NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Mars - The north polar sand sea and related wind patternsViking Orbiter 2 images of the north polar region reveal an enormous sand sea (erg) covering an area of greater than 500,000 sq km around the perennial ice cap. All dunes are either transverse or barchan. The various dune morphologies and modifications of primary dune types reflect a wind regime having more than one wind direction. In the summer, two major wind directions prevail: (1) off-pole winds that become easterly due to coriolis forces and (2) on-pole winds that become westerly. During the winter and/or spring, only the on-pole winds exist. Strong winds greater than 75 m/s are required for sand accumulation to form the thick transverse dunes. The strongest winds in the north polar region are thought to exist during summer over the transverse dune field between 110 deg and 220 deg W; this area is a relatively warm belt (temperature greater than 230 K) between two ice zones (temperature less than 220 K). The lack of well-developed longitudinal dunes implies that the dune field is young. The relationship of the present dune field to the perennial ice indicates that the dunes began to form after the formation of the present ice cap.
Document ID
19800042200
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Tsoar, H.
(Arizona State University Tempe, Ariz.; Negev, University, Beersheba, Israel)
Greeley, R.
(NASA Ames Research Center Space Sciences Div., Moffett Field, Calif.; Arizona State University, Tempe, Ariz., United States)
Peterfreund, A. R.
(Arizona State University Tempe, Ariz., United States)
Date Acquired
August 10, 2013
Publication Date
December 30, 1979
Publication Information
Publication: Journal of Geophysical Research
Volume: 84
Subject Category
Lunar And Planetary Exploration
Accession Number
80A26370
Funding Number(s)
CONTRACT_GRANT: NSG-7415
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available