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Influence of Black Carbon Aerosol on the Atmospheric Instability
Author(s) -
Talukdar Shamitaksha,
Venkat Ratnam M.,
Ravikiran V.,
Chakraborty Rohit
Publication year - 2019
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1029/2018jd029611
Subject(s) - convective available potential energy , atmospheric instability , atmospheric sciences , environmental science , planetary boundary layer , convection , aerosol , aethalometer , deep convection , precipitable water , climatology , precipitation , lapse rate , buoyancy , wind speed , carbon black , meteorology , geology , geography , chemistry , turbulence , physics , mechanics , natural rubber , organic chemistry
To date, influence of aerosols on the atmospheric stability and hence on the convection/precipitation is not well understood. From the detailed analysis carried out using high‐accuracy radiosonde and Aethalometer measurements, a significant decrease in the convective available potential energy has been noticed in association with the increase in surface concentration of black carbon (BC) for a restricted range of precipitable water vapor and under similar environmental background (wind speed, direction, and cloud cover) over Gadanki (13.5°N, 79.2°E), a tropical rural site in southern peninsular India. A number of case studies along with statistical analysis indicate a notable perturbation in the temperature profile associated with high‐surface BC concentration conditions compared to the regional mean concentration of the same. A discernible fall in the temperature lapse rate within and above the local boundary layer in association with the higher BC concentration has been observed, which in turn reduces the available potential energy for convection decreasing the positive buoyancy required for a rising moist air parcel. This observation has been noticed over a nonurban location, but the phenomenon is not location dependent and is more applicable to the urban regions where BC concentration is likely to be much higher.