Annual Heat Balance of Martian Polar Caps: Viking Observations

The Infrared Thermal Mappers aboard the two Viking orbiters obtained solar reflectance and infrared emission measurements of the Martian north and south polar regions during an entire Mars year. The observations were used to determine annual radiation budgets, infer annual carbon dioxide frost budge...

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Bibliographic Details
Published in:Science
Main Authors: Paige, David A., Ingersoll, Andrew P.
Format: Article in Journal/Newspaper
Language:English
Published: American Association for the Advancement of Science (AAAS) 1985
Subjects:
Online Access:http://dx.doi.org/10.1126/science.228.4704.1160
https://www.science.org/doi/pdf/10.1126/science.228.4704.1160
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Summary:The Infrared Thermal Mappers aboard the two Viking orbiters obtained solar reflectance and infrared emission measurements of the Martian north and south polar regions during an entire Mars year. The observations were used to determine annual radiation budgets, infer annual carbon dioxide frost budgets, and constrain spring season surface and atmospheric properties with the aid of a polar radiative model. The results provide further confirmation of the presence of permanent CO 2 frost deposits near the south pole and show that the stability of these deposits can be explained by their high reflectivities. In the north, the observed absence of solid CO 2 during summer was primarily the result of enhanced CO 2 sublimation rates due to lower frost reflectivities during spring. The results suggest that the present asymmetric behavior of CO 2 frost at the Martian poles is caused by preferential contamination of the north seasonal polar cap by atmospheric dust.