1 November 17, 2009 Jim Russell - EOPM Review GATS James M. Russell III Principal Investigator...

1November 17, 2009Jim Russell - EOPM Review

GATS

James M. Russell IIIPrincipal InvestigatorHampton University

Scott M. BaileyDeputy Principal Investigator

Virginia Tech

November 17, 2009

AIM End of Prime Mission ReviewScience Results


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Unprecedented advances in observation of noctilucent

clouds

- Solar occultation - Panoramic UV nadir imaging - In-situ and remotely sensed

dust

Aeronomy of Ice in the Mesosphere (AIM)

Major step forward in understanding noctilucent clouds, their formation and variability

- World class science team

- State of the art modeling


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AIM Science Team

Principal Investigator: James M. Russell III Hampton University

Deputy PI: Scott M. Bailey Virginia Tech

Co-Investigators

Gary Thomas, CU Cora Randall, CU

David Rusch, CU David Siskind, NRL

Michael Taylor,USU Michael Stevens, NRL

Larry Gordley, GATS Mihály Horányi, CU

Patrick Espy, NTNU Michael Summers, GMU

Mark Hervig, GATS Christoph Englert, NRL

William McClintock, LASP Steven Eckermann, NRL


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Noctilucent Clouds and Polar Mesospheric Clouds are the same phenomenon

Tom Eklund, July 28, 2001, Valkeakoski, Finland

Ground-based observers: Noctilucent Clouds (NLCs)Satellite observers: Polar Mesospheric Clouds (PMCs)


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NLCs display complicated structuredriven by atmospheric dynamics

BandsBandsBillowsBillows Timo Leponiemi, 2001


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Brief mission overview

What we know about NLCs

AIM goals, objectives and Level 1 requirements

AIM instruments and measurements

Science results

Summary

AIM overview and science results outline


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AIM was launched from VAFB by a Pegasus XL rocket

April 25, 2007, 1:26:03 PM PDT launch

Near perfect 600 km orbit

First satellite mission dedicated to the study of NLCs

Observed five seasons thus far

Extended mission approved for June 1, 2009 to September 30, 2012


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NLCs have been photographed from the ground

Omaha, NB PhotoJuly 14, 2009

Omaha, NB July 14, 2009Mike Hollingshead


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Commercial airline NLC PhotoJohn Boardman, Pilot

NLCs have been photographed from the ground, aircraft





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Space Station NLC PhotoDonald Pettit, Science Officer


NLCs have been photographed from the ground, aircraft and space






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NLCs have been photographed from the ground, aircraft and space

There has been a growing publicand scientific interest in theseclouds in recent years






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Mysterious, Glowing Clouds Appear Across America’s Night SkiesBy Alexis Madrigal, July 16, 2009 | 1:00 pm | WIRED SCIENCE

“Photographers and other sky watchers in Omaha, Seattle, Paris and other locations

have run outside to capture images of what scientists call noctilucent (”night shining”)

clouds.”

Scientists seek noctilucent cloud enlightenmentBy Lester Haines, New Scientist, UK June 3, 2009

“According to New Scientist, skywatchers last week snapped the first examples of the

clouds, although NASA's AIM spacecraft got the first indications back on 22 May.”

Discover Magazine interview to appear in February 2010

CBS Evening News segment (3 minutes) on March 14, 2008

NPR and WTOP-DC radio segments, image in Nature magazine, more

than 50 public media articles worldwide

NLCs capture the imagination and concern of the public


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NLCs are changing in ways we do not understand

Earth’s Atmosphere

Alt

itu

de

(km

)

Troposphere

-80 -60 -40 -20 0 20 ºC

Temperature

Usually seen poleward of 55O but have been sighted at ~ 40ON in recent years

Have been getting brighter and occurring more frequently over the last 27 years

20

40

60

80

0

100

DeLand, Shettle, Thomas, and Olivero (JGR, vol. 112, D10315, 2007)

SH NH

1980 1985 1990 1995 2000 2005 1980 1985 1990 1995 2000 2005

50o – 82o N 50o – 82o S

Ave

rag

e B

rig

htn

ess

Ave

rag

e B

rig

htn

ess


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Three things are needed for PMC formation

Water vapor

Presence of particles

Cold temperatures

What could be causing the observed PMC changes?


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While not proven, the most plausible reasons for long-term NLC change are CO2 and CH4 increases

CO2 increases in the lower atmosphere cause the the atmosphere to warm

The same increases at 83km cause cooling

CH4 increases lead to more water vapor in the atmosphere

Both effects make conditions more favorable for NLCs to form


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NLCs are ice clouds that occur more than 70km above tropospheric clouds

Why do these clouds form and vary?

Why are long-term changes occurring?

Is there a connection with global change?

AIM July 4, 2008


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Resolve why NLCs form and how and why they vary

Quantify the connection between the clouds and the meteorology of the polar mesosphere by measuring the thermal, chemical and dynamical environment in which NLCs form

Provide the basis for study of long-term variability in the mesospheric climate and its relationship to global change

AIM goals are clearly defined


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The fundamental question: Why do PMCs form and vary?

4. Chemistry

H2O

OH HO2

H

O

O

O3O2, M

O1D, h

h

CH4

OH O1D

3. TemperatureVariability

5. Nucleation Environment

1. Microphysics2. Gravity Wave Effects

6. Long-term Mesospheric Change - What is needed?

AIM is providing the answers


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Mission

Type

Length Parameters Preci- sion

Vert.

Range

Resolu- tion

Spatial Coverage

Baseline

2 North

2 South

PMC seasons

Obtain each day:

PMCs , - 5%

r – 10%

75 km to

85 km

2 km vertical

15 SR or 15 SS poleward of 55oT, H2O, O3,

CH4,NO,CO2~ 5 K

~ 15 %

Nadir UV images

N/A N/A 2 km horizontal

Poleward of 30o

Particle influx for r > 0.7 m

10% N/A N/A N/A

Minimum*

One PMC season, North or South

Obtain each day:

PMCs , - 10%

r - 15%

78 km to

85 km

3 km vertical

15 SR or 15 SS poleward of 55oT, H2O, O3,

NO,CO2

~ 10 K~ 25 %

Nadir UV images

N/A N/A 3 km horizontal

Poleward of 50o

AIM Level 1 science baseline and minimum missions

* CDE instrument is not included in the minimum mission


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Cosmic Dust Experiment (CDE) measures the input of cosmic dust into the atmosphere

Three Instruments on the AIM observatory

Cloud Imaging Particle Size (CIPS)Nadir imagesCloud particle size

Solar Occultation for Ice Experiment (SOFIE)T, H2O, Ice mass,

cosmic dust


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CIPS: Cloud Imaging and Particle Size Experiment

Four CCD cameras image NLCs at ~ 83 km

0.265 µm; 1 X 2.5 km pixel size

Cloud morphology and particle sizes


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SOFIE: Solar Occultation for Ice Experiment

Operates over 0.3m to 5.3 m range

T, NLCs, CO2, H2O, CH4, NO, O3, aerosols, cosmic smoke

2 km vertical resolution

A 16-band differential absorption radiometer (UV to IR) to simultaneously measure cloud properties and the PMC environment


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CDE: Cosmic Dust Experiment

Differential mass measurements for masses, 10 -11 < m < 10 -8 g

Cumulative mass measurements for masses, m > 10 - 8 g

Data span June 2007 to Feb 2008

- CDE data showed increased noise after February 2008 S/C safehold

Data loss mitigated by SOFIE cosmic smoke measurements

14 polyvinylidene fluoride detectors to measure the incoming cosmic dust flux


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SOFIE

H2O, Ice, T, Chemistry

AIM observing approach: SOFIE


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CIPS

Ice images

6 min

AIM observing approach: SOFIE, CIPS


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6 min

CDE

Cosmic Dust

o

o

ooo

o o oo

o

o

AIM observing approach: SOFIE, CIPS, CDE


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A space view gives an entirely new picture of what the clouds look like:

NLCs occur all the time Highly variable orbit-to-orbit and day-to-day More structure than expected

AIM Jul 8, 2008 NHGround

60NTom Eklund, July 28, 2001, Valkeakoski, Finland


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One orbit of CIPS data in July 2008


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NPNP

60NMin Lat = 60N

11-Jul-2008Three successive orbits on July 15, 2007


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NPNP

60NMin Lat = 60N

6-Jul-2008


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Ice Void

AIM science focus before launch was on a narrow visible NLC layer centered around 83 km

92

90

88

86

84

82

80

78

Alt

itu

de

1-Jun 1-Aug 1-Sep1-Jul2007


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Ice Void

AIM observed subvisible ice particles for the first time

92

90

88

86

84

82

80

78

Alt

itu

de


High SOFIE sensitivity SNR ~106

Ice exists from 78km to ~ 90km

Visible layer centered at ~ 83km


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Ice Void92

90

88

86

84

82

80

78

Alt

itu

de


AIM observed subvisible ice particles for the first time and showed NLCs are highly variable with “Ice Voids”

CIPS shows the presence of “Ice voids”

An entirely new mechanism for NLC formation

Not known before the AIM launch

Ice Void

High SOFIE sensitivity

Ice exists from 78km to ~ 90km

Visible layer centered at ~ 83km


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What is the role of temperature and water vapor in the formation of PMCs?


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Temperature is a controlling factor in PMC formation

Merkel et al., 2007

CIPS PMC frequency at 77º latitude and SABER temperature


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SOFIE PMC altitude and SABER mesopause - 3.5 km for 2007 - 2008 NH/SH seasons

10d

Russell et al., 2009

Mesopause temperature is a driver for PMC peak altitude formation


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Black dots: Mesopause vapor pressureRed dots: Mesopause saturated vapor pressureBlue line: Ice mass density

SOFIE PMC ice mass density and MLS saturation vapor pressure and vapor pressure

Sharply decreasing saturated vapor pressures at season start and rapidly rising values at the end point to temperature as the dominant factor in controlling the beginning and ending of PMC season


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The NLC season turns on and off like a geophysical light bulb providing clues to why NLCs form

NorthernHemisphere

SouthernHemisphere


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How do planetary waves and gravity waves affect PMC formation and destruction?


