1 / 14

First Experience with KENDA at MeteoSwiss

First Experience with KENDA at MeteoSwiss. Daniel Leuenberger, MeteoSwiss a big thanks to Hendrik Reich, Andreas Rhodin and Harald Anlauf ( DWD). Project COSMO-NExT. Boundary conditions : IFS 10km 4x daily. Boundary conditions : VarEPS 20km 2x daily.

kira
Download Presentation

First Experience with KENDA at MeteoSwiss

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. First Experience with KENDA atMeteoSwiss Daniel Leuenberger, MeteoSwiss a bigthanks toHendrik Reich, Andreas Rhodinand Harald Anlauf (DWD)

  2. Project COSMO-NExT Boundaryconditions: IFS10km4x daily Boundaryconditions: VarEPS20km2x daily ensembledataassimilation: LETKF COSMO-E: 2x daily 5 dayforecasts2.2km gridsize (convectionpermitting) O(21) ensemblemembers COSMO-1: 8x daily O(24 hour) forecasts1.1km gridsize (convectionpermitting)

  3. First real casestudy • LETKF integrated in MeteoSwiss NWP suite • Assessthequalityofthedeterministicanalysisandcomparewith a nudgingexperimentand a freeforecast (work in progress) • Summer 2012 period 25.7.-31.7.2012 (7 days) withmoderate convectiveactivityand a cold front passage

  4. Experimental setup I • Operational COSMO-2 setup • 1h update cycles • LETKF • 40 members + deterministicanalysis (LETKF_DET) • DWD namelistadaptedto COSMO-2 • Constant covarianceinflation (error in oursetup) • LETKF_SPPT • Same asLETKF, but withuseof SPPT duringforecaststep • NUDGING • As operational COSMO-2 analysis but without LHN andwithoutassimilationof TD_2M • NO_OBS • Same as NUDGING, but noassimilationofobservations

  5. Experimental setup II • Identicalsetofobservations(cdfinfiles) forall experimentsTEMP, AMDAR, SYNOP,WINDPROF • LBC from operational ECMWF EPS (first 40 members) forLETKFandECMWF deterministicforecastforLETKF_DET, NUDGINGandNO_OBS • Idential IC atstartofperiodforLETKF_DET, NUDGINGandNO_OBSfrom COSMO-2 opranalysisof 25.7.2012 00UTC • Initial ensemblefor LETKF atstartofperioddownscaledfrom ECMWF EPS. Soilfieldsfrom COSMO-2 opranalysisfor all members • COSMO 4.26 and LETKF 1.26 from 27.6.2013

  6. Comparisonwithsurfaceobs Meandailycycleoverca 450 stations and 7 days T_2M FF_10M Ps TD_2M

  7. Comparisonwithsurfaceobs Temporal evolutionof RMSE, meanoverca 450 stations T_2M FF_10M TD_2M Ps

  8. Analysis time evolution • Domain average, lower 3000m • Generally similarevolutionof all experiments (weare in a LAM!) • LETKF ensemblemeangenerallyverysimilarto LETKF det (thisisgoodnews!) • Influenceof SPPT not really large • EXCEPT… • All aboveis not reallytrueforhumidity! ps T qv

  9. Spread «reduction» after LETKF

  10. Spread «reduction» after LETKF • Large reduction in surfacepressurespread, boundaryeffects… • Onlysmallreduction in temperaturespreadat 900m ps K K T@900m

  11. First impression • LETKF technicallyworks • Comparisonwithsurfaceobservationssuggest • Generally: LETKF betterthan NO_OBS, but worsethannudging • Assimilation ofsurfacepressureappearstoworkparticularlywell • Differencesbetween LETKF andnudginglargestatnoonand in the Po valley • Large RMSE in Td_2m (not assimilated in anyoftheexperiments) • LETKF_DET analysisgenerallyverycloseto LETKF ensemblemean • SPPT hasonlysmall but positive impact

  12. Next steps • Look atcovarianceinflation (seemstobe a technicalproblem) • Revise LBC strategy (IFS det + IFS EPS perturbations) • Look atdiagnosticsandinnovationstatistics (NEFFprove!) • Continuewithidealizedtestsanddeveloptoolforsyntheticobservations • Start withdeterministicanalysisfor COSMO-1

  13. Thankyouforyourattention

  14. Adaptive Inflation

More Related