Journal of Water and Climate Change (Jun 2021)
Study of regional heterogeneity of cloud properties during different rainfall scenarios over monsoon-dominated region
Abstract
Variability in precipitation pattern is increasing even at regional scale due to advancement in global warming, which could be of higher importance in study for monsoon-dominated region such as India. Precipitation varies with region, thus the present study focuses on two types of heterogeneous regions: a region closer to the coast and an inland region. Long-term analysis over inland region shows that the high cloud fraction and low penetration of outgoing radiation at the top of the atmosphere may be due to the presence of thicker clouds during southwest monsoon. Further study of cloud parameters shows domination of stratiform clouds over nearby coastal region with high range specific humidity (6.67 × 10−6–1.81 × 10−2 kg/kg) and higher cloud effective radius (13.35–15.75 μm), probably due to fewer hygroscopic nuclei. Heterogeneity in rainfall may also depend on types of monsoon (viz., normal, excess and deficit) by altering cloud formation processes. During periods of low rainfall over the coast, clouds are observed at low altitude with high cloud top temperature (−0.52 ± 3.08 °C) but have low specific humidity and lower cloud effective radius, which depict mixed characteristics of stratiform and convective clouds. Thus, it has been observed that cloud characteristics depend largely on the region than on the rainfall scenario. Such studies can be useful to understand uneven rainfall patterns. HIGHLIGHTS It helped to quantify regional heterogeneity.; It analyze formation of stratiform clouds as well as convective clouds.; It also identified mixed characteristics of stratiform and convective nature of clouds.; It clarified that the nature/type of cloud depends largely on the region as compared to rainfall scenario.; A longer time period and more parameters would help strengthen the findings of this study.;
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