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Sequence of CIPS Daisies showing 5-day wave

Merkel et al., 2007

June 5June 3 June 4 June 6 June 7

June 8 June 9 June 10 June 11 June 12

CIPS sequence of daily images showing the influence of the 5-day wave on PMCs

Merkel et al., 2007

June 3 June 4 June 5 June 6 June 7


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Temperature wavelet amplitudes (grey and black)

Observed SOFIE clouds for ice >30 ng/m3

(white dots)

NRL NOGAPS model and SOFIE data show that dynamics can extend the length of the PMC season

Tim

e

The atmospheric 5-day wave modulates

PMC occurrence and can effectively

extend the period of PMC occurrence by

providing many days of localized regions

of saturated air in the trough of the wave.

Nielsen et al., 2009


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Correlation with PMC -0.94Correlation with SABER temperature 0.72

Chandran et al., 2009

Gravity wave frequency, PMC frequency and SABER temperature amp for 2007/2008 SH season

CIPS PMC observations


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What are the mechanisms leading to hemispheric coupling effects on PMC formation?


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AIM NH PMC data and MLS SH Temp show that the atmosphere is a coupled global system

CIPS NH frequency of PMC occurrence

Karlsson et al., 2009


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What is the role of cosmic dust in PMC formation?


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SOFIE has provided the first satellite observations of meteoric smoke particles

Cosmic smoke flux into the atmosphere is constantly changing and is at a minimum during the PMC season. (White area extinction < 6 x 10-9 km-1)

2008 20092007

Hervig et al., 2009


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2008 2009

10-D average cosmic smoke particle extinctions normalized to the respective peak value in each time series

SOFIE cosmic smoke particles and models at ~ 60 km show excellent agreement

Hervig et al., 2009


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What is needed to establish a physical basis for the study of mesospheric climate change and its relationship to global change?


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Significant progress has occurred in multi-dimensional PMC modeling

On the left are shown 30 years of PMC brightness observations by SBUV at three latitudes (DeLand et al. 2007). On the right are modeled PMC brightness for the same time and locations by Marsh and Merkel (2009). The model results are in excellent agreement with observed trends.

27 Year PMC Data Set 30 Year WACCM Model Run


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What have we learned from AIM data?

NLCs occur all the time, they are highly variable from orbit-to- orbit and day-to-day with more structure than expected

Ice exists in a broad layer from 78 km to 90 km with a narrow visible layer centered at ~ 83 km

NLC structures have complex features like those seen in low altitude clouds suggesting that mesospheric weather harbors similar dynamical processes as those in the troposphere

The NLC season turns on and off like a geophysical light bulb providing an important clue to what governs cloud formation

The atmosphere is a coupled global system even on small scales

Temperature appears to control season onset, variability during the season and season end. H2O plays an important and minor role.


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AIM Lessons Learned

Recognize the wisdom and advice of the TMCO panel

Place high importance on cost as well as science

Have a very thorough knowledge of requirements and hold them sacrosanct

Anticipate problems before they occur

Plan backup approaches and work arounds

Engage the entire AIM team in problem solving

Involve the Executive Advisory Council in critical matters

Make timely decisions

Never lose sight of the mission science goal


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Backup


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CSR ChangeAction Date

(2003)Risk Reduction

SOFIE mass 50kg Streamlined design,better science

March 15 Mass

First build spacecraft

5th generation spacecraft

June 3 Cost, mass

Four science instruments

SHIMMER removed, science impact

June 6Cost, mass,

data volume

IPA Removed June 15 Cost, mass

New LV contract Use existing contract June 19 Cost

CDE new development

Use New Horizons

SDC copyJuly 25 Cost, schedule

Six CIPS camerasFour cameras, small science impact

August 1 Cost, mass, data volume

Timeline of major AIM actions taken after August 2002 debrief


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CSR ChangeAction Date

Risk Reduction

Use Pegasus HAPS to trim orbit

Remove HAPS

Feb 2004 -----

Total overall estimated resource savings

$ 10.7 M

61 kg -----

Last major AIM action taken after August 2002 debrief and before confirmation


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AIM timeline of other major actions taken after August 2002 debrief

Actively pursued alternate spacecraft bus starting in October 2002

Pursued Minotaur launch vehicle from Nov 2002 to June 2003; potentially significant cost savings

Replaced baseline gyros with more expensive but more reliable and more capable units in Oct 2003

Dealt with changing launch loads from Nov 2004 to launch

Replaced SOFIE steering mirror with a rigid mirror in July 2006 Developed work around to overcome intermittent loss of command capability in orbit

1 November 17, 2009 Jim Russell - EOPM Review GATS James M. Russell III Principal Investigator...

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