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(2$ !  ($$   1  ,dZ+s TABLE A#AZ*Humanst521 Cn BT TABLE B?Level 1Level 2Level 3Level 4Level 5TABLE C                                                                ,@0AZArial                                                                                                                                                                                                   d"  _Aa)` dE` A X   XXX,XC XXCorrespondingauthorsaddress:MichikoMasutani,  NOAA/NWS/NCEP/EMC,5200AuthRd.CampSprings,MD  20746.Email:michiko.masutani@noaa.gov.#XX C#W` XX                                                                                                                                                                                                                                                                                                                                ,@0AZArial                                                                                                                                 TABLE A                                                                Level 1Level 2Level 3Level 4Level 5                                                                Level 1Level 2Level 3Level 4Level 5                                                                Level 1Level 2Level 3Level 4Level 5                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 !  _ XXX,X3.3   fCXX Impact_Assesment_ԀofaDopplerWind_Lidar_Ԁfor_NPOESS_/_OSSE_#XXfCx#   &%~%XXStephenJ.Lord,Michiko_Masutani_,JohnC.Woollen,JohnC._Derber_  _NOAA_/_NWS_/_NCEP_/_EMC_,CampSprings,MD | #XX%&%~#,,XX&%~%,,G.David_Emmitt_,SidneyA.Wood,StevenGreco   SimpsonWeatherAssociates,Charlottesville,VA#,,%&%~A#   Ѐ x  &%~%,,RobertAtlas,JosephTerry  <  NASA/_GSFC_,_Greenbelt_,MD#,,%&%~D#    Ѐ    &%~%,,ThomasJ._Kleespies_ `  _NOAA_/_NESDIS_,CampSprings,MD#,,%&%~;# 8  ',,http://www.emc.noaa.gov/research/osse#,,'8# 4  h   ',,((#(#(1.INTRODUCTION   h    ThefutureNational_POES_ԀSystem @ (_NPOESS_)isscheduledtoflyduringthe2007-2010  period.Forthenext10years,aconsiderable p amountofeffortmusttakeplacetodefine,develop 0 andbuildthesuiteofinstrumentswhichwill @ comprisethe_NPOESS_.Theforecastimpactof  currentinstrumentscanbeassessedbyObserving p SystemExperiments(_OSEs_),inwhichalready 0 existingobservationsaredeniedoraddedto @ observationsfromastandarddatabase.However,  theimpactoffutureinstrumentsmustbeassessed p withexperimentsusingsimulatedobservations. 0 TheseexperimentsareknownasObservingSystem @ SimulationExperiments(_OSSEs_).(Atlas,1997)VV)V     Thisprojectisacollaborationamongthe p! NationalCentersforEnvironmentalPrediction 0" (_NCEP_),NASA/DataAssimilationOffice(DAO), @# SimpsonWeatherAssociates(_SWA_),andthe $ NationalEnvironmentalSatellite,Dataand p % InformationService(_NESDIS_).Throughthis 0!& collaboration,thedataassimilationandmodeling !