摘要
Inthispaper,five-yearsimulateddatafromalow-resolutionglobalspectralmodelwithtriangulartrunca-lionatwavenumber10areanalyzedinordertostudydynamicalfeaturesandpropagationcharacteristicsofintraseasonaloxillationsoverthemid-latitudesandthetropicalatmosphere.Thesimulationsshowthatthereisthe30-50dayperiodicoscillationinthelow-resolutionspectralmodelwithoutnon-seasonalexternalforcing,andspatialscaleoftheintraseasonaloscihationsisoftheglobe.Furtheranalysisfindsthatpropagationcharac-tersofintraseasonaloscillationsoverthemid-latitudesandthetropicsaredifferent.The30-50dayoscillationoverthetropicsexhibitsstructureofthevelocitypotentialwavewithwavenumber1inthelatitudinalandthecharacterofthetravelingwaveeastwardatspeedof8longitudes/day.However,the30-50dayoscillationsinmid-latitudeatmosphereexhibitphaseandamplitudeoscillationofthestandingplanetarywavesandtheyarerelatedtotransformofteleconnectionpatternsoverthemid-latitudes.Theenergyisnotonlytransferredbetweenthetropicsandthemiddle-highlatitudes,butalsobetweendifferentregionsoverthetropics.Basedontheanalysisof5-yearbandpassfiltereddatafroma5-layerglobalspectralmodelofJow-ordetwithtruncatedwavenumberl0,investigationisdoneofthesourceofintraseasonaloscillationsintheextratropicalmodelatmosphereanditsmechanism.Resultsshowthat(1)theconvectiveheattransferredeastwardalongtheequatorservesasthesourceoftheintraseasonaloxillationbothinthetropicalandtheextratropicalatmos--phere;(2)thevelocity-potentialwaveofazonalstructureofwavenumber1givesrisetooxillationindivergentandconvergentwindfieldsofadipole-formasseenfromtheequatorialIndianOceantothewesternPacificduringitseastwardpropagation,thusindicatingtheoscillationinthedipole-formheatsoure:e/sinkpattertl;(3)thetropicalheat-sourceoscillationisresponsibleforthe
出版日期
1991年04月14日（中国期刊网平台首次上网日期，不代表论文的发表时间）
