IPID4allDoctorateResearchExchangewithCarlvonOssietzkyUniversityOldenburgFeedbackreportShogoUchiyama,BachelorofMaritimeSciences CarlvonOssietzkyUniversityOldenburgGraduateschoolofMaritimeSciences,KobeUniversity5-5-1,Fukaeminamimachi,Higashinada-ku,Kobe-shi,Hyogo,658-0022,Japan

InstituteofPhysics(ForWind)Küpkersweg70,26129Oldenburg,Germany

TeruoOhsawa,AssociateProfessor Dr.DetlevHeinemann,Dr.GeraldSteinfeld

01.08.2017-30.09.2017 AnalysisoftheresultofWRFsimulationsonthechoiceofthedrivingobjectiveanalysisdataset

IntroductionTheWeatherResearchandForecastingmodel(WRF)isthemostwidespreadmodel,usedforoffshorewindresourceassessment.WRFcancalculatealotofweatherelementsbyinputtingmeteorologicalandgeographicaldatafromdifferentsources.ConfigurationsoftheWRFcalculationscanbechangedfreelyandeasilyaccordingtoaneededaccuracy,time-step,ordomain.Actually,NeoWins(http://app10.infoc.nedo.go.jp/Nedo_Webgis/top.html),thewindatlasinJapan,wasmadefromWRFsimulation.AlthoughassessmentsofwindresourcescanbedonewithlessmoneybyusingWRFinsteadofametmast,animprovementoftheaccuracyinthemodelisessential.AnimprovementofaninputdataforWRFisapossibilitytodothat.Forthisreason,thisstudyfocusesonobjectiveanalysisdatasetsusedfortheinitialandboundaryconditionsforWRFsimulations.ResearchUndertakenAtfirst,acomparisonoffourobjectiveanalysisdatasetsiscarriedoutinJapaneseandGermancoastalwaters.Thedetailsofthesedatasetsaredescribedintable1.MANALisadatasetmadeforcomplexJapaneseterrainfeaturesandwasusedtomakeNeoWins(describedintheformersection).Figure1showsthelocationofin-situobservationsinGermanandJapanesecoastalwaters.Toderivewindspeedsateachsitefromtheinformationprovidedatthegridpointsoftheobjectiveanalysis,thehorizontalbilinearinterpolationisused.Moreover,alinerinterpolationusinglogarithmicheightisusedtoadjustwindspeedstoeachdifferentheightofobservations.TheVerificationsareconductedforayear(lowheightobservation:2014,hubheightinGermany:2014,andhubheightinJapan:dependingonthoseobservationperiods).Tocomparealldatasetswithdifferenttemporalresolutionsandsamples,relativebiasandRMSEareused.ThesestatisticsarederivedbydividingbiasandRMSE(RootMeanSquareError)bymeanwindspeed.Figure2and3showtheresultatlowheightandhubheightobservationsrespectively.AtChoshi(ahubheightobservationinJapan),onlymonthlyaveragedmeanwindspeedsareavailable.Thus,relativeRMSEcannotbecalculated.

ECMWFOperational ERAinterim ERA5 MANAL

Source ECMWF ECMWF ECMWF JMA

Spatialresolution 0.25°x0.25° 0.25°x0.26° 0.3°x0.3° 0.05°x0.05°

Temppralresolution 6-hourly 6-hourly hourly 3-hourly

Coverage Global Global Global Japan

Table1:DetailsofObjectiveanalysisdatasets

Figure1:In-situobservationsinGermanyandJapan(dots:lowheight,crosses:hubheight)

IPID4allDoctorateResearchExchangewithCarlvonOssietzkyUniversityOldenburgFeedbackreportIntermsofacomparisonbetweentwocountrieswithoutMANAL,whichisunavailableinGermany,alldatasetshavebetteraccuraciesatGermansites.Thisimpliesthattheaccuracyofthesamedatasetvariesfromcountrytocountry.Intermsofacomparisonbetweenfourdatasets,EC-OperseemstobethemostaccurateofthreedatasetsinGermany,takingbothbiasandRMSEintoaccount.InJapan,MANALhashighaccuraciesaswellasEC-Oper.However,MANALseemstobeamoreaccuratedatasetthanEC-Operconsideringthemathubheight.ThisresultimpliesMANALissuitableforinputdataforWRFsimulation.

