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Holocene climate forcings and lacustrine regime shifts in the Indian summer monsoon realm |
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| Authors: | Sushma Prasad Norbert Marwan Deniz Eroglu Bedartha Goswami Praveen K. Mishra Birgit Gaye A. Anoop N. Basavaiah Martina Stebich Arshid Jehangir |
| Affiliation: | 1. ERA Scientific Editing, Grosse Fischerstrasse 10, Potsdam, D-14467 Germany;2. Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, P.O. Box 60 12 03, Potsdam, D-14412 Germany Institute for Earth Science, University of Potsdam, Karl-Liebknecht-Straße 24-25, Potsdam, D-14476 Germany;3. Department of Bioinformatics and Genetics, Kadir Has University, Istanbul, 34083 Turkey;4. Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, P.O. Box 60 12 03, Potsdam, D-14412 Germany;5. Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun, 248001 India;6. Universität Hamburg, Institute for Geology, Hamburg, Germany;7. Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Manauli, Punjab, 140306 India;8. Indian Institute of Geomagnetism, New Panvel, Mumbai, Maharashtra, 410206 India;9. Senckenberg Research Institute, Research Station of Quaternary Palaeontology, Am Jakobskirchhof 4, Weimar, D-99423 Germany;10. Department of Environmental Science, University of Kashmir, Srinagar, Jammu & Kashmir, 190006 India |
| Abstract: | Extreme climate events have been identified both in meteorological and long-term proxy records from the Indian summer monsoon (ISM) realm. However, the potential of palaeoclimate data for understanding mechanisms triggering climate extremes over long time scales has not been fully exploited. A distinction between proxies indicating climate change, environment, and ecosystem shift is crucial for enabling a comparison with forcing mechanisms (e.g. El-Niño Southern Oscillation). In this study we decouple these factors using data analysis techniques [multiplex recurrence network (MRN) and principal component analyses (PCA)] on multiproxy data from two lakes located in different climate regions – Lonar Lake (ISM dominated) and the high-altitude Tso Moriri Lake (ISM and westerlies influenced). Our results indicate that (i) MRN analysis, an indicator of changing environmental conditions, is associated with droughts in regions with a single climate driver but provides ambiguous results in regions with multiple climate/environmental drivers; (ii) the lacustrine ecosystem was ‘less sensitive’ to forcings during the early Holocene wetter periods; (iii) archives in climate zones with a single climate driver were most sensitive to regime shifts; (iv) data analyses are successful in identifying the timing of onset of climate change, and distinguishing between extrinsic and intrinsic (lacustrine) regime shifts by comparison with forcing mechanisms. Our results enable development of conceptual models to explain links between forcings and regional climate change that can be tested in climate models to provide an improved understanding of the ISM dynamics and their impact on ecosystems. © 2020 John Wiley & Sons, Ltd. |
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