The analysis, relying on rainfall data going back a century, showed that unusually heavy rainfalls in East Africa over the past century preceded peak sunspot activity by about one year. The scientists also used historical records of water levels at lakes Victoria, Tanganyika, and Naivasha for the analysis.
'With the help of these findings, we can now say when especially rainy seasons are likely to occur, several years in advance,' said paleoclimatologist and study leader Curt Stager of Paul Smith's College in Paul Smiths, New York.
Smith said since intense rainfall in the region often led to flooding and outbreaks of disease, public health officials, forewarned by such predictions, could ramp up preventive measures long before the outspread of the epidemics.
'We expect East Africa to experience a major intensification of rainy season precipitation, along with widespread Rift Valley Fever epidemics, a year or so before the solar maximum of 2011-2012. As mosquitoes and other disease-carrying insects thrive in wet conditions, heavy rains may herald outbreaks of diseases such as Rift Valley Fever,' he said.
The study appears in the August 7 issue of the Journal of Geophysical Research - Atmospheres.