Desert dust from West Asia stimulates Indian summer monsoon rainfall, reports a study published online in Nature Geoscience. The findings suggest that future changes in desert dust emissions, due to human activities or natural causes, could modify rainfall over India.
Philip Rasch and colleagues used satellite data and climate model simulations to examine the relationship between desert dust levels over the Arabian Sea, West Asia and the Arabian peninsula, and the intensity of the Indian summer monsoon. They find that desert dust levels are positively correlated with the intensity of monsoon rainfall. Model simulations suggest that, by warming the atmosphere, the dust particles increase the flow of moisture over India, thereby stimulating rainfall in the region.
In an accompanying News and Views article, William Lau notes that “the expected expansion of desert and arid regions under global warming… could enhance dust transport from the deserts of the Middle East and North Africa to the Asian monsoon regions, further enhancing monsoon rainfall.”