PALEOCLIMATES OFF NORTHWEST AFRICA (28-DEGREES-35-DEGREES-N) ABOUT 18,000 YR BP BASED ON CONTINENTAL EOLIAN DEPOSITS

Most conceptual models of atmospheric circulation deduced from bottom sediments or isopollen maps off NW Africa assume the occurrence of int ensified NNE trade winds about 18,000 yr B.P. in latitudes of 28 degre es-35 degrees N, and oversimplify the glacial atmospheric circulation over Africa. An alternative method for reconstructing paleowinds of th e last glacial maximum in these latitudes was recently put forward, an d uses sedimentological records from the Canary Islands and coastal re gions of Morocco. The continental data do not agree with the previous models and show the prevalence of westerlies. All the data from deep s ea cores (reduction of sea surface temperature, increase of biogenic o pal accumulation, distribution patterns of pollen or dinoflagellate cy sts, and xeric conditions on the adjacent continent) can be explained without increased activity of the trade winds, but with a discharge cu rrent of cold meltwater from the European and North American ice sheet s. The model is backed up by a comparison with the present-day Humbold t Current off subtropical South America. (C) 1996 University of Washin gton.