GSI Hybrid EnKF-3DVAR Upgrade

1. GSI Hybrid EnKF-3DVAR Upgrade • Components • GPS RO bending angle rather than refractivity • Inclusion of compressibility factors for atmosphere • Retune SBUV ob errors – fix bug at top • Update radiance usage flags • Prepare for monitoring NPP and Metop-B (Use of data?) • Add GOES-13 data • Add Severi CSBT radiance product • Satellite monitoring stats code included in Ops. • New Sat wind data and QC • EnKF hybrid system • Update to current version of trunk • New version of Forecast model • Restructured to include options for Semi-Lagrangian & NSST ModelUpdated postprocessor • CAPE, CIN, & Lifted Index calculated from virtual temperature • Ability to output GRIB2 directly • Ability to read GFS spectral coefficient file which will be exercised during this implementation to save post run time • 4 new variables for Fire Wx, 8 for Wind Energy, 3 for severe weather • Switch to use CRTM 2.0.2 lib and coefficient files

2. Motivation from Var • Current background error covariance (applied operationally) in VAR • Isotropic recursive filters • Poor handle on cross-variable covariance • Minimal flow-dependence added • Implicit flow-dependence through linearization in normal mode constraint (Kleist et al. 2009) • Flow-dependent variances (only for wind, temperature, and pressure) based on background tendencies • Tuned NMC-based estimate (lagged forecast pairs)

3. EnKF/3DVar hybrid J : Penalty (Fit to background + Fit to observations + Constraints) x’ : Analysis increment (xa – xb) ; where xb is a background BVar : Background error covariance H : Observations (forward) operator R : Observation error covariance (Instrument + representativeness) yo’ : Observation innovations Jc : Constraints (physical quantities, balance/noise, etc.) B is typically static and estimated a-priori/offline

4. Hybrid Variational-Ensemble • Incorporate ensemble perturbations directly into variational cost function through extended control variable • Lorenc (2003), Buehner (2005), Wang et. al. (2007), etc. bf & be: weighting coefficients for fixed and ensemble covariance respectively xt: (total increment) sum of increment from fixed/static B (xf) and ensemble B ak: extended control variable; :ensemble perturbation L: correlation matrix [localization on ensemble perturbations]

5. Dual-Res Coupled Hybrid member 1 forecast member 1 analysis EnKF member update member 2 forecast recenter analysis ensemble member 2 analysis member 3 analysis member 3 forecast GSI Hybrid Ens/Var high res forecast high res analysis Previous Cycle Current Update Cycle

6. Status • Coding/parallel scripting completed • Except possible changes due to NPP and GOES-15 data • Optimized version of post being used – so no delay in delivery of post fields expected. • Some data handling issues being worked. • Parallel without relocation and ozone hybrid from June 1, 2011- Oct. 7, 2011 • Problems with extrapolation of ozone into data void regions (South Pole) • Initial hurricane location degraded (forecast improved)

7. Status • Modification to system • Reinstate hurricane relocation • Uncouple ozone analysis from hybrid • New parallels started • Rerun beginning June 1, 2011 (will start when backup machine returns) • Real time catch up starting Nov. 1, 2011 (up to Nov. 15, 2011) • Results that follow are from previous parallel • Significant changes to meteorological fields not expected (except hurricane relocation)

8. 500mb Anomaly Correlation

9. 1000mb Anomaly Correlation

10. 200mb Tropical winds

11. 850mb Tropical winds

12. 12-36 hour precipitation scores

13. 36-60 hour precipitation scores

14. 60-84 hour precipitation scores

18. Hurricane track

19. More complete diagnostics Retrospective http://www.emc.ncep.noaa.gov/gmb/wd20rt/experiments/prd12q3h/vsdb/ Real Time catch up http://www.emc.ncep.noaa.gov/gmb/wd20rt/experiments/prd12q3r/vsdb/

20. Cost • Analysis/GSI side • Minimal additional cost (~2 nodes) • Reading in ensemble (3-9 hour forecast from previous cycle) • Some additional computations in J calculations • 1 additional field • Coding complete/in place • Additional “GDAS” Ensemble (T254L64 GDAS) • EnKF-based perturbation update • Cost comparable to current analysis [ 8-10 nodes, <40 minutes] • Includes ensemble of GSI runs to get O-F and actual ensemble update step • Work ongoing to optimize coding and scripting • 9hr forecasts, needs to be done only in time for next (not current) cycle

21. Concerns • Rain/no-rain for 12-36 hour forecast (spin-up?) • Changes in initial clouds • Part of spin-up? • Tasked to attempt to incorporate NPP data. • Biggest concern is computer resources to catch up to real time.

22. NPP • ATMS data available • Needs some development because of different size FOVs for different channels (code change or preprocessor) • Quality control check out • Bias correction spin up • CrIS instrument to be turned on in Dec. • Major calibration of CrIS– Jan. 15 • Should be similar to AIRS and IASI – significant development (code changes) unlikely • Quality control check out • Bias correction spin up

23. NPP • Tentative Schedule • RFC to NCO 1/3/12 • Complete development for ATMS ~1/15/12 • Major calibration update for CrIS 1/15/12 • Check out quality control/bias correction 2/6/12 • Short off-line test ends 2/16/12 • NCO parallel testing begins 2/16/12 • Implementation 4/1/12 • Any unexpected finding that delays the schedule will stop the implementation of NPP. • No chance for completion of NPP impact studies prior to NCO parallel. (JCSDA)