Publications

Lima, CB; Krishna, SVSS; Verma, S; Prijith, SS; Ramana, MV (2022). Satellite-Derived AerosolCloud Relationships Under Anthropogenic Polluted Conditions of Arabian Sea. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, 60, 4105607.

Abstract
Uncertainty associated with estimating the impact of anthropogenic aerosols on clouds is hindering accurate projections of future climate. Here, we evaluate the effect of aerosols on clouds under anthropogenic polluted conditions and relatively maritime conditions, over the Arabian Sea (AS), under the influence of the same large-scale meteorology and spatiotemporal domains. The relationship between diurnal mean cloud macrophysical properties, namely, cloud fraction (CF) and cloud top temperature (CTT) from geostationary satellite (INSAT-3D), and aerosol properties, from Moderate Resolution Imaging Spectroradiometer (MODIS), is examined for the winter months of 2018. During winter, trade winds transport large quantities of continental aerosols over to the AS, where the semipermanent field of stratocumulus cloud layers exists. We observed distinctively different cloud macrophysical properties over polluted conditions compared to maritime conditions. The strengths of aerosol & x2013;cloud interaction on CF and CTT are, respectively, 0.3 and & x2212;0.02 for polluted conditions and are 0.1 and & x2212;0.005, respectively, for maritime conditions, with an increase in the aerosol index from 0.0 to 0.6. Absorbing aerosol radiative effects at elevated layers over polluted conditions majorly drive the observed changes in cloud properties. Further analysis of Cloud-Aerosol LiDAR and Infrared Pathfinder Satellite Observations (CALIPSO) profiles illustrates the bimodal structure of cloud occurrence over polluted conditions. Elevated absorbing aerosol layers above stratus clouds enhance low-level cloud cover. Besides, warming due to elevated absorbing aerosols reduces intermingled cumulus cloud layers and, at the same time, enhances the development of growing cloud layers above elevated pollution layers. The observed changes in cloud macrophysical properties in relation to the mutual position of aerosol and cloud layers suggest a more complicated cloud regime-dependent process over this region.

DOI:
10.1109/TGRS.2021.3137089

ISSN:
1558-0644