Research Projects

The summer monsoon's intensity variations are expected to have significant socio-economic impacts in South Asian developing countries. Paleoclimate records can help evaluate past monsoon changes, cyclicity, and intensity, and understand their potential societal implications. Continental archives for monsoon reconstructions are particularly useful in evaluating the linkages between societal and environmental changes. The plains of NW India, once densely populated, are now projected to be one of the most fragile ecosystems due to projected warming. Regional climate reconstructions present a spatially and temporally incongruent picture. Existing independent records of monsoon variability from lakes Riwasa and Kotla Dahar in Haryana suggest long-term changes in monsoon rainfall responded to boreal summer insolation and abrupt events linked to North Atlantic variability and tropical ocean-atmosphere phenomena. However, these records are of coarse resolution and incomplete. This project aims to reconstruct high-resolution monsoon variability records using paleolake sediments from the time these lakes appeared in response to strengthening monsoon rainfall. Sediment grain size analysis and elemental composition will be used to interpret precipitation changes, while oxygen and carbon isotopes in gastropod and ostracod carbonates will infer past hydrological and vegetational changes. Ostracod assemblage changes will indicate lake level and salinity changes. These multiproxy records will be compared with general circulation model simulations of seasonal precipitation fields carried out as part of the third phase of the Paleoclimate Modelling Intercomparison Project (PMIP3) for key intervals, such as the Mid-Holocene (6ka), last glacial maximum, abrupt events at 8.2 ka and 4.2 ka BP, and during the Last Millennium (CE 850-1849).