aerosol and Gas Experiment (SAGE) II satellite

instrument (1984–2005) to calculate decadal trends in stratospheric ozone between 60°S

and 60°N. A multi-instrument, multi-decade, deseasonalized and merged stratospheric

ozone record (1984–present) is produced by analyzing the measurements during the

operational overlap of both satellites (2001–2005). The deseasonalized monthly time series

is fit using linear regression with six non-linear predictor basis functions: three quasi-biennial

oscillation proxies, the El Niño- Southern Oscillation index, a solar activity proxy, and the

NCEP pressure at the tropical tropopause; and two linear trends: before and after 1997,

which give the decadal trends in ozone. From 1984–1997, statistically significant negative

trends of 5–10% per decade exist throughout the stratosphere (30–50 km). From 1997–

present, statistically significant recovery rates of 3–8% per decade exist throughout most of

the stratosphere. Below 22 km and between 40°S–40°N a negative trend is measured

before and after 1997. The recovery is not significant in the tropical stratosphere between

25–35 km.



57

Earth Science with the Stratospheric Aerosol and Gas Experiment III (SAGE III)

on the International Space Station

David Flittner1, Joe Zawodny1, Larry Thomason1, Charles Hill1, Marilee Roell1, Mike Pitts1,

Rob Damadeo1, Mike Cisewski1, Randy Moore2

1. NASA Langley Research Center

2. SSAI at NASA Langley Research Center

The Stratospheric Aerosol and Gas Experiment (SAGE) III is the fourth generation of

solar occultation instruments operated by NASA, the first coming under a different acronym,

to investigate the Earth’s upper atmosphere. Three flight-ready SAGE III instruments were

built by Ball Aerospace in the late 1990s, with one launched aboard the former Russian

Avaiation and Space Agency (now known as Roskosmos) Meteor-3M platform on 10

December 2001 (continuing until the platform lost power in 2006). Another of the original

instruments was manifested for the ISS in the 2004 time frame, but was delayed because of

budgetary considerations. Fortunately, that SAGE III/ISS mission was restarted in 2009 with

a major focus upon filling an anticipated gap in ozone and aerosol observation in the second

half of this decade. Here we discuss the mission architecture, its implementation, and data

that will be produced by SAGE III/ISS, including their expected accuracy and coverage. The

52-degree inclined orbit of the ISS is well-suited for solar occultation and provides near-

global observations on a monthly basis with excellent coverage of low and mid-latitudes.

This is similar to that of the SAGE II mission (1985-2005), whose data set has served the

international atmospheric science community as a standard for stratospheric ozone and

aerosol measurements. The nominal science products include vertical profiles of trace

gases, such as ozone, nitrogen dioxide and water vapor, along with multi-wavelength

aerosol extinction. Though in the visible portion of the spectrum the brightness of the Sun is

one million times that of the full Moon, the SAGE III instrument is designed to cover this

large dynamic range and also perform lunar occultations on a routine basis to augment the

solar products. The standard lunar products were demonstrated during the SAGE III/M3M

mission and include ozone, nitrogen dioxide & nitrogen trioxide. The operational flexibility of

the SAGE III spectrometer accomplishes the main goal of producing ozone and aerosol

extinction profiles, while allowing exploration of new possibilities for the occultation

technique, such as night-time aerosol extinction profiles or other trace gases not measured

by SAGE in the past.

Invited speaker


58

ACE-FTS and HALOE observations of Hydrogen fluoride (HF) and their

comparison with SLIMCAT chemical transport model calculations

Jeremy Harrison1, Martyn Chipperfield2, Chris Boone3, Peter Bernath4, Lucien Froidevaux5,

John Anderson6, James Russell III6

1. National Centre for Earth Observation (NCEO), University of Leicester, UK

2. School of Earth and Environment, University of Leeds, UK

3. Department of Chemistry, University of Waterloo, Canada

4. Department of Chemistry and Biochemistry, Old Dominion University, USA

5. Jet Propulsion Laboratory, USA

6. Department of Atmospheric and Planetary Sciences, Hampton University, USA

The majority of fluorine in the atmosphere has resulted from the anthropogenic

emission of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and

hydrofluorocarbons (HFCs). Most tropospheric fluorine is present in its emitted 'organic' form

due to the molecules having long lifetimes (up to a decade or longer). Thus they are able to

reach the stratosphere where they are broken down, liberating fluorine. The principal

degradation products are carbonyl fluoride (COF2), carbonyl chloride fluoride (COClF), and

hydrogen fluoride (HF); of these HF is the most abundant. In fact at the top of the

stratosphere most of the fluorine is present as HF, which, due to its extreme stability, is an

almost permanent reservoir of stratospheric fluorine. Since anthropogenic emissions of

fluorine continue unabated, the amount of HF in the atmosphere continues to increase. The

use of satellite remote-sensing techniques allows the measurement of HF atmospheric

abundances with impressive global coverage, and the investigation of HF trends, and

seasonal and latitudinal variability. This work presents global distributions and trends of HF

using data from two satellite limb instruments: the Atmospheric Chemistry Experiment

