Dry or humid? Mid-Holocene humidity changes in arid and semi-arid China

Spatial changes of effective moisture during the mid-Holocene have been reconstructed based on the compilation of recently published paleoclimate records, including ice core, lake level, pollen assemblage, and loess-paleosol records. Both geological data and the spatial pattern indicate that it was dry in deserts during the mid-Holocene, but the timing of the beginning and end of dry intervals differs from place to place. Deserts having higher aridity index values remain dry longer. Dry intervals during the mid-Holocene are more possibly asynchronous than synchronous in and and semi-arid China. In the Xinjiang region, except in sites located in deserts, the climate is generally wet during 7000-5000a BP. In the northern Qinghai-Tibetan Plateau, effective moisture in most sites began to decrease after 5000a BP. The climate became dry after 4000a BP except in the deserts in the Loess Plateau and the Inner Mongolia Plateau. (c) 2005 Elsevier Ltd. All rights reserved.