1 / 28

MPO 674 Lecture 18

MPO 674 Lecture 18. 4 /3/ 12. NCEP vs ECMWF 3d-Var vs 4d-Var. 3d-Var vs EnKF. 3d-Var vs EnKF. Innovation 10 m/s Ob error 0.1 m/s 4 (u,v) obs 1 degree from center in GSI 1 v ob 150km east of center in WRF/EnKF. CAVEAT: Different Storms!. GSI Analysis Increment of v (m/s)

rumor
Download Presentation

MPO 674 Lecture 18

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. MPO 674 Lecture 18 4/3/12

  2. NCEP vs ECMWF3d-Var vs 4d-Var

  3. 3d-Var vsEnKF

  4. 3d-Var vsEnKF • Innovation 10 m/s • Ob error 0.1 m/s • 4 (u,v) obs 1 degree from center in GSI • 1 v ob 150km east of center in WRF/EnKF. • CAVEAT: Different Storms!

  5. GSI Analysis Increment of v (m/s) Operational Lz WRF/EnKF Analysis Increment of v (m/s)

  6. GSI Analysis Increment of v (m/s) 2 x Lz WRF/EnKF Analysis Increment of v (m/s)

  7. GSI Analysis Increment of v (m/s) 4 x Lz WRF/EnKF Analysis Increment of v (m/s)

  8. Summary: 3d-Var vsEnKF • 3d-Var • Geostrophic & hydrostatic correction (needed 4 “obs”). • Local horizontal correction. • Significant increment only through boundary layer. • Increasing Lz improved storm structure and track forecast. • EnKF • Gradient wind correction (used only 1 “obs”). • Stronger winds associated with shifting the storm further east and increasing intensity of winds. • Troposphere-deep increment: vertical error correlation lengthscale equivalent to 4x of GSI.

  9. 3d-Var vs 4d-Var

  10. From Tom Hamill

  11. NOAA/ESRL: EnKF with GFS ECMWF: 4d-Var

  12. Sampling Errorand Covariance Localization

  13. Petrie (1998, MS Thesis)

  14. Filter Divergence

  15. Hamill et al. (2001, MWR)

  16. Hamill et al. (2001, MWR)

More Related