40 11 2015 11 GeomaticsandInformationScienceofWuhanUniversity Vol.40No.11 Nov.2015 DOI:10.13203/j.whugis20150279 :1671-8860(2015)11-1467-06 CryoSat-2 1 12 1 2 1 1 430079 2 430079 : 以北极为研究区 使用 CryoSat-2 数据 利用现有海冰厚度卫星测高研究中 4 种主流算法 (Laxon03 算 法 Kurtz09 算法 Yi11 算法和 Laxon13 算法 ) 分别对北冰洋海冰厚度进行估算 并将估算结果与研究区 Ice- Bridge 机载激光测高冰厚数据进行了比较 探索各算法海冰厚度估算的差异 寻找最优的估算算法 为估算长 时序海冰厚度提供基础和参考结果表明 4 种算法估算的海冰厚度空间分布较为一致 但不同算法估算的 结果差异较大 可达 0.476m4 种算法估算结果大小依次为 Laxon03 算法 Yi11 算法 Laxon13 算法 Kurtz09 算法 4 种算法估算的平均海冰厚度差异 在北极波弗特海海域最大 其次是北极中心海域 格陵兰和挪威海 Laxon13 算法估算结果相对于 IceBridge 观测结果与其他算法相比 具有最小的平均偏差和均方根误差 是卫 星测高估算海冰厚度的最优算法 : 海冰厚度 卫星测高 最优算法 CryoSat-2IceBridge :P228.41P237.9 :A - [1] ( ) [2-15] ( [8] [16] 2003 : h i = ( ρ wh fi +ρ sh fs)/ ( ρ w -ρ ) (1) i ρ w ρ i ρ s [6-15] Laxon03 [6] Kurtz09 [9] Yi11 [11] Laxon13 [13] 4 4 ( ) CryoSat-2 4 Laxon03 (PP) IceBridge 1 ) h fi h fs Kurtz09 :2015-05-05 : (41301463) (20130141120009) (CHINARE2014-04-07) : E-mail:jqwhu12@163.com : E-mail:pxp@whu.edu.cn
1468 2015 11 Yi11 ( 50km Kurtz09 ( ) 2% ) AMSR-E W99 Laxon13 Laxon03 Yi11 W99 PP Laxon13 (SSD) W99 ( 1) Laxon03 ( W99) [17] (915kg m -3 1024kg m -3 ) 1 Tab.1 AlgorithmsandParametersAppliedinSeaIceThicknessEstimatedbySateliteAltimetry ( ρ i)/(kg m -3 ) (h fs ) ( ρ s) ( ρ w)/(kg m -3 ) Laxon03 ρ i= 915 hfs= hfs (W99) ρ s= ρ s (W99) ρw= 1024 Kurtz09 ρ i= 915 hfs= hfs (AMSR-E+W99) ρ s= 320kg m -3 ρw= 1024 Yi11 ρ i= 915 hfs= hfs (W99) ρ s= (W99) ρ s ρw= 1024 Laxon13 FYI: ρ i= 916.7 MYI: ρ i= 882.0 h fs= h fs (W99/2+W99) ρ s= ρ s (W99) ρw= 1024 [17] :h fs (W99) Warren h fs (AMSR-E+W99) AMSR-E Warren h fs (W99/2+W99) Warren Warren ρ s(w99) Warren ρ s (W99) [8] Warren FYI MYI 2 25km (ESA) 2011-03 CryoSat-2 (htp://www.esa.int/our Activ- ities/observing the Earth/The Living Planet Programme/Earth Explorers/CryoSat-2) ( (NSIDC) AMSR-E 1) (htp://nsidc.org/data/docs/daac/ae si12 12km tb sea ice and snow.gd.html) (BYU) QuikSCAT ASCAT (htp://podaac-opendap. jpl. nasa. gov/opendap/aldata/quikscat/pre- view/l3/byu scp/sea ice age/arctic/v1/) (NASA)2011-03 IceBridge (htp://icebridge.gsfc.nasa. gov/ page id=732) NASAIceBridge ATM Snow Radar 0.05m [18] (65 N ) [1131619] 3 4 CryoSat-2 ( 40 m) [18] [691113] Farrel IceBridge 3 (
40 11 : CryoSat-2 1469 CryoSat-2 ) 2 4 Laxon03 Kurtz09 0.476 m 4 (FYI) 0.713m ( 2)4 4 1 IceBridge 0.471 m (0.435 m) Fig.1 StudyAreaandIceBridgeSeaIceThickness (0.402m) ) IceBridge ( 25km IceBridge 2 4 Fig.2 SeaIceThicknessDistributionBasedonFourDiferentAlgorithms
