Link between sunspots, rain helps predict disease in east Africa

August 07, 2007

The research, conducted by paleoclimatologist Curt Stager of Paul Smith's College in Paul Smiths, N.Y. and colleagues, can be used by public health officials to increase measures against insect-borne diseases long before epidemics begin. The results are published online in the August 7 issue of the Journal of Geophysical Research.

The scientists showed that unusually heavy rainfalls in East Africa over the past century preceded peak sunspot activity by about one year.

"The hope is that people on the ground will use this research to predict heavy rainfall events," Stager said. "Those events lead to erosion, flooding and disease. With the help of these findings, we can now say when especially rainy seasons are likely to occur, several years in advance."

"These results are an important step in applying paleoclimate analyses to predicting future environmental conditions and their impacts on society," said Dave Verardo, director of the National Science Foundation's paleoclimate program, which funded the research. "It's especially important in a region [East Africa] perennially on the knife-edge of sustainability."

Sunspots indicate an increase in the sun's energy output, and peak on an 11-year cycle. The next peak is expected in 2011-12. If the pattern holds, rainfall would peak the year before.

Because mosquitoes and other disease-carrying insects thrive in wet conditions, heavy rains may herald outbreaks of diseases such as Rift Valley Fever.

The research relied on rainfall data going back a century. Historical records of water levels at lakes Victoria, Tanganyika, and Naivasha also demonstrated the link.

Stager demonstrated that while the link between sunspots and rainfall seemed to grow weaker from 1927 to 1968, the cyclic pattern held true throughout the 20th Century. Previous statistical analysis discounted the link for a variety of reasons, including the influence of climatic disturbances not associated with sunspots.

The researchers, who represent five institutions from the United States and Great Britain, offered several reasons why sunspot peaks may affect rainfall. The increased solar energy associated with sunspots, they suggest, heats both land and sea, forcing moist air to rise and triggering precipitation. It may also induce El Niño events, which increase rainfall in East Africa.

While sunspot peaks augur extraordinarily wet rainy seasons, heavy rains are possible at other times as well, Stager acknowledged. But most of the rainiest times, he said, are consistently coupled with the predictable rhythms of sunspot peaks.

"When you think of climate troubles in Africa, it's usually about drought," Stager said. "You don't often think of the opposite situation.

"Too much rain can create just as many problems."
-end-
NSF-PR 07-094

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering, with an annual budget of $5.58 billion. NSF funds reach all 50 states through grants to nearly 1,700 universities and institutions. Each year, NSF receives about 40,000 competitive requests for funding, and makes nearly 10,000 new funding awards. The NSF also awards over $400 million in professional and service contracts yearly.

Receive official NSF news electronically through the e-mail delivery and notification system, MyNSF (formerly the Custom News Service). To subscribe, visit http://www.nsf.gov/mynsf/ and fill in the information under "new users".

Useful NSF Web Sites:

NSF Home Page: http://www.nsf.gov

NSF News: http://www.nsf.gov/news/

For the News Media: http://www.nsf.gov/news/newsroom.jsp

Science and Engineering Statistics: http://www.nsf.gov/statistics/

Awards Searches: http://www.nsf.gov/awardsearch/

National Science Foundation

Related Rainfall Articles from Brightsurf:

Study projects more rainfall in Florida during flooding season
A new study by researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science projects an increase in Florida's late summertime rainfall with rising Atlantic Ocean temperatures.

Importance of rainfall highlighted for tropical animals
Imagine a tropical forest, and you might conjure up tall trees hung with vines, brightly colored birds, howling monkeys, and ... rain.

New study could help better predict rainfall during El Niño
Researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science have uncovered a new connection between tropical weather events and US rainfall during El NiƱo years.

Mediterranean rainfall immediately affected by greenhouse gas changes
Mediterranean-type climates face immediate drops in rainfall when greenhouse gases rise, but this could be interrupted quickly if emissions are cut.

Future rainfall could far outweigh current climate predictions
Scientists from the University of Plymouth analysed rainfall records from the 1870s to the present day with their findings showing there could be large divergence in projected rainfall by the mid to late 21st century.

NASA estimates Imelda's extreme rainfall
NASA estimated extreme rainfall over eastern Texas from the remnants of Tropical Depression Imelda using a NASA satellite rainfall product that incorporates data from satellites and observations.

NASA estimates heavy rainfall in Hurricane Dorian
Hurricane Dorian is packing heavy rain as it moves toward the Bahamas as predicted by NOAA's NHC or National Hurricane Center.

NASA looks at Barry's rainfall rates
After Barry made landfall as a Category 1 hurricane, NASA's GPM core satellite analyzed the rate in which rain was falling throughout the storm.

NASA looks at Tropical Storm Barbara's heavy rainfall
Tropical Storm Barbara formed on Sunday, June 30 in the Eastern Pacific Ocean over 800 miles from the coast of western Mexico.

NASA looks at Tropical Storm Fani's rainfall rates
Tropical Storm Fani formed in the Northern Indian Ocean over the weekend of April 27 and 28, 2019.

Read More: Rainfall News and Rainfall Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.