@' communitiescanbeinvolvedininstrumentdesign "( andcanprovideinformationabouttheexpected p#) impactofnewinstruments.Furthermore,through 0$* the_OSSEs_,operationaldataassimilationsystems $@ + willbereadytohandlenewdataintimeforthe %!, launchofnewsatellites.Thisprocessinvolves p&!- preparationforfuturedatavolumesinoperations, 0'". thedevelopmentofthedatabaseanddata '@#/ processing(includingformatting)andaquality ($0 controlsystem.Allofthisdevelopmentwill p)$1 acceleratetheoperationaluseofdatafromthe 0*%2 futureinstruments(Lordetal.1997). *@&3 wbA1-j|&" `@Ep,""p,"w p,'5  p Foreach_OSSE_,alongintegrationofan h 5 atmosphericgeneralcirculationmodel(GCM)is (x 6 requiredtoprovidea"trueatmosphere"forthe 87 experiment.Thisiscalledthe"naturerun"(NR). 8 Thenaturerunneedstobesufficiently h9 representativeoftheactualatmospherebut (x: differentfromthemodelusedforthedata 8; assimilation.Theobservationaldataforexisting < andfutureinstrumentsissimulatedfromNRand h= impacttestsareperformedforbothrealand (x> simulateddata.Thenaturerunusedinthis 8? project,thedataassimilationsystemandforecast @ modeusedintheseexperimentsisdescribedin hA _Masutani_Ԁetal(2002). (xB  p Amongvariouscandidateinstruments 8C Dopplerwind_lidar_Ԁ(_DWL_)winddataareproduced D aslineofsight(LOS)windsby_SWA_Ԁusingtheir hE _Lidar_ԀSimulationModel(_LSM_).Bracketing (xF sensitivityexperimentsarebeingperformedfor 8G various_DWL_Ԁtechnologyneutralconceptsto H boundthepotentialimpact(Lordetal.2001a). h I Scanning,andvariousdatasamplingstrategies, (!xJ arebeingtestedwiththeseexperiments. !8K  3.SIMULATIONOFOBSERVEDDATA  h#M  p  p Detailsofprocedurestosimulate $@ O observationaldataaredescribedin_Masutani_Ԁet %!P al.(1999b)andLordetal.(2001a,2001b)and p&!Q thesepapersareavailableatthe_OSSE_Ԁwebsite. 0'"R ЀTheinitialsimulationusesrealobservationaldata '@#S distributionsavailableinFebruary1993._ACARS_ ($T andsatellitederivedwindsaresimulatedwith p)$U distributioninFebruary1993._TOVS_Ԁlevel1B 0*%V radiance(T1B)dataissimulatedby *@&W _NOAA_/_NESDIS_ԀanddetailsaredescribedinLord +'X etal.(2001a)and_Kleespies_Ԁ(2001).NASA/DAO p,'Y istakingtheleadinthesimulationofrealistic 0-(Z conventionalobservations,includingcloudmotion -@)[ vectors(_CMV_,_Velden_Ԁetal.1997)and_ACARS_.  Morerealistic_CMVs_ԀbasedonNRcloudandthe p morerecentdistributionof_CMVs_Ԁaresimulatedwith 0 collaborationwith_SWA_. @   Inthispapertheimpactof_DWL_Ԁis  assessedwithexistinginstruments.However,itis p importantthatassessmentisalsodonewithmore 0  advancedinstrumentsexpectedwhen_DWL_Ԁwould  @ beactuallylaunched.Higherdensity_CMVs_Ԁand   moreadvancedsoundersneedtobeincludedin p   impactassessment.TheatmosphericInfrared 0   Sounder(AIRS,Goldbergetal2001)isscheduled  @  tobeincludedinthe_NPOESS_ԀPreparatoryProject   (_NPP_)instrumentsuite.Asoneoftheadvanced p  sounders,AIRSisplannedtobeincludedinthe 0  calibrationandimpactassessment.Outlineofthe @  simulationofAIRSdataisgivenin_Masutani_Ԁetal.   (2001).TheAIRSsimulationpackagewasoriginally p  developedbyEvan_Fishbein_Ԁof_JPL_.Thesimulation 0  (i.e.,forwardcalculation)isbasedonradiative @ transfercodedevelopedby_Larrabee_Ԁ_Strow_  (_UMBC_).AIRSwillbesimulatedby_NOAA_/_NESDIS_ p usingthesimulationpackagefrom_JPL_.A 0 _scatterometer_Ԁ(e.g.,_ASCAT_)isalsoconsideredto @ beaddedandmethodsimulationisbeing  investigated. ` 0 0 V VpVV 3.1Simulationof_DWL_Ԁdata 0     Thesimulationof_DWL_Ԁdataincludes  effortswith_DWL_Ԁperformancemodels,atmospheric t circulationmodelsandatmosphericopticalmodels 4 (Atlasand_Emmitt_,1995;_Emmitt_,1995a;_Emmitt_ D andWood,1996;Woodetal.,1993;Woodetal.,   1995;Woodetal.,2001).Thestepsbetweena t! notionalconceptfora_DWL_Ԁandtheblueprintsfor 4" instrumentconstructionincludeaconsiderable D# amountofperformancemodelingand,for $ space-basedsystems,anintensiveseriesof t % _OSSEs_.DuringandsubsequenttotheLaser 4!& AtmosphericWindSounder(LAWS)study(Bakeret !D' al.,1995),amethodforassessingthepotential "( impactofanew_DWL_Ԁobservingsystemwas t#) established.Theinstrumentparametersare 4$* providedbytheengineeringcommunity.Scanning $D + andsamplingrequirementsareprovidedbythe %!, sciencecommunityanddefinevariousinstrument t&!- scenarios.Thesescenariosaretestedinitiallyby 4'". examiningthesensitivityofanalysestothevarious 'D#/ scenarios.Acandidate_DWL_Ԁconceptisthen ($0 chosenforafull_OSSE_,andanimpactstudyisthen t)$1 conductedandevaluatedbyatechnologyneutral 4*%2 group. *D&3   Thebracketing_OSSEs_Ԁarebeingperformed +'4 forvarious_DWL_Ԁconceptstoboundthepotential t,'5 impact.Later_OSSEs_Ԁwillbeperformedformore 4-(6 specificinstruments(_Emmitt_,1999).Thefollowing -D)7  technologyneutralobservationcoverageand 7 measurementerrorcharacterizationswillbe p8 explored . 09 EXP1(Best): Ultimate_DWL_Ԁthatprovidesfull ; troposphericLOSsoundings,cloudspermitting. <  EXP2(_PBL_+cloud): Aninstrumentthatprovides  X> onlywindobservationsfromcloudsandthe_PBL_.  ? Ѐ0 p  @p(#p(#  EXP3(Upper): Aninstrumentthatprovidesmid P A anduppertroposphericwindsonlydowntothe  hB levelsofsignificantcloudcoverage.  ( C  Exp4(NonScan): Anonscanninginstrument X E thatprovidesfulltroposphericLOSsoundings,  p F cloudspermitting,alongasinglelinethatparallels 0 G thegroundtrack.  H  _TRV_ :200kmx200kmxT  pJ  p T:Thicknessofthe_TRV_Ԁ 8K  p 0.25kmifz<2km,1kmifz>2km L Ѐ0 p 0.25kmforcloudreturnhMp(#p(#  Swathwidth: 2000kmexceptforEXP4(non 8O scanning) P  p Nomeasurementerrorisassignedforthe 0R initialtest.Strategiesforsystematicerrorsare @S discussedby_Emmitt_Ԁ(2000).Onemeasurement T isanaverageofmanyshots.Dataproducts pU baseduponclusteredanddistributedshotsare 0V generatedforeachexperiment.Theclustered @W dataproductisbaseduponaveragingthe X observationsassociatedwithshotsclustered pY withinanareathatisverysmallcomparedtothe 0Z baseareaofthe_TRV_.Thedistributeddata @[ productisbaseduponaveragingtheobservations  \ ofshotsdistributedthroughoutthe_TRV_Ԁaswould p!] resultfromcontinuousconicalscanning. 