Introduction to WRFDA

Transcription

1 Introduction to WRF Hns Hung WRF is Dt Assimiltion system built within the WRF sotwre rmework, used or ppliction in both reserch nd opertionl environments Acknowledge: WRF tem nd mny visitors, AFWA, NCAR, AirDt, NSF-AGS, USWRP, NSF-OPP, NASA, PSU,CWB, BMB, CAA, KMA, EUMETSAT, NUIST WRF Overview - Tutoril 31 Jn

2 WRF in WRF Modeling System WRF Overview - Tutoril 31 Jn

3 Why dt ssimiltion? Initil conditions Clibrtion nd vlidtion Observing system design, monitoring nd ssessment Renlysis Better understnding: Dt ssimiltion methods Model errors Dt errors Physicl process interctions WRF Overview - Tutoril 31 Jn

4 Ktrin trck orecsts (Zhiqun Liu) - Impct o dt Trck 4 WRF Overview - Tutoril 31 Jn

5 Ktrin trck orecsts (Zhng, Zhng, Hung, Zhng) - Impct o methods WRF Overview - Tutoril 31 Jn

6 Modern wether orecst (Bjerknes,1904) A suiciently ccurte knowledge o the stte o the tmosphere t the initil time A suiciently ccurte knowledge o the lws ccording to which one stte o the tmosphere develops rom nother Vilhelm Bjerknes ( ) Anlysis: using observtions nd other inormtion, we cn speciy the tmospheric stte t given initil time: Tody s Wether Forecst: using the equtions, we cn clculte how this stte will chnge over time: Tomorrow s Wether (Peter Lynch) WRF Overview - Tutoril 31 Jn

7 initil stte Model orecst Anlysis observtions WRF Overview - Tutoril 31 Jn

8 Observtions y o, ~ Model stte x, ~10 7 WRF Overview - Tutoril 31 Jn

9 Assimiltion methods Empiricl methods Successive Correction Method (SCM) Nudging Physicl Initilistion (PI), Ltent Het Nudging (LHN) Sttisticl methods Optiml Interpoltion (OI) 3-Dimensionl VARitionl dt ssimiltion (3DVAR) 4-Dimensionl VARitionl dt ssimiltion (4DVAR) Advnced methods Extended Klmn Filter (EKF) Ensemble Klmn Filter (EnFK) Hybrid VAR/Ens WRF Overview - Tutoril 31 Jn

10 WRF Gol: Community WRF system or regionl/globl, reserch/opertions, nd deterministic/probbilistic pplictions Techniques: 3D-Vr 4D-Vr (regionl) Ensemble, Hybrid Vritionl/Ensemble Model: WRF (ARW, NMM, Globl) Observtions: Conv + St + Rdr (+Bogus) Support: NCAR/NESL/MMM/S WRF Overview - Tutoril 31 Jn

11 WRF 3/4D-Vr δx Vr = Uv 3D-Vr: Brker et l D-Vr: Hung et l 2009 x x 3/4D-Vr δx Vr x y o x = x + Uv n J = 1 2 vt v + 1 [ d i H i M i Uv] T R 1 i d i H i M i Uv 2 i=0 [ ] WRF Overview - Tutoril 31 Jn

12 x 1 x 1 δx 1 δx 1 x 1 x 2 x N x 2 x N δx 2 δx N H(x 1 ),σ o H(x 2 ),σ o E T K F δx 2 δx N x 2 x N H(x N ),σ o x 3/4D-Vr δx Vr Vr nd ETKF y o x n = x + Uv +δx ETKFn n J = 1 2 vt v + 1 [ d i H i M i Uv] T R 1 i d i H i M i Uv 2 i=0 [ ] WRF Overview - Tutoril 31 Jn

13 x 1 x 1 δx 1 δx 1 x 1 x 2 x N x 2 x N δx 2 δx N H(x 1 ),σ o H(x 2 ),σ o E T K F δx 2 δx N x 2 x N H(x N ),σ o Hybrid Vr+ETKF (Wng et l 2008) x 3/4D-Vr δx Vr J = W b 2 vt v + W α 2 T A n y o x n = x + Uv +δx ETKFn [ d i H i M i Uv] T R 1 i d i H i M i Uv i=0 [ ] WRF Overview - Tutoril 31 Jn

14 WRF Observtions (35) In-Situ: Surce (SYNOP, METAR, SHIP, BUOY) Upper ir (TEMP, PIBAL, AIREP, ACARS, TAMR) Remotely sensed retrievls: Atmospheric Motion Vectors (geo/polr) SATEM thickness Ground-bsed GPS Totl Precipitble Wter/Zenith Totl Dely SSM/I ocenic surce wind speed nd TPW Sctterometer ocenic surce winds Wind Proiler Rdr rdil velocities nd relectivities Stellite temperture/humidity/thickness proiles GPS rerctivity (eg COSMIC) Stge IV precipittion/rin rte dt (4D-Vr) Rditive Trnser (RTTOV or CRTM): HIRS NOAA-16, NOAA-17, NOAA-18, NOAA-19, METOP-A AMSU-A NOAA-15, NOAA-16, NOAA-18, NOAA-19, EOS-Aqu, METOP-A AMSU-B NOAA-15, NOAA-16, NOAA-17 MHS NOAA-18, NOAA-19, METOP-A AIRS EOS-Aqu SSMIS DMSP-16, DMSP-17, DMSP-18 IASI METOP-A ATMS Suomi-NPP MWTS FY-3 MWHS FY-3 Bogus: TC bogus Globl bogus WRF Overview - Tutoril 31 Jn

15 WRF Rdince Assimiltion Liu nd Auligne, NCAR BUFR 1b rdince ingest RTM interce (v351): RTTOV (v101) or CRTM (v202) NESDIS microwve surce emissivity model Rnge o monitoring dignostics Qulity Control or HIRS, AMSU, AIRS, SSMI/S Bis Correction: Adptive or Vritionl Vritionl observtion error tuning Prllel: MPI Flexible design to esily dd new stellite sensors NOAA (HIRS, AMSU) Aqu (AMSU, AIRS) DMSP(SSMI/S) WRF Overview - Tutoril 31 Jn

16 WRF tutorils July 2008 NCAR Feb 2009 NCAR July 2009 NCAR Aug 2010 NCAR July 2011 NCAR July 2012 NCAR Jul 2013 NCAR 18 April 2009 South Kore Oct 2009 Nnjing, Chin 10 April 2010 Seoul, South Kore 16 April 2011 Busn, South Kore Oct 2011 Bngkok, Thilnd 21 April 2012 Seoul, South Kore Sept 2013 Chengdu, Chin Oct 2013 Vienn, Austri WRF online tutoril nd user guide WRF Overview - Tutoril 31 Jn

17 Recent Tutorils t NCAR 1 WRF Overview 2 Observtion Pre-processing 3 WRF System 4 WRF Set-up, Run 5 WRF Bckground Error Estimtions 6 Rdr Dt 7 Stellite Dt 8 WRF 4D-Vr 9 WRF Hybrid Dt Assimiltion System 10 WRF Tools nd Veriiction 11 Observtion Sensitivity Prctice 1 obsproc 2 wrd (3D-Vr) 3 Single-ob tests 4 Gen_be 5 Rdr 6 Rdince 7 4D-Vr 8 Hybrid 9 Advnced (optionl) The next: July 2014 WRF Overview - Tutoril 31 Jn

18 Google WRF: wwwmmmucredu/wr/users/wrd WRF Overview - Tutoril 31 Jn