Complexity Digest 2002.25 - 16

24-Jun-2002

A 160,000-Year Record of Dune Development and Atmospheric Circulation, Science Bookmark and Share

Summary: The orientation and sedimentary structure of sand dunes depend on the strength and direction of the prevailing winds, so ancient dunes should contain important clues to paleoatmospheric circulation patterns--if their ages can actually be determined. Preusser et al. (p. 2018) used difficult luminescence techniques to construct a 160,000-year record of dune formation in Oman. Their results indicate that models of past atmospheric circulation over southern Arabia during times of high-latitude glaciation, which assume that the intensity of the prevailing westerly winds strengthens during these periods, need to be revised. The dominant wind direction was from South to North, and general atmospheric circulation was not very different from present conditions.