Mars Mesospheric Wind around Northern Spring Equinox from ... · Slide: 11 Motivation Instrument &...
Transcript of Mars Mesospheric Wind around Northern Spring Equinox from ... · Slide: 11 Motivation Instrument &...
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut Slide: 1
Mars Mesospheric Wind around Northern Spring Equinox from
High Resolution IR spectroscopy of CO2
Manuela Sornig1, Guido Sonnabend1, Peter Krötz1, Dušan Stupar1, Rudolf Schieder1,
1I. Physikalisches Institut, Universität zu Köln
Slide: 2
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
Overview:
•Motivation•Technique
- THIS - Tunable Heterodyne Infrared Spectrometer- Doppler winds from high resolution spectroscopy
of CO2
•Observations - LS=335 (2005), LS=357 (2007), LS=42 (2008)
•Results & Comparison to MCD
Slide: 3
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
Motivation:
- GCMs predict upper atmosphere zonal winds... but observations are few
- Mid-IR spectroscopy of CO2 non-LTE emission @ 10µm ideal tool to probe mesospheric zonal winds
- Ultra-high heterodyne resolution provides Doppler-winds down to 10 m/s precision
- Higher spatial resolution compared to sub-mm
- Circulation changes around LS=0 from northern to southern hemisphere jet
Slide: 4
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
THIS - Tuneable Heterodyne Infrared Spectrometer
wavelength: 7-13µmresolution: up to 107 @ 10µm
bandwidth: 3 GHzframe dim.: 60x80x45 cm
weight: 80 kgF/#: adjustable
Instrument:
Slide: 5
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
Methode of Wind Measurements:
• precise frequency determination of non-LTE emission line of CO
2 at 10 µm
• Doppler shift provides information about "line of sight" velocity
• Altitude of emission features determined from TES observations
inte
nsity
frequencyin
tens
ity
frequency
inte
nsity
frequency
Slide: 6
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
Observations:Nov 2005 (LS=335)McMath/Kitt Peak Nov 2007 (LS=357)
McMath/Kitt Peak
Mar 2008 (LS=42)IRTF/Mauna Kea
Mars:9” FOV:0.8”Mars:16” FOV:1.7”
Mars:15” FOV:1.7”
Slide: 7
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
CO2 Spectrum from Mars Atmosphere:
200 300 400 500 600 700 800 900 1000 110025
30
35
40
45
50
55
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65
isotopic CO2 feature
continuum leveldetermined by Marssurface temperature
mesospheric CO2
non-LTE emission
inte
nsi
ty [erg
cm
-2 s
-1 S
r-1/c
m-1]
i.f. [MHz]
broad CO2 absorptionfrom lower atmosphere
Slide: 8
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
2005 Observations:(LS=335)
Slide: 9
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
2007 Observations:
(LS=357)
Slide: 11
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
2008 Observations:
(LS=42)
Slide: 12
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
Temporal variations:
~25 m/s wind velocity change from MUT5 to MUT10 in agreement with MCD
Slide: 13
Motivation Instrument & Method Observation Results & Outlook
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut
Conclusion and Outlook:
• Observations are in reasonable agreement with MCD predictions
• High latitudes winds tend to be stronger than predicted• Short term variations observed
• Improved coverage needed• Seasonal extension• Altitude extraction from data
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut Slide: 14
Thank you!
Please visit our poster!
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut Slide: 15
-80 -60 -40 -20 0 20 40 60 80-150
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east
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KP05 LS332 KP07 LS354 IRTF 08 LS42
MARS ATMOSPHERE: MODELING AND OBSERVATIONSWilliamsburg, Va, November 10th 2008
Universität zu KölnI. Physikalisches Institut Slide: 16
-80 -60 -40 -20 0 20 40 60-150
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MCD 0-30 MCD 330-360