简介:Aseriesof96-htyphoontrackpredictionexperimentswerecarriedoutusingmediumrangeforecastingsystemofNMCbyaddingBOGUStyphoon(simplifiedasB-TC)intothefirstguessfieldortheanalysisfieldinordertoprovidelongertimetyphoontrackforecast.TheresultsshowthatT106L19couldprovideabetterforecasttotyphoontrackswhentheB-TCwasadded,especiallywhenthetyphoonvortexisevenweaker.ThesensitiveexperimentsonwheretoaddtheB-TCshowthattheresultsfromaddingtheB-TCintothefirstguessfieldarebetter.TheresultsalsoshowthattheinitializationsmoothestheB-TCalotandthiswillaffectthetyphoontrackprediction.
简介:Basedonresearchesmadebytheauthorinrecentyears,discussionismadeofthequasi-40-dayoscillation(QDO)natureanditscharacteristicpropagation,withemphasisontheSouthernHemispheremill-latitudequasi-periodiccoldairforcingonthetropicalatmospherequasi-40-dayoscillationalongwithitseffectupontheNorthernHemispheresummermonsoon.Itisproposedthattheinteractionbetween,orlateralcouplingof,meridionalcirculationsystemsmayserveasthemechanismoftheoscillationpropagationinameridionaldirection.
简介:L波段雷达经过多年业务运行,故障频发,极易造成记录缺测或中断。如何在故障出现时完成观测任务,保证气象数据准确和完整,值班员的应急处置方法及时得当显得尤为重要。在总结经验的基础上,以西安泾河站2017年11月23日02时的一次L波段雷达系统突发性故障为例,从故障研判、仪器准备、数据观测、记录处理、编发报文等方面详细记录了单独测风应急观测业务流程和操作技巧,供同行参考。
简介:这研究分析了interdecadal变化在日报夏天(JuneAugust)的可变性在东方中国上的降水在时期期间19662005时时使用车站雨计量器数据。结果揭示了那降雨日报变化经历了重要interdecadal变化。在到在Yangtze和黄河之间的长江,以及区域的南方的区域上,到全部的降雨的早上降雨(00001200LST)的百分比以数量,频率和紧张,所有展出增加的interdecadal趋势。在诺思中国上,相反减少趋势被发现。作为结果,日报也介绍的降雨山峰读了interdecadal变化。在在Yangtze和黄河之间的区域上,从有下午(12000000LST)的46个车站有16频率在学习的40年的时期的开始的20年里达到顶点,当仅仅八留在后者时20年。在诺思中国,七个车站经历了相反的变化,它占了车站的大约21%全部的数字。为interdecadal变化在的可能的原因日报特征被讨论。作为在活跃季风的降雨,时期介绍早上日报山峰与在裂缝时期的下午山峰,在在诺思中国(在Yangtze和黄河之间的长江和区域的区域南方)上的活跃季风时期的降雨的减少(增加)可以贡献interdecadal变化在日报降雨可变性。
简介:TheKotoda-Bortan(KB)model(LiuandKotoda1998)usedforestimatingevapotranspirationwasmodified.ThemonthlyevapotranspirationforvarioussurfacesintheYangtzeDelta(118-123■,28-33■)wascalculatedusingthemodifiedmodel,andtheannualregionalaverageofevapotranspirationfrom1961to1998wasobtainedusingaweightingmethod.Thespatialandtemporaldistributioncharacteristicsofevapotranspirationwereanalyzed.Itisfoundthattheregionalaveragedannualevapotranspirationhasadecreasingtrendoverthepast40years;thevaluedroppedbyabout24mmfrom1961to1998.Themainreasonforthistendencyisduetothechangeoflandsurfacecondition.Comparedwiththecaseof1980,thecurrentproportionsofpaddyfield,farmlandandwatersurfacehavedecreasedby1.353%,4.42%and2.597%respectively,whiletheproportionsofurbanareaandnon-agriculturelandhaveincreasedby3.345%.Thesechangesclearlyresultinadecreaseoftheregionalaveragedevapotranspiration.