assimilation of himawari-8 atmospheric motion...

AssimilationofHimawari-8AtmosphericMotionVectorsintotheNumericalWeatherPredictionSystemsofJapanMeteorologicalAgency

Koji YamashitaJapanMeteorologicalAgency

[email protected],Monterey,

California,USA,27June- 1July,2016113thInternationalWindsWorkshop

OperationalAMVs(OPE-AMVs)SatelliteStatusupdateforNWPuse inJMA

* K.Yamashta 2016:AssimilationofHimawari-8atmosphericmotionvectorsintoJMA’soperationalglobal,mesoscaleandlocalNWPsystems.CAS/JSCWGNERes.Activ.Atmos.OceanicModel,Submitted.

2

EQ

N60

S60

MTSAT-2 GOES-15(Hourly)

GOES-13(Hourly)

METEOSAT-7

METEOSAT-10

From 6 May 2014

From 10 Aug. 2010

From 6 May 2014

From 5 Feb. 2007

From 18 Feb. 2013

NESDIS and CIMSS MODIS polar winds (Terra and Aqua) from 28 May 2004 AVHRR polar winds from 1 Jul. 2013LEO-GEO winds from 1 Jul. 2013

Same as the North Pole region

Himawari-8

From 17 Mar. 2016*

Himawari-8 AMVs have also assimilated into JMA’s operational regional NWP Systems as same method except Super-observation scheme as the operational global NWP Systems since 17 March 2016.

13thInternationalWindsWorkshop

TODAY’STALK

AssimilationofHimawari-8AMVsintotheoperationalglobalNWP

SystemofJMA

3

Hereafter the items associated with regional NWP Systems are abbreviated.（The impacts for regional NWP system will be presented by Michiko Otsuka and Kenichi Nonaka in presentations tomorrow.)

Outline

• Background• Purpose• NWPsystemforObservingSystemExperiment(OSE)• CharacteristicsofHimawari-8AMVs• Qualitycontrol• OSEresults• Summaryandfutureplans

13thInternationalWindsWorkshop 4

Background

• TheMeteorologicalSatelliteCenterofJMAstartedproductionofHimawari-8AMVsonJuly7th,2015.– TheAMVsarebeingproducedusingthreesequentialHimawari-8imageswith10minutesinterval.

• ItwasreportedthatthequalityoftheHimawari-8AMVshasbeenimprovedbyemployingnewtrackingandnewheightassignmentalgorithms.(PresentedbyKazuki Shimoji inpresentationsyesterday)


Purpose

• TostartassimilatingHimawari-8AMVsinJMA’soperationalNWPSystemswithmaximizing itsimpact

• Forthispurpose,– ItneedstoreviewthequalityofHimawari-8AMVsbycomparingwithMTSAT-2AMVsindetail.• CharacteristicsofHimawari-8AMV

– Anditneedstorevisethequalitycontrol(QC)suitablefortheHimawari-8AMVs.


NWPSYSTEMFOROSE


NWPsystemforOSE

8

Global(GSM-DA)

Purposes Short- andmedium-rangeforecasts

Forecastdomain Globe

Gridsize 20km

Verticallevels/Top 100/0.01hPa

Forecastrange(Initialtime) 84hours(00,06,18UTC)264hours(12UTC)

Initialcondition 4D-VarAnalysisTimewindow 6-hourInner-loopmodelres. 55km


CHARACTERISTICSOFHIMAWARI-8AMVS


CharacteristicsofHimawari-8AMV• EvaluatedstatisticallyagainstthefirstguessesoftheGSM-DA

• ComparedwithMTSAT-2AMVs• Conditions

– Over60QualityIndicator(QI)withforecast– Period:From5Februaryto20March2015– Investigationitems

• Histogramsofthenormalizeddifference(O-B)betweentherelevantwindspeedsandfirstguesses

• Results– ProperGaussiandistributionsindataassimilation– BetteraccuracyHimawari-8AMVscomparingtoMTSAT-2AMVs


O-BnormalizedhistogramsofHimawari-8AMVsintheNorthernHemisphere(polewardof20N)

11

NH-IR-HL NH-IR-ML NH-IR-LL

NH-VS-LLNH-WV-HL

0.15 2.63 -0.77 3.22

1184701398727

H8 sample num.MT2 sample Num.

H8: ME STDMT2：ME STD

1238220254619

-0.08 2.39 -0.76 3.15 2655491

1779867-0.16 1.65 0.03 1.73

1100327502840

-0.09 1.56 0.02 1.60

0.44 2.65 0.31 3.28 1884951

517113

ME: Mean Error (unit m/s)STD: Standard Deviation (unit m/s)

IR(B07+B13)

VIS(B03)

WV(B08+B09+B10)

HL：≦400 hPaML：400～700 hPaLL：≧700 hPa

HL ML LL

O-B normalized histograms for other regions has the same characteristics.


