Impact of the uplift of the Central Asian Orogenic Belt and NE Tibetan Plateau on the East Asian climate since the late Miocene

Abstract

The uplift of the Central Asian Orogenic Belt (CAOB) and the northeastern (NE) Tibetan Plateau has exerted an important effect on the evolution of the East Asian climate since the late Miocene. However, previous modeling studies were generally based on modern boundary conditions, a direct comparison between the impacts of the uplift of the CAOB and NE Tibetan Plateau was still absent, and the climatic effects of the uplift of these mountains since the late Miocene remain ambiguous. Here, we use the Community Atmosphere Model version 4 (CAM4) with a high horizontal resolution (∼0.63° × 0.47°) combined with late Miocene boundary conditions to investigate the effects of the CAOB and NE Tibetan Plateau uplift on the East Asian climate since the late Miocene. The results indicate that the combined uplift of these landmasses increased the annual precipitation in the uplifted regions and eastern Asia, decreased the annual precipitation in central Asia, strengthened summer monsoon winds over northern East Asia, weakened winter monsoon winds over southern East Asia, and strengthened summer and winter high tropospheric westerly wind at northern high latitudes. Of the two uplifting landmasses, the uplift of the CAOB increased the summer precipitation and strengthened the summer high tropospheric westerly wind at higher latitudes and had a greater impact on the changes in winter monsoon winds and winter high tropospheric westerly wind. By comparison, the uplift of the NE Tibetan Plateau was also important in some aspects, such as the increased annual precipitation in eastern Asia. These results emphasized the important climate effects of the CAOB and NE Tibetan Plateau on the East Asian climate and improved our understanding of the dynamic link between orogenic evolution and paleoclimatic change since the late Miocene.