Monsoon-driven vegetation changes during glacial MIS 16 in the core monsoon zone of India

• Main Authors: Deb, Ankur, Oliveira, Dulce, Desprat, Stéphanie, Krishnamurthy, Anupama, Prasad, Sirinivasan, Zorzi, Coralie, Yin, Qiuzhen, Schneider, Ralph, Alonso-Garcia, Montserrat, Abrantes, Fatima, Martinez, Philippe, 21st Congress of the International Union for Quaternary Research (INQUA)
• Other Authors: UCL - SST/ELI/ELIC - Earth & Climate
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: Indian; Ice Sheet; North Atlantic
• Online Access: http://hdl.handle.net/2078.1/281790

The Indian Summer Monsoon (ISM) is responsible for 80-90% of the annual precipitation in Central India yet understanding the ISM natural variability during past glacial periods remains a challenge in paleoclimate research. The ISM dynamics during the Last Glacial Maximum (LGM) are fairly well-documented but the fundamental drivers of India’s hydroclimate are still highly debatable. While boreal summer insolation and the North Atlantic circulation have been commonly considered as the primary forcings at orbital and millennial timescales, respectively, other studies point to the influence of mechanisms related to ice sheet volume, atmospheric CO2 concentrations and the export of latent heat from the Southern Hemisphere. Paleorecords from glacials prior to the LGM are, therefore, needed to disentangle the forcings driving ISM changes and to evaluate the responses of fragile ecosystems dependent on monsoon rainfall, such as the forests and savannas of India. Here, we focus on the glacial MIS 16 (676-621 ka) which represents one of the most severe glacial periods of the Quaternary, occurring right after the end of the middle Pleistocene transition. Moreover, it is known to be marked by the first instabilities of the Laurentide ice sheet that resulted in the development of Heinrich layers in the northern North Atlantic. We present the first MIS 16 vegetation reconstruction from India's Core Monsoon Zone (CMZ) based on pollen analysis from IODP Site U1446 strategically recovered at the exit of the Mahanadi River to capture a robust signal of the ISM rainfall. Our pollen analysis results will be compared with records from the same site and other proxy and modelling data to unravel the drivers of the ISM dynamics during the cold MIS 16 in the CMZ of India.