Central Asian Drying at 3.3 Ma Linked to Tropical Forcing?

Abstract

Abstract The processes controlling middle‐latitude environmental changes are poorly understood. Both high‐latitude ice sheets and tropical oceans can affect climate and environments in middle latitudes, but separating their relative contribution is challenging. Coincidence of intensive Northern Hemisphere glaciations and increased dust accumulation rates at ~2.7 Ma on the Chinese Loess Plateau and North Pacific Ocean is often used to indicate high latitudes' dominant role on middle‐latitude climate change. Here we present new and compile available evidence from the Qaidam Basin and the Tarim Basin of central Asia demonstrating a phase of drying at ~3.3 Ma. The drying is synchronous with proposed timing of closure of the Indonesian Seaway, which has been suggested to cause significant oceanic surface heat adjustments and corresponding decreased heat and moisture transport to middle/high latitudes. These new results suggest a tropical forcing of aridification for the late Pliocene central Asian environmental evolution.