Dr. Manish Tiwari awarded the INSA Medal for Young Scientist (2009)

Dr. Manish Tiwari of NCAOR has been awarded the prestigious INSA Medal for Young Scientist for the year 2009 in the Earth Sciences section for his study regarding the past variability of Indian monsoon at high resolution using sediment cores from the Arabian Sea.

His study raises several important points such as Northeast monsoon intensification during the early deglacial period (~19,000 to ~17,000 yr BP) and not during LGM as proposed earlier; excellent correlation between SW monsoon precipitation and the SW monsoon wind intensity on centennial time scales, which provides the first paleoclimatic evidence for the control exerted by SW monsoon precipitation over the SW monsoon wind strength via latent heat release. This study further illustrates that variations in the SW monsoon precipitation correspond very well with the polar temperature records with enhanced monsoons during interstadials (warmer periods) and reduced precipitation during the stadials (cooler periods). Importantly he has found that, contrary to some of the earlier single proxy records from the western margin of the Arabian Sea, the Southwest monsoon did not decline during the Holocene (past ~10,000 yrs) whereas northern hemisphere insolation declines uniformly from 9,000 yr BP. This implies that, in the Holocene, SW monsoon did not follow insolation, highlighting the importance of internal feedbacks.