Publications

Dahutia, P; Pathak, B; Bhuyan, PK (2019). Vertical distribution of aerosols and clouds over north-eastern South Asia: Aerosol-cloud interactions. ATMOSPHERIC ENVIRONMENT, 215, 116882.

Abstract
Eleven years of CALIOP and MODIS data are used to investigate the vertical distribution of aerosols and clouds and their possible interactions over the north-eastern South Asia (22-30 degrees N, 88-98 degrees E). Distinct seasonality in the vertical aerosol structure with the presence of elevated aerosol layers (EALs) is observed. The EALs vary from similar to 1.4 to 4.8 km in post monsoon to similar to 4.8-7.4 km in monsoon. Strong convective activities mainly in pre-monsoon and monsoon and upper air transportation of aerosols contribute to the formation of EALs. The contribution of polluted dust, polluted continental/smoke and elevated smoke are found to be predominant in the vertical column during pre-monsoon and monsoon. Contrarily, clean continental, clean marine and dusty marine are dominant during winter and post monsoon. Small spherical particles are abundant during winter while in monsoon hygroscopically grown spherical particles predominate. Seasonally, the cloud occurrence frequency (COF) as a function of altitude is maximum during monsoon. An increase in cloud top height (CTH) is observed within this region corresponding to an increase in number of cloud layers, thus revealing invigoration effect. The occurrence of cirrus and deep convective clouds is maximum in monsoon and minimum in the dry season. Significant inhibition/invigoration is observed for mixed-phase/liquid clouds.

DOI:
10.1016/j.atmosenv.2019.116882

ISSN:
1352-2310