Mars atmospheric CO[subscript 2] condensation above the north and south poles as revealed by radio occultation, climate sounder, and laser ranging observations
[1] We study the condensation of CO[subscript 2] in Mars' atmosphere using temperature profiles retrieved from radio occultation measurements from Mars Global Surveyor (MGS) as well as the climate sounding instrument onboard the Mars Reconnaissance Orbiter (MRO), and detection of reflective clo...
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| Format: | Article |
| Language: | en_US |
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American Geophysical Union (AGU)
2013
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| Online Access: | http://hdl.handle.net/1721.1/81160 https://orcid.org/0000-0003-2652-8017 https://orcid.org/0000-0002-7791-5124 |
| _version_ | 1826212342685237248 |
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| author | Hu, Renyu Cahoy, Kerri Zuber, Maria |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Hu, Renyu Cahoy, Kerri Zuber, Maria |
| author_sort | Hu, Renyu |
| collection | MIT |
| description | [1] We study the condensation of CO[subscript 2] in Mars' atmosphere using temperature profiles retrieved from radio occultation measurements from Mars Global Surveyor (MGS) as well as the climate sounding instrument onboard the Mars Reconnaissance Orbiter (MRO), and detection of reflective clouds by the MGS Mars Orbiter Laser Altimeter (MOLA). We find 11 events in 1999 where MGS temperature profiles indicate CO[subscript 2] condensation and MOLA simultaneously detects reflective clouds. We thus provide causal evidence that MOLA non-ground returns are associated with CO[subscript 2] condensation, which strongly indicates their nature being CO[subscript 2] clouds. The MGS and MRO temperature profiles together reveal the seasonal expansion and shrinking of the area and the vertical extent of atmospheric saturation. The occurrence rate of atmospheric saturation is maximized at high latitudes in the middle of winter. The atmospheric saturation in the northern polar region exhibits more intense seasonal variation than in the southern polar region. In particular, a shrinking of saturation area and thickness from L[subscript S] ∼ 270° to ∼300° in 2007 is found; this is probably related to a planet-encircling dust storm. Furthermore, we integrate the condensation area and the condensation occurrence rate to estimate cumulative masses of CO[subscript 2] condensates deposited onto the northern and southern seasonal polar caps. The precipitation flux is approximated by the particle settling flux which is estimated using the impulse responses of MOLA filter channels. With our approach, the total atmospheric condensation mass can be estimated from these observational data sets with average particle size as the only free parameter. By comparison with the seasonal polar cap masses inferred from the time-varying gravity of Mars, our estimates indicate that the average condensate particle radius is 8–22 μm in the northern hemisphere and 4–13 μm in the southern hemisphere. Our multi-instrument data analysis provides new constraints on modeling the global climate of Mars. |
| first_indexed | 2024-09-23T15:20:12Z |
| format | Article |
| id | mit-1721.1/81160 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:20:12Z |
| publishDate | 2013 |
| publisher | American Geophysical Union (AGU) |
| record_format | dspace |
| spelling | mit-1721.1/811602024-05-15T08:53:24Z Mars atmospheric CO[subscript 2] condensation above the north and south poles as revealed by radio occultation, climate sounder, and laser ranging observations Hu, Renyu Cahoy, Kerri Zuber, Maria Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Hu, Renyu Cahoy, Kerri Zuber, Maria T. [1] We study the condensation of CO[subscript 2] in Mars' atmosphere using temperature profiles retrieved from radio occultation measurements from Mars Global Surveyor (MGS) as well as the climate sounding instrument onboard the Mars Reconnaissance Orbiter (MRO), and detection of reflective clouds by the MGS Mars Orbiter Laser Altimeter (MOLA). We find 11 events in 1999 where MGS temperature profiles indicate CO[subscript 2] condensation and MOLA simultaneously detects reflective clouds. We thus provide causal evidence that MOLA non-ground returns are associated with CO[subscript 2] condensation, which strongly indicates their nature being CO[subscript 2] clouds. The MGS and MRO temperature profiles together reveal the seasonal expansion and shrinking of the area and the vertical extent of atmospheric saturation. The occurrence rate of atmospheric saturation is maximized at high latitudes in the middle of winter. The atmospheric saturation in the northern polar region exhibits more intense seasonal variation than in the southern polar region. In particular, a shrinking of saturation area and thickness from L[subscript S] ∼ 270° to ∼300° in 2007 is found; this is probably related to a planet-encircling dust storm. Furthermore, we integrate the condensation area and the condensation occurrence rate to estimate cumulative masses of CO[subscript 2] condensates deposited onto the northern and southern seasonal polar caps. The precipitation flux is approximated by the particle settling flux which is estimated using the impulse responses of MOLA filter channels. With our approach, the total atmospheric condensation mass can be estimated from these observational data sets with average particle size as the only free parameter. By comparison with the seasonal polar cap masses inferred from the time-varying gravity of Mars, our estimates indicate that the average condensate particle radius is 8–22 μm in the northern hemisphere and 4–13 μm in the southern hemisphere. Our multi-instrument data analysis provides new constraints on modeling the global climate of Mars. United States. National Aeronautics and Space Administration (Earth and Space Science Fellowship NNX11AP47H) 2013-09-25T14:30:00Z 2013-09-25T14:30:00Z 2012-07 2012-05 Article http://purl.org/eprint/type/JournalArticle 0148-0227 http://hdl.handle.net/1721.1/81160 Hu, Renyu, Kerri Cahoy, and Maria T. Zuber. “Mars Atmospheric CO 2 Condensation Above the North and South Poles as Revealed by Radio Occultation, Climate Sounder, and Laser Ranging Observations.” Journal of Geophysical Research 117.E7 (2012). ©2012. American Geophysical Union https://orcid.org/0000-0003-2652-8017 https://orcid.org/0000-0002-7791-5124 en_US http://dx.doi.org/10.1029/2012je004087 Journal of Geophysical Research Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Geophysical Union (AGU) MIT web domain |
| spellingShingle | Hu, Renyu Cahoy, Kerri Zuber, Maria Mars atmospheric CO[subscript 2] condensation above the north and south poles as revealed by radio occultation, climate sounder, and laser ranging observations |
| title | Mars atmospheric CO[subscript 2] condensation above the north and south poles as revealed by radio occultation, climate sounder, and laser ranging observations |
| title_full | Mars atmospheric CO[subscript 2] condensation above the north and south poles as revealed by radio occultation, climate sounder, and laser ranging observations |
| title_fullStr | Mars atmospheric CO[subscript 2] condensation above the north and south poles as revealed by radio occultation, climate sounder, and laser ranging observations |
| title_full_unstemmed | Mars atmospheric CO[subscript 2] condensation above the north and south poles as revealed by radio occultation, climate sounder, and laser ranging observations |
| title_short | Mars atmospheric CO[subscript 2] condensation above the north and south poles as revealed by radio occultation, climate sounder, and laser ranging observations |
| title_sort | mars atmospheric co subscript 2 condensation above the north and south poles as revealed by radio occultation climate sounder and laser ranging observations |
| url | http://hdl.handle.net/1721.1/81160 https://orcid.org/0000-0003-2652-8017 https://orcid.org/0000-0002-7791-5124 |
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