AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Aerosol Vertical Distribution Climatology Over India: Dust, Smoke and Polluted Dust
Padmavati Kulkarni, SREEKANTH VAKACHERLA, CSTEP, India
Abstract Number: 875 Working Group: Remote and Regional Atmospheric Aerosol
Abstract Despite several independent observational studies, a comprehensive and climatological picture on the aerosol vertical distribution and its spatial gradients has not yet evolved over the Indian subcontinent. The present study analyses around 10 years of version 3, level 3, Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) spaceborne lidar (light detection and ranging), retrieved night time, cloud free vertical extinction profiles (at 532 nm) of composite aerosol, and its major species (dust, polluted dust, and smoke), to understand the three-dimensional distribution of aerosols over India.
The shape and vertical extent of the extinction profiles varied in space (from south to north of India) and time (across seasons). Altitudinal decay (decrease with increasing altitude, here and elsewhere) in the aerosol extinction values is steeper over the northern and eastern parts of India, compared to the southern regions of the country. The vertical extent of the aerosol distribution is shallower in the colder seasons compared to warmer seasons, which could potentially be due to suppressed convection during the colder months. Meridional gradients have been observed in the surface extinction coefficients. Polluted dust, which can be defined as a mixture of dust and smoke, emerged as the dominant aerosol species over most parts of the study region.
Over the north-western and central India, dust aerosols contributed the most to aerosol optical depths and extinction profiles, during the summer and monsoon months. Smoke aerosols, which have been attributed to biomass, agricultural burning, and long-range transport, prevailed over the southern and north-eastern regions of India. Boundary layer aerosol optical depths (AOD) contributed to columnar AOD significantly during the post-monsoon and winter seasons. Meanwhile the elevated AOD has an equal share in columnar AOD during the summer and monsoon seasons.