0"^  p Distributedshotsforthenonscan "@_ experiment(EXP4)arenotrealistic.However,it #` isusedtotestthepenetrationthroughcloud.In p$a therealatmosphere,cloudhasporositywhichis 0% b notdescribedintheNRarchive.Cloudporositylet %@!c some_DWL_Ԁshottogothroughthecloud.This &"d notpossiblefortheNRcloudasthecloudsare p'"e uniformwithinagridintheNR.Distributed 0(#f measurementscollectmanyshotswithinthe_TRV_ (@$g andthereismorechancetopenetratethroughthe )%h atmosphere.Thisdoesnotexactlymodelthe p*%i porosityofthecloudbutitisusedtocheckthe 0+&j penetrationduetoporosity. +@'k  p EXP2andEXP3aresimulatedtotest ,(l variouswavelengthandmeasurementmethods. p-(m Theyaretestedbutnotpresentedinthispaper.  Morerecentdevelopmentsarediscussedby p _Emmitt_Ԁ(2001). 0  4.INITIALRESULTSFORIMPACT  ASSESSMENTFOR_DWL_Ԁ x    Priortotestingfutureinstruments,data  P impacttestofexistinginstrumentsareperformedto   calibrate_OSSEs_Ԁ(_Masutani_Ԁetal.2002).Theresults    showedtherearereasonableagreementsbetween @   simulatedandrealdataimpactbuttheinterpretation  P  needstobeconductedwithgreatcaution.      InTable1partofexperimentsusedfor   calibrationand_DWL_Ԁimpactassessmentsarelisted. @  InTable2timeandareaaveragedrootmean P  squareerror(_RMSE_)betweencontrolexperiment   andtheNRarelisted.Theperiodusedforthe   averagingisfromFebruary14toMarch6.The @  valuesarezonallyaveragedandaveragedinthe P latitudebandindicatedinthetableforthesouthern  hemisphere(_SH_),thetropics(TROP),andthe  northernhemisphere(NH).Impactonzonalwind(U) @ for200_hPa_,500_hPa_Ԁand850_hPa_Ԁarepresented. P Changeinthe_RMSE_Ԁfromthecontrolexperiments  arepresentedasimpactinTable3.    ThefirstthreeexperimentsinTable3are @ denialtestsforexistinginstrument.These P experimentsarealsousedforcalibrationandthe  impactsarecomparedwithrealanalysis.Forthe  calibrationtheanalysiswascomparedwith1B @ experiment.Now,forthesimulateddatathe P analysiscanbecomparedwithtruth.Theyshow   theRWindhasthelargestimpactinNHandT1Bin ! _SH_.Thisresultsagreeswiththeimpacttestin @" forecastskillscore(_Masutani_Ԁetal.2001).The P# impactofRTemponwindfieldsissmallanditis $ notcleariftheyhavepositiveimpact.  % 4.1Results "P'   Amongmanycandidateinstrumentsforthe #) _OSSE_,_DWL_Ԁwindsaresimulatedby_SWA_. D$* Accordingtothestrategyforbracketingsensitivity %T + experiments(Lordetal.2001a,Lordetal.2001b, %!, _Masutani_Ԁetal.2001),scanningornonscanning, &!- variouswavelengths,numbersofLOSper D'". measurement,arebeingtested.Sensitivityto (T#/ weightinthedataassimilationisalsobeingtested. ($0   Forfirstfewdays,morethan20casesare D*%2 testedwithvariouscombinationsandselectedcases +T&3 arecompletedforthewhole_OSSE_Ԁperiod(00z +'4 February1300zMarch7,1993).Experiments ,'5 discussedinthispaperarelistedinTable1.The D-(6 distributeddataforthenonscanningscenarioisnot .T)7 realistic.However,itisusedtotesttheeffectof 7 penetration.Becauseoftheaveragingofeach p8 200Kmsquarearea,more_DWL_Ԁshotspenetrate 09 tolowerlevelsfordistributedshots.Theamount @: ofpenetrationisstillanunknownquantityand ; needstobeinvestigated. p<  p Theimpactsaremeasuredasthechange 0 = in_RMSE_ԀfromtheNR.Table2showszonallyand  @> timeaveragedvaluesforthreelatitudebandsas  ? differencesfromthe_RMSE_Ԁbetweenthecontrol p @ experiment(_CTL_)andNR.Apositivevalue 0 A indicatestheexperimenthaspositiveimpact  @B comparedto_CTL_.  