Southern Hemisphere paleoclimates. First Results

Abstract

First results of a project devoted to reconstruction of Upper Quaternary scenarios in the Southern Hemisphere suggest a rather simple pattern in the system. Relatively small continental masses are quite regularly located inside an oceanic realm. The ITCZ and the Westerlies are the main structures of the general atmospheric circulation. One anticiclonic cell develops in each ocean at tropical latitudes. Anti-clockwise circulations are forced in sea waters, which provokes climatic asimmetries on the continents: in South America, Southern Africa and Australia eastern regions are moister and warmer than their western counterparts. Secondary anticyclones develope on each continent, which grow during dry climates and weaken or disappear in humid phases. During the LGM the climatic belts migrated about 10 degrees of latitude to the north of their present positions. Conversely, at the Hypsithermal such belts shifted approximately 10º to the south of today's locations. During the warm Hypsithermal period, coastal erosion and frequent storm beaches indicate a phase of high energy in the oceans.