Thread by @weatherindia

#SciSimplified: Here’s How Dust from the #MiddleEast Can Shape Our Experience of #Monsoons

weather.com/en-IN/india/mo…

(📸: Rajtilak Naik/BCCL)

By Poorvasha Kar

A new study from the University of Kansas has offered some crucial insight into the mechanisms behind the world's most powerful monsoon systems: Indian summer monsoon or the southwest monsoon.

#Monsoon

The study showcases that the Indian monsoon is intensified by atmospheric dust particles swept up by the winds from deserts in the #MiddleEast.

#Monsoon

When carried by strong winds into the atmosphere, the dust particles from the Middle East absorb solar radiation & become extremely hot. The heat from these particles raises the heat of its surrounding environment enough to change air pressure & circulation patterns of the wind.

This phenomenon is termed an “elevated heat pump” that is responsible for driving moisture from the sea to the Indian subcontinent.

#Monsoon

Ever heard of positive feedback loops? In this case too, a positive feedback loop plays a role when the dust particles boost the power of Indian monsoons, and the monsoons increase the winds in the Middle East and subsequently produce more dust aerosols.

#Monsoon

These waves have distinct parts facing either high pressure or low pressure and are responsible for transporting air back to the #MiddleEast. This air goes downwards and strikes the surface to pick up more dust particles, in turn starting the process again.

#Monsoon

Meanwhile, another Asian source fueling the impact of aerosolized dust upon the Indian summer monsoons is the Iranian Plateau, located between the Middle East and the Tibetan Plateau.

#Monsoon

The study explores three other mechanisms influencing the Indian summer monsoon. One is the snow-darkening effect, where black carbon and dust particles suspended in the air—known as aerosols—land in snow-covered regions.

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Another mechanism is the solar-dimming effect where aerosols block the solar radiation from reaching the land surface. This causes the surface temperature to cool down which interferes with hydrological processes by reducing evaporation and in turn reducing rainfall.

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Understanding these mechanisms will prove to be of increasing importance in the face of global #climatechange, especially for Asia, as projections forecast that the land will become drier which will amplify dust emissions.

#Monsoon