Fourier transform spectrometer (ACE-FTS), onboard the SCISAT satellite, which has been

recording atmospheric spectra since 2004, and the HALogen Occultation Experiment,

onboard the Upper Atmosphere Research Satellite (UARS), which recorded atmospheric

spectra between 1991 and 2005. These observations are compared with the output of

SLIMCAT, a state-of-the-art three-dimensional chemical transport model (CTM). The model

aids in the interpretation of the HF satellite observations, and the comparison provides a

validation of emission inventories and the atmospheric degradation reaction schemes used

in the model.



59

Stratospheric acetonitrile (CH3CN) observed by SMILES

Atsushi Hirakawa1,2, Kota Kuribayashi1,2, Naohiro Yoshida1, Yasko Kasai1,2



The final target of this study is to understand a behavior of acetonitrile (CH3CN) over

wide vertical range between upper troposphere and the upper stratosphere from SMILES

observation. Currently we are performing a comparison of SMILES data (v3.0) with

AURA/MLS (version3.3) and error analysis for the validation of SMILES data version 3.0 for

SMILES observation period from 10 October 2009 to 21 April 2010. Coincidences of

SMILES and Aura/MLS were taken ±1.0 hours of observation time and ±300 km of

observation area between 38S and 65N. Total number of the vertical profiles was 9203 and

agreed within the range of error bar. The seasonal variation of latitude-altitude distribution

showed that the higher the concentration in the equatorial region at altitude 30 km between

November to January, which was also consistent with MLS observation. The abundance of

CH3CN was obtained to be 5 -10 ppt at 50 km, which derived from the observation from

space for the first time.



60

Uncertainties in recent satellite ozone profile trend assessments : A ground

network-based assessment of fourteen limb and occultation data records

Daan Hubert1, J.-C. Lambert1, T. Verhoelst1, J. Granville1, A. Keppens1, J.-L. Baray2, U.

Cortesi3, D. A. Degenstein4, L. Froidevaux5, S. Godin-Beekmann6, K. W. Hoppel7, E. Kyrölä8,

T. Leblanc9, G. Lichtenberg10, C. T. McElroy11, D. Murtagh12, H. Nakane13, J. M. Russell III14,

J. Salvador15, H. G. J. Smit16, K. Stebel17, W. Steinbrecht18, K. B. Strawbridge19, R. Stübi20,

D. P. J. Swart21, G. Taha22, A. M. Thompson23, J. Urban12, J. A. E. van Gijsel24, P. von der

Gathen25, K. A. Walker26, E. Wolfram27, J. M. Zawodny28

1. Belgian Institute for Space Aeronomy (BIRA-IASB)

2. LMP

3. IFAC-CNR

4. U Saskatchewan

5. JPL-Pasadena

6. LATMOS-IPSL

7. NRL

8. FMI

9. JPL-TMF

10. DLR

11. U York

12. Chalmers U

13. Kochi U, NIES

14. CAS

15. CEILAP-UNIDEF

16. FJ-IEK8

17. NILU

18. DWD

19. EC

20. MeteoSwiss

21. RIVM

22. USRA, NASA-GSFC

23. NASA-GSFC

24. KNMI

25. AWI

26. U Toronto, U Waterloo

27. CEILAP-UNIDEF

28. NASA-LaRC

The recent SPARC/IO3C/IGACO-O3/NDACC Initiative (SI2N) and WMO’s ozone assessment consider vertical ozone profile measurements by a number of limb and occultation instruments deployed in space over the past three decades. Each instrument and its retrieved ozone profile record is unique, due to the particular combination of measurement principle, wavelength range, detector technology, instrument degradation, sampling pattern, smoothing characteristics, retrieval method, etc… It is of utmost importance to understand and quantify the consistency between all data records, e.g. for a

61

proper interpretation of the trend results on merged data sets or for a sound comparison of the trends derived from different single instruments. We present a comprehensive assessment of fourteen limb/occultation ozone profile records, using NDACC/GAW/SHADOZ ozonesonde and NDACC lidar network observations as reference standards. We derive altitude- and (whenever possible) latitude-resolved estimates of the decadal stability, overall bias, and short-term variability of each satellite data record, and their dependence on auxiliary data. This allows us to discuss the mutual consistency of all fourteen records, and to identify some implications for data merging activities or ozone trend assessments. In particular, we are able to reinterpret recently observed differences between ozone profile trend assessments in terms of instrumental drift. We conclude by a reflection on the capability of the current ozone profile observing systems to verify the compliance of satellite data quality with user requirements set by GCOS and climate research groups.