Figure2:Resultofthecomparisonatlowheightobservations(left:relativebiasandright:relativeRMSE)

Figure3:Resultofthecomparisonathubheightobservations(left:relativebiasandright:relativeRMSE)

Afterthat,WRFsimulationsforhubheightobservationsinbothcountriesarecarriedout,inordertolookattheeffectofinputdataontheWRFresult.Inthesesimulations,EC-OperisusedasaninputdatasetforWRF.Moreover,mostofphysicaloptionsaresimilartothoseusedformakingNeoWins,Japanesewindatlas.Table2showstheseconfigurations.Figure4showstwoexampleofdomainsettings.ThesesimilarconfigurationsenableustocomparebetweenMANAL(usedformakingNeoWins)andEC-Oper(usedinthisstudy).Inthisreport,theaccuracycomparisonofWRFsimulationsusingEC-Operasaninputdataisdescribed.Figure5showstheresultatsixhubheightobservations.Accordingtothisfigure,there'snolargedifferenceaboutthesebiases,whichareapproximatelywithinplusorminus5%exceptNoshiro.However,RMSEsinJapanaretwiceaslargeasthoseinGermany.Allthingconsidered,WRFsimulationsforGermanyhavebetteraccuracythanJapan.Throughthisstudy,thefactthattheaccuracyinWRFsimulationdependsonanaccuracyofinputdatasetsisconfirmed.Moreover,anothercomparisonbetweenMANALandEC-Oper,asaninputforWRF,willbecarriedoutafterthisexchange.Finally,IwouldliketoacknowledgeBMWi(BundesministeriumfürWirtschaftundEnergie),PTJ(ProjektträgerJülich)andBSH(BundesamtfürSeeschifffahrtundHydrographie)forFINO2,FINO3andotherbuoydatainGermany.ForJapanesehubheightandlowheightobservations,IwouldalsoliketoappreciateNEDO(NewEnergyandIndustrialTechnologyDevelopmentOrganization)projectformakingoffshorewindresourcemap.

IPID4allDoctorateResearchExchangewithCarlvonOssietzkyUniversityOldenburgFeedbackreport

Figure5:ResultofthecomparisonofWRFsimulations(left:relativebiasandright:relativeRMSE)

PersonalExperienceInthisprogram,IstayedinGermanyforthefirsttime.Itwasalwayschallengingformetocommunicatewithallpeopleandlivealoneindifferentcountry.However,itwasalsoexcitingdays.IlearnedalotofthingsrelatedtoGermany.Especially,Iwassurprisedatanumberofonshoreandoffshorewindturbines,whichisoneofthebiggestdifferencesbetweenJapanandGermany.ForWindisaniceplaceformetoconcentrateonmystudy.Iwashappytobeinsuchanawesomeenvironment.Duringfreetime,IwasabletoenjoyeverythingwiththemembersofForWind.Thisenabledmetolearnnotonlythestudy,butalsothelifestyle,culture,andpeople'skindness.ConclusionsTheIPID4allprogramgavemeagreatopportunitytostayinCarlvonOssietzkyUniversityOldenburg.Ispentanicetimehere,thankstothisprogram.Iwouldliketoexpressmygratitudetoeveryoneconcernedmystay,especiallyDr.GeraldSteinfeld,whokindlysupportedmystudyandlifeinOldenburg.OutlookoPublicationsrelatedtotheresultswithDr.GeraldSteinfeld

Table2:ConfigurationusedinWRFsimulations

Figure4:Examplesofdomainsusedinthesimulations(left:forHazakiandChoshi,right:forFINO2)

Model AdvancedResearchWRF(ARW)Ver.3.6.1

Period Japan:Dependingonobs.,Germany:2014(Annual)

ECMWFOperationalAnalysis

Japan:MOSST,Germany:OSTIA

NCEPFNL(forSoil)

Domain1:12.5kmgrids,100x100

Domain2:2.5kmgrids,100x100

Domain3:0.5kmgrids,Approx.1°x1°

Level 40levels(surfaceto50hPa)

Domain1:Enable

Domain2:Enable

Domain3:Enable,butexcludingbelowPBLheight

Dudhiashortwavescheme

RRTMlongwavescheme

Ferrier(newEta)microphysicsscheme

Mellor-Yamada-Janjic(Eta)TKEPBLscheme

Monin-Obukhov(JanjicEta)surface-layerscheme

Noahlandsurfacescheme

Inputdata

Domain

4DDA

PhysicalOption