Mon Mar 24 05:19:33 UTC 2025: ## Kerala University Study Reveals 15,000-Year Monsoon History, Links to Solar Activity

**Kasaragod, March 24, 2025** – A groundbreaking study by the Central University of Kerala has unveiled a detailed history of the Indian Summer Monsoon over the past 15,000 years. By analyzing ocean sediments from the Bay of Bengal and the Andaman Sea, researchers have established a clear link between monsoon variations and changes in salinity and marine productivity.

The research, published in the April 25th issue of *Quaternary International*, utilized fossil shells of planktonic foraminifera to reconstruct monsoon patterns. The findings indicate that monsoon intensity peaked during the early Holocene epoch (11,000-7,000 years ago), leading to high freshwater influx, reduced salinity in the Bay of Bengal, and decreased marine productivity. Conversely, weaker monsoons during colder periods resulted in better water mixing, increased nutrient upwelling, and enhanced marine life.

A significant contribution of the study is its identification of correlations between monsoon cycles and solar activity, suggesting that solar radiation has influenced rainfall patterns over millennia. Lead researcher Prof. A.V. Sijinkumar highlighted the importance of incorporating Bay of Bengal data, providing a more comprehensive picture than previous research focused solely on the Andaman Sea.

Co-author S.J. Gayatri emphasized the study’s implications for future climate projections. The researchers warn that ongoing global warming could intensify summer monsoons, impacting agriculture, water resources, and biodiversity. The study, funded by the Anusandhan National Research Foundation, involved collaboration with the National Institute of Oceanography and the National Centre for Polar and Ocean Research, Goa.

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