学科分类
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2 个结果
  • 简介:整理DSC2型称重式降水传感器在业务运行中出现的问题,对DSC2型称重式降水传感器存在的采集器连接、量筒内壁粘雪、小雨时的缺测等问题进行分析。提出提高DSC2型称重式降水传感器运行稳定性的方法,提升其监测的准确性、时效性;提高观测数据的可用性的相应建议。

  • 标签: 称重式降水传感器 问题分析 对策
  • 简介:Aregionalsurfacecarbondioxide(CO_2)fluxinversionsystem,theTan-Tracker-Region,wasdevelopedbyincorporatinganassimilationschemeintotheCommunityMultiscaleAirQuality(CMAQ)regionalchemicaltransportmodeltoresolvefine-scaleCO_2variabilityoverEastAsia.Theproperorthogonaldecomposition-basedensemblefour-dimensionalvariationaldataassimilationapproach(POD-4DVar)isthecorealgorithmforthejointassimilationframework,andsimultaneousassimilationsofCO_2concentrationsandsurfaceCO_2fluxesareappliedtohelpreducetheuncertaintyininitialCO_2concentrations.ApersistencedynamicalmodelwasdevelopedtodescribetheevolutionofthesurfaceCO_2fluxesandhelpavoidthe'signal-to-noise'problem;thus,CO_2fluxescouldbeestimatedasawholeatthemodelgridscale,withbetteruseofobservationinformation.Theperformanceoftheregionalinversionsystemwasevaluatedthroughagroupofsingle-observation-basedobservingsystemsimulationexperiments(OSSEs).TheresultsoftheexperimentssuggestthatareliableperformanceofTan-Tracker-Regionisdependentoncertainassimilationparameterchoices,forexample,anoptimizedwindowlengthofapproximately3h,anensemblesizeofapproximately100,andacovariancelocalizationradiusofapproximately320km.Thisisprobablyduetothestrongdiurnalvariationandspatialheterogeneityinthefine-scaleCMAQsimulation,whichcouldaffecttheperformanceoftheregionalinversionsystem.Inaddition,becauseallobservationscanbeartificiallyobtainedinOSSEs,theperformanceofTan-Tracker-RegionwasfurtherevaluatedthroughdifferentdensitiesoftheartificialobservationnetworkindifferentCO_2fluxsituations.TheresultsindicatethatmoreobservationsiteswouldbeusefultosystematicallyimprovetheestimationofCO_2concentrationandfluxinlargeareasoverthemodeldomain.TheworkpresentedhereformsafoundationforfutureresearchinwhichathoroughestimationofCO_2fluxvariability

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