hide
Free keywords:
-
Abstract:
In recent decades, some researches show that various tropical sea surface temperature variability contributes to Antarctic climate change, especially the sea ice there. On seasonal to interdecadal time scales, atmosphere teleconnections arise from three tropical ocean basins, including the El Niño-Southern Oscillation, the Madden-Julian Oscillation, the Indian Ocean Dipole/Basin Mode, the Atlantic Meridional Mode, the Interdecadal Pacific Oscillation and the Atlantic Multidecadal Oscillation, are thought to have an impact on Antarctic sea ice via different mechanisms. However, the specific processes of some teleconnections are still unclear. In particular, there’s a lack of quantitative simulation of the impact of tropical teleconnections on Antarctic sea ice. Moreover, the relative impact of AMO and IPO on Antarctic circulation and sea ice over different time periods has yet to be clearly discussed. Here, using a hierarchy of numerical models with different levels of complexity, we directly and quantitatively simulate the anomalous response of Antarctic sea ice to different specific tropical basin forcings, results show that since 1979, the tropical Atlantic Ocean has made the greatest contribution to the dipole-like multidecadal trend of the west Antarctic sea ice, the variation of SIC can reach about 10%. Meanwhile, the atmospheric model simulation shows that before 2000, AMO dominated the deepening of ASL and the corresponding sea ice variability in austral winter, but after 2000, although the specific location of the low pressure anomaly was slightly different, +AMO and -IPO jointly contributed to the continuous deepening of ASL in austral winter.
