Joint Seminar: Energetics of the Indian monsoon evolution over the last 22,000 years

Substantial evidence from proxies suggests that monsoon variations in the past are due to variations in Earth's orbit. These variations modulate the amount of incident solar radiation and thus the energy available to run the monsoon system. The major focus in the literature has been on the effect of incident solar radiation but not on the resulting feedbacks. In this talk, I will give examples of two different types of feedbacks that affect the Indian monsoon. Using the energetics framework of monsoons we have delineated the role of forcings and feedbacks quantitatively. During the deglacial (22 to 10 Kyrs ago) positive feedback from water vapor amplifies the increase in insolation, leading to a doubling of the Indian monsoon rainfall. Across the Holocene, insolation drives monsoon through its influence on the net energy at the top of the atmosphere, cloud radiative feedbacks are prominent during this period. These examples underscore that the changes in solar radiation are only a trigger and the final response of monsoon depends on factors internal to the climate system.

Date

28.09.2021

Time

15:15 h

Place

Virtual Seminar
Hamburg

Speaker

Chetankumar Jalihal, Max-Planck-Institute für Meteorology

Organizers

Diego Jiménez-de-la-Cuesta Otero

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