简介：Theroleofwintersea-iceintheLabradorSeaasaprecursorforprecipitationanomaliesoversoutheasternNorthAmericaandWesternEuropeinthefollowingspringisinvestigated.Ingeneralterms,astheseaiceincreases,theprecipitationalsoincreases.Inmoredetail,however,analysesindicatethatboththewintersea-iceandtheseasurfacetemperature（SST）anomaliesrelatedtoincreasesinwintersea-iceintheLabradorSeacanpersistintothefollowingspring.Thesefeaturesplayaforcingroleinthespringatmosphere,whichmaybethephysicalmechanismbehindtheobservationalrelationshipbetweenthewintersea-iceandspringprecipitationanomalies.TheoceanicforcingsinspringincludeArcticsea-iceanomaliesandSSTanomaliesinthetropicalPacificandhigh-latitudeNorthAtlantic.Multi-modelCoupledModelIntercomparisonProjectPhase5andAtmosphericModelIntercomparisonProjectsimulationresultsshowthattheatmosphericcirculationresponsetothecombinationofsea-iceandSSTissimilartothatobserved,whichsuggeststhattheoceanicforcingsareindeedthephysicalreasonfortheenhancedspringprecipitation.SensitivityexperimentsconductedusinganatmosphericgeneralcirculationmodelindicatethattheincreasesinprecipitationoversoutheasternNorthAmericaaremainlyattributabletotheeffectoftheSSTanomalies,whiletheincreasesoverWesternEuropearemainlyduetothesea-iceanomalies.AlthoughmodelsimulationsrevealthattheSSTanomaliesplaytheprimaryroleintheprecipitationanomaliesoversoutheasternNorthAmerica,theobservationalstatisticalanalysesindicatethattheareaofsea-iceintheLabradorSeaseemstobetheprecursorthatbestpredictsthespringprecipitationanomaly.