Abstract~In recent decades, Antarctic ice sheet/shelf melting has been accelerated, releasing freshwater into the Southern Ocean. It has been suggested that the meltwater~flux could lead to cooling in the Southern Hemisphere, which would retard global warming and further induce a northward shift of the Intertropical Convergence Zone (ITCZ). In this study, we use experimental ensemble climate simulations to show that Antarctic meltwater forcing has distinct regional climate impacts over the globe, leading in particular to regional warming in East Asia, which offsets the global cooling effect by the meltwater forcing. It is suggested that Antarctic meltwater forcing leads to a negative precipitation anomaly in the Western North Pacific (WNP) via cooling in the tropics and the northward shift of the ITCZ. This suppressed convection in WNP induces an anticyclonic~flow over the North Pacific, which leads to regional warming in East Asia. This hypothesis is supported by analyses of interensemble spread and long-term control simulations.
Plain Language Summary~In recent decades, greenhouse warming has accelerated the melting of Antarctic glaciers, which discharges freshwater into the Southern Ocean and therefore reduces the surface density. Surface freshening in the Southern Ocean induces cooling and sea ice expansion on the surface, such that it could delay global warming and further lead to a northward shift of the
Intertropical Convergence Zone (ITCZ). Here, we examine the distinct regional impacts of Antarctic meltwater forcing over the globe by analyzing experiments with and without meltwater forcing. For example, the Antarctic meltwater forcing induces a global cooling but leads to regional warming in East Asia. We~find that Antarctic meltwater forcing leads to reduced convection in the Western North Pacific (WNP) due to the northward shift of the ITCZ and an overall cooling in the tropics. This circulation change in WNP induces regional warming in East Asia via atmospheric teleconnection.
}, year = {2020}, journal = {Geophysical Research Letters}, volume = {47}, url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020GL089951?casa_token=OOKYzoXqiXsAAAAA\%3AR9I95RBQKpVoOu52YDez88S36BRKvLQVLQzGR_R-kercvsoa4Ev9M0lKkk21DiEjilY2CXSDwdt3ZCAt}, language = {eng}, }