Sensitivity of East Asian climate to the progressive uplift and expansion of the Tibetan Plateau under the mid-Pliocene boundary conditions

Abstract

A global atmospheric general circulation model has been used to perform eleven idealized numerical experiments, i.e., TP00, TP10, · · · , TP100, corresponding to different percentages of the Tibetan Plateau altitude. The aim is to explore the sensitivity of East Asian climate to the uplift and expansion of the Tibetan Plateau under the reconstructed boundary conditions for the mid-Pliocene about 3 Ma ago. When the plateau is progressively uplifted, global annual surface temperature is gradually declined and statistically significant cooling signals emerge only in the Northern Hemisphere, especially over and around the Tibetan Plateau, with larger magnitudes over land than over the oceans. On the contrary, annual surface temperature rises notably over Central Asia and most parts of Africa, as well as over northeasternmost Eurasia in the experiments TP60 to TP100. Meanwhile, the plateau uplift also leads to annual precipitation augmentation over the Tibetan Plateau but a reduction in northern Asia, the Indian Peninsula, much of Central Asia, parts of western Asia and the southern portions of northeastern Europe. Additionally, it is found that an East Asian summer monsoon system similar to that of the present initially exists in the TP60 and is gradually intensified with the continued plateau uplift. At 850 hPa the plateau uplift induces an anomalous cyclonic circulation around the Tibetan Plateau in summertime and two anomalous westerly currents respectively located to the south and north of the Tibetan Plateau in wintertime. In the mid-troposphere, similarto-modern spatial pattern of summertime western North Pacific subtropical high is only exhibited in the experiments TP60 to TP100, and the East Asian trough is steadily deepened in response to the progressive uplift and expansion of the Tibetan Plateau.

Climate modelling study on mountain uplift and Asian monsoon evolution

“…Kitoh (2004) also found that there are significant changes in the East Asian climate when the mountain reached about 60% of the present elevation. Jiang et al (2008) confirmed the 60% criteria by a different climate model. Modulations of El Niño/Southern Oscillation (ENSO) by mountain uplift are investigated by Kitoh (2007), where model ENSO becomes systematically weaker, shorter and less periodic when the mountain height increases.…”

The impact of regional uplift of the Tibetan Plateau on the Asian monsoon climate

“…The elevation of the TP is assumed to increase linearly based on the present elevation, and this is referred to as plateau bulk uplift simulation. In such simulations, model results generally show that the uplift of the TP can induce, for instance, drier conditions in regions to the north and west of the TP, wetter conditions across the TP, and intensified Asian summer monsoon circulation and precipitation (Manabe and Terpstra, 1974;Ruddiman and Kutzbach, 1989;An et al, 2001;Liu and Yin, 2002;Jiang et al, 2008). However, this plateau bulk uplift simulation seems too simplistic when compared to the latest geological evidence of TP uplift, which suggests asynchronous uplifts across different regions of the TP (Tapponnier et al, 2001;Mulch and Chamberlain, 2006;Wang et al, 2014).…”

“…The climatic effect of TP uplift is also of interest among paleoclimate researchers (Manabe and Terpstra, 1974;Kutzbach et al, 1989;Ruddiman and Kutzbach, 1989;Ramstein et al, 1997;An et al, 2001;Liu and Yin, 2002;Abe et al, 2003;Kitoh, 2004;Zhang et al, 2007a,b;Jiang et al, 2008;Lunt et al, 2010). These studies show that the uplift of the TP plays an important role in the formation and development of Asian monsoon climate and inland aridity.…”

The Spatial and Temporal Variation of Temperature in the Qinghai-Xizang (Tibetan) Plateau during 1971–2015

“…The elevation of the principal part of TP is mainly over 4500 m. Therefore, the TP is also called the "Third Pole", and is sensitive to climate change. The thermal and dynamic processes over the TP also have great influence on the global climate change [15][16][17]. Many researches on the temperature variations over the TP have been done so far.…”