Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sunspot abundance linked to heavy rains in East Africa

06.08.2007
A new study reveals correlations between plentiful sunspots and periods of heavy rain in East Africa.

Intense rainfall in the region often leads to flooding and disease outbreaks.

The analysis by a team of U.S. and British researchers shows that unusually heavy rainfalls in East Africa over the past century preceded peak sunspot activity by about one year. Because periods of peak sunspot activity, known as solar maxima, are predictable, so too are the associated heavy rains that precede them, the researchers propose.

"With the help of these findings, we can now say when especially rainy seasons are likely to occur, several years in advance," says paleoclimatologist and study leader Curt Stager of Paul Smith's College in Paul Smiths, New York. Forewarned by such predictions, public health officials could ramp up prevention measures against insect-borne diseases long before epidemics begin, he adds.

The sunspot-rainfall analysis is scheduled to appear on 7 August in the Journal of Geophysical Research - Atmospheres, a publication of the American Geophysical Union.

Increasing sunspot numbers indicate a rise in the sun's energy output. Sunspot abundance peaks on an 11-year cycle. The next solar maximum is expected in 2011-2012. If the newfound pattern holds, rainfall would also peak the year before.

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

The new analysis relies on rainfall data going back a century. The scientists also used historical records of water levels at lakes Victoria, Tanganyika, and Naivasha.

The work counters previous research that found no connection between sunspot cycles and rainfall in East Africa. Stager's team concludes that, although the link between sunspots and rainfall was weak between 1927 and 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 El Nino and other climatic disturbances not associated with sunspots.

Scientists have investigated apparent correlations between solar variability and Lake Victoria's water levels since the beginning of the last century, says co-author Alexander Ruzmaikin of NASA's Jet Propulsion Laboratory in Pasadena, California. The new research "shows that these correlations are, in fact, not accidental, effectively resolving a longstanding historical puzzle and improving our knowledge of how solar variability affects Africa's climate," he adds.

Stager, Ruzmaikin and their colleagues offer several reasons why sunspot peaks may affect rainfall. In a simple scenario, increased solar energy associated with sunspots heats both land and sea, forcing moist air to rise and triggering precipitation.

While sunspot peaks augur extraordinarily wet rainy seasons, heavy rains are possible at other times as well, Stager acknowledges. But, most of the rainiest times, he says, are consistently coupled with the predictable rhythms of sunspot peaks. And, to be forewarned is to be forearmed.

"The hope is that people on the ground will use this research to predict heavy rainfall events," Stager says. "Those events lead to erosion, flooding, and disease."

The National Science Foundation funded the study.

Peter Weiss | AGU
Further information:
http://www.agu.org

More articles from Earth Sciences:

nachricht New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>