Paleoclimate of Peninsular India

Abstract

The limited spatial and temporal coverage of instrumental weather records precludes the knowledge of long-term climatic changes. To infer such changes, recourse is taken to natural archives that serve as climate proxies. The prominent proxies that offer annual to seasonal temporal resolution include annual rings of trees (Ramesh et al., 1985; Ramesh et al., 1986a; Ramesh et al., 1986b; Ramesh et al., 1988; Ramesh et al., 1989; Managave et al., 2010a; Managave et al., 2010b; Sano M. et al., 2010; Managave et al., 2010c; Managave et al., 2010d; Managave et al, 2010e), corals (Chakraborty et al., 1992; Chakraborty et al., 1993a; Chakraborty et al., 1993b; Chakraborty et al., 1993c; Chakraborty et al., 1994; Chakraborty et al., 1997), ice cores (Nijampurkar et al., 1986), speleothems (Yadava et al., 2004) in some cases and varved sediments (Von Rad et al., 1999). Among these, tree-rings have specific advantages: they have a wide geographic distribution, are annually resolved, show a continuous record, and are easily dated by ring-counting. Seasonality in the growth rate of trees driven by seasonality in the climatic factors can result in well-defined annual growth rings in trees. Individual tree-rings faithfully record contemporary climatic signatures and hence provide an opportunity to decipher the variation in climatic parameters for a duration equivalent to the life-span of the tree.