Sea ice concentration(SIC)is one of the most important indicators when monitoring climate changes in the polar region.With the development of the Chinese satellite technology,the Feng Yun(FY)series has been applied to...Sea ice concentration(SIC)is one of the most important indicators when monitoring climate changes in the polar region.With the development of the Chinese satellite technology,the Feng Yun(FY)series has been applied to retrieve the sea ice parameters in the polar region.In this paper,to improve the SIC retrieval accuracy from the passive microwave(PM)data of the Microwave Radiation Imager(MWRI)aboard on the Feng Yun-3 B(FY-3 B)Satellite,the dynamic tie-point(DT)Arctic Radiation and Turbulence Interaction Study(ARTIST)Sea Ice(ASI)(DT-ASI)SIC retrieval algorithm is applied and obtained Arctic SIC data for nearly 10 a(from November 18,2010 to August 19,2019).Also,by applying a land spillover correction scheme,the erroneous sea ice along coastlines in melt season is removed.The results of FY-3 B/DT-ASI are obviously improved compared to that of FY-3 B/NT2(NASA-Team2)in both SIC and sea ice extent(SIE),and are highly consistent with the results of similar products of AMSR2(Advanced Microwave Scanning Radiometer 2)/ASI and AMSR2/DT-ASI.Compared with the annual average SIC of FY-3 B/NT2,our result is reduced by 2.31%.The annual average SIE difference between the two FY-3 Bs is 1.65×10^(6) km^(2),of which the DT-ASI algorithm contributes 87.9%and the land spillover method contributes12.1%.We further select 58 MODIS(Moderate-resolution Imaging Spectroradiometer)cloud-free samples in the Arctic region and use the tie-point method to retrieve SIC to verify the accuracy of these SIC products.The root mean square difference(RMSD)and mean absolute difference(MAD)of the FY-3 B/DT-ASI and MODIS results are 17.2%and 12.7%,which is close to those of two AMSR2 products with 6.25 km resolution and decreased 8%and 7.2%compared with FY-3 B/NT2.Further,FY-3 B/DT-ASI has the most significant improvement where the SIC is lower than 60%.A high-quality SIC product can be obtained by using the DT-ASI algorithm and our work will be beneficial to promote the application of Feng Yun Satellite.展开更多
近年来,由于“北极放大”的气候效应,使得北极海冰变化受到了越来越多的关注。而作为海冰被动微波遥感的主要参数,海冰密集度SIC(Sea Ice Concentration)能够表征海冰的主要状态,可用于指导极区走航以及进行不同尺度的海冰变化研究。通...近年来,由于“北极放大”的气候效应,使得北极海冰变化受到了越来越多的关注。而作为海冰被动微波遥感的主要参数,海冰密集度SIC(Sea Ice Concentration)能够表征海冰的主要状态,可用于指导极区走航以及进行不同尺度的海冰变化研究。通过该参数还可以计算出海冰面积、海冰范围等信息,对极区冰情预测以及气候变化研究具有重要意义。本研究探讨了如何利用FY-3B/MWRI(FY-3B/MicroWave Radiometer Imager)较高分辨率通道数据来反演北极地区海冰密集度。基于ASI(ARTIST(Arctic Radiation and Turbulence Interaction STudy)Sea Ice)算法,本研究通过改进算法系点值的方法反演了北极地区海冰密集度,并将反演结果与MWRI海冰密集度产品进行了对比。首先利用Aqua/MODIS(Moderate Resolution Imaging Spectroradiometer)反射率数据获得的海冰密集度对二者进行了验证。结果表明,本研究选用的新系点值ASI算法在全部数据集范围内的平均偏差与MWRI海冰密集度产品相当,但标准偏差和均方根误差均较之明显降低,且在海冰密集度低于95%时精度远高于MWRI产品;然后将二者与不莱梅大学的SIC_UB(Sea Ice Concentration from University of Bremen)海冰密集度产品进行了对比,其中本研究反演海冰密集度与SIC_UB产品的平均偏差和标准偏差分别为3.3%和10.6%,低于MWRI产品与SIC_UB产品之间的5.9%和16.4%;最后,对本研究反演结果、MWRI产品、NSIDC/AMSR-E(National Snow and Ice Data Center/Advanced Microwave Scanning Radiometer-EOS)产品以及SIC_UB产品的日均海冰密集度和海冰面积、海冰范围进行了时间序列对比,结果表明本研究反演海冰密集度的数值在3种统计方式下均显著低于MWRI产品,且较之更接近NSIDC/AMSR-E和SIC_UB产品。本研究利用国产卫星亮温数据反演的北极地区海冰密集度具有较高空间分辨率和较高精度,有利于北极地区气候变化的长时间序列研究。展开更多
