L波段微波辐射传输模型可以模拟微波辐射信号在北极冰雪内的物理传播过程,是北极冰面雪厚反演的有效手段.然而当前可用于北极海冰积雪上L波段亮温模拟的模型非常有限,极大地限制了基于L波段微波辐射传输模型的雪厚反演算法的发展.2018年由欧空局赞助开发的积雪微波辐射传输模型(Snow Microwave Radiative Transfer model,SMRT)已被证实可以用于北极海冰积雪上的L波段亮温模拟,但还未有研究利用该模型进行北极雪厚反演.为此,文章利用2018年开发的新一代积雪微波辐射传输模型SMRT,开展了基于L波段辐射传输模型的北极多年冰上雪厚反演研究.文章首先在SMRT模型基础上改进了积雪隔热效应计算这一前向模拟关键过程,简化计算的同时提高了模拟的准确性.然后选取L波段模型结合雷达高度计的雪厚反演算法展开研究,利用该算法对改进模拟过程的SMRT模型进行了雪厚敏感性分析,验证了 SMRT改进模型应用于多年冰上雪厚反演的可行性.最后对2012年11月至2021年4月期间每年1-3月的月平均雪厚进行了反演,反演结果与雪厚数据集的对比分析表明,反演结果能较好地得到北极多年冰上雪厚分布.并利用2013-2015年OIB(Operation Ice Bridge)实测雪厚进行了准确性印证,反演结果与OIB实测雪厚的一致性较好,二者的均方根误差RMSE为0.07m,说明了基于SMRT模型的多年冰上雪厚反演算法的有效性.
Retrieval of Snow Depth in Arctic Multi-year Ice Based on SMRT Model
The L-band microwave radiative transfer model can simulate the physical propagation process of microwave radiation signals in the Arctic ice and snow,and serves as an effective tool to invert the snow thickness of the Arctic ice.However,at present,the models available for L-band brightness temperature simulation over Arctic sea ice and snow cover are scarce,which greatly limits the development of snow depth retrieval algorithms based on L-band microwave radiative transfer models.The Snow Microwave Radiative Transfer model(SMRT),developed under the sponsorship of ESA in 2018,has been proved to be suitable for L-band brightness temperature simulation on Arctic sea ice and snow,but there is no research using this model for Arctic snow depth.Therefore,in this paper,a new generation of microwave radiative transfer model of snow,SMRT,developed in 2018,is used to carry out the retrieval research of multi-year ice snow depth in the Arctic based on the L-band radiative transfer model.Based on the SMRT model,the key process of forward simulation is improved to simplify the calculation and improve the accuracy of the simulation.Then the L-band model combined with the snow depth retrieval algorithm of radar altimeter is selected to carry out research,and the snow depth sensi-tivity of the SMRT model with improved simulation process is analyzed by using this algorithm,and the feasibility of applying the improved SMRT model to the multi-year ice snow depth re-trieval is verified.At last,the average monthly snow depth in January to March of each year from November 2012 to April 2021 is inverted.The comparison between the retrieval results and the snow depth dataset shows that the retrieval results can better capture the snow depth distribution on the Arctic ice.The accuracy of the snow depth measured by Operation Ice Bridge(OIB)from 2013 to 2015 is verified.The retrieval results are in good agreement with the snow depth measured by OIB,and the Root Mean Square Error(RMSE)for both is 0.07m,indicating the validity of the multi-year ice snow depth retrieve algorithm based on SMRT model.
ArcticSnow depth retrievalMicrowave radiative transfer modelL-band brightness temperature
万方数据
维普
