【摘要】 近几十年来北极的增温幅度是全球平均的2倍以上,这种被称为"北极放大"的现象是全球气候变化的最显著特征之一。从北极局地气候反馈和北极外热输送2个方面总结了北极放大原因的最新进展。局地方面,海冰—反照率正反馈以及云和水汽增加导致的向下长波辐射增强是北极放大的重要原因,而较低的背景温度和相对稳定的大气层结使得温度反馈在北极为正,有利于变暖信号被放大。向极热输送方面,大气环流和洋流的输送作用对北极放大均有贡献,大西洋和太平洋海温的年代际变化和热带太平洋海温异常是驱动大气环流变化的主要原因。最后提出了尚需解决的关键问题。更多还原

【Abstract】 The pace of Arctic warming is about double that at lower latitudes in the recent decades,a robust phenomenon known as Arctic Amplification(AA),which has become one of the most notable features of climate change.This review summarized the major advances of the mechanism of AA from both local factors and poleward heat transport from lower latitudes.Local factors,including positive ice-albedo feedback and increasing downwelling longwave radiation caused by water vapor and cloud,play an important role in AA.Due to the colder background temperatures and the more stable vertical structure than the lower latitudes,the temperature feedback is therefore positive,which induces the warm signal amplified in the Arctic.The poleward heat transport via atmosphere circulation and ocean currents is also a contributor to AA,and the multidecadal variability in the Pacific,the Atlantic and the tropical Pacific surface temperature are the dominant forcing of the atmosphere circulation.Finally,several issues that remain to be solved were proposed.更多还原