Man-Made Aerosols Identified as Driver in Shifting Global Rainfall Patterns

Typography

In a new study, scientists found that aerosol particles released into the atmosphere from the burning of fossil fuels are a primary driver of changes in rainfall patterns across the globe.

The results of the climate system-model simulations conducted by researchers Brian Soden and Eui-Seok Chung from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science revealed that changes in clouds, as a result of their interaction with these man-made aerosols in the atmosphere, are driving large-scale shifts in rainfall and temperature on Earth.

In a new study, scientists found that aerosol particles released into the atmosphere from the burning of fossil fuels are a primary driver of changes in rainfall patterns across the globe.

The results of the climate system-model simulations conducted by researchers Brian Soden and Eui-Seok Chung from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science revealed that changes in clouds, as a result of their interaction with these man-made aerosols in the atmosphere, are driving large-scale shifts in rainfall and temperature on Earth.

A southward shift of the tropical rain belt is thought to be the leading cause of the severe drought conditions experienced in large portions of Africa and South America during the second half of the 20th century, which have caused significant impacts to local communities and water availability in these regions.

Using multiple climate model projections, the researchers measured the effects man-made aerosols have had on rainfall changes in the 20th and 21st centuries to discover that when only greenhouse gases or natural climate forces are considered, climate models are not able to capture the southward shift of the tropical rain belt. The analysis suggests that man-made aerosols are the primary driver of the observed southward shift in rainfall patters throughout the latter half of the 20th century.

Read more at Rosenstiel School of Marine and Atmospheric Science

Image(s):

Temporal variations of the annual-mean precipitation over the Sahel region of Africa
 

Top map: Spatial distribution of the annual=mean precipitation averaged from 1979-2008. 

Credit: Global Precipitation Climatology Project (GPCP) data set. 
 

Bottom: Time series of the annual mean precipitation anomaly relative to the 1971-2000 climatology over the Sahel region of Africa. 

Credit: Global Historical Climatology Network (GHCN) data set.
 

Background image: Drought – George Safonov