Holocene climate variability and Indian Summer Monsoon: An overview

Abstract

The response of the Indian Summer Monsoon (ISM) to forcing factors and climate variables has not yet fully explored, even though the ISM plays a pivotal role in the socio-economics of the Indian subcontinent and nearby areas. The ISM progression over Indian landmass is a manifestation of the Intertropical Convergence Zone (ITCZ) migration over the northern Indian Ocean and the Indian subcontinent. The recent anomalous behaviour of ISM raises the need for a better understanding of its spatio-temporal changes during the ongoing interglacial period termed as the Holocene period. The Holocene period has been classified further based on the globally observed abrupt climatic events at 8.2 and 4.2 ka. The 8.2 ka global cooling events have been recorded from northern Indian Ocean marine archives but limited records from the continental archives of the Indian landmass has demonstrated the 8.2 ka event. At the same time, the 4.2 ka dry climate has been endorsed by both marine as well as continental records and agrees with the global studies. During the ‘Little Ice Age’ (LIA), in the India subcontinent, wet conditions prevailed in the northern, central and western regions while a dry climate existed over the greater part of peninsular India. The present review offers an account of ISM signatures and possible mechanisms associated with the monsoon variability in the Indian subcontinent and the northern Indian Ocean during the Holocene period.

The Importance of the Orbital Parameters for the Indian Summer Monsoon During the Mid-Holocene, as Deciphered From Atmospheric Model Experiments

“…Signatures of changes in insolation are reflected in the changes of the northern hemisphere monsoon systems (Staubwasser et al, 2003). Past climate records based on proxy reconstructions from India and neighborhood surroundings of the Indian region (see the review by Dixit and Tandon, 2016;Banerji et al, 2020;Tejavath et al, 2020 for the details and references) report centennial to millennial-scale changes in the ISMR during the Holocene ( 12 kyr BP to present). These studies, in general, show that from the early Holocene period (9 kyr BP) to late Holocene (3 kyr BP), the ISMR shows a long-term decreasing trend.…”

Hydroclimate variability during the last two millennia from the mudflats of Diu Island, Western India

“…The studies revealed that the climate over the Indian subcontinent was warm and wet during the MWP while a dry climate prevailed during LIA. However, the prevalence of cool and wet climates has been delineated form northern and central India, which was associated with the plausible strengthening of western disturbances due to southward migration of the Inter Tropical Convergence Zone (ITCZ; Banerji et al, 2020;Kotlia et al, 2012).…”

“…But dry conditions were demonstrated for the Mediterranean and the China/ Tibetan Plateau (Helama et al, 2017). In the Indian context, only a few studies have focussed on the climate of RWP and DACP (Banerji et al, 2015(Banerji et al, , 2017(Banerji et al, , 2019(Banerji et al, , 2020Misra et al, 2018;Naidu et al, 2020) of the first millennium.…”

“…The ISM has been associated with other modes of climate variability such as El Niño Southern Oscillation (ENSO; Banerji et al, 2020;Maity & Kumar, 2006), Total Solar Irradiance (TSI; Agnihotri et al, 2002) Indian Ocean Dipole (IOD; Abram et al, 2009), North Atlantic Oscillation (NAO; Banerji et al, 2019Banerji et al, , 2020Menzel et al, 2014), Volcanic forcing (Banerji et al, 2019), and ITCZ (Banerji et al, 2019(Banerji et al, , 2020Saraswat et al, 2013) thereby having huge impact on the global climate system.…”

Holocene hydroclimatic variability in the Zanskar Valley, Northwestern Himalaya, India

“…Similarly, the influence of the mid-latitude westerlies shows a progressive decrease from the NW (Karakoram and Ladakh) to northeastern Himalaya (Benn and Owen, 1998). As far as the paleoclimatic/paleoenvironmental proxy record of the Higher Himalaya is concerned, the data are rudimentary, especially in relation to the sheer size of this sector; more specifically, the paleoclimatic data from the NW Himalaya are scarce (Ali et al, 2018; Bhushan et al, 2018; Banerji et al, 2020). In the case of the Higher Himalaya, focus must be given to the ISM, as it drives the majority of environmental and ecological changes in the region (Patnaik et al, 2012; Xu et al, 2018).…”