C  p Rows47inTable3showanadvantage p D ofascanninginstrument(rows4,5)overanon 0 E scanninginstrument(rows6,7).Thedifferences @ F arelargestintheuppertroposphereandare  G reducedinthelowertroposphere.Distributed p H shotsarebetterthanclusteredshotsinmostof 0 I thecases.Comparisonbetweenrows4,6and @J 5,7showsthatpenetrationindistributeddatais K importantinthelowertroposphere. pL  p Representativenesserrorsof1m/sand 0M 7m/saretestedforthefirstweekandtheresults @N arepresentedinLordetal(2001c).Theimpact O withrepresentativenesserror7m/sisabout10 pP 20%lessthat_that_Ԁof1m/s,butthegeographical 0Q distributionoftheimpactdoesnotchange. @R  p  p WithT1Bin_CTL_,_DWL_Ԁdataimprovedthe pT windfieldsgloballyatalllevelsforallexperiments 0U (row47inTable3).Majorimprovementsare @V overthetropicsifT1Bisincludedin_CTL_. W Marseilleetal.(2001)showedmajorimpactin pX _SH_,becauseintheirexperiment_CTL_Ԁdoesnot 0Y includeT1B.IfT1Bareincluded,themajor @Z improvementin_SH_ԀhasalreadyachievedbyT1B [ andofthemajorimprovementsdueto_DWL_Ԁmove p \ totropics.HoweverwithoutT1Bin_CTL_,using 0!] NTVas_CTL_Ԁmoreimprovementisachievedin !@^ _SH_Ԁevenbyworstcaseof_DWL_Ԁ(Dex4cr7,row9), "_ comparedtoT1B(row8).AlthoughT1Band p#` Dex4cr7showsimilarmagnitudeofimpactin_SH_ 0$a andminimumimpactinNH,row1inTable4 $@ b showstherearesignificantdifferencesbetween %!c experiment1BandexperimentDex4cr7. p&!d Therefore,bothT1BandDex4cr7togetherallow 0'"e afurtherimprovementtobeachieved(row10in '@#f table3).InNHneithertheT1Bnorworstcaseof ($g _DWL_Ԁ(Dex4cr7)producesignificantimpact. p)$h Significantimpactisachievedbythebestcaseof 0*%i _DWL_Ԁ(Dex1dr1inrow11) *@&j  p Dex4cr7isrunwithoutRWind +'k (_NTVNWIN_)as_CTL_Ԁandtheimpactiscompared p,'l withRWind(Row12,14,table3).Theresults 0-(m showworstcaseof_DWL_Ԁ(Dex4cr7)dotproduce -@)n asmuchasimpactoverNH_compareed_ԀtoRwind.  However,theimpactofthebestcaseof_DWL_ p (Dex1dr1)istwiceasmuchasRwind(row15, 0 Table3)inNH.AddingT1Bonlycouldcause @ negativeimpactoverNH(row13,table3).The  distancebetweenNTVandF'Dex4cr7NWIN#'F:`#Ԁintable4 p indicatesthattheimpactofRwindandtheimpact 0  of_DWL_Ԁarequitedifferent.  @ 4.2CommentsontheResults  p       _DWL_Ԁisevaluatedwith1993data  D  distribution.However,_DWL_Ԁwindsalsoneedtobe    evaluatedwithboththecurrentdatadistribution t  andtheanticipatedfuturedatadistribution 4  correspondingtowhenthe_DWL_Ԁdatawillbeused. D    Inthispaperno_measuserment_Ԁerroris t  includedin_DWL_.Systematicerrorsarediscussed 4  by_Emmitt_Ԁ(2000)andotherlargescalecorrelated D errorneedtobedesignedandaddedto  assessment.Varioussamplingstrategiessuchas t separationbetweenforwardandbackwardscan, 4 adaptiveobservationneedtobetested. D   InthispaperonlyresultsfromUare  presented.Theimpactonmeridionalwind(V)is t similartothatonU.Impactintemperaturefieldsis 4 moresensitiveandcomplicated.Impacton D temperaturefromradiancedataandRTemp  