62

Sonde validation of improved SCIAMACHY ozone limb data on global scale

Jia Jia

IUP Bremen

SCIAMACHY (Bovensmann et al., 1999) measurements have been used to produce

a unique database of different atmospheric parameters during 2002-2012. In this

presentation, the latest SCIAMACHY limb ozone scientific vertical profiles, namely the

current V2.9 and the new version, are extensively compared with ozone sonde data from the

WOUDC database. The comparisons are discussed in terms of vertical profiles and

stratospheric partial columns. Our results indicate that the V2.9 ozone profile data between

20 km - 30 km is in good agreement with ground based measurements with less than 5%

relative differences in the latitude range of 90°S-40°N, which corresponds to less than 5 DU

partial column differences. In the tropics the differences are within 3% with exception of the

tropical Pacific region where an overestimation of more than 10% is observed. However, this

data set shows a significant underestimation northwards of 40°N (up to 15%). The newly

developed version reduces this bias to below 10% while maintaining a good agreement

southwards of 40°N with slightly increased relative differences of up to 5% in the tropics. The

results demonstrate an improvement of 2-20 DU in the stratospheric ozone amounts.



63

Denitrification and Polar Stratospheric Cloud Occurrance during the Arctic

winter 2009/2010 and 2010/2011: Comparison of EMAC Simulations with

CALIPSO, Odin/SMR and Envisat/MIPAS Observations

Farah Khosrawi, O. Kirner, J. Urban, S. Kellmann, M. Kiefer, G. Stiller, D. Murtagh, P.

Braesicke

IMK-ASF, Karlsruhe Institute of Technology

The sedimentation of HNO3 containing polar stratospheric cloud (PSC) particles

leads to a permanent removal of HNO3 from the stratosphere. The so-called denitrification is

an effect that plays an important role in stratospheric ozone depletion. The Arctic winter

2009/2010 and 2010/2011 were both quite unique. The Arctic winter 2010/2011 was one of

the coldest winters on record leading to the strongest depletion of ozone measured in the

Arctic. Though the Arctic winter 2009/2010 was rather warm in the climatological sense it

was distinguished by an exceptionally cold stratosphere from mid December 2009 to mid

January 2010 leading to prolonged PSC formation and significant denitrification. Model

simulations and space-borne observations are used to investigate PSC formation and

denitrification during these two winters. Model simulations were performed with the

atmospheric chemistry-climate model ECHAM5/MESSy Atmospheric Chemistry (EMAC) and

compared to observations by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite

Observations Satellite (CALIPSO) and the Odin Sub-Millimetre Radiometer (Odin/SMR) as

well as with observations from the Michelson Interferometer for Passive Atmospheric

Soundings (Envisat/MIPAS). While PSCs were present during the Arctic winter 2010/2011

over nearly four months, from mid December to end of March, they were not as persistent as

the ones that occurred during the shorter (one month) cold period during the Arctic winter

2009/2010. Although the PSC season during the Arctic winter 2009/2010 was much shorter

than in 2010/2011, denitrification during the Arctic winter 2009/2010 was similar in

magnitude than during 2010/2011.



64

Preparatory study for SAGE II / MIPAS / OMPS merging

Alexandra Laeng1, T. von Clarmann1, G. Stiller1, U. Grabowski1, N. Glatthor1, S. Lossow1, S.

Kellmann1, M. Kiefer1, A. Linden1, N. Kramarova2, J. Zawodny2, S. Godin-Beekmann3, I.

