Martian north polar cap recession: 2000 Mars Orbiter Camera observations

被引:56
作者
James, PB
Cantor, BA
机构
[1] Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA
[2] Malin Space Sci Syst, San Diego, CA 92191 USA
关键词
Mars; atmosphere; climate;
D O I
10.1006/icar.2001.6653
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The wide-angle cameras of the Mars Orbiter Camera (MOC) on the Mars Global Surveyor have recorded the 2000 recession of the seasonal CO2 cap in the north polar region from L-S = 330degrees to 90degrees. In stark contrast to the asymmetric behavior of the south seasonal cap, the seasonal north cap remains relatively circular and uniform until mid-spring when the retreat reaches the circum-polar dune field, which is the one major nonuniformity in the cap. The recession of cap edge latitude versus areocentric longitude (L-S) is very well represented as a linear function until late spring; there is no evidence for the plateau or standstill in the recession curve that has been observed in some prior years. The Lambert albedo of the seasonal frost deposits in the north polar region demonstrates the increase with insolation first observed by Paige in 1985, increasing to approximately 0.57 at L-S = 40degrees. The north polar cap near solstice visually appears smaller than that observed by MOC at the start of mapping in 1999, but later images acquired in summer show the residual cap returning to its more usual shape. The most likely explanation for these changes in albedo is precipitation and subsequent removal of dust on the cap as a result of frequent dust storms near the cap edge. (C) 2001 Elsevier Science.
引用
收藏
页码:131 / 144
页数:14
相关论文
共 35 条
[1]   Variability of Mars' north polar water ice cap - I. Analysis of Mariner 9 and Viking Orbiter imaging data [J].
Bass, DS ;
Herkenhoff, KE ;
Paige, DA .
ICARUS, 2000, 144 (02) :382-396
[2]   Variability of Mars' north polar water ice cap - II. Analysis of viking IRTM and MAWD data [J].
Bass, DS ;
Paige, DA .
ICARUS, 2000, 144 (02) :397-409
[3]   Regression of Martian North Polar Cap: 1990-1997 Hubble Space Telescope Observations [J].
Cantor, BA ;
Wolff, MJ ;
James, PB ;
Higgs, E .
ICARUS, 1998, 136 (02) :175-191
[4]  
CANTOR BA, 2001, IN PRESS J GEOPHYS R
[5]   MARTIAN NORTH POLAR CAP, 1962-1968 [J].
CAPEN, CF ;
CAPEN, VW .
ICARUS, 1970, 13 (01) :100-&
[6]   MARTIAN NORTH POLAR HAZES AND SURFACE ICE - RESULTS FROM THE VIKING SURVEY COMPLETION MISSION [J].
CHRISTENSEN, PR ;
ZUREK, RW .
JOURNAL OF GEOPHYSICAL RESEARCH, 1984, 89 (NB6) :4587-4596
[7]   NEW OPTICAL MEASUREMENTS OF PLANETARY DIAMETERS .4. SIZE OF NORTH POLAR-CAP OF MARS [J].
DOLLFUS, A .
ICARUS, 1973, 18 (01) :142-155
[8]  
FISCHBACHER GE, 1969, MARTIAN POLAR CAP BO
[9]  
HERSCHEL W, 1784, PHILOS T, V24, P233
[10]   Orographic control of storm zones on Mars [J].
Hollingsworth, JL ;
Haberle, RM ;
Barnes, JR ;
Brider, AFC ;
Pollack, JB ;
Lee, H ;
Schaeffer, J .
NATURE, 1996, 380 (6573) :413-416