Publications

Ahmed, A; Tikuye, BG; Manjunatha, BR; Jose, J; Ramaraju, HK; Venkatesha, G (2025). Influence of Hygroscopic Aerosols for Understanding the Cloud Microphysical Properties in the Atmosphere Over Mangaluru, Southwest Coast of India. JOURNAL OF THE INDIAN SOCIETY OF REMOTE SENSING.

Abstract
Atmospheric aerosols are important precursors in affecting the cloud microphysical properties and rainfall. This study examines the importance of aerosols on cloud properties in the summer monsoon-dominated region of Mangaluru, on the southwest coast of India. Aerosol optical depth (AOD), Angstrom exponent (AE), and meteorological datasets have been used to examine the spatial and temporal distributions of aerosols. The air mass back trajectories were computed from the hybrid single-particle Lagrangian integrated trajectory model to understand the sources and movement of air masses transporting aerosols. The AOD values are lower during the winter and autumn seasons as compared to the spring and summer seasons (0.38 to 0.42 and 0.58 to 0.62, respectively). The computation of air mass back trajectories indicates that the study area is dominated by the marine air mass throughout the year; however, it is considerably affected by airmass arriving over the landmass. Seasonally, the coarse particles dominate during the summer and, to some extent, during the spring, whereas fine-mode aerosols dominate during the winter and autumn seasons. This suggests the dominance of the natural source aerosols during the former seasons as compared to those from anthropogenic sources during the latter seasons, respectively. The positive correlations of AOD with cloud fraction and water vapor (WV; r = 0.35 and r = 0.33 statistically significant at p < 0.001 level, respectively) suggest that aerosols are hygroscopic in nature for the cloud formation. In contrast, negative correlations of AOD with cloud top pressure and cloud top temperature (CTT; r = -0.34 and r = -0.23 with p < 0.001 level, respectively) imply negative relationships of the latter parameters during the cloud condensation process. The AOD level during most of the seasons tends to increase interannually from 2007 to 2018 due to anthropogenic activity but dropped to the minimum level recorded before the year 2006 as a result of the massive lockdown during the COVID pandemic during 2019-2020. There is a tendency to increase the seasonal-to-interannual variations in the AE, suggesting the impact of anthropogenic activity even during the summer monsoon rainy season. Thus, the impact of anthropogenic activity on increasing the aerosols in the atmosphere over the study area was found to be significant.

DOI:
10.1007/s12524-025-02138-7

ISSN:
0974-3006