基于CryoSat-2测高数据的北极格陵兰海海冰干舷高提取研究

ESTIMATION OF SEA ICE FREEBOARD FROM CRYOSAT-2 DATA IN THE ARCTIC GREENLAND SEA

北极是全球气候和环境变化的驱动器之一,获取北极海冰的时空特征和变化规律对研究北极以及全球气候变化意义重大。格陵兰海是北极海冰剧烈变化的区域之一,采用CryoSat-2的雷达测高数据,获取了格陵兰海的海冰干舷高分布,并利用波弗特环流计划(BGEP)仰视声呐(ULS)数据进行了验证。研究结果表明,格陵兰海海冰干舷高和分布范围存在明显的季节性变化特征,具体体现在格陵兰海海冰从10月份进入冻结期开始,海冰分布范围不断扩张,海冰干舷高也逐渐增大,2月份平均干舷高达到最大(0.2 m),之后格陵兰海海冰开始消融,覆盖范围不断内缩,9月海冰干舷高降至最小(0.13 m)。

The Arctic region has an important role in global climate, and changes in Arctic sea ice represent one of the most visible consequences of climate change. The Greenland Sea is one of the areas of the Arctic that have undergone drastic changes. In this study, Cryo Sat-2 radar altimeter data were used to retrieve the distribution of sea ice freeboard in the Greenland Sea. The sea ice thicknesses converted from the freeboard were validated using the Beaufort Gyre Experiment Program upward-looking sonar data. The results showed that both the freeboard and the extent of sea ice in the Greenland Sea have remarkable seasonal variations. It was found that the freeboard and extent of the sea ice kept increasing after the Greenland Sea had entered the frozen season in October. The average sea ice freeboard reached a maximum of 0.2 m by February. Then, the sea ice began to melt, and as the sea ice extent continued to decrease, the sea ice freeboard reached a minimum of 0.13 m by September.