Petropavlovskih4, R. Stubi5, G. Ancellet3, E. Maillard-Barass5, T. Leblanc6, W. Steinbrechält7,

T. Portafaix8, A. v. Gijsel9

1. KIT, Germany

2. NASA, USA

3. LATMOS, France

4. NOAA, USA

5. Meteo Swiss, Switzerland

6. JPL, NASA, USA

7. DWD, Germany

8. Université de la Reunion, France

9. KNMI, Neetherlands

MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) on board the ESA

ENVISAT spacecraft has been taking limb emission measurements of ozone profiles from

2002 to April 2012.The Stratospheric Aerosol and Gas Experiment II (SAGE II) took solar

occultation measurements of ozone number densities from 1984–2005 and has been used

in many studies of long-term ozone trends. The Ozone Mapping and Profiler Suite (OMPS)

Limb Profiler (LP) instrument, launched in October 2011 and currently operated, measures

solar radiances scattered from atmospheric limb in UV and visible spectral ranges to retrieve

vertical ozone profiles from cloud top to 60 km with vertical resolution of about 2 km. This

information can be used to merge the three data records, SAGE II, MIPAS and OMPS, into a

single ozone record from 1984 to the present. We present the validation of ozone vertical

profiles from MIPAS with SAGE II v7.0 and OMPS, in view of future merging of the three

datasets. The overall agreement of MIPAS with SAGE v7.0 and OMPS v2.0 and biases

between datasets are investigated. Vertical profiles from ozonesondes and Umkehr are used

as reference instruments. The deseasonalized anomalies of datasets participating in the

merging are compared with those of reference instruments.



65

Trend analyses of stratospheric O3 and NO2 from OSIRIS and SAGE II data

Marko Laine, Simo Tukiainen, Erkki Kyrölä

Finnish Meteorological Institute

We have analyzed long-time trends of stratospheric O3 and NO2 from the satellite

measurements of Stratospheric Aerosol and Gas Experiment II (SAGE II) and Optical

Spectrograph and InfraRed Imager System (OSIRIS). We use multivariate dynamic

regression for the time series analysis of the combined 1984-2015 data. We model

observations from several altitudes simultaneously and the long-term trends and the

amplitudes of the seasonal cycles are allowed to change dynamically. The model accounts

for solar activity and Quasi-Biennial Oscillation. The effect of solar zenith angle is studied,

also. We will review our results of the trend analyses and discuss the methodological

challenges.



66

Equatorial middle atmospheric chemical composition changes during sudden

stratospheric warming events

Oindrila Nath, S. Sridharan

National Atmospheric Research Laboratory, India

Chemical composition data obtained from the Microwave Limb Sounder (MLS) and

Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instruments onboard

EOS-Aura and ENVISAT satellites are used to investigate the variation of ozone

(O3), water 5 vapor (H2O) and methane (CH4) volume mixing ratios (VMRs) in the height

range 20–60 km over the equatorial region during the sudden stratospheric warmings

(SSWs) of 2004, 2009 and 2012, the occurrence of which are identified using the ERA

(European Center for Medium Range Weather Forecasting Reanalysis) Interim temperature

and zonal wind data sets. It is found that the O3 VMR shows increment whereas

10 H2O VMR shows decrement during the SSW event and the possible reasons for these

changes in the VMRs are investigated. In the upper stratosphere, the source of water

vapor is oxidation of CH4 which takes place either by hydroxyl (OH) or by atomic

oxygen (O). However, the OH VMR available for the year 2009 SSW event does not

show any significant variation. The decrease of zonal mean MLS temperature over the

15 equator during the SSW suggests that the rate of the reaction of ozone production

(O+O2 �!O3+M), which increases with decreasing temperature, shifts the O=O3 ratio

towards O3, resulting in the decrease of CH4 oxidation and consequent decrease in

water vapor.



67

Preview of an ozone loss study based on data assimilation of Odin/SMR ozone

Kazutoshi Sagi, Donal Murtagh

Chalmers University of Technology, Sweden

Odin is a Swedish-led satellite project in collaboration with Canada, France and Finland and carries OSIRIS (Optical Spectro graph/InfraRed Imaging System) and SMR (Sub-Millimetre Radiometer). Odin is continuing to produce profiles of chemical species relevant to understanding the middle and upper atmosphere since it launched in February 2001. The long-term observation of stratospheric ozone can be useful for trend analysis of chemical ozone loss. This study concerns polar ozone loss over the Arctic and Antarctic hemisphere utilizing the 12 years (02-13) of ozone data from Odin/SMR. In order to quantify the chemical loss, it is necessary to clearly understand the contribution of dynamics in ozone changes. We have applied the data assimilation technique with a number of improvements to study the inter-annual variability during the entire Odin period.



