Sunspots Linked to Hard Rains in Africa
You read that right: a study linking something other than climate change to adverse weather events in Africa. A group led by J. Curt Stager of New York's Paul Smith College has just published a study citing a possible connection between sunspots and heavy rain, flooding and even incidents of insect-borne diseases in East Africa. The key element driving the rains is not the sunspots themselves but the added brightening of the sun that accompanies them, explained Stager.
Though not particularly intense, the brightening may be sufficient to slightly warm the oceans and the surrounding land — increasing the region's humidity and prompting the creation of more rain clouds, leading to increased precipitation. "So you get a double-whammy amplifying effect from what would otherwise be a weak solar signal," Stager said. Furthermore, the solar cycle (which occurs in 11-year phases) can cause more rain by affecting winds in the upper atmosphere and changing the flow of air. While the influence of the 11-year sunspot cycle in affecting local water levels and weather patterns had been largely dismissed by scientists as recently as 5 decades ago, Stager pursued the theory by analyzing past studies of African lakebed sediments — noting a pattern that helped account for the climate shifts he saw in the sediment layers. "I got the lake-level data from the last century and saw these pulses that matched the sunspot cycle," he explained. In addition, he found the same fluctuations in two other lakes and corresponding variations in rainfall patterns.
Other scientists are still unsure about the connection. J. Marshall Shepherd, a meteorologist at the University of Georgia, expressed doubts about the study, noting that other factors could be at play and that more work would need to be done before any solid conclusions could be drawn. If Stager's hypothesis holds, heavy rains should peak in East Africa a year ahead of the next peak in sunspot activity in 2011 and 2112. We'll be keeping our eyes peeled.
See also: ::What Could Global Warming do to the Northeastern United States?, ::Snow in Buenos Aires: Was it Global Warming?
Image courtesy of ff137 via flickr