Holocene Variations of Monsoon Rainfall in Rajasthan

Abstract

Two reconstructed histories of the monsoon rainfall in Rajasthan show that the monsoon was weak or absent in latest glacial time. With the advent of Holocene climatic patterns, fresh water lakes formed in dune fields and the pollen rain preserved in these reservoirs provides a basis for the reconstruction of the monsoon history. The two reconstructions, separated by only 150 km, have some features in common and some striking differences. Both show maximum monsoon amounts in the early Holocene, with a roughly two-thirds decrease to the present. Both show salinization in sub-Boreal time. Both show long intervals of near complete desiccation in the last four millennia. The shorter term variations, however, are not closely parallel. These shorter term variations may be explained in terms of the behavior of the present day interannual variability.

Signatures of Tibetan Plateau heating on Indian summer monsoon rainfall variability

“…In early Holocene time, not only were lakes widespread in northern India where desert conditions now prevail [e.g., Bryson and Swain, 1981;Enzel et al, 1999;Prasad and Enzel, 2006;Prasad et al, 1997;Singh et al, 1972Singh et al, , 1990Sinha et al, 2004], but winds associated with the Somali Jet seem to have been stronger [e.g., Gupta et al, 2003]. By contrast, before~10 Ma, winds associated with the Somali Jet seem to have been weaker than today, and some have inferred that the monsoon strengthened since that time [e.g., Harrison et al, 1992;Kroon et al, 1991;Molnar et al, 1993;Prell and Kutzbach, 1992].…”

The 1920S Drought Recorded by Tree Rings and Historical Documents in the Semi-Arid and Arid Areas of Northern China

“…In extreme cases, a drought disaster can cause flourishing societies and highly developed civilizations to collapse abruptly (Bryson and Swain, 1981;Fang, 1999;deMenocal, 2001;Weiss and Bradley, 2001;Huang et al, 2003). Knowledge of past drought disasters could aid in the evaluation of potential regional hazards in the future and facilitate the assessment of the links between regional and worldwide droughts (Wilhite, 2000).…”

High-Resolution Monsoon Records Since Last Glacial Maximum: A Comparison of Marine and Terrestrial Paleoarchives from South Asia

“…Paleomonsoon studies in the Indian region were initiated around 30 years ago by Prell et al [74] and Bryson and Swain [75]. Since then, a large number of workers ( [2, 16-27, 29-32, 41-44, 76-78] and references therein) have carried out high-resolution monsoon studies in archives from various locations in and around the subcontinent that are influenced by the monsoon winds/precipitation.…”