Atmospheric Water Cycle over the Tibetan Plateau as the

Due to the fact that the Tibetan Plateau (TP) has the highest total radiation in the world and is one of the extreme regions of the global super solar constant, it has formed a huge heat source that is "embedded" in the central atmosphere of the troposphere and can extend to the free atmosphere, surpassing the "hollow heat island" effect produced by any supercity cluster in the world. The "thermal forcing" of the two-step terrain from the Tibetan Plateau to the Loess Plateau can serve as a monsoon effect from an "amplified sea-land temperature difference", which has an unpredictable effect on the dynamic "driving" of changes in regional and even global atmospheric circulation systems. The TP is featured with the highest concentration of low cloud cover and the most active convective activity in Asia. This special turbulence-convection triggering mechanism provides a key energy driving source for the cloud water resources of the "Asian Water Tower". The unique "thermal forcing" and "two-step water pump" effect of the TP provide a dynamic mechanism for the strong "convergence" of water vapor flows from low latitude oceans and even across hemispheres. During active monsoons, the key influence area of the "large triangular sector" water vapor transport in the low latitude tropical ocean have become important water vapor source areas for the atmospheric water cycle of the "Asian water tower", and the source areas can be traced across the equator to the southern hemisphere. In summer, the cross-equatorial airflow in the southern and northern hemispheres is characterized with lower-level southward flow and upper-level northward flow. They occur in the equatorial regions corresponding to two major terrains respectively: East Asia (90E) and North America (90W). The extreme value areas of these two cross-equatorial reversed airflows coincide with the positions of the TP in Asia and the Rocky Mountains in North America respectively. From the perspective of planetary-scale circulation characteristics, it also confirms that the topographic features of the TP and the Rocky Mountains at different heights are responsible for the construction of the vertically latitudinal and meridional circulations across the hemispheres. The study evidences the crucial "window effect" of the TP in global energy and water vapor transport, manifesting the key role of thermal forcing in the energy and water cycle processes of the TP, namely the "Asian water tower". Significant correlation of the convective activity over the TP to the global stratospheric water vapor transport in the Antarctic and Arctic is identified, highlighting the linkage of the "three poles". The coupling mechanism of high-level divergence and low-level convergence driven by the heat source over the TP leads to a strong "convergence" effect of multi-scale water vapor transport over long distances on the TP, forming the thermal forcing and the "self-excited feedback" effect of energy and water cycle on the TP. The glaciers, snow, and lakes scattered on the "Roof of the World" store abundant water resources, which can to some extent serve as a "water tower storage pool". The TP maintains an important mutual feedback effect with the global atmospheric energy and water cycle processes. This land-ocean-cryosphere atmospheric energy and water exchange mechanism can depict a systematic image of multi-layer water cycle between the TP and the Earth''s atmosphere.