68

ESA Ozone Climate Change Initiative: Towards combined use of high vertical resolution satellite data for climate research

Johanna Tamminen1 , V.F. Sofieva1, , E. Kyrölä1, M. Laine1 , S. Tukiainen1, J. Hakkarainen1,

M. Weber2, N. Rahpoe2, A. Laeng3, T. von Clarmann3, G. Stiller3, A. Hauchecorne4,

D. Degenstein5, D. Murtagh6, K. A. Walker7, D. Hubert8, M. Van Roozendael8,

C. Zehner9

1. Finnish Meteorological Institute, Finland

2. Institute of Environmental Physics, University of Bremen, Germany

3. Karlsruhe Institute of Technology, Germany

4. LATMOS, France

5. University of Saskatchewan, Canada

6. Chalmers University, Sweden

7. Department of Physics, University of Toronto, Canada

8. BIRA-IASB, Belgium

9. ESA/ESRIN, Italy

The ESA Ozone Climate Change Initiative (Ozone_CCI) is part of ESA Programme

on Global Monitoring of Essential Climate Variables. The aim of the Ozone_CCI is to

generate high-quality satellite data sets needed to assess the fate of atmospheric ozone and

to better understand its link with anthropogenic activities. The data measured by the limb-

viewing satellite instruments on-board ENVISAT (GOMOS, MIPAS, SCIAMACHY) and ESA

Third Party Missions (OSIRIS, SMR and ACE-FTS) are used to create harmonized,

homogenized and merged ozone data sets with high vertical resolution. The use of

combined data from different limb sensors is of high interest, because they provide much

better spatio-temporal coverage than each of the instruments separately. However, the data

from different instruments can be biased with respect to each other, have different vertical

resolution, are attributed to different local times, and might use different a priori information

in the inversion process. In this presentation, we discuss recent developments in the project,

introduce developed datasets and methods for combined use of data, as well as show some

data analyses. In particular, challenges related to the upper troposphere – lower

stratosphere data are discussed.



69

Ozone transport in the stratosphere during two polar winters from Aura MLS

and OMPS-Limb Profiler assimilation

Krzysztof (Kris) Wargan1,2, Steven Pawson1, Lawrence Coy1,2, Matthew DeLand2, Philippe

Xu1,3, Pawan K. Bhartia1

1. NASA Goddard Space Flight Center, Greenbelt, MD, USA

2. Science Systems and Applications Inc., Lanham, MD, USA

3. Science Applications International Corporation, Mclean, VA, USA

An accurate representation of global 3-dimensional stratospheric ozone

concentrations and their evolution is of great importance for studies of trace gas transport,

ozone recovery and radiative forcing. Data assimilation offers a statistically optimal method

of estimating meteorological and trace gas fields by combining available observations with

forecasts produced by global circulation models at a potentially high horizontal and vertical

resolution. Previous work done at NASA's Global Modeling and Assimilation Office (GMAO)

over the past 10 years has demonstrated that ozone analyses are of particularly high quality

when limb sounder data are assimilated. This presentation will focus on a process-based

analysis of two side-by-side assimilation experiments performed with a recent configuration

of NASA's Goddard Earth Observing System version 5 (GEOS-5) data assimilation system.

The first experiment uses the now well-established ozone data sets from the EOS Aura

satellite: the total ozone column observations from the Ozone Monitoring Instrument (OMI)

and stratospheric profiles retrieved from the Microwave Limb Sounder (MLS) data version

4.2. In the second experiment the MLS observations are replaced by version 2 profiles from

the Ozone Mapping and Profiler Suite - Limb Profiler (OMPS-LP) on the Suomi National

Polar-orbiting Partnership satellite. The principles of measurement are very different

between MLS and OMPS-LP: while the former detects the atmosphere's microwave

emissions, the latter measures backscattered ultraviolet and visible radiation. In particular,

OMPS-LP observes the sunlit atmosphere only. In both cases the limb sounding technique

enables retrievals of high vertical resolution information on ozone in the stratosphere. We

will use these assimilation experiments to discuss stratospheric ozone transport during the

boreal winters of 2012/2013 and 2014/2015, the first of which featured a very strong major

sudden stratospheric warming. The areas of agreement as well as differences between the

analyses will help us assess the robustness of the results.



70

Information on stratospheric aerosol from SCIAMACHY solar occultation

measurements.

Jacob Zalach, Christian von Savigny

Greifswald University

Information on stratospheric Aerosol from SCIAMACHY solar occultation

measurements. The ROMIC-ROSA joint project analyses stratospheric aerosol extinction

profiles and its size distribution. For this work SCIAMACHY (EnviSat) solar occultation

measurements are analysed. The data set covers a time period of ten years within a

wavelength interval between 240 and 2380 nm. Satellite born occultation measurements are

an established method to obtain information on vertical profiles of atmospheric composition

and stratospheric aerosol extinction. However, due to spatial resolution and sampling rate of

the measured solar profiles a direct application of existing analysis tools and algorithms to

SCIAMACHY solar occultation masurements is not possible. This work presents the

necessary data processing and retrieved aerosol extinction profiles which are verified by

comparison with other measurements.



