Role of dynamics on the formation and maintenance of the elevated aerosol layer during monsoon season over south-east peninsular India

Publication date: September 2018
Source:Atmospheric Environment, Volume 188
Author(s): M. Venkat Ratnam, P. Prasad, M. Roja Raman, V. Ravikiran, S. Vijaya Bhaskara Rao, B.V. Krishna Murthy, A. Jayaraman
The existence of elevated aerosol layer is common over India during monsoon season. Though its sources are well explained through long-range transport, its formation and maintenance is not explained to date. The formation and maintenances of an elevated aerosol layer, starting from ∼2 km and extending up to ∼5.5 km noticed is explained using two nearby lidars located in peninsular India. Existence of a cleaner environment with low aerosol loading below 2 km is attributed to the wet scavenging and existence of no strong local source. The low level jet (LLJ) from Arabian Sea persisting between 2 and 3 km is the main mechanism suggesting strong role of dynamics in the formation of these elevated layers. Persistent strong shears existing between LLJ and tropical easterly jet during this season restrict the up-liftment of aerosols to the higher altitudes. Observed features are explained in the light of dynamics, meteorology and long-range transport.



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