Dynamic responses of Indian Summer Monsoon variability during past warm intervals

Anand, Pallavi; Nilsson-Kerr, Katrina; Quamar, F; Holden, Philip; Leng, M. J.; Clemens, S. C. and Naidu, P. D. (2022). Dynamic responses of Indian Summer Monsoon variability during past warm intervals. In: ICP 14: 14th International Conference on Paleoceanography, 29 Aug - 2 Sep 2022, Bergen, Norway.

URL: https://icp14.w.uib.no/program/book-of-abstracts/

Abstract

The South Asian or Indian Summer Monsoon (ISM) is an iconic reflection of land-ocean-atmosphere inter- actions on Earth, affecting over a billion people. Future predictions of northern hemisphere monsoon rainfall are fraught with large uncertainties in the Intergovernmental Panel on Climate Change (IPCC) reports. To better understand monsoon rainfall pattern/behaviours in future, we need to investigate its response to cli- matic drivers, including past warm intervals. We present multi-proxy geochemical and vegetation records of monsoon variability from the Bay of Bengal using sediment sequences recovered during the Integrated Ocean Discovery Programme (IODP) expedition 353. We utilise these multi-proxy records to assess re- sponses of ISM dynamics to past warming by comparing Holocene and last interglacial warm intervals at sub-millennial timescale. We integrate proxies’ records and intermediate complexity climate model outputs to present evidence for heterogenous rainfall pattern across global tropical landmasses when comparing the Holocene and last interglacial warm intervals. We also find regional differences in monsoon rainfall pattern along with changing loci of the precipitation when comparing these warm intervals. Further, we will present results of seasonal rainfall variability extremes, inferred from continental and marine proxy data, covering cool and warm climate states of the late Pleistocene.