Late quaternary to holocene southwest monsoon reconstruction: A review based on Lake and Wetland Systems (Studies Carried Out during 2011-2016)

Abstract

The recent trends in Late Quaternary researches, particularly, for the Holocene period is mainly focused on reconstructing the past climate dynamics, fluctuations in the intensity of the southwest monsoon (SWM) and applications of these datasets for predicting future trends. During the years 2010-2015, the published data, although shows chronological constraints, by covering different physiographies of India, which presently display a highly variable climate from hot to cold desert and from high to low rainfall region. An integrated multidisciplinary, multiproxy data provide a comprehensive understanding of the trend in climate change, from moist mid-Holocene to dry Late Holocene conditions from the Indian subcontinent although with a slight variation in time brackets which is attributed to external forces responding to varied landscape, geographical setting and altitudinal changes. Most of the lake records show a decline in SWM since the middle Holocene with intermittent intense wetter conditions. This allowed the lake margins to shrink and expand. Some lakes hold the signatures of abrupt and extreme events such as the 8200 yr BP solar insolation event, 4200 extreme aridity, 3800 dry and warm conditions, Medieval warm period (MWP) and the Little Ice age (LIA) events. Till date, however, these data are few and far in between and the need of the day is to rigorously generate quantification of SWM intensity using lake sediments and compile the dataset for climatic modeling such as the Regional Climate Models (REGCMS) to predict future climate change if any with greater degree of correctness.