Surface energy budget diagnosis reveals possible mechanism for the different warming rate among Earth’s three poles in recent decades

With the introduction of the‘‘Third Pole'[1],the Arctic,Antarctic,and Tibetan Plateau(TP)can be collectively referred to as the‘‘three poles of the Earth'.The cryosphere is an important component of the climate system because of its effect on Earth’s surface albedo and its role in reducing the amount of heat exchanged between the atmosphere and ocean or land(2)As the dominant parts of the cryosphere,the Arctic,Antarctic,and TP are pivotal and sensitive areas of global climate change.Global warming will weaken the inherent stability of the cryosphere,such as its ice shelves,glaciers and permafrost[3,4].

Co-varying temperatures at 200 hPa over the Earth’s three poles

The Earth’s three poles,the North Pole,South Pole,and Third Pole(i.e.,the Tibetan Plateau and its surroundings),hold the largest amount of fresh water on Earth as glaciers,sea ice,and snow.They are sensitive to climate change.However,the linkages between climate variations of the three poles,particularly between the South Pole and Third Pole,remain largely unknown.The temperatures at 200 hPa over the three poles are the highest in the summer and are less affected by surface conditions,which could reflect large-scale dynamic linkages.Temperatures at 200 hPa peak the three poles during their respective hemispheric summer and exhibit in-phase variations on interdecadal timescales(10–100 years).The 200 hPa temperatures over the North Pole and South Pole were significantly correlated with the Brewer-Dobson circulation(BDC),which transports stratospheric ozone poleward,heating the air at 200 hPa.Tropopause warming over the Third Pole was found to enhance the poleward BDC,particularly to the South Pole,linking the Third Pole’s climate to the other two poles.Additionally,the Interdecadal Pacific Oscillation(IPO)also exhibits links with the 200 hPa temperatures of the three poles.

Climate change:Impact on the Arctic,Antarctic and Tibetan Plateau

The Arctic, Antarctic and Tibetan Plateau are very sensitive to global climate change. Hence, it is urgent that we improve our understanding ot＇ how they respond to climate change, and how those responses in turn affect both regional and global climate. Against a background of current global warming, the three poles display climate diversities temporarily and spatially, which to different degrees affect the weather and climate over China. Enhanced monitoring of climate change in these three areas, as well as connected work on the responses and feedbacks of the three regions to climate change, will provide necessary support for adaptation and the sustainable development of the Chinese economy.