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The climate of the Tibetan Plateau is influenced by the monsoons and the Westerlies due to land-sea thermal contrasts. However, few quantitative temperature reconstructions have been made for the region, and this hinders our ability to validate climate models and to understand the coupling process between monsoon, ocean and ice sheets through time. Here we report a quantitative temperature reconstruction for the last deglaciation from a terrace of Lake Dangxiong Co in the southwestern Tibetan Plateau. Based on the unsaturation index of long-chain alkenones, the reconstructed mean annual air temperature during the late Last Glacial Maximum was about 0.2 °C, while the Bølling/Allerød (B/A) period was characterized by a rapid increase in temperature from 0.8 °C to 2.4 °C, (2.9) followed by an abrupt decrease in temperature to −0.9 °C in the early Younger Dryas (YD). The alkenones and n -alkanes record indicates that Dangxiong Co experienced a cold and wet climate in the early part of the last deglaciation after the Last Glacial Maximum, a warm-dry B/A, and a cold and dry YD. Our temperature reconstruction confirms that the thermal and dynamical effects of the Tibetan Plateau are one of the main elements contributing to abrupt changes in the Indian Summer Monsoon. [ABSTRACT FROM AUTHOR]

Knowledge of the origin of past climatic variations on annual to decadal timescales is important for assessing the likelihood of the occurrence of similar variations in the future. Here we present a high-resolution (82-μm) element record, obtained using Synchrotron Radiation X-ray Fluorescence, from the sediments of Toson Lake in the northeastern Tibetan Plateau. The record, which spans the last ∼1100 yr, exhibits variability on an annual to decadal scale. The results of principal component analysis of the element dataset indicates that the first three principal components reflect variations in detrital inputs (via runoff and possibly eolian activity), drought conditions and temperature variations, respectively. Spectral analysis of samples scores on these components reveals strong El Niño-Southern Oscillation (ENSO)-like variability at periods of 3–8 years which indicates that the regional climatic variability was effected by ENSO events over the last ∼1100 yr. On the centennial time scale, the element data and TOC record suggest a warm and dry climate during the Medieval Warm Period (MWP) and a cold and wet Little Ice Age (LIA). The early 20th century was a warm interval, and drier than the LIA but wetter than the MWP. [ABSTRACT FROM AUTHOR]