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Why is the north polar cap on mars different than the south polar cap?
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Lindner, Bernhard Lee |
| Copyright Year | 1994 |
| Description | One of the most puzzling mysteries about the planet Mars is the hemispherical asymmetry in the polar caps. Every spring the seasonal polar cap of CO2 recedes until the end of summer, when only a small part, the residual polar cap, remains. During the year that Viking observed Mars, the residual polar cap was composed of water ice in the northern hemisphere but was primarily carbon dioxide ice in the southern hemisphere. Scientists have sought to explain this asymmetry by modeling observations of the latitudinal recession of the polar cap and seasonal variations in atmospheric pressure (since the seasonal polar caps are primarily frozen atmosphere, they are directly related to changes in atmospheric mass). These models reproduce most aspects of the observed annual variation in atmospheric pressure fairly accurately. Furthermore, the predicted latitudinal recession of the northern polar cap in the spring agrees well with observations, including the fact that the CO2 ice is predicted to completely sublime away. However, these models all predict that the carbon dioxide ice will also sublime away during the summer in the southern hemisphere, unlike what is observed. This paper will show how the radiative effects of ozone, clouds, airborne dust, light penetration into and through the polar cap, and the dependence of albedo on solar zenith angle affect CO2 ice formation and sublimation, and how they help explain the hemispherical asymmetry in the residual polar caps. These effects have not been studied with prior polar cap models. |
| File Size | 140218 |
| Page Count | 2 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19940023386 |
| Archival Resource Key | ark:/13960/t8z945b6r |
| Language | English |
| Publisher Date | 1994-02-07 |
| Access Restriction | Open |
| Subject Keyword | Lunar And Planetary Exploration Water Atmospheric Pressure Sublimation Carbon Dioxide Ozone Ice Mars Atmosphere Zenith Solar Position Ice Formation Mars Environment Viking Mars Program Dust Albedo Asymmetry Annual Variations Polar Caps Environment Models Mars Surface Polar Regions Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