1470 2015 11 2 Laxon03 3.131 m /m Kurtz09 3.040 myi11 Tab.2 ComparisonofSeaIceThicknessofArcticMajor SeaAreaRetrievedfrom FourAlgorithms/m Laxon03 3.403 0.570 2.853 0.498 3.318 0.781 Kurtz09 3.057 0.564 2.382 0.510 2.983 0.814 Yi11 3.374 0.576 2.768 0.504 3.230 0.791 Laxon13 2.968 0.548 2.416 0.540 2.916 0.809 Laxon13 3.107m 3.057m4 IceBridge (3.003m) Farrel IceBridge [18] Laxon13 IceBridge (0.191m) (0.252 m) 4 Ice- Bridge 3 IceBridge 134 4 3 4 IceBridge Fig.3 ComparisonofIceBridgeandCryoSat-2SeaIceThicknessBasedonFourAlgorithms 1)4 2)4 Laxon03 Yi11 Laxon13 Kurtz09 Laxon03 4 Kurtz09 0.476m
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1472 2015 11 ComparisonofSeaIceThicknessRetrievalAlgorithmsfrom CryoSat-2SateliteAltimeterData JI Qing 1 PANG Xiaoping 12 ZHAO Xi 12 CHENG Zian 1 1 ChineseAntarcticCenterofSurveyingand MappingWuhanUniversityWuhan430079China 2 KeyLaboratoryofPolarSurveyingand MappingNASGWuhan430079China Abstract:Seaicethicknessisanimportantparameterandindicatorofclimatechangesensitivetoeco- systeminpolarregions.foraccurateforecastingofclimatechangeseaicemassbalanceoceancir- culationandsea-atmosphereinteractionsitisrequiredtohavelongtermrecordsofseaicethickness. Satelitealtimetryprovideusefultechnologyforobtainingtimeseriesseaicethicknessinformationon hemisphericscale.sofarfourmainstreamalgorithmsbasedonsatelitealtimeterdatahavebeenused toestimateseaicethicknessefectively.diferentalgorithmsandparametervaluesasselectedbydif- ferentresearcherswilleadtoresultsunsuitableforcomparisonandlargeuncertainties.tosolvethis problemthisstudycomparedseaicethicknessoverthearcticresearcharearetrievedfromthesefour mainstreamalgorithmsbasedoncryosat-2satelitealtimeterdata.ourresultsdemonstratethat:(1) whencomparedtoeachothertheretrieved meanseaicethicknessestimatedfromthesefouralgo- rithmshavesimilarspatialdistributionbutwithlargerdiferenceinthevalueupto0.476 m(2) ticorgreenlandsea(4)thelaxon13algorithm wastheoptimalalgorithmwiththeminimumbias andrmse whencomparedtoicebridgeseaicethickness measurements.theseresultscanprovide usefulreferenceandbasisforfurtherstudytoimprovealgorithmssoastoquantifydynamicchanges ofseaicethicknessmoreaccurately. Keywords:seaicethicknesssatelitealtimeteroptimalalgorithmCryoSat-2IceBridge thesequenceofestimatedseaicethicknessforthearcticspatialaveragebasedonfouralgorithmsis Laxon03algorithmYi11algorithmLaxon13algorithmandKurtz09algorithm(3)thediferenceof themeanseaicethicknessfromthesefouralgorithmswashigherinbeaufortseathanincentralarc- Firstauthor:JIQingPhDspecializesinsatelitealtimetryanddatamodelanalysis.E-mail:jqwhu12@163.com Correspondingauthor:PANG XiaopingPhDprofessor.E-mail:pxp@whu.edu.cn Foundationsupport:TheNationalNaturalScienceFoundationofChinaNo.41301463theSpecializeResearchFundfortheDoctoral ProgramofHigherEducationofChinaNo.20130141120009thePolarEnvironmentComprehensiveInvestigationandAssessmentPro- grammesofchinano.chinare2014-04-07.