A westerly-dominated climate in Arid Central Asia during the Holocene revealed by ostracods from Bosten Lake in Xinjiang, China

Abstract

The westerlies, a major atmospheric circulation system, have a crucial role in driving climate and environmental changes in the middle latitudes of the Northern Hemisphere, particularly in arid Central Asia (ACA). However, the influence of variations in the westerlies on biota remains elusive due to less sedimentary archives. Here, we focus on Holocene ostracods from a core in the Bosten Lake in Xinjiang of the ACA area. We conducted a comparative analysis of our ostracod records, including radiocarbon dating results, with ostracod and salinity records from other cores within Bosten Lake, and suggested that alternative ostracod assemblages can serve as indicators of salinity changes in the lake over the past 8,000 years, which corresponded to westerlies dynamics. We propose that over the course of 8,000 years, precipitation patterns in the Bosten Lake region were influenced by intensified westerlies, which were associated with high sea surface temperatures (SSTs) in the North Atlantic. This climatic shift, in turn, led to changes in the local ostracod communities.