北大西洋涛动对我国冬季辽东湾海冰的影响

The impact of North Atlantic Oscillation on sea ice of China's Liaodong Bay

利用经验正交函数分析NCEP1月份海平面气压确认冬季NAO为主要模态,在高压区和低压区分别取三个点的平均分别代表高压区和低压区的平均气压,标准化处理后,用这两者的差来代表冬季NAO指数。对该指数进行功率谱分析得出冬季NAO不仅有2—3年、8年的年际变率,还有50—70年的年代际变率。冬季NAOI与我国辽东湾底两个测点的冰量呈负相关,相关系数都达到-0.7,在对我国辽东湾海冰的预报时,可将NAOI考虑进去。

The data of NCEP January sea level pressure was analyzed using the empirical orthogonal function to determine the first mode of NAO; three points were selected respectively from high pressure and low pressure areas,and the average pressure of the three points represents the average pressures of the high and low pressure zones respectively; the index of NAO was represented by the D-value of the two zone＇s averaged pressures after being standardized.Power spectrum analysis shows that the winter not only has NAO2-3a and 8 a＇s inter-annual variability,but also 50-70a＇s decadal variability.Strong negative correlation exists between winter NAOI and the total amount of sea ice in two sample stations of Liaodong Bay,the correlation coefficient reaches-0.7,which means that the NAOI should be taken into consideration during prediction of sea ice in that area.