Open AccessA comparison of Martian north and south polar cold spots and the long‐term effects of the 2001 global dust storm
Author(s) -
Cornwall C.,
Titus T. N.
Publication year - 2010
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2009je003514
Subject(s) - cold spot , dust storm , storm , atmospheric sciences , climatology , mars exploration program , cold front , martian , atmosphere of mars , environmental science , polar , latitude , sublimation (psychology) , spots , geology , physical geography , geography , astrobiology , physics , oceanography , chemistry , geodesy , astronomy , psychology , psychotherapist
In the 1970s, Viking and Mariner observed areas in the polar regions of Mars with winter brightness temperatures below the expected kinetic temperatures for CO 2 ice sublimation. These areas have since been termed “cold spots” and have been identified as surface deposits of CO 2 atmospheric condensates and, occasionally, active CO 2 storms. Three Mars years of data from the Mars Global Surveyor Thermal Emission Spectrometer were used to observe autumn and winter cold spot activity. In this study, cold spots that occur near and on the southern perennial cap were compared to those found near or on the northern perennial cap. On the southern perennial cap, cold spots associated with topographic features (induced by orographic lifting) were less common than cold spots independent of topography, similar to the north. However, the cold spots in the south lasted longer than those observed in the north. There is also evidence that cold spot formation in the south was affected by the global dust storm of 2001, even though the dust storm occurred during the southern spring and summer seasons. Prior to the dust storm, the amount of overall cold spot activity closer to the perennial cap increased and the average CO 2 grain size for most of the cold spots increased as well. Following the dust storm, the majority of cold spots in the south increased in size and duration but they did not form north of 62°S latitude, whereas, in other years, cold spots formed as far north as 48°S.