Anthropogenic atmospheric aerosols reduce incoming solar radiation
Q. Anthropogenic atmospheric aerosols affect the monsoon in which of the following ways?- Published on 21 Apr 16a. They reduce incoming solar radiation
b. They capture solar radiation, heating the atmosphere over land and sea affecting temperature difference needed for monsoon
c. They absorb water vapour reducing rains
d. All of the above
ANSWER: They reduce incoming solar radiation
- Anthropogenic atmospheric aerosols, including sulphates, black carbon, nitrates and dust accumulate over the Indo-gangetic plains. These reduce incoming solar radiation over northern India and the northern Indian Ocean and lead to cooling on both land and sea resulting in a lowered thermal contrast.
- Hence, monsoon winds and circulation are weakened as both land and sea are cooled. Evaporation is also suppressed. Over South Asia, over 50 per cent of aerosol emissions are caused by biomass and agricultural burning. There is mounting evidence of the emissions from South Asia and China in changing the timing, spatial distribution and strength of the monsoon.
- However, negative impacts of these aerosols can be reduced quickly as they have a short lifetime of few weeks compared to GHGs which can stay in the atmosphere for up to 80 years.