71

Session 5

UTLS and troposphere

72

New instrumentation for limb profiling aerosol and water vapour in the UTLS

A.E. Bourassa, B. Solheim, B.J. Elash, D. Zawada, N.D. Lloyd, S.R. Dueck, P.R. Loewen

and D.A. Degenstein


The design, development and test results from two new prototype limb scatter

instruments developed within Canada are presented. The Spatial Heterodyne Observations

of Water (SHOW) instrument is designed to measure vertically resolved water vapour in the

upper troposphere and lower stratosphere (UTLS) with high vertical resolution. The limb

scatter spectra are obtained through the use of a field widened monolithic Spatial

Heterodyne Spectrometer (SHS) operating within the 1.3 micron absorption band of water

vapour. The Aerosol Limb Imager (ALI) instrument concept uses a large aperture Acousto-

Optical Tunable Filter (AOTF) to successively image limb scattered sunlight in a selectable

narrow wavelength band from the visible to the near infrared to retrieve spatially resolved

information of the stratospheric aerosol distribution, including extinction coefficient and

particle size. Both the SHOW and ALI prototype models were tested on a stratospheric

balloon flight from the Canadian Space Agency (CSA) launch facility in Timmins, Canada, in

September, 2014, on the CNES CARMEN gondola. Results from both of these test flights

are presented.

Invited speaker


73

Japanese future mission for air quality uvSCOPE and APOLLO

Tamaki Fujinawa1, Yasko Kasai2,1, Mona Mahani2, uvSCOPE team, and APOLLO mission

team


2. NICT

Space-based observations of the vertical profile of tropospheric ozone(O3), nitrogen

dioxide (NO2), PM2.5, and other related species, which influence the air quality of

troposphere, provide a great understanding to study the status of air quality, relevant

emission inventories and its chemical processes. Concerns about the environmental impact

of tropospheric ozone and NO2 have recently been increasing and importance of them has

also been recognized because of its influence on human health, vegetation and future

climate change. The purpose of this study is to obtain quantitative knowledge on how to

better constrain the vertical profiles of tropospheric ozone and NO2 by using a joint

synergetic retrieval technique that utilizes spectra measurements, such as Ultraviolet (UV),

Thermal Infrared (TIR), and Sub-millimeter-wave (MW) at the same time from the space by

three different instruments.For Ozone, we performed a feasibility study using 20 vertical

profiles that are created by a chemical transport model over two Asian regions in summer

and winter 2009. The joint retrieval using UV, TIR, and MW provided averaging kernel and

degree of freedom to be more than unity for upper, lower, and lowermost tropospheric ozone

simultaneously for the most of atmospheric scenarios. The interesting feature was found that

the poor boundary layer ozone measurements showed improvements in both degree of

freedom up to 25-28 % and averaging kernel up to unity by adding MW measurements to UV

+ TIR combination.



74

Analysis of aerosols optical properties in the atmosphere over Ukraine based

on ground (AERONET) and satellite (MODIS, CALIOP) observational data

Evgenia Galytska1,2, Vassyl Danylevskyi3, Sergiy Snizhko2

1. Institute of Environmental Physics, University of Bremen, Germany

2. Meteorology and Climatology Department, Taras Shevchenko National University of

Kyiv, Ukraine

3. Astronomical Observatory, Taras Shevchenko National University of Kyiv, Ukraine

To improve the knowledge of aerosols behavior in the atmosphere over Ukraine we

analyse remote ground-based and satellite measurements of aerosols optical properties and

simulate particles transport under different weather conditions. The dynamics of aerosol

layers over large Ukrainian cities (Kiev, Lugansk, Sevastopol) is the subject of the remote

sensing investigation made by the sunphotometers network AERONET/PHOTONS.

Sunphotometers of the AERONET network measure spectral Aerosol Optical Depth (AOD)

at visible and near infrared spectrum every 15 minutes during sunlight time of the day with

high accuracy (~0.01). Also Angstrom exponent (AE) and aerosol particles microphysical

properties, namely size distribution, spectral single-scattering albedo, complex refractive

index and phase function in the atmospheric column over observational site are retrieved by

AERONET algorithms from sunphotometer measurements. We analyse AOD at 500 nm

together with AE at 440 – 870 nm spectral range for summer 2010, provide short statistical

analysis of AOD, and examine weather conditions for high AOD values events. To improve

the spatial resolution of our research the AOD at 550 nm from MODIS instruments installed

on board of NASA Aqua and Terra satellites were applied. An adequacy of the MODIS

aerosols models and accuracy of the inverse solution are estimated by comparison of AOD

at 550 nm obtained by MODIS and AERONET Kyiv site sunphotometer for summer 2010.

