Earth, Atmosphere & Environment Sciences
Title : | Indian monsoon seasonal dynamics across mid-Pleistocene transition |
Area of research : | Earth, Atmosphere & Environment Sciences |
Principal Investigator : | Dr. Prem Raj Uddamdam, Birbal Sahni Institute Of Palaeosciences, Lucknow, Uttar Pradesh |
Timeline Start Year : | 2022 |
Timeline End Year : | 2024 |
Contact info : | premraj@bsip.res.in |
Equipments : | "Centifuge Machine
Ultrasonicator
Microscope" |
Details
Executive Summary : | Indian monsoon records spanning the last glacial-interglacial cycle has reached statistically meaningful size. However, before the last glacial cycle, variability of the Indian monsoonal circulation and precipitation patterns in the northern Indian Ocean, is still poorly understood. Despite the influence by summer and winter monsoon often, the Arabian Sea records are interpreted in terms of only summer monsoon variability. Besides records of clear distinction between summer precipitation and summer wind intensity changes beyond Holocene are also lacking. Also, the records of winter monsoon variability and its evolution on long-term scales is sparse. The current proposal focuses on the early to mid-Pleistocene time slice, characterised with large-scale natural changes in the CO2 levels, major Ice sheets development, the major reorganization of atmospheric circulation from weak to strong zonal Walker circulation (Etourneau et al. 2010). A remarkable transition in the climatic cycles from 41 kyr to 100 kyr periodicity occurred during the mid-Pleistocene period (1.2-0.7 Ma), which is known as mid-Pleistocene transition (MPT). The evolution of MPT and the causing mechanisms is yet to be resolved. Indian monsoon evolution during MPT is poorly constrained. A few studies suggest a strengthened summer monsoon circulation during MPT (eg. MIS-13) based on Chinese Loess Plateau (Yin et al 2008), the equatorial Indian ocean, (Bassinot et al 1994) and the Mediterranean records (Rossignol-Strick et al 1998). In contrast, the Arabian Sea (AS) high productivity records during late MPT are also attributed to increased meridional overturning circulation (MOC) enhancing nutrient and productivity than summer monsoon intensification (Ziegler et al., 2010). The role of winter monsoon wind-driven processes is clearly under-evaluated to enhance productivity during this time period. This proposal aims to reconstruct the Indian monsoonal records from the EAS during the Pleistocene period utilising IODP Expedition 355 core site U1457 (influence by summer and winter seasons) employing multi-proxy approach (micropaleontological, isotopic and geochemical records). The proposal will address certain crucial questions as to How the seasonal monsoon varied in the early to mid-Pleistocene? How did the monsoon precipitation vary across MPT? How primary productivity responded to the seasonal monsoon changes associated with rapid climatic changes across MPT? Whether the monsoon wind and precipitation intensity are similar or varied in the geological past? Whether productivity patterns are similar between the precipitation dominated the eastern Arabian Sea and wind dominated western the Arabian Sea? Investigation of monsoon response during global warming/cooling events in the geological past is crucial to our understanding of modern anthropogenic climatic changes and its consequences. |
Total Budget (INR): | 25,48,800 |
Organizations involved