QUALITYCONTROL(QC)


QCforHimawari-8AMVs

• TosupporttheeffectiveuseofHimawari-8AMVs,theAMVpre-processingsystemwasupdatedinthreemainways.– Revisedqualityindicator(QI,Holmlund 1998)withforecastthresholds

forlow-qualityAMVrejection– Revisedclimatologicalchecking

• RejectionofIRandVISAMVsoverlandbelow700hPa• UseofAMVsinthemiddle troposphere (utilization limitationrelease)

– Introduceda100-kmsuper-observationtechniqueforJapanandthesurroundingareas intotheglobalNWPsystem (introduceda200-kmthinningschemefortheotherregions)

• DetailsofotherQCmeasuresareprovidedontheNWPSAFAMVmonitoringpage*.*http://nwpsaf.eu/monitoring/amv/amvusage/jmamodel.html


Super-observation(SPOB)technique• Purpose

– PreventionofobservedinformationlossofmanyAMVsbythinning

– Reductionofbothobservationerrorsandfirstguesserrors– Improvementofmeantyphoonpositionalerrors

• ImprovementoftyphoontrackforecastsbyOSEsforMTSATRS-AMVswithSPOBin2013and2014(Yamashita2014,IWW12)

• Method– AveragingofAMVs(observationtime,level,space,winddirectionsandspeeds)by100kmx100kmx100hPa (definedas100kmSPOB)intervalsineachhourlytimewindowinassimilationforJapanandthesurroundingareas(20Nto45Nand120Eto150E)


VerificationsofSPOBtechnique• UsingMTSAT-1RRapidScanAMVsfromOct.1toOct.30,

2014• Targetedfora100kmSPOBgridpointaroundCHICHIJIMA• InvestigationitemsØ Histogramofthenormalizeddifference betweenwindspeedsand

CHICHIJIMASonde ObservationsorfirstguessesØ ComparedwithSPOBAMVsandallsensorsAMVs

15

TOKYO

CHICHIJIMA

One SPOB grid point

HL：≦400 hPa LL：≧700 hPaHL：≦400 hPa LL：≧700 hPa

Rel

ativ

e fre

quen

cy

First guess departure (O-B) (m/s)Sonde departure (AMV-SONDE) (m/s)

■SPOB AMVs after QC ■All sensors AMVs after QC

・Improved Gaussian distribution・Almost reduction of AMV-SONDE and O-B wind speed differences

improved improvedimproved


OSEFORHIMAWARI-8AMV


ExperimentalDesignforGlobalNWPsystem

17

Name Specification(Maindifferences)CNTL Aschemeofthe200kmthinningofOPE-AMVs

inthe6hourtimewindow

TEST CNTL+QCforHimawari-8AMVs(100kmSPOBetc.)(100kmSPOBforJapanandthesurroundingareasand200kmthinningfortheotherregions)+NOMTSAT-2AMVs

• Period– Winter2015

• Assimilation :From17Januaryto11March2015• Forecast:From17Januaryto28February2015

– Summer2015• Assimilation:From 3Julyto11September2015• Forecast:From3Julyto11September2015


DatacoverageandwindspeedSTDdifferencesbetweenTESTandCNTLonanalyzedfields

18

●GOES-15 ●MET-7 ●LEOGEO

00 UTC 20 July 2015

CNTL TEST

O-B wind speed STD differences below 700 hPa for summer 2015

BetterW

orse

Normalized O-B wind speed STD differences against JMA’s wind profiler observations for summer 2015

●MTSAT ●Himawari-8

WorseBetter

• Improved data coverage• Reduction of O-B wind speed differences

over the Himawari-8 observation area( especially around Japan )

• Impact of revision of derived wind vector methods and introduced SPOB around Japan


ResultsofOSEinsummer2015

19

Forecast lead time (hours)

BetterW

orse

Normalized RMSE differences around Japan between TEST and CNTL for 850 hPa wind vectors Average of typhoon positional errors

TESTCNTLBST

Typhoon track forecast of NANGKA (T1511) initialized at 12 UTC on 13 July 2015.

