ASAC Meeting, 22-23 March 2011, Norderstedt, Germany Observation of OH rotational temperatures with...

ASAC Meeting, 22-23 March 2011, Norderstedt, Germany

Observation of OH rotational temperatures with GRIPS at ALOMAR

Carsten Schmidt, Verena Kopp, Christoph Pilger, Sabrina Wildner, Christoph Harsch, Sabine Wüst, Kathrin Höppner and Michael Bittner

German Aerospace Center (DLR-DFD)

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outline

instrument

GRIPS 9, ground-based infrared p-branch spectrometer

OH(3-1) rotational temperatures (~87 km height)

ndmc

network for the detection of mesopause change

measurements and data obtained at ALOMAR

NICC-1, ndmc intercomparison campaign 1

preliminary results

future activities

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detector: 512 element InGaAs PDA, TE cooled (-60°C)

polychromator: focal length f = 163mm, f-number F# = 3.7

Etendue: ~ 1.85 * 10-3 cm2sr

λ/Δλ @ λ=1550nm: 505

Compact design:

The GRIPS instrument

Bittner et al. (2010)

30 cm

30 cm

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GRIPS – GRound-based Infrared P-branch Spectrometer

rotational temperatures estimated from transitions of OH(3-1) p-branch

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Instrument setup at ALOMAR

entrance slit

coolant recirculator

detector

sensors for ambient temperature (3)

protective shutter

instrument located in dome 3,next to the LIDAR facilities

instrument completely housed “inside” the ceiling

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Is the climate of the mesopause region (80-100km) changing?If so, how and why?

NDMC objectives:

promote international cooperation among research groups investigatingthe mesopause region

Early identification of changing climate signals (identifying and quantifying climate changes by monitoring key parameters e.g. mesopause temperature, airglow brightness)

Validation of satellite-based measurements and its use for intercomparison of ground-based instruments

Answering other scientific questions related to atmospheric dynamics at different time scales including the description and the causes of the variability of periodic and quasi-periodic processes (e.g. gravity or planetary waves)

Detection of solar activity effects at all time scales (“Space Weather”)

Cooperation in the development of instrumentation

The network for the detection of mesopause change


NDMC objectives:








NDMC objectives:







current activities at ALOMAR

and near future activities at ALOMAR

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NDMC is currently composed of 50 ground-based research stations

initial emphasis on the airglow in the mesopause

http://wdc.dlr.de/ndmc

NDMC

current GRIPS instrumentsGRIPS stations planned in 2011Sicily, Tel Aviv, Mallorca (campaign)

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GRIPS measurements at ALOMAR

performed since 2010-11-24 (every night)

temporal resolution: 15 seconds, uncertainty ~ 2% to 6%

status 2011-03-18:

115 nights, successful measurements longer than:

2 hours: 104 (90%)

6 hours: 93 (81%)

12 hours: 62 (54%)

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high resolution data

quicklooks and related information available via

http://wdc.dlr.de/ndmc

scientific interests

gravity wave activity

search for infrasonic waves

comparison with other sites

first statistics of wave activityfor two Alpine stations

identical instruments used:GRIPS 5,6,7,8,9

instruments have performed intercomparison measurements

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preliminary results

τB

τa

infrasonic wave activity?

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preliminary resultsgravity wave activity?

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NICC-1, NDMC intercomparison campaign

comparison of GRIPS 9 at ALOMAR with Advanced Mesosphere Temperature Mapper (AMTM, Mike Taylor)

comparison of ground-based OH rotational temperatures with satellite data

GRIPS 9 OH(3-1)

AMTM OH(3-1)

ENVISAT Sciamachy OH(3-1) (IUP Bremen, Christian von Savigny)

comparison of ground-based GRIPS OH rotational temperatures andSABER v1.07 temperatures

GRIPS temperatures vs. Na-LIDAR temperature profiles

Satellite validation

estimation of the impact of geophysical variability - expressed as mistime and misdistance – on the comparison between ground- and satellite-based data –

NDMC Network intercomparison


comparison of GRIPS 9 at ALOMAR with Advanced Mesosphere Temperature Mapper (AMTM, Mike Taylor) – ongoing


GRIPS 9 OH(3-1)

AMTM OH(3-1)

