The importance of solar insolation on the temperature variations for the past 110 kyr on the Chinese Loess Plateau

Abstract

The late Quaternary temperature history on the Chinese Loess Plateau (CLP) is little known due to the absence of suitable paleothermometers. Here, we present a quantitative temperature record for the last 110kyr from Lantian county, southern CLP, based on the distributions of bacterial tetraethers. Lantian loess temperature variations display significant correlation with the Northern Hemisphere insolation (35°N) as well as the cave monsoon records at the precession band. We attribute such correlation to both the latent heat release from the East Asian summer monsoon and the direct influence of Sun's sensible heat over the semi-arid landscape. The long term cooling during the Marine Isotope Stage (MIS) 3 and the modest temperature drop of ~5°C from 79 to 65ka are best explained by interactions among multiple climate forcings including insolation, atmospheric CO2 concentration, global ice volume, and regional glacier activities. The cold and modestly wet climate during MIS 3 may have promoted maximum regional glacial advances, whereas the minimal temperature during local LGM reduced moisture transfer and led to glacial recession. The unusually early deglacial warming at ~22.5ka highlights the importance of regional climate records to decipher the complex continental climate dynamics.