1.Shizuishan Meteorological Bureau,Ningxia Hui Autonomous Region 753000;2.China
作为一个可以对全球范围气候变化产生影响的重要参照物理量，北极海冰发生任何细 微的变化都会对局地乃至更大尺度的气候产生重要影响。由于北极地区环境恶劣，测站稀缺，地面观测资料较为缺乏，而卫星观测资料的范围可以覆盖全球，这在很大程度上弥补了北极地区观测资料不足的问题。本文主要基于1979~2020年美国冰雪数据中心海冰密集度反演资料和ERA-Interim再分析资料，利用集合经验模态分解方法对这段时间的海冰和大气风压场变化进行了分析。结果显示：（1）海冰覆盖面积范围近四十年来整体呈现出缩减的趋势，缩减速率约为：1.4×10^3 km^2/(10yr)。其中，巴伦支海和喀拉海海域的海冰密集度下降趋势最为显著。同时，海冰覆盖面积在9月夏季达最小值，在3月冬季达最大值。（2）在1979年至2014年间，极地海平面气压场在北极中心呈减少趋势，北极外部呈增加趋势，其空间分布特征与北极涛动正位相的空间分布特征相似。同时自大西洋吹向巴伦支海海域的地面风明显增强，考虑表层风场对于海表洋流以及海冰的拖曳作用等，进而推测来自大西洋温暖海水在巴伦支海海域将有所增多，从而可能造成该区域海冰消融。
As an important reference physical quantity that can have an impact on global climate change, any slight change in Arctic sea ice will have an important impact on the local and even larger-scale climate.Due to the harsh environment in the Arctic region, the station is scarce, and the ground observation data is relatively lacking. The scope of satellite observation data covers the whole world, which largely makes up for the lack of observation data in the Arctic region. Based on the inversion data of sea ice concentration from the US Snow and Ice Data Center and the ERA-Interim reanalysis data from 1979 to 2020, this paper make use of the ensemble empirical mode decomposition method to analyze the changes of sea ice and atmospheric wind pressure during this period. The results show that: (1) The area of sea ice coverage has shown a decreasing trend in the past 40 years, and the decreasing rate is about 1.4×10^3 km^2/(10yr). Among them, the decreasing trend of sea ice concentration in the Barents Sea and Kara Sea is the most significant. At the same time, sea ice coverage reaches a minimum in the summer of September and a maximum in the winter of March. (2) From 1979 to 2014, the polar sea level pressure field showed a decreasing trend in the center of the Arctic and an increasing trend outside the Arctic, and its spatial distribution characteristics were similar to those of the positive phase of the Arctic Oscillation. At the same time, the surface wind blowing from the Atlantic Ocean to the Barents Sea has increased significantly. Considering the dragging effect of the surface wind field on the surface current and sea ice, it is speculated that the warm water from the Atlantic Ocean will increase in the Barents Sea. May cause sea ice to melt in the area.