基金The National Key Research and Development Program of China under contract No.2016YFC1402704the National Natural Science Foundation of China under contract Nos 41941012 and 42076228the Guangdong Basic and Applied Basic Research Foundation under contract No.2019A1515110295。
文摘Sea ice concentration(SIC)is one of the most important indicators when monitoring climate changes in the polar region.With the development of the Chinese satellite technology,the Feng Yun(FY)series has been applied to retrieve the sea ice parameters in the polar region.In this paper,to improve the SIC retrieval accuracy from the passive microwave(PM)data of the Microwave Radiation Imager(MWRI)aboard on the Feng Yun-3 B(FY-3 B)Satellite,the dynamic tie-point(DT)Arctic Radiation and Turbulence Interaction Study(ARTIST)Sea Ice(ASI)(DT-ASI)SIC retrieval algorithm is applied and obtained Arctic SIC data for nearly 10 a(from November 18,2010 to August 19,2019).Also,by applying a land spillover correction scheme,the erroneous sea ice along coastlines in melt season is removed.The results of FY-3 B/DT-ASI are obviously improved compared to that of FY-3 B/NT2(NASA-Team2)in both SIC and sea ice extent(SIE),and are highly consistent with the results of similar products of AMSR2(Advanced Microwave Scanning Radiometer 2)/ASI and AMSR2/DT-ASI.Compared with the annual average SIC of FY-3 B/NT2,our result is reduced by 2.31%.The annual average SIE difference between the two FY-3 Bs is 1.65×10^(6) km^(2),of which the DT-ASI algorithm contributes 87.9%and the land spillover method contributes12.1%.We further select 58 MODIS(Moderate-resolution Imaging Spectroradiometer)cloud-free samples in the Arctic region and use the tie-point method to retrieve SIC to verify the accuracy of these SIC products.The root mean square difference(RMSD)and mean absolute difference(MAD)of the FY-3 B/DT-ASI and MODIS results are 17.2%and 12.7%,which is close to those of two AMSR2 products with 6.25 km resolution and decreased 8%and 7.2%compared with FY-3 B/NT2.Further,FY-3 B/DT-ASI has the most significant improvement where the SIC is lower than 60%.A high-quality SIC product can be obtained by using the DT-ASI algorithm and our work will be beneficial to promote the application of Feng Yun Satellite.
文摘近年来,由于“北极放大”的气候效应,使得北极海冰变化受到了越来越多的关注。而作为海冰被动微波遥感的主要参数,海冰密集度SIC(Sea Ice Concentration)能够表征海冰的主要状态,可用于指导极区走航以及进行不同尺度的海冰变化研究。通过该参数还可以计算出海冰面积、海冰范围等信息,对极区冰情预测以及气候变化研究具有重要意义。本研究探讨了如何利用FY-3B/MWRI(FY-3B/MicroWave Radiometer Imager)较高分辨率通道数据来反演北极地区海冰密集度。基于ASI(ARTIST(Arctic Radiation and Turbulence Interaction STudy)Sea Ice)算法,本研究通过改进算法系点值的方法反演了北极地区海冰密集度,并将反演结果与MWRI海冰密集度产品进行了对比。首先利用Aqua/MODIS(Moderate Resolution Imaging Spectroradiometer)反射率数据获得的海冰密集度对二者进行了验证。结果表明,本研究选用的新系点值ASI算法在全部数据集范围内的平均偏差与MWRI海冰密集度产品相当,但标准偏差和均方根误差均较之明显降低,且在海冰密集度低于95%时精度远高于MWRI产品;然后将二者与不莱梅大学的SIC_UB(Sea Ice Concentration from University of Bremen)海冰密集度产品进行了对比,其中本研究反演海冰密集度与SIC_UB产品的平均偏差和标准偏差分别为3.3%和10.6%,低于MWRI产品与SIC_UB产品之间的5.9%和16.4%;最后,对本研究反演结果、MWRI产品、NSIDC/AMSR-E(National Snow and Ice Data Center/Advanced Microwave Scanning Radiometer-EOS)产品以及SIC_UB产品的日均海冰密集度和海冰面积、海冰范围进行了时间序列对比,结果表明本研究反演海冰密集度的数值在3种统计方式下均显著低于MWRI产品,且较之更接近NSIDC/AMSR-E和SIC_UB产品。本研究利用国产卫星亮温数据反演的北极地区海冰密集度具有较高空间分辨率和较高精度,有利于北极地区气候变化的长时间序列研究。
