GeomaticsandInformationScienceofWuhanUniversity Vol.40No.11 Nov.2015 DOI: /j.whugis : (2015) CryoSat-2

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1 GeomaticsandInformationScienceofWuhanUniversity Vol.40No.11 Nov.2015 DOI: /j.whugis : (2015) CryoSat : 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 : : ( ) ( ) (CHINARE ) : [email protected] : [email protected]

2 Yi11 ( 50km Kurtz09 ( ) 2% ) AMSR-E W99 Laxon13 Laxon03 Yi11 W99 PP Laxon13 (SSD) W99 ( 1) Laxon03 ( W99) [17] (915kg m kg 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= MYI: ρ i= 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) CryoSat-2 (htp:// 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) IceBridge (htp://icebridge.gsfc.nasa. gov/ page id=732) NASAIceBridge ATM Snow Radar 0.05m [18] (65 N ) [ ] 3 4 CryoSat-2 ( 40 m) [18] [691113] Farrel IceBridge 3 (

40 11 : CryoSat-2 1469 CryoSat-2 ) 2 4 Laxon03 Kurtz09 0.

3 40 11 : CryoSat CryoSat-2 ) 2 4 Laxon03 Kurtz m 4 (FYI) 0.713m ( 2)4 4 1 IceBridge m (0.435 m) Fig.1 StudyAreaandIceBridgeSeaIceThickness (0.402m) ) IceBridge ( 25km IceBridge 2 4 Fig.2 SeaIceThicknessDistributionBasedonFourDiferentAlgorithms

4 Laxon m /m Kurtz myi11 Tab.2 ComparisonofSeaIceThicknessofArcticMajor SeaAreaRetrievedfrom FourAlgorithms/m Laxon Kurtz Yi Laxon Laxon m 3.057m4 IceBridge (3.003m) Farrel IceBridge [18] Laxon13 IceBridge (0.191m) (0.252 m) 4 Ice- Bridge 3 IceBridge IceBridge Fig.3 ComparisonofIceBridgeandCryoSat-2SeaIceThicknessBasedonFourAlgorithms 1)4 2)4 Laxon03 Yi11 Laxon13 Kurtz09 Laxon03 4 Kurtz m

5 40 11 : CryoSat )4 mationofseaicethicknessdistributionsthrough m thecombinationofsnow DepthandSateliteLaser AltimetryData [J].Journalof GeophysicalRe- search200914(c10):c )Laxon13 IceBridge [10]KurtzN TMarkusTCavalieriDJetal.Com- parisonoficesatdatawithairbornelaseraltime- ter Measurementsover ArcticSea-Ice[J].IEEE Transationson Geoscience and Remote Sensing (7): [11]YiDZwaly HJRobbinsJ W.ICESatObserva- IceBridge tionsofseasonalandinterannualvariationsofsea- IceFreeboardandEstimatedThicknessinthe Wed- delsea Antarctica ( ) [J].Annalsof Glaciology201152(9):43-51 [1] IPCC.ClimateChange2013:thePhysicalScience Basis [M/OL].htp:// wgl2013 [2] BourkeR HGarretRP.SeaIceThicknessDistri- butioninthearcticocean [J].Cold RegionsSci- enceand Technology198713: [3] HudsonR.AnnualMeasurementofSea-IceThick- nessusinganupward-lookingsonar[j].nature (6262): [4] ShimodaHEndohTMuramotoKetal.Obser- vationsofsea-iceconditionsintheantarcticcoast- alapplicationofremotesensingtotheestimation of Sea-Ice Thickness Distribution Region Using Ship-BoardVideoCameras [J].Antarctic Record (1): [5] HaasC.EvaluationofShip-BasedElectromagnetic- InductiveThickness MeasurementsofSummerSea- arctica[j].cold RegionsScienceand Technology :1-16 IceintheBelingshausenand AmundsenSeasAnt- [6] LaxonSPeacock NSmith D.HighInterannual VariabilityofSeaIceintheArcticRegion[J].Na- ture (6961): [7] KwokRZwaly H JYiD.ICESatObservations ofarcticseaice:a FirstLook [J].Geophysical Research Leters200431(16):L16401 [8] KwokRCunningham GF.ICESatoverArcticSea Ice:EstimationofSnow DepthandIce Thickness [J].Journalof GeophysicalResearch : C08010 [9] KurtzN TMarkusTCavalieriDJetal.Esti- [12] Kurtz N TMarkus T.Satelite Observationsof AntarcticSeaIceThicknessandVolume[J].Jour- nalof GeophysicalResearch:Oceans ( ) (C8):C08025 [13]LaxonS WGilesK ARidoutA Letal.Cryo- Sat-2 Estimates of Arctic SeaIce Thicknessand Volume[J].GeophysicalResearch Leters : [14]KernSKhvorostovsky KSkourup Hetal.A- bout Uncertaintiesin SeaIce Thickness Retrieval from Satelite Radar Altimetry:Resultsfrom the ESA-CCISeaIceECV ProjectRound RobinExer- cise[j].thecryosphere Discusions20148(2): dar-waveforminterpretation [J].TheCryosphere 20148(2): [15]RickerRHendricksSHelm Vetal.Sensitivity ofcryosat-2 ArcticSea-IceVolumeTrendsonRa- [16]KwokR.SateliteRemoteSensingofSea-IceThick- nessand Kinematics:A Review[J].Journalof Glaciology201056(200): [17] WarrenS GRigorR GUntersteiner Netal. Snow DepthonArcticSeaIce[J].Journalof Cli- mate199912(6): [18]FarrelSLKurtzNConnorL Netal.A First AssessmentofIcebridgeSnow andice Thickness DataoverArcticSeaIce[J].IEEE Transactionson Geoscienceand Remote Sensing (6): [19]SpreenGKernSStammerDetal.Fram Strait SeaIceVolumeExportEstimatedBetween2003and 2008from SateliteData[J].GeophysicalResearch Leters200936(19):L19502

6 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. [email protected] Correspondingauthor:PANG XiaopingPhDprofessor. [email protected] Foundationsupport:TheNationalNaturalScienceFoundationofChinaNo theSpecializeResearchFundfortheDoctoral ProgramofHigherEducationofChinaNo thePolarEnvironmentComprehensiveInvestigationandAssessmentPro- grammesofchinano.chinare

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