Improved

Enhancement ofwind speed to the northward

Enhancement of jet stream


U V

Analyzed field of U-component and V-component winds around Japan (Zonal mean meridional cross sections: TEST-CNTL)

Summary(1/2)• CharacteristicsofHimawari-8AMV

– Useofnewtrackingandnewheightassignmentalgorithms– ProperGaussiandistributionsindataassimilation– BetteraccuracyHimawari-8AMVscomparingtoMTSAT-2AMVs

• QCforHimawari-8AMV– RevisedQIwithforecastthresholdsforlow-qualityAMVrejection– Revisedclimatologicalchecking– Introductionofa100-kmsuper-observationtechnique(SPOB)forJapan

andthesurroundingareas

• ResultsofOSEs– Modificationofatmosphericgeneralcirculation(especiallyHimawari-8

observationarea)Ø Enhancementof windspeedtothenorthwardØ Enhancementof jetstream,andshiftofthestreamtothesouthward


Summary(2/2)• ResultofOSE(continuation)

– ReductionofO-BwindspeeddifferencesovertheHimawari-8observationarea(especiallyaroundJapan)

– Significantimprovements(upto3– 6%onaverage)for850hPawindvectorsuntiltwo-dayforecastsaroundJapanforsummer2015

– Improvementofmeantyphoonpositionalerrors(Thereductionwasaround6%with24-hourto48-hourforecastleadtimes.)

– PositiveimpactsonmostphysicalelementsandheightsintheSouthernHemispherewerealsoseeninfour-dayforecastsforwinter2015(notshown)

– Positiveorneutralimpactsforotherphysicalelementsandheights/regions

• Himawari-8AMVswiththerevisedpre-processingsystemhaveintroducedintheJMA’soperationalNWPsystemssince17March2016.


Futureplans• IntroductionofminorrevisionofQCforHimawari-8AMVinOctober2016– RejectionofHimawari-8AMVswithnegativewindspeedbiasesassociatedinjetstream

• ProperregionexpansionfromJapanareasofAMVswithSPOBmethodintotheglobalNWPsystem

• UseofHimawari-8AMVswithSPOBmethodintotheregionalNWPsystems– Considerationofsuper-observationprocedureintheappropriateareaandgridsize

• UseofnewpolarAMVsin2017– S-NPP/VIIRS,Dual-Metop/AVHRR,Terra/MISR,Aqua/AIRS


THANKYOUFORYOURATTENTION


BACKUP


NWPsystemforOSE

25

Global(GSM-DA)

Meso-Scale(MSM-DA)

Local(LFM-DA)

Purposes Short- andmedium-rangeforecasts

Very-short-rangeforecasts,aviationforecasts

Forecastdomain GlobeJapananditssurroundingareas

Japananditssurroundingareas

Gridsize 20km 5km 2km

Verticallevels/Top 100/0.01hPa 48/21.8km 58/20.2km

Forecastrange(Initialtime)

84hours(00,06,18UTC)264hours(12UTC)

39hours(00,03,06,09,12,15,18,21UTC)

9hours(hourly)

Initialcondition 4D-VarAnalysis 4D-VarAnalysis 3D-VarAnalysis

Timewindow 6-hour 3-hour3D-Varanalysesand1-hforecastsarerepeatedinturnfor3hours.

Inner-loopmodelres.55km 15km 5km

Today’s talk


QIthresholds• RevisedinconsiderationofHimawari-8AMVcharacteristics

26

Area Sensor HL（≦400hPa）

ML（400-700hPa）

LL（≧700hPa）

NH（polewards of20N）

IR(B07+B13) 85 94 88

VIS(B03) 88 95 85

WV(B08+B09+B10)

85 85 ―

EQ（20S-20N）

IR 85 85 88

VIS 95 90 85

WV 85 85 ―

SH（polewards of20S）

IR 92 91 93

VIS 96 96 85

WV 95 85 ―


Climatologicalchecking

• RejectionofIRandVISAMVsoverlandbelow700hPa• UseofAMVsinthemiddletroposphere


OSEFORHIMAWARI-8AMVUSINGMESO-SCALENWPSYSTEM

(MSM)


ExperimentalDesignforMeso-scaleNWPsystem

29

Name Specification(Maindifferences)CNTL Aschemeofthe200kmthinningofOPE-AMVs

inthe3hourtimewindow

TEST CNTL+QCforHimawari-8AMVs(sameasaschemeofCNTL)+NOMTSAT-2AMVs

• Period– Summer2015

• Assimilation:From 7August to11September2015• Forecast:From7August to11September2015


ResultofOSE(RainScoreandCaseStudyofheavyrain)

30

CNTL TEST

OBS

A case study of Kanto-Tohoku heavy rain （FT=03 at 03 UTC 9 September, 2015）

CNTLTEST

CNTLTEST

Equitable Threat Score (ETS)

Bias Score (BS)

Better

improved


Incrementofgeopotentialheightandwindsfor850hPa at03UTC9September2015


Strengthened convergence winds along E140 line

CNTL

TEST

Himawari-8 AMVs

NO AMV

assimilation of himawari-8 atmospheric motion...

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