ENVISAT Sciamachy OH(3-1) (IUP Bremen, Christian von Savigny)








GRIPS 9 OH(3-1)

AMTM OH(3-1)

ENVISAT Sciamachy OH(3-1) – ongoing (IUP Bremen, Christian von Savigny)








GRIPS 9 OH(3-1)

AMTM OH(3-1)


comparison of ground-based GRIPS OH rotational temperatures andSABER v1.07 temperatures – first results







GRIPS 9 OH(3-1)

AMTM OH(3-1)



GRIPS temperatures vs. Na-LIDAR temperature profiles – first results






GRIPS 9 OH(3-1)

AMTM OH(3-1)



GRIPS temperatures vs. Na-LIDAR temperature profiles – first results


estimation of the impact of geophysical variability - expressed as mistime and misdistance – on the comparison between ground- and satellite-based data– first results

(Sam Yee, John Hopkins, APL)

(Ulf Peter Hoppe, Oslo)

(near future: Patrick Espy)

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GRIPS 9 vs. SABER 1.07

Coincidence criteria:misdistance: ±500 km

Intercomparison starts2011/01/15 due toSABER Yaw-Cycle

SABER data weighted with OH 1.6µm VER profile

58 overpasses

TSABER-TALOMAR :

-0.7K ± 6.3K

preliminary results!

Δ GRIPS nocturnal mean (uncertainty < 1K)+ SABER 1.07 temperature (uncertainty 3-6K)

tem

pera

ture

[K

]

date

GRIPS 9SABER

190

195

200

205

210

215

220

225

230

235

240

190 200 210 220 230 240

SABER temperature [K]

GR

IPS

OH

te

mp

era

ture

[K

]

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satellite validation

non-perfect coincidence:

mistime / misdistance

quantify impact of natural variability

mean difference explainedby mismatched measurements

mean differences in SABER temperatures (1,6µm OH VER)


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Na Lidar data courtesy by Prof. Hoppe

adiabatic heating due to downwelling?


~15K

GRIPS 9 temperatures

altit

ude

[km

]O

H t

empe

ratu

re [

K]v

uncertainty [K]

number of averages

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Lidar – GRIPS comparison

preliminary results

Na Lidar data courtesy by Prof. Hoppe

87 km centroid height of OH layer

daytime

daytime

comparison of coincident Lidar/GRIPS measurements during ECOMA 2010

good agreement concerning temperature variation

comparison of absolute temperatures still ongoing

GRIPS 9

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Comparison with Na LIDAR data


date Beam Mean Temp. @87km [K]

Duration[hh:mm]

GRIPS OH temperature [K]

Duration[hh:mm]

BeginStart

GRIPSmean

26.11.2010 1 200.6 06:37 201.5 06:16 16:4523:30

204.1

2 201.207.12.2010 1 210.6 04:13 198.9 06:00 13:27

19:30196.7

2 211.413.12.2010 1 210.9 04:40 206.4 06:42 01:00

07:45209.6

2 211.419.12.2010 1 219.2* 17:07 205.3 15:43 01:30

22:00204.7

2 221.9* 208.1

*issues with Laser modes led to higher temperatures

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Future activity

UFS – ALOMAR cooperation

UFS: Environmental Research Station „Schneefernerhaus“

Project BHEA:study of orographic gravity waves observed with different viewing anglesstarted: 2011/02/15

Alps

Kjø

len

GRIPS 6

GRIPS 7,8(UFS)

GRIPS 9 (ALOMAR)

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summary and conclusion

successful operation of GRIPS 9 instrument during its first season

measurements will be continued during the next winter seasons

first results indicate very good agreement between SABER 1.07 and ground-based GRIPS 9 temperatures

mean differences may be explained with geopysical variability

obtained results agree with other similar stations,

ALOMAR 69°N OH(3-1) vs. SABER : -0.7K ± 6.3K

Davis 68.6°S OH(6-2) vs. SABER: -1.5K ± 1.5K*

detailed analyses still ongoing

first examples of Na Lidar and GRIPS 9 temperatures intercomparisons indicate agreement

more data needed for a reliable comparison

subsequent activities and projects already started* presentation by Wildner et al. at EGU GA 2010

ASAC Meeting, 22-23 March 2011, Norderstedt, Germany Observation of OH rotational temperatures with...

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