The Impact of Mesoscale Processes on the Atmospheric Circulation of Mars
The study of the modern martian atmosphere is (1) a key to the climate of Mars’s past; (2) useful for comparison with other terrestrial planets such as the Earth; and (3) can support hazard analysis and weather forecasting for future exploration and habitation of the planet. Recently, it was found t...
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ftdatacite:10.7907/b693-ee28 2023-05-15T18:23:21+02:00 The Impact of Mesoscale Processes on the Atmospheric Circulation of Mars Heavens, Nicholas Gray 2010 PDF https://dx.doi.org/10.7907/b693-ee28 https://resolver.caltech.edu/CaltechTHESIS:04222010-152158923 en eng California Institute of Technology No commercial reproduction, distribution, display or performance rights in this work are provided. atmosphere clouds Planetary Science dust Mars observations Thesis Text Dissertation thesis 2010 ftdatacite https://doi.org/10.7907/b693-ee28 2021-11-05T12:55:41Z The study of the modern martian atmosphere is (1) a key to the climate of Mars’s past; (2) useful for comparison with other terrestrial planets such as the Earth; and (3) can support hazard analysis and weather forecasting for future exploration and habitation of the planet. Recently, it was found that middle atmospheric downwelling near the south pole during southern winter is much more vigorous than predicted by most Mars general circulation models. This underestimate may be due to models erroneously representing the radiative forcings in the atmosphere due to aerosol and/or the mechanical forcings due to wave breaking. Errors of this kind would influence middle atmospheric dynamics and likely would result from incomplete understanding of lower atmospheric processes such as dust transport. Here, retrievals of vertical profiles of temperature, pressure, dust, and water ice from the Mars Climate Sounder (MCS) on Mars Reconnaissance Orbiter (MRO) are used to characterize the atmospheric circulation of Mars and its forcings. First, I consider the annual cycle of the thermal structure and aerosol distributions of the lower and middle atmosphere and investigate the degree of coupling between the lower and middle atmospheric mean meridional circulations. To evaluate the role of wave breaking, I look for local convective instabilities in the Martian middle atmosphere: a key indicator of saturating vertically propagating waves such as the gravity waves and the thermal tides, which are important sources of wave drag in the Earth’s mesosphere. I then characterize the vertical distribution of dust and its approximate radiative effects during northern spring and summer and show there is usually a maximum in dust mass mixing ratio at ~15—25 km above the tropics, which is not currently simulated by models. Next, I evaluate the relative importance of dust storm activity, pseudo-moist convection due to the solar heating of dust, orographic effects, and scavenging by water ice clouds in producing this maximum. Finally, I show that published models underestimate the thickness and altitude of water ice clouds in northern summer. Thesis South pole DataCite Metadata Store (German National Library of Science and Technology) South Pole |
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English |
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atmosphere clouds Planetary Science dust Mars observations |
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atmosphere clouds Planetary Science dust Mars observations Heavens, Nicholas Gray The Impact of Mesoscale Processes on the Atmospheric Circulation of Mars |
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atmosphere clouds Planetary Science dust Mars observations |
description |
The study of the modern martian atmosphere is (1) a key to the climate of Mars’s past; (2) useful for comparison with other terrestrial planets such as the Earth; and (3) can support hazard analysis and weather forecasting for future exploration and habitation of the planet. Recently, it was found that middle atmospheric downwelling near the south pole during southern winter is much more vigorous than predicted by most Mars general circulation models. This underestimate may be due to models erroneously representing the radiative forcings in the atmosphere due to aerosol and/or the mechanical forcings due to wave breaking. Errors of this kind would influence middle atmospheric dynamics and likely would result from incomplete understanding of lower atmospheric processes such as dust transport. Here, retrievals of vertical profiles of temperature, pressure, dust, and water ice from the Mars Climate Sounder (MCS) on Mars Reconnaissance Orbiter (MRO) are used to characterize the atmospheric circulation of Mars and its forcings. First, I consider the annual cycle of the thermal structure and aerosol distributions of the lower and middle atmosphere and investigate the degree of coupling between the lower and middle atmospheric mean meridional circulations. To evaluate the role of wave breaking, I look for local convective instabilities in the Martian middle atmosphere: a key indicator of saturating vertically propagating waves such as the gravity waves and the thermal tides, which are important sources of wave drag in the Earth’s mesosphere. I then characterize the vertical distribution of dust and its approximate radiative effects during northern spring and summer and show there is usually a maximum in dust mass mixing ratio at ~15—25 km above the tropics, which is not currently simulated by models. Next, I evaluate the relative importance of dust storm activity, pseudo-moist convection due to the solar heating of dust, orographic effects, and scavenging by water ice clouds in producing this maximum. Finally, I show that published models underestimate the thickness and altitude of water ice clouds in northern summer. |
format |
Thesis |
author |
Heavens, Nicholas Gray |
author_facet |
Heavens, Nicholas Gray |
author_sort |
Heavens, Nicholas Gray |
title |
The Impact of Mesoscale Processes on the Atmospheric Circulation of Mars |
title_short |
The Impact of Mesoscale Processes on the Atmospheric Circulation of Mars |
title_full |
The Impact of Mesoscale Processes on the Atmospheric Circulation of Mars |
title_fullStr |
The Impact of Mesoscale Processes on the Atmospheric Circulation of Mars |
title_full_unstemmed |
The Impact of Mesoscale Processes on the Atmospheric Circulation of Mars |
title_sort |
impact of mesoscale processes on the atmospheric circulation of mars |
publisher |
California Institute of Technology |
publishDate |
2010 |
url |
https://dx.doi.org/10.7907/b693-ee28 https://resolver.caltech.edu/CaltechTHESIS:04222010-152158923 |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_rights |
No commercial reproduction, distribution, display or performance rights in this work are provided. |
op_doi |
https://doi.org/10.7907/b693-ee28 |
_version_ |
1766202933623390208 |