An Regional Enemble Kalman Filter Data Assimilation System Employing GSI Observation Processing and Initial Tests for Rapid Refresh Forecast Configurations Kefeng Zhu, Yujie Pan, Xue Ming and Xuguang Wang CAPS

Code development status EnKFv1----we modified the global EnSRF code from Dr. Jeff Whitaker of ESRL and linked this EnSRF package with the regional GSI for RR application. EnKFv2---- we merged regional EnKF with the latest global EnKF, by moving codes specific to regional EnKF into a unified version. And a new flag ‘iflagreg’ was added to control the regional analysis option. In this unified version, the variables updated during the regional EnKF assimilation were x-component wind (U), y-component wind (V), potential temperature (T), perturbation geopotential (PH, not used in the previous EnKFv1), water vapor mixing ratio (Q) and perturbation dry air mass in column (Mu). EnKFv3----instead of interpolating the U and V to the A grid during the EnKF analysis process, we keep the U and V in the original C grids

~13km Rapid Refresh(RR) Diabatic integration Full physics integration

Verification followed

EnSRF EnSRF—RR RUC EnKF Test Domain 207x207 grid points ~40 km, 51 levels The 13 km RR-like forecast Domain 532x532 grid points ~13 km, 51 levels Current RUC Domain as indicated Domains

Experiment flowchart

ADPSFC SFCSHP ADPSFC 280/ / / / ADPUPA SFCSHP 282 ADPUPA 220/120 Observation type used for verification Surface: Land ,281,284 (U,V) 187,181,184 (RH,T,PRMSL) Sea---280,282 (U,V) 180 (RH,T,PRMSL) Up air: 220,221,223 (U,V) 120 (RH,T,PRMSL) Quality mark: 2 PROFLR 223

ExperimentSimple covariance State-dependentHorizontal (km) EnKFnofixA02L0 6 b=0c=0.2r cut =600 EnKFfixA02L06b=0.2c=0.2r cut =600 EnKFfixA09L12b=0.2c=0.9r cut =1200 GSI Inflation factors and horizontal cutoff radius configuration test Note: Here the EnKF comes from the 40 members 3-h forecast ensemble mean; GSI is a single deterministic forecast. The verification period are from 00 UTC May 8 ~ 06 UTC May 16, There are 66 samples collected for the observation type ADPSFC, SFCSHP, PROFLR, but 16 samples for the ADPUPA

Horizontal and vertical localization factor where

Inflation algorithms Simple covariance State-dependent covariance inflation Double inflation taper(r)

RH---ADPUPA T---ADPUPA V---ADPUPA U---ADPUPA U---PROFLR V---PROFLR

ExperimentSimple covariance State- dependent VerticalHorizontal (km) EnKFLn20VHb=0.2c=0.9lncut=2.0r cut =1200*500/p ob EnKFLn12VObb=0.2c=0.9lncut=1.2Varies with ob type EnKFLn11VObHb=0.2c=0.9lncut=1.1 lncutps=1.5 Varies with ob type and height GSI Vertical and horizontal cutoff radius setting test Note: Here the EnKF comes from the 40 members 3-h forecast ensemble mean; GSI is a single deterministic forecast. The verification period are from 00 UTC May 8 ~ 06 UTC May 16, There are 66 samples collected for the observation type ADPSFC, SFCSHP, PROFLR, but 16 samples for the ADPUPA

RH---ADPUPA T---ADPUPA V---ADPUPA U---ADPUPA U---PROFLR V---PROFLR

CasenameDFI setting VerticalHorizontal (km) EnKFdfi20m40sBackward 20m Forward 10m dfi_cutoff_seconds=3600s time_step_dfi=40s lncut=1.1 lncutps=1.5 Varies with ob type and height EnKFdfi40m60sBackward 40m Forward 20m dfi_cutoff_seconds=3600s time_step_dfi=60s lncut=1.2 lncutps=1.2 Varies with ob type EnKFdfi40m40sBackward 40m Forward 20m dfi_cutoff_seconds=2800s time_step_dfi=40s lncut=1.2 lncutps=2.0 Varies with ob type GSIBackward 20m Forward 10m dfi_cutoff_seconds=3600s time_step_dfi=40s DFI setting test

EnKFdfi20m40s3600s/GSI/GFSEnKFdfi40m60s3600s EnKFdfi40m40s2800s

RH---ADPUPA T---ADPUPA V---ADPUPA U---ADPUPA U---PROFLR V---PROFLR

land sea Surface verification: The plots above are the average forecasts innovation of single forecast from ensemble mean analyses for the time period from 00UTC May 8 to 03 UTC May 16, The cycle interval is 3 hours. Totally, there are 66 samples for this statistic. Up air verification: since the observation of ADPUPA are only available at 00, 12 Z. Therefore, for the vertical profile followed, we average the 12 hour forecasts innovation from 00, 12Z. There are totally 17 samples. Longer hour single forecast from ensemble mean analyses

Temperature at 2m-LandTemperature at 2m-Sea RH at 2m-Land RH at 2m-Sea

U at 10m-LandU at 10m-Sea V at 10m-Land V at 10m-Sea

3h 6h9h 12h15h 18h RH

3h 6h9h 12h15h 18h Tmperature

3h 6h9h 12h15h 18h UGRD---ADPUPA

3h 6h9h 12h15h 18h VGRD---ADPUPA

3h 6h9h 12h15h 18h UGRD---PROFLR

3h 6h9h 12h15h 18h VGRD---PROFLR

13 km Verification followed Against Stage IV---GSS(ETS)

GSS (ETS) scores

00~12 UTC May 10,2010 Stage IV 00~12 UTC May 11, ~12 UTC May 13,2010 GSI based forecastEnKF based forecast