近半个多世纪以来渤海冰情对全球气候变化的响应

Response of the Sea Ice Conditions in the Bohai Sea to Global Climate Change in the Last over Half Century

渤海是季节性的结冰海域,属于北半球结冰海区的南边缘,其冰情状况是对大气场和海洋场共同作用的响应。1951—2004年渤海海冰冰级与中国大陆气温距平具有很强的负相关性,渤海海冰状况是对我国北方地区、尤其是对华北地区的中短期气候变化的响应。从20世纪50年代至90年代,海冰偏轻年数逐年代增加,同时海冰平均等级也逐渐降低,是对全球气候变暖的响应。渤海重冰年出现的周期大约为10a,与太阳黑子活动周期很接近,反映太阳活动对渤海冰情具有相当大的影响,尤其是极值事件。分析表明,渤海冰情与厄尔尼诺事件之间不存在显著的线性关系,厄尔尼诺不是渤海冰情变化的原因,相反,渤海冰情的加重,预示着厄尔尼诺的来临。

The Bohai Sea is the seasonal icing sea and belongs to the south margin of the icing sea area in the Northern Hemisphere; its ice condition is the response to the conjunct actions of the atmospheric circulation and the oceanic field. There is a high negative correlation between the ice condition in the Bohai Sea and anomalies of surface air temperature in Chinese Mainland from 1951 to 2004. Changes of the ice condition are the responses to the climate changes in short and medium term scale in the north of China, especially in North China. From 1950s to 1990s, the years with mild ice had increased gradually with decades, in the in the meantime the ice grade becomes lower and lower in the Bohai Sea, which is related to the tendency of the global warming. The year of severe ice appears about every 10 years, which approaches the cycle of the sunspot, and the solar activity has great influence on the ice condition variation of the Bohai Sea, especially on extreme events. The research in this article shows that there is not a distinct linear correlation between the ice conditions and E1-Nino events, so the E1-Nino event is not the causation for the changes of the Bohai Sea ice condition, to the contrary, the ice condition becoming severe implies the coming of the E1-Nino event.