The correlation between AERONET and MODIS data was found to be more than 0.9. We

also used data from lidar CALIOP on board of CALISPSO satellite. We analysed AOD and

vertical profiles of the extinction coefficient at the wavelength of 532 nm. CALIOP AOD data

coincident with Kyiv AERONET AOD were not found for the comparison, therefore

MODIS/Aqua data were used for CALIOP AOD validation. It was revealed that the level of

consistency between MODIS/Aqua AOD and CALIOP AOD is not so good (R 0.6). It is

explained by low accuracy of CALIOP data during daytime measurements, the incorrect

choice of aerosols model and lidar ratio, incorrect optical properties of the Earth's surface

taken into account and by differences of cloud discrimination algorithms of CALIOP and

MODIS instruments.



75

Global climatology of trace gases (including hydrocarbons) based on

Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-

FTS) measurements

Ja-Ho Koo1, Kaley A. Walker1, Ashley Jones1, Patrick E. Sheese1, Chris D. Boone2, Peter F.

Bernath3, Dylan B. A. Jones1, Gloria L. Manney4,5

1. Department of Physics, University of Toronto, Toronto, Ontario, Canada

2. Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada

3. Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia,

USA

4. NorthWest Research Associates

5. New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA

A climatology of trace gases can provide useful information to understand the

spatiotemporal characteristics of atmospheric composition. Also, it plays a significant role in

global model simulations by providing initial or prescribed conditions. ACE-FTS has

measured profiles of trace gases using the solar occultation technique since 2004, which

can be used to estimate a global climatology. Using ACE-FTS version 3.5 profiles from 2004

to 2013, we present a climatology of 21 trace gases on a global scale including several

hydrocarbon species (C2H6, C2H2, HCN, CH3OH, HCOOH, and H2CO). Unrealistic outliers

are filtered out of the data set prior to the climatological estimation using the data quality

flags recently developed for ACE-FTS. The climatology is provided on 48 pressure levels

which can cover from the upper troposphere to the upper mesosphere. These levels were

adapted from the Stratosphere-troposphere Processes And their Role in Climate (SPARC)

Chemistry-Climate Model Validation (CCMVal) activity up to the upper stratosphere, and the

Whole Atmosphere Community Climate Model (WACCM) in the mesosphere. The ACE-FTS

climatology also provides the local daytime and nighttime distributions separately enabling

diurnal changes to be discerned. The climatology contains zonal mean profiles of 21 species

for monthly and 3-monthly (DJF, MAM, JJA, and SON) periods. These are presented with 5-

degree spacing in latitude and a version is provided in equivalent latitude, which is useful to

consider the influence of the polar vortex. Also, we compare this climatology to the global

simulations from the GEOS-Chem chemical transport model to investigate the seasonal

variations and regional features of different hydrocarbon species.



76

Broader impact of Sudden Stratospheric Warming (SSW) on polar and tropical

dynamics

Vinay Kumar1, S. K. Dhaka1, R. K. Choudhary2, Shu-Peng Ho3

1. Radio and Atmospheric Physics Lab, Rajdhani College, University of Delhi, India

2. Space Physics Laboratory, VSSC, Trivanduram

3. COSMIC Program Office, University Corporation for Atmospheric Research, Boulder,

Colorado, USA

A significant change in temperature in the tropopause and stratosphere, from pole to

the tropics was observed during a major Sudden Stratospheric Warming (SSW) occurring in

January 2009. The SSW event strongly modified the pattern of polar and tropical

stratospheric circulation. After termination of SSW, a new pattern emerged that prevailed for

~ 2-3 months. After SSW, a clear descending cold phase completely replaced the warm

phase in the polar regions. During warm phase, temperature increased to ~ 40°C in

stratosphere (>30 km) in the polar region (80°N-90°N), then it dropped down to - 80°C during

cold phase. Interestingly, new warm anomalies appeared over the tropical region during cold

phase at polar regions. Possible implications of these unusually warm and cold phases are

demonstrated in this study. These phases altered significantly the cold point tropopause

temperature and its height. SSW also affected the tropical atmospheric stability. Cross

equatorial response (from northern to southern hemisphere) up to 40°S was observed in the

form of persisting anomalies as a consequence of the SSW event.