involvemanyprocedurestoaltertheresults,such t asbiascorrection.Impactontemperaturefrom 4 _DWL_Ԁwindisevenmorecomplicated.Itis D interestingtonotethatwhendistributed,data   usuallygivepositiveimpactinwindfields t! comparedtoclustereddata,althoughsometimes 4" thetemperaturefieldsisbetterwiththeclustered D# data.Analysisandsimulationproceduresneedtobe $ evaluatedanddevelopedformorereliableresults. t %  5.FUTUREPLANS   !D'   Thecalibrationwillbecontinuedtogain |#) furtherconfidenceinthe_OSSE_Ԁ_system._ԀVarious <$* techniquesforaddingsystematicerrorswillbe $L + tested.ThesimulationprocedureofT1Brequires % !, furtherevaluation,includingtheformulationof |&!- observationalerrors. <'".   Inadditiontoa_DWL_ԀandAIRS,theCross 'L#/ TrackInfraredSounder(_CrIS_),Conicallyscanning ( $0 Microwave_Imager_/Sounder(CMIS),andthe |)$1 AdvancedTechnologyMicrowaveSounder(_ATMS_) <*%2 havebeenproposedascandidateinstrumentstobe *L&3 testedby_OSSEs_.Weareproceedingtodevelop + '4 appropriateforwardmodelsfortheseinstruments. |,'5   Inordertomakereliablerecommendations, <-(6 thetechniquesforcreatingsimulatedobservations -L)7 needtoberefined.Additionoflargescale 7 spatiallycorrelatederrorandsystematicerrorin p8 simulateddatamayaltertheresults. 09  p _OSSEs_Ԁalsoneedtobetestedwith @: upgradedtechniquesfordatahandlinganddata ; assimilationsystem.Sincetheamountofdata p< involvedinthefutureinstrumentsincreases 0 = drastically,effectivesuperobservationsto  @> reducethesizesofdatasetsneedtobestudied  ? (Purseretal.2001).Includinganadaptive p @ correctionforthebiasinthedataassimilationwill 0 A alsobetested(Purserand_Derber_,2001).  @B  p Futureinstrumentsneedtobetestedwith  C 2001andfuturedatadistributionssincethe1993 p D datadistributionisoutdated.Alternative_NRs_Ԁfor 0 E thesameperiodandsummertimehavealsobeen @ F generatedbyNASA/DAOandcanbeusedto  G investigateadditionalatmosphericregimes._NRs_ p H totestnorthernsummertimeresponseare 0 I important,especiallytostudytheimpacton @J tropicalstormprediction. K  p Theevaluationmetricswillbeexpanded pL toincludediagnosticsofstrengthandpositionof 0M cyclonesandjetsandastudyofextremeevents, @N aswellasstandardforecastskillscores.Cost O benefitandflightplanningwillalsobestudied. pP  ACKNOWLEDGMENT  HR  p Wereceivedmuchassistancefromthe T DataServicesSectionandDr.Anthony @U _Hollingsworth_Ԁof_ECMWF_Ԁinsupplyingthenature PV run.Throughoutthisproject_NOAA_/_NWS_/_NCEP_, W NASA/DAOand_NOAA_/_NESDIS_Ԁstaffsprovided X muchtechnicalassistanceandadvice. @Y Especially,wewouldliketothankW.Yang,R. PZ _Treadon_,Y._Zhu_,W.S.Wu,M._Iredell_,D. [ _Keyser_,W.Collins,andR._Kistler_Ԁof_NCEP_,G.  \ _Brin_,S.BloomandN.WolfsonofDAO,andV. @!] Kapoor,P.LiandW.Wolfof_NESDIS_.Wewould "P^ liketothankEvan_Fishbein_Ԁof_JPL_Ԁforproviding "_ simulationcodeforAIRSdata.Drs.E._Kalnay_, #` W.Baker,J._Yoe_ԀandR.Daleyprovidedexpert @$a advice.Weappreciatetheconstructive %P b commentsfrommembersofthe_OSSE_ԀReview %!c Panel.ThisprojectissponsoredbytheIntegrated &!d Progr