Dormant dune fields and ameliorative moisture conditions in the West Gobi Desert in East Asia during the Last Interglacial

Abstract

Arid and semiarid regions are environmentally vulnerable to global warming. Thus, studying their environmental history during warm periods (e.g., the Last Interglacial, LIG) is crucial for understanding their future changes too. The West Gobi Desert is a transitional zone influenced by the westerlies and the East Asian monsoon system. Therefore, the variation in atmospheric circulation profoundly affects its water vapor transport and landscape evolution. Due to the scarcity of continuous records, the moisture transport process remains ambiguous, which limits further research on paleolake evolution and aeolian activity. Here, we combine paleoclimate simulations from the Coupled Model Intercomparison Project 6 (CMIP6)-Paleoclimate Modeling Intercomparison Project 4 (PMIP4) and geological records to clarify the water vapor transport pathways and aeolian activity in the West Gobi Desert during the LIG, compared to the reference period (the piControl). Our results show that increased rainfall and meltwater were possible supplies for surface water during the LIG and were associated with enhanced East Asian summer monsoon and higher surface air temperatures. Concomitantly, weakening aeolian activity and dormant dune fields occurred in the West Gobi Desert, resulting from higher surface moisture content and weaker surface wind regimes associated with the weakening westerlies and East Asian winter monsoon. Notably, the limited weakening of aeolian activity that occurred in the LIG winter and spring was caused by weaker surface wind and deteriorating surface moisture conditions, while the significant dormancy of dune fields in the LIG summer and autumn was initiated by the combined effects of ameliorative surface moisture conditions and lower surface wind speed.