77

A “Match” approach to quantifying processes affecting TTL humidity based on

MLS observations

Nathaniel Livesey1, Michelle Santee1, William Read1, Michael Schwartz1, Alyn Lambert1,

Lucien Froidevaux1, Gloria Manney2,3

1. Jet Propulsion Laboratory, California Institute of Technology

2. NorthWest Research Associates

3. New Mexico Institute of Mining and Technology

The humidity of the lower stratosphere is influenced by a combination of factors,

notably the freeze-drying of air that slowly ascends in the Tropical Tropopause Layer (TTL),

through the Lagrangian cold point, into the lower stratosphere, as well as the convective

injection that effectively bypasses the cold point, depositing ice directly into the lowermost

stratosphere. Long-term variability in both of these processes and their relative contributions

has important implications for stratospheric humidity and thus Earth’s radiative balance.

Here we describe a new application of observations from the Aura Microwave Limb Sounder

(MLS) to the study of TTL processes. The “Match” approach uses trajectory calculations to

identify cases where MLS has observed the same airmass on multiple occasions.

Examination of the changes in water vapor between these observations gives insight into the

extent to which overshooting convection hydrates the lower stratosphere. We investigate the

suitability of this approach to quantifying such hydration, and examine the relationship

between the estimated hydration and other climate variables.



78

Assessment of the aerosol pollution in Russian largest cities based on the

remote sensing data

Elizaveta Malinina1, Natalia Chubarova2, Mikhail Sviridenkov3

1. University of Bremen

2. Lomonosov Moscow State University

3. A.M. Obukhov Institute of Atmospheric Physics RAS

The assessment of aerosol urban pollution in more than 50 largest cities of Russia

was fulfilled. We used MODIS aerosol optical thickness (AOT) data during the warm period

of 2000-2014 at the wavelength 550 nm to understand the value of the urban aerosol

pollution (we defined urban aerosol pollution as difference between AOT in the city and the

value of regional background AOT). Our research showed that urban aerosol pollution varies

in Russian cities from 0.01 to 0.08. Basing on these calculations we coarsely evaluated the

radiative forcing, caused by this pollution. Depending on the location, size, and level of the

aerosol pollution of city radiative forcing varies from -4.1 W/m2 to -0.4 W/m2. Besides, we

compared MODIS data with AERONET data to verify the quality of MODIS radiometers AOT

data. This comparison showed a good quality of MODIS AOT retrieval, and a possibility of

these radiometers to detect fine effects like urban aerosol pollution. We decided to assess

more precisely urban aerosol pollution and its effects in Moscow region. For this purpose, we

used simultaneous measurements from September 2006 till June 2014 on two AERONET

network sites: one of them is located in the city of Moscow (Moscow University

Meteorological Observatory) and another one is located 55 km to the west from the city of

Moscow (Zvenigorod Scientific Station). The average difference in AOT between these two

sites for the taken period is 0.02 for the wavelength 500 nm. The largest difference was

observed in winter and is 0.03. All of these results agree with the similar research that was

done previously. We also tried to assess the dominating aerosol component in different cities

basing on the data on emissions and concentrations of main pollutants from 1998 till 2011

from Russian regular network. We evaluated the ratio of sulfur dioxide emissions to nitrogen

dioxide emissions and its trends to assess the dominating aerosol properties and their

temporal variability.



79

Impact of Climate variability in the troposphere : Implication to Indian

Monsoon

Jayaraju Nadimikeri, Yogi Vemana University

Variability in the sea surface temperature and salinity are the certain parameters to

be understood from the Indian Seas in order to understand Monsoon and other sea induced

processes. Indian monsoon is not a local phenomenon but one of the major components of

the global circulation. It interacts with other components of the global circulation in a

significant and systematic manner . Fluctuations in the monsoon are the reflections of the

fluctuations in the global circulations. Global circulation comprises of planetary scale

disturbances having wave like character. Zonal asymmetry between land and ocean in the

tropics plays a dominant role in the dynamics of the tropical atmosphere. During northern

summer, the lower tropospheric temperature, pressure, wind direction, humidity and

circulation features over land and oceans show a marked contrast. Lands are warmer than

the oceans causing lows over land and highs over ocean while meridional wind is southerly

over land and northerly over ocean at lower levels. In the northern tropics, the low level jet,

heat low over Pakistan, oceanic anticyclones and cyclonic circulations over Indian sub-

continents are the major standing eddies which are seen throughout the northern summer in

the lower troposphere. This paper attempts to understand the climate phenomena and

processes in which the Indian Ocean is, or appears to be, actively involved in the climate

variability of the troposphere from the Indian sub continent.



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