UsingtheNationalCenterforEnvironmentalPredictionreanalysisdataon1.0°×1.0°gridsanddatafromtheTropicalCycloneyearbook(2000),adiagnosticanalysisandnumericalsimulationwereperformedtoinvestigatethecharacteristicsandmechanismunderlyingtherapidweakeningoftyphoonXangsane.TheresultsshowthatasharpdeclineintheintensityoftyphoonXangsaneresultedfromitsmovementintothecoolseasurfacetemperatureareaintheEastChinaSea,theintrusionofcoldairfromthemainlandintothetyphoon,andarapidincreaseoftheverticalwindshearinthesurroundingenvironment.Animportantfactorthatledtothedemiseofthetyphoonwasasignificantdecreaseinthemoisturetransportintothetyphoon.Furthermore,theresultsofthenumericalsimulationandsensitivityexperimentsindicatethatseasurfacetemperaturelargelymodulatedtherapidweakeningoftyphoonXangsane.
