秋季巴伦支海海冰与中国京津冀地区2月气温变化的联系

Relationship between autumn sea ice in the Barents Sea and change of temperature in February in Beijing-Tianjin-Hebei region of China

利用中国京津冀地区94个气象台站气温观测资料以及美国国家环境预报中心和国家大气研究中心联合制作的再分析资料、美国国家海洋和大气管理局海冰密集度资料,采用经验正交函数分解、相关分析、回归分析、合成分析等方法,研究冬季气候变暖背景下近32 a中国京津冀地区Feb_(4-20)(2月4—20日)平均气温异常与前期秋季北极海冰异常的关系,探讨秋季巴伦支海海冰影响中国京津冀地区Feb_(4-20)气温的可能机制。结果表明:(1)1988/1989年冬季是中国京津冀地区冬季变暖的突变点,暖背景下Feb_(4-20)气温第一模态呈空间一致变化型,其时间系数年际变化特征明显;(2)秋季巴伦支海、喀拉海和东西伯利亚海关键区海冰密集度与中国京津冀地区Feb_(4-20)气温存在显著正相关,可作为Feb_(4-20)气温预测的前兆信号;(3)秋季巴伦支海关键区多(少)冰年,其冬季海冰也偏多(少),为持续冷(热)源,在欧亚大陆对流层中高层激发出负(正)位相的斯堪的纳维亚遥相关型分布,西伯利亚高压偏弱(强),欧亚中高纬近地面多为南(北)风异常,东亚114°E—119°E范围45°N附近为异常上升(下沉)气流,使得中国京津冀地区自地面至对流层顶Feb_(4-20)气温偏高(低),显著暖(冷)异常区随高度升高逐渐减小并向北倾斜。

Based on temperature observation data at 94 meteorological stations of Beijing-Tianjin-Hebei region of China,reanalysis data of National Center for Environmental Prediction/National Center for Atmospheric Research(NCEP/NCAR),sea ice concentration data of National Oceanic and Atmospheric Administration(NOAA),the relationship between average temperature anomaly from 4 to 20 February(Feb_(4-20))in Beijing-Tianjin-Hebei region of China under the background of winter climate warming from 1989 to 2020 and Arctic sea ice anomaly in previous autumn was analyzed by using empirical orthogonal function(EOF)decomposition and correlation,regression,synthesis analysis methods,etc.And on this basis,the possible influencing mechanism of autumn sea ice in the Barents Sea on Feb_(4-20) temperature anomaly in Beijing-Tianjin-Hebei region was investigated.The results are as follows:(1)The warming mutation of winter temperature in Beijing-Tianjin-Hebei region of China occurred in 1988/1989.The first mode of Feb_(4-20) temperature decomposed by EOF appeared the same anomaly in whole area from 1989 to 2020,and the inter-annual change characteristic of corresponding time coefficients was obvious.(2)The sea ice concentration in the key areas of the Barents Sea,Kara Sea and east Siberia Sea in autumn was significantly and positively correlated with Feb_(4-20) average temperature in Beijing-Tianjin-Hebei region of China,which could be used as a precursor signal of Feb_(4-20) temperature anomaly prediction.(3)When the sea ice was anomalous more(less)in the key areas of the Barents Sea in autumn,the sea ice was also more(less)in winter,the Barents Sea was a continuous cold(heat)source,the negative(positive)phase distribution of Scandinavian teleconnection was excited in middle and high layer of troposphere over Eurasia,the Siberian high was weaker(stronger),the anomalous southerly(northerly)wind dominated near surface in middle and high latitude of Eurasia,and the anomalous updraft(downdraft)controlled near 45°N over 114°E-119°E of East Asia,which were beneficial to Feb_(4-20) temperature abnormally high(low)from surface to tropopause in Beijing-Tianjin-Hebei region of China,and the significant warm(cold)anomalous area decreased and inclined to the north with the rise of height.