南极海冰是极地气候系统的重要组成部分,对全球气候有着深远影响.海冰厚度作为海冰的关键属性之一,了解其时空分布特征和变化趋势对理解和预估气候变化进程具有重要意义.然而,目前对于南极海冰厚度的监测局限在时空分布有限的实地观测和短时间序列的卫星观测阶段,长时间序列的冰厚数据仍然缺失.针对这一问题,基于时空连续的卫星雷达高度计Envisat和CryoSat-2,构建了一致性较高的雷达干舷高度数据,定量估算了高度计雷达信号在积雪中的穿透深度,发展了一种适用于南极海冰的厚度遥感估算方法.估算的冰厚与Australian Antarctic Data Centre实测数据的平均绝对偏差约为0.28 m;与ICESat激光雷达高度计冰厚的平均绝对偏差约为0.65 m,相关系数为0.71,一致性较高.2002-2023年南极海冰厚度时空变化分析结果表明,厚冰主要分布于西威德尔海和别林斯高晋海/阿蒙森海,其他海域海冰相对较薄.南极海冰厚度在2011年之前呈现轻微降低趋势,在2011年后加速降低(-0.03m/a).南极海冰厚度的分布和变化趋势存在明显的季节和区域特征.
The estimation of Antarctic sea ice thickness from multi-source satellite radar altimeters
Antarctic sea ice is a crucial component of the polar climate system,with profound implications for glob-al climate.Sea ice thickness,as one of the key properties of sea ice,holds significant importance for understanding and predicting the influences of climate change by revealing its spatial and temporal distribution patterns and vari-ation trends.However,current monitoring of Antarctic sea ice thickness is constrained by limited ground observa-tions with restricted spatial and temporal coverage or short-term satellite observations,long-term sea ice thickness data remains elusive.To address this issue,this study utilized the continuous satellite radar altimetry data from En-visat and CryoSat-2 and constructed a consistent dataset of radar freeboard of Antarctic sea ice.Then,the penetra-tion depth of radar signals through the snow covers over Antarctic sea ice was quantitatively estimated,and a meth-od applicable to various sea ice-snow scenarios for estimating Antarctic sea ice thickness was developed.The estim-ated sea ice thickness shows an average absolute bias of approximately 0.28 m compared to in situ measurements from the Australian Antarctic Data Centre,and an average absolute bias of approximately 0.65 m compared to ICESat laser altimeter with a high correlation coefficient of 0.71.Analysis of the spatiotemporal variations of Ant-arctic sea ice thickness from 2002 to 2023 reveals that thick ice is predominantly concentrated in the western Wed-dell Sea and Bellingshuan/Amundsen Seas,while ice in other sea sectors is relatively thin.Antarctic sea ice thick-ness exhibited a slight decreasing trend before 2011,followed by an accelerated decline after 2011(-0.03 m/a).The distribution and trends of Antarctic sea ice thickness exhibit distinct seasonal and regional characteristics.
sea ice thicknesssea ice freeboardradar signal penetration depthradar altimetersAntarctica
万方数据
维普
