The quantitative reconstruction of the palaeoclimate between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China

Abstract. The quantitative reconstruction of the palaeoclimate is a prerequisite for understanding climate processes at time scales of centuries and millennia. Here, the coexistence approach (CA) was applied to reconstruct climatic factors quantitatively based on the fossil charcoal records between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China. The CA analysis showed that the climate of the Tianshui Basin belonged to the northern subtropical zone between 5200 and 4300 cal yr BP. The mean annual temperature (MAT) was approximately 13.2 °C, and the mean annual precipitation (MAP) was approximately 778 mm between 5200 and 4900 cal yr BP. The MAT was approximately 13.2 °C, and the MAP was approximately 688 mm between 4800 and 4300 cal yr BP. The MAT was approximately 2.2 °C higher than today, and the MAP was approximately 280 mm higher than today from 5200 to 4900 cal yr BP. The MAT was also approximately 2.2 °C higher than today from 4800 to 4300 cal yr BP, while the MAP was approximately 196 mm higher than today. No abrupt cold event occurred between 5200 and 4300 cal yr BP; however, a drought tendency appeared after around 4800 cal yr BP.