Remote Impact of Black Carbon Aerosols Through Rossby Wave Phase Shift
Arindam Chakraborty, R S Nanjundiah and J Srinivasan
It was shown by several previous studies that black carbon aerosols could
impact convection, especially over Asian region, locally. However, the exact
impact of black carbon aerosols on monsoon remains inconclusive. The present
study uses an atmospheric general circulation model to that remote influence of
aerosol-like heating can be as strong as local influence on Indian summer
monsoon. Precipitation in northern Arabian Sea increased by 28% when
aerosols were present only over south Asia, and was increased by 13% when
aerosols were present only over east Asia. The remote heating of aerosols
modulated the phase of the upper tropospheric Rossby waves to favour upper
level divergence and subsequent convection over South Asia. Our results show
that atmospheric heating of one region can influence convection of remote
location through atmospheric teleconnection.