2009年春夏季北极海冰运动及其变化监测

极地海冰对全球气候变化具有指示作用，北极海冰监测对全球气候环境变化研究意义重大。利用中国第3次北极科学考察（CHINARE-2008）长期冰站获取的海冰物质平衡浮标数据和MODIS影像对北极海冰运动及其变化进行监测。结果表明MODIS影像分类得到的海冰密集度效果较好，海冰与海水之间界线清晰。4月16日至30日长期冰站在自西北向东南的漂移过程中，海冰逐渐分裂，密集度下降，速度总体上不断减小。4月30日至5月19日期间海冰密集度变化比较大，尤其是5月8日，海冰密集度突然升高。结合对漂移轨迹的分析发现，这可能是受大风、洋流等因素影响，海冰产生回旋运动导致的。5月19日至7月6日海冰密集度上升，在格陵兰岛附近海冰运动受地形影响产生聚集现象，因此在该区域海冰密集度呈现上升趋势。

MONITORING THE MOTION OF ARCTIC SEA-ICE AND ITS CHANGES IN SUMMER AND WINTER 2009

The polar sea-ice has an indicative function on the global climate changes. Monitoring of the Arctic sea-ice is of great significance for the study of global climate environment changes. On the basis of IMB data which was acquired at the long-term ice station during the CHINARE-2008 and MODIS images, the Arctic sea-ice motion and changes were investigated. The results showed that better effect was gained while using MODIS images. The boundaries between water and ice were clear on the classified images. The sea-ice concentration decreased from 16 to 30 April. While the long-term ice station drifted from northwest to southeast, sea ice broke gradually. Sea-ice concentration dropped, and the speed of sea-ice continually decreased. During the period between 30 April and 19 May, the sea-ice concentration changed sharply. Especially on 8 May, it increased. According to the analysis of the track, rotations of the sea-ice introduced by strong wind and ocean current and so on, might result in the change. From 19 May to 6 July, the sea-ice concentration increased. There was a phenomenon of sea-ice gathering because of topography effect near the Greenland. So the sea-ice concentration showed a rising trend in this area.