We investigate winter Arctic Amplification (AA) on synoptic timescales and at regional scales using a daily version of the Arctic Amplification Index (AAI) and examine causes on a synoptic scale. The persistence, frequency and intensity of high AAI events show significant increases over the Arctic. Similarly, low AAI events are decreasing in frequency, persistence and intensity. In both cases, there are regional variations in these trends, in terms of significance and timing. Significant trends in increasing persistence, frequency and intensity of high AAI events in winter are concentrated in the period 2000–2009, with few significant trends before and after this. There are some decreases in sea-ice concentration in response to synoptic-scale AA events and these AA events can contribute to the decadal trends in AA found in other studies. A sectoral analysis of the Arctic indicates that in the Beaufort–Chukchi and East Siberian–Laptev Seas, synoptic scale high AAI events can be driven by tropical teleconnections while in other Arctic sectors, it is the intrusion of moisture-transporting synoptic cyclones into the Arctic that is most important in synoptic-scale AA. The presence of Rossby wave breaking during high AAI events is indicative of forcing from lower latitudes, modulated by variations in the jet stream. An important conclusion is that the increased persistence, frequency and intensity of synoptic-scale high AAI events make significant contributions to the interannual trend in AA.

我们使用每日版本的北极放大指数（AAI）在天气尺度和区域尺度上调查冬季北极放大（AA），并在天气尺度上检查原因。高AAI事件的持续性，频率和强度显示出北极地区的显着增加。同样，低AAI事件的频率，持续性和强度也在降低。在这两种情况下，就趋势和重要性而言，这些趋势都存在地区差异。2000-2009年期间，冬季持续高发性禽流感的持续性，频率和强度增加的显着趋势集中在2000-2009年期间，在此之前和之后几乎没有显着趋势。由于天气尺度的AA事件，海冰浓度有所降低，而这些AA事件可能会导致其他研究中AA的年代际趋势。北极的一个部门分析表明，在波弗特-楚科奇海和东西伯利亚-拉普捷夫海中，天气尺度的高AAI事件可能是由热带遥相关引起的，而在其他北极地区，这是水汽输送的天气气旋进入北极的入侵。在天气尺度的AA中最重要。在高AAI事件中出现Rossby波浪破碎表明存在受喷射流变化调制的较低纬度强迫。一个重要的结论是，天气尺度的高AAI事件持续性，频率和强度的增加，对AA年际趋势做出了重要贡献。在天气尺度的机管局中，最重要的是水分输送的天气旋风侵入北极。在高AAI事件中出现Rossby波浪破碎表明存在受喷射流变化调制的较低纬度强迫。一个重要的结论是，天气尺度的高AAI事件持续性，频率和强度的增加，对AA年际趋势做出了重要贡献。在天气尺度的机管局中，最重要的是水分输送的天气旋风侵入北极。在高AAI事件中出现Rossby波浪破碎表明存在受喷射流变化调制的较低纬度强迫。一个重要的结论是，天气尺度的高AAI事件持续性，频率和强度的增加，对AA的年际趋势做出了重要贡献。