Determining the spatial and temporal patterns of climate changes in China's western interior during the last 15 ka from lacustrine oxygen isotope records

Abstract

Colman, S. M. 2009. Determining the spatial and temporal patterns of climate changes in China's western interior during the last 15 ka from lacustrine oxygen isotope records.ABSTRACT: China's western interior is a climatologically complex region, where climatic conditions are primarily controlled by the westerly jet stream and the Asian monsoon system. Observations reveal that the d 18 O signatures of these atmospheric elements as expressed in their meteoric waters are different, and these differences are reflected in the lacustrine systems that are ultimately fed by the meteoric waters. Empirical orthogonal function (EOF) decomposition of 17 lacustrine d 18 O records from this area clearly reveals the spatial and temporal structures of climate changes during the last 15 ka. The first EOF mode, dominated by sites in the NW sector, captures the temperature effect on the variability of the d 18 O dataset. We interpret the variations through time in the amplitude of this mode to be indicative of changes in summer air temperature. The second EOF mode, heavily weighted by sites in the SE sector, reveals the 'amount effect' on d 18 O, and thus its amplitude time series indicates changes in the intensity of the Asian summer monsoon. Our EOF-based reconstructions of regional climate are generally consistent with the d 18 O records of ice cores, cave speleothems and marine carbonates.

Late Holocene isotope hydrology of Lake Qinghai, NE Tibetan Plateau: effective moisture variability and atmospheric circulation changes

“…Liu et al (2009) show that during the late Holocene an intensified Asian winter monsoon correlated with cold events in the North Atlantic and a significant shift in climate between the MWP and LIA was mediated by an enhanced westerly jet stream. Yu et al (2008a) also propose there has been a gradual decay in the strength of the Asian summer monsoon system over the last 2000 years, with a step-wise shift to a weakened monsoon state during the LIA over the northern Tibetan Plateau. A multi-proxy ice core record from Mt.…”

Postglacial changes in the Asian summer monsoon system: a pollen record from the eastern margin of the Tibetan Plateau

“…a BP (Fig. 2), indicating a progressive increase of wetland biomass in response to the gradual strengthening of the summer monsoon (Jarvis 1993; Sirocko et al 1993; Wang et al 1999; Gupta et al 2003; Morrill et al 2003; Dykoski et al 2005; Yu et al 2009).…”

Climate variability on the south-eastern Tibetan Plateau since the Lateglacial based on a multiproxy approach from Lake Naleng – comparing pollen and non-pollen signals

“…According to Morrill et al (2003), this cold event which was recorded between 5.0 and 4.5 cal ka BP was apparently widespread across central Asia and was also inferred from Lake Donggi Cona and adjacent thermokarst lakes (Opitz et al, 2012(Opitz et al, , 2013, Lake Ximencuo (Zhang and Mischke, 2009) and Lake Bangong (Van Campo and Gasse, 1993;Gasse et al, 1996) on the TP. Within dating uncertainty, this cold event is also referred to as the "4.2 event" (Yu et al, 2000(Yu et al, , 2009.…”

“…Cooling after 5.0 cal ka BP can be regarded as a widespread climate event in eastern and central to southern Asia (Yu et al, 2009;Mischke and Zhang, 2010), and the Indian subcontinent (Staubwasser et al, 2003). This incipient cold period might have resulted in significant aridification and the collapse of 'Old World' cultures (Yu et al, 2000) and ancient civilizations in central China (deMenocal, 2001;Wu and Liu, 2004;Shao et al, 2006;Mischke and Zhang, 2010).…”