利用ICESat/GLAS数据获取北极海冰出水高度的研究

摘要

利用ICESat激光测高卫星数据获取2003-10～2008-03北冰洋秋季与冬季海冰出水高度,结果与国外相关研究基本一致.出水高度数据的拟合结果表明,北极海冰出水高度以每年约2.3 cm的速度递减,该速度比此前的相关研究结果更快.在不同作者利用ICESat数据计算的北极海冰出水高度的对比中,不同方法得到的结果之间存在明显的系统误差.对引起系统误差的原因进行深入分析表明,高程滤波的窗口长度、确定海面高的范围以及海面观测值的选取方式都会使出水高度的计算产生cm级的误差.%Arctic sea ice freeboards during autumns and winters between October 2003 and March 2008 are determined using ICESat laser altimetry data;the results are consistent with foreign research.Trends derived from freeboard results show a decline of about 2.3 cm each year,which is faster than suggested by previous research.Obvious systematic error is shown in the comparison of ICESat derived Arctic sea ice freeboards obtained by different author and methods.This systematic error is analyzed.The results show that the window size of height filtering,the range of sea surface height determination,and the method of sea surface observation filtering,all lead to biases of several centimeters in freeboard calculation.