The Indian Ocean brown cloud or Asian brown cloud is a layer of air pollution that recurrently covers parts of South Asia , namely the northern Indian Ocean , India , and Pakistan. The term atmospheric brown cloud is used for a more generic context not specific to the Asian region. The Asian brown cloud is created by a range of airborne particles and pollutants from combustion e. The cloud was also reported by NASA in  and
Researchers in Sweden, India and the Republic of Maldives have discovered that a sooty cloud of pollution that hangs over South Asia between January and March every year is created by a combination of the burning of both fossil fuels and biomass. The discovery, which used the The discovery, which used the first-ever micro-scale measurements of natural C a carbon dating method , gives the green light for action to be undertaken to reduce the cloud's insidious effects, including the thousands of deaths it causes every year. The brown cloud that covers South Asia for most of each winter is responsible for the deaths of approximately , people in India and China every year from related cardiovascular and respiratory problems. Some studies have put the figures much higher, possibly even into the millions. The cloud is also contributing to climate change in Asia and is affecting the area's climate as much, if not more, than carbon dioxide, as the soot particles in the cloud absorb sunlight, which contributes to a rise in temperature.
Now the chief proponent of the phenomenon, Veerabhadran Ramanathan, director of the Center for Atmospheric Sciences at the Scripps Institution of Oceanography, University of California, USA, says these clouds are a problem for other regions of the world as well. He spoke to Dinesh C Sharma. Brown clouds have been seen all over the world, including the us , Europe, India and China.
The most visible impact of air pollution is the haze, a layer of pollutants and particles from biomass burning and industrial emissions. This cloud of pollution at times has a brownish color e. Due to long-range transport, the mostly urban fossil fuel related or rural biomass burning related phenomenon is transformed into a regional haze or cloud that can span an entire continent.