| 王宏,周晓,黄菲.大气环流优势模态对北极海冰变化的响应Ⅰ.北极涛动[J].海洋学报,2015,37(11):57-67 |
| 大气环流优势模态对北极海冰变化的响应Ⅰ.北极涛动 |
| Response of dominant mode for atmospheric circulation in northernhemisphere to the accelerated decline of Arctic sea ice:I.the Arctic Oscillation |
| 投稿时间：2015-04-15 |
| DOI：10.3969/j.issn.0253-4193.2015.11.006 |
| 中文关键词: 北极海冰 北极涛动 大气环流 年际振荡 年代际差异 |
| 英文关键词:Arctic sea ice Arctic Oscillation atmospheric circulation interannual variability decadal changes |
| 基金项目:全球变化研究国家重大科学研究计划项目(2015CB953904,2012CB955604);国家自然科学基金委员会-山东省人民政府联合资助海洋科学研究中心项目(U1406401)。 |
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| 中文摘要: |
| 利用美国冰雪中心海冰密集度数据,分析了1979-2012年北极海冰面积的时间变化特征,发现北极海冰具有显著的年代际变化特征,分别在1997和2007年前后存在两次年代际转型突变点,相应的大气环流优势模态——北极涛动(AO)也存在显著的时空变化。1979-1996年阶段海冰下降趋势较弱并以较强的年际振荡为主,AO模态较强且显示出低频振荡特征;1997-2006年阶段北极海冰快速减退趋势占优,同时伴随着较弱的年际振荡,AO模态减弱且振荡周期缩短;2007-2012年阶段海冰范围较快下降同时具有极强的年际振荡,方差变化是前两个阶段的2~3倍,AO不仅强度加强,空间结构也发生了变化,极涡中心分别向格陵兰岛和白令海峡一侧延伸,这种结构有利于极地冷空气入侵欧洲和北美。利用ECHAM5大气模式进行的数值试验结果也证实了较强振荡的海冰强迫对AO模态的改变具有决定作用。 |
| 英文摘要: |
| Based on the data of Arctic sea ice concentration from National Snow and Ice Data Center (NSIDC), the variability of Arctic sea ice extent (SIE) from 1979 to 2012 has been analyzed. The result shows that the changes of Arctic SIE had two decadal shift points in 1997 and 2007 respectively, and experienced three different periods: during 1979-1996, the SIE is downtrend and with strong interannual variability. Arctic Oscillation(AO) is in its strong phase and has low frequency oscillation; during 1997-2006, the interannual variability of SIE is weak but the linear downtrend is strongest. The strength of AO is weakened and AO has shorter period oscillation; during 2007-2012, the sea ice experienced a strongest interannual variability and slower downtrend than in 1997-2006. The interannual variability of AO is stronger that induces two negative anomaly centers move toward Greenland north Atlantic and stretch to Bering Strait, respectively. This pattern is conducive to transport the cold air to the North America and Europe. Experiments with ECHAM5 atmospheric circulation model proved that the strong interannual variability of sea ice is the key for the changes of AO mode for 2007-2012 period. |
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