简介：Therelationshipbetweenthetropicalintra-seasonaloscillation(ISO)andtropicalcyclones(TCs)activitiesovertheSouthChinaSea(SCS)isinvestigatedbyutilizingtheNationalCentersforEnvironmentalPrediction/NationalCenterforAtmosphericResearch(NCEP/NCAR)globalreanalysisdataandtropicalcyclonebest-trackdatafrom1949to2009.Themainconclusionsare:(1)AnewISOindexisdesignedtodescribethetropicalISOactivityovertheSCS,whichcansimplyexpressISOforSCS.AfterexaminingtheapplicabilityoftheindexconstructedbytheClimatePredictionCenter(CPC),wefindthattheconvectionspatialscalereflectedbythisindexistoolargetocharacterizethesmall-scaleSCSandfailstodividetheTCsactivitiesovertheSCSintoactiveandinactivecategories.Consequently,theCPCindexcan’treplacethefunctionofthenewISOindex;(2)TheeastwardspreadprocessoftropicalISOisdividedintoeightphasesusingthenewISOindex,thephasevariationofwhichcorrespondswellwiththeTCsactivitiesovertheSCS.TCsgenerationandlandingaresignificantlyreducedduringinactiveperiod(phase4-6)relativetothatduringactiveperiod(phase7-3);(3)ThecompositeanalysesindicatedistinctTCsactivitiesovertheSCS,whichisconsistentwiththeconcomitantpropagationoftheISOconvectiveactivity.DuringISOactiveperiod,theweathersituationsarefavorableforTCsdevelopmentovertheSCS,e.g.,strongconvection,cyclonicshearandweaksubtropicalhigh,andviceversa;(4)Thecondensationheatingcenters,strongconvectionandwatervaporfluxdivergencearewellcollocatedwitheachotherduringISOactiveperiod.Inaddition,theverticalprofileofcondensationheatindicatesstrongascendingmotionandmiddle-levelheatingovertheSCSduringactiveperiod,andviceversa.Thus,theeastwardpropagationoftropicalISOiscapabletomodulateTCsactivitiesbyaffectingtheheatingconfigurationovertheSCS.

简介：在广播电视数字化、网络化和频道专业化的背景下，今天的气象广播业在全球迅猛发展，专门的栏目甚至专业气象电台和电视频道的建立都成为可能并陆续实现。在欧美等发达国家，气象频道的发展已有20多年的历史。例如，美国有天气频道（TheWeatherChannel），加拿大天气网络（TheWeatherNetwork），法国气象频道（MetroChannel）都在加速发展中。尽管这些国家的公共电视网和综合类电视网都有大量的天气预报节目，但专业化的气象频道具有非常高的影响力和重要性。