caa a22 4500 469052678 CHVBK 20180323132834.0 cr unu---uuuuu 170328e19920601xx s 000 0 eng 10.1007/BF01025621 doi (NATIONALLICENCE)springer-10.1007/BF01025621 Bryson R. Center for Climatic Research, Institute for Environmental Studies, University of Wisconsin, 53706, Madison, Wisconsin, USA aut A macrophysical model of the holocene intertropical convergence and jetstream positions and rainfall for the Saharan region [Elektronische Daten] [R. Bryson] Summary: Using a macrophysical model, it has been found possible to model the Late Pleistocene and Holocene history of glacial volume and mean temperature as a function of solar radiation seasonality and modulation of the solar radiation by volcanic aerosols (Bryson, 1988). From this model it has been possible to model the Indian monsoon with fair agreement with the field data (Bryson, 1989). The present paper represents an extension of this effort to the modeling of the position of the Intertropical Convergence in North Africa and the latitude of the atmospheric polar jetstream in the same longitudes. From these two latitudes it is possible to simulate the seasonal rainfall history of the Saharan region. The preliminary results suggest that maximum intrusion of summer rains into North Africa should have occurred between 11,000 and 5000 BP, with a lesser intrusion between 30,000 and 28,000 BP. Winter rains, though not abundant, should have been present in the central sahara until 12,000 BP then diminishing to negligible by 8000 BP, according to the model. On the Mediterranean coast of North Africa, the winter rains should have been about 100% greater than the present until about 18,000 BP, diminishing to near the present value by about 8000 BP. Radiocarbon dated occupation sites appear to be most abundant at about the indicated times of greatest rainfall in sub-Saharan Africa, as does the frequency of high lake levels. A collateral purpose of this paper is to test the utility of the present inter-monthly changes in the parameterization of inter-century changes. Springer-Verlag, 1992 Meteorology and Atmospheric Physics Springer-Verlag 47/2-4(1992-06-01), 247-258 0177-7971 47:2-4<247 1992 47 703 https://doi.org/10.1007/BF01025621 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01025621 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Bryson R. Center for Climatic Research, Institute for Environmental Studies, University of Wisconsin, 53706, Madison, Wisconsin, USA aut NATIONALLICENCE 773 0- Meteorology and Atmospheric Physics Springer-Verlag 47/2-4(1992-06-01), 247-258 0177-7971 47:2-4<247 1992 47 703 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer