安徽农学通报,AnhuiAgri,Sci,Bull,2021,27(15)
重庆永川大风分布特征分析
邓霞董丹丹*何青青屈长青
(重庆市永川区气象局,重庆402160)
摘要:利用2010—2017年常规气象观测资料,分析了重庆永川大风时空分布规律、极端性特征及其天气学背景,为大风预报提供参考。结果表明:(1)永川出现了58次大风过程,风向以NNW或N为主,集中在中部地区和河谷地带。(2)四季皆有大风出现,4月、5月、8月大风较为频繁,主要出现在凌晨前后、傍晚前后。(3)非单站型较单站型大风偏多近40%,非单站型在午后到夜间易发生,影响全区大部地区;单站型02—07时最多,集中在永川中部偏北一带。(4)每年均有9级以上大风出现,区域性最强大风过程为2013年4月5日(A过程),城区最强大风过程为2015年5月10日(B过程),均具有持续时间长、范围广、强度大的特征。(5)对比A、B过程,相同点在于高空有深厚低槽东移过境重庆,地面有冷高压发展,永川受较强冷空气的影响;不同的是,A过程是受冷高压前沿气压梯度差造成的梯度大风,B过程在高空为槽前西南气流,地面上有热低压发展,出现了混合性大风。关键词:大风;分布特征;天气系统中图分类号P425文献标识码A文章编号1007-7731(2021)15-0179-06
DistributionCharacteristicsofStrongWindsinYongchuanDistrictofChongqingCity
DENGXia1etal.
(1ChongqingYongchuanDistrictMeteorologicalBureau,Chongqing402160,China)Abstract:Inordertoprovidesreferenceforgaleforecast,basedontheconventionalmeteorologicalobservationdatafrom2010to2017,thispaperanalyzesthespatialandtemporaldistribution,extremecharacteristicsandsynopticbackgroundofstrongwindsinYongchuanDistrictofChongqingCity.Theresultsshowthat:(1)Thereare58GaleprocessesinYongchuan,thewinddirectionismainlyNNWorN,concentratedinthecentralregionandtheriverval⁃leyofYongchuan.(2)Therearestrongwindsinallseasons,andthemorefrequentinApril,MayandAugust,mainlyaroundthemorningandevening.(3)Thestrongwindfrequencyofnon-singlestationtypeis40%morethanthatofsinglestationtype,andthenon-singlestationtypeiseasytooccurfromafternoontonight,affectingmostareasoftheregion;thesinglestationtypeisthemostfrequentfrom02:00to07:00,concentratedinthenorthofCentralYongch⁃uan.(4)Thegalesabove9gradehappeneveryyear,thestrongestregionalgaleprocessisApril5,2013(ProcessA),andthestrongestgaleprocessofYongchuanmeteorologicalstationisMay10,2015(ProcessB),whichallhavethecharacteristicsoflongduration,widerangeandstrongintensity.(5)ComparedwithAandBprocesses,thesamepointisthatthereisadeeptroughmovingeastwardthroughChongqing,withthedevelopmentofcoldhighpressureontheground,andYongchuanisaffectedbystrongcoldair;thedifferenceisthatprocessAisagradientgalecausedbythepressuregradientdifferenceinthefrontofthecoldhighpressure,whiletheprocessBisamixedgalecausedbythedevelopmentofthethermallowpressureonthegroundandsouthwestairflowinfrontofthehightrough.