学科分类
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5 个结果
  • 简介:表面降雨过程并且日报与热带海洋的传送对流联系的变化被从一系列二维的解决云的模拟基于时时带平均数的数据分析一个表面降雨方程和热预算检验。模型是综合的因为有从热带海洋全球空气获得的强加的大规模垂直速度,带的风,和水平移流的21天在控制实验联合了海洋空气反应实验(宽外袍COARE)。日报分析表演在日落,以及移流的冷却以后的红外线的放射的冷却与强加的大规模上升运动联系了,使动摇空气和版本给与能量夜的对流开发的对流可得到的势能。实质的本地人大气的弄干在清早与夜的降雨山峰被联系,它在蒸汽预算是大冷凝作用和免职率的结果。敏感实验显示出那日报放射和大规模强迫罐头的变化生产一座夜的降雨山峰通过红外线、移流分别地冷却。

  • 标签: 降雨过程 昼夜变化 耦合响应 试验期 海气 对流冷却
  • 简介:这研究在东亚上在地区性的气候模型(版本4.3)(RegCM4.3)讨论对流parameterization计划(每秒字符数)的敏感。用在RegCM的不同每秒字符数的模拟与相比为这个区域发现一个合适的计划,,不同计划的表演被区域和seasonality极大地影响。在东南中国和孟加拉的海湾上,Grell计划与观察数据相比展出夏天降水的最低RMSE。而且,在土地上的Emanuel和在海洋(ELGO)上的Grell计划提高模拟与在西方的Ghats上的任何单个每秒字符数(Grell/Emanuel)比较,斯里兰卡,和东南印度。在Huang-Huai-Hai平原(3H)和西藏的高原(TP)上中国的区域,Tiedtke计划与高关联系数和可比较的振幅模仿更合理的夏天降水。特别,它复制8公里d的最小的对流降水偏爱<啜class=“a-plus-plus”>在整个在东亚上的一年的1和最低RMSE。为降水的季节的变化,而且,Tiedtke计划结果在3H和TP区域上接近观察数据。然而,任何一个每秒字符数都不能在诺思巴基斯坦(NP)上模仿季节的变化。与以前的研究比较,这研究的结果在南亚上支持Grell计划。然而,Tiedtke计划为3H,TP和NP区域显示出优势。更厚的PBL,潜伏的热流动,深传送对流的唯一的能力和在Tiedtke的乘火车过程策划的更少的表面负责减少湿偏爱。

  • 标签: 对流参数化方案 区域模拟 使用性能 中国东南部 亚洲 区域气候模式
  • 简介:AtmosphericInfraredSounder(AIRS)datashowthattheSaharanairlayer(SAL)isadry,warm,andwell-mixedlayerbetween950and500hPaoverthetropicalAtlantic,extendingwestwardfromtheAfricancoasttotheCaribbeanSea.TheformationsofbothHurricaneIsabelandTropicalDepression14(TD14)wereaccompaniedwithoutbreaksofSALairduringtheperiod1-12September2003,althoughTD14failedtodevelopintoanamedtropicalcyclone.TheinfluenceoftheSALontheirformationsisinvestigatedbyexaminingdatafromsatelliteobservationsandnumericalsimulations,inwhichAIRSdataareincorporatedintotheMM5modelthroughthenudgingtechnique.AnalysesoftheAIRSandsimulationdatasuggestthattheSALmayhaveplayedtworolesintheformationoftropicalcyclonesduringtheperiod1-12September2003.First,theoutbreaksofSALairon3and8Septemberenhancedthetransverse-verticalcirculationwiththerisingmotionalongthesouthernedgeoftheSALandthesinkingmotioninsidetheSAL,triggeringthedevelopmentoftwotropicaldisturbancesassociatedwithHurricaneIsabelandTD14.Second,inadditiontothereducedenvironmentalhumidityandenhancedstaticstabilityinthelowertroposphere,theSALdryairintrudedintotheinnerregionofthesetropicaldisturbancesastheircyclonic?owsbecamestrong.ThiseffectmayhavesloweddowntheformationofIsabelandinhibitedTD14becominganamedtropicalcyclone,whiletheenhancedverticalshearcontributedlittletotropicalcycloneformationduringthisperiod.The48-htrajectorycalculationsconfirmthattheparcelsfromtheSALcanbetransportedintotheinnerregionofanincipienttropicalcyclone.

  • 标签: 热带气旋 热带大西洋 空气层 撒哈拉 数值模拟 SAL
  • 简介:TheNCEP/NCARIIdailymeanreanalysisdataandobservedprecipitationdataareemployedtoinvestigatethewestwardextensionofthewesternPacificsubtropicalhigh(WPSH)duringtheheavyrainperiodoverthesouthernChinainJune2005.Resultsshowthattheremayexistarelationshipbetweentheeast-westshiftoftheWPSHandtheprocessofasouthernChinaheavyrain.TheanalysisindicatesthattheverticalmotionintheWPSHareaismainlycausedbythelatentheatreleaseofmonsoonrainbeltsonitsnorthernandsouthernsides.TheverticalmotioncouldcausetheaccumulationofairmassinthecenterandwestoftheWPSH,whichleadstoitsstrengthening.TheappearanceofthenorthernandsouthernmonsoonrainbeltscouldnotonlyenhancetheWPSHbystrengtheningthedescendingdraft,butalsoexcitethedevelopmentofpositivevorticityandrestricttheWPSH'smovementinthenorth-southdirection.Moreover,theIndianmonsoonrainfalltothewestoftheWPSHmayexcitethedevelopmentofanticyclonicvorticityonitseasternside,whichleadstothewestwardextensionoftheWPSH.

  • 标签: 暴雨 亚热带地区 热带气象 观测
  • 简介:TheonsetofSouthChinaSeasummermonsoonin1998occurredonMay21st.UsingtheU.S.NationalCentersforEnvironmentalPredictionreanalysisdata,thispaperexaminesthephysicalprocessoftheweakeningofasubtropicalanticycloneinWestPacificduringtheonsetperiodusingtheZwack-Okossivorticityequation.Resultsshowthatduringthepre-onsetperiod,thepositivevorticityadvectioninfrontofanuppertropospherictroughwasthemostdominantphysicalmechanismfortheincreaseofthecyclonicvorticityonthe850-hPalayerovertheSouthChinaSeaanditsnearbyregion.Thesecondarycontributiontotheincreaseofthecyclonicvorticitywasthewarm-airadvection.Aftertheonset,themagnitudeofthelatent-heatwarmingtermrapidlyincreasedanditseffectontheincreaseofthecyclonicvorticitywasaboutthesameasthepositive-vorticityadvection.Theadiabatictermanddivergencetermcontributednegativelytotheincreaseofthecyclonicvorticitymostofthetime.Thus,thepositivevorticityadvectionisthemostimportantphysicalmechanismfortheweakeningoftheWestPacificsubtropicalanticycloneovertheSouthChinaSeaduringtheonsetperiod.

  • 标签: 华南海夏天季风 Zwack-Okossi 涡度方程 涡度移流 向西和平的副热带的反气旋