On drastic change in the relationship between snow cover and Indian monsoon rainfall

• Published in: Journal of Earth System Science 2023-06, Vol.132 (3), p.101, Article 101
• Main Authors: Sandhya, M, Sridharan, S
• Format: Article
• Language: English
• Subjects: Cooling; Correlation; Earth and Environmental Science; Earth Sciences; Hydrologic data; Influence; Monsoon rainfall; Monsoons; Monthly rainfall; Precipitation; Radiation; Rain; Rainfall; Rainfall data; Sea surface; Sea surface temperature; Snow; Snow cover; Southwest monsoon; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Surface temperature; Weather; Wind
• ISSN: 0973-774X; 0253-4126; 0973-774X
• DOI: 10.1007/s12040-023-02115-z

The monthly 1°×1° global snow cover (SC) data taken from version three of the twentieth-century reanalysis (20CR) project and the high-resolution gridded rainfall data provided by the India Meteorological Department (IMD) for the years 1957–2015 are used to study the relation between southwest monsoon rainfall (SWMR) over India and the SC over Eurasia (35°–65°N; 40°–80°E) and Himalayas (20°–50°N; 50°–110°E) for the four sesquidecades 1957–1970, 1971–1985, 1986–2000 and 2001–2015. It is observed that the SC over Eurasia in April–May shows generally the well-known negative correlation with the all India averaged SWMR. However, the correlation became positive in the recent sesquidecade 2001–2015. Though the correlation between Himalayan SC and SWMR is increasingly positive during the first three sesquidecades, it becomes negative during 2001–2015 over the majority of the grid points. This drastic change in the relationship is attributed to the decreasing trend in the area of SC and the increasing trend in the North Atlantic Sea surface temperature (SST) during the last decade.