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Motivation

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Motivation

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  1. Some Comparisons Between IMPROVE2 and IPEX Bulk Microphysical Verification     Brian A. Colle*, Yanluan Lin*, Justin B. Wolfe*, W. James Steenburgh@, David E. Kingsmill+, Mark Stoelinga#, and Chris Woods#*Stony Brook University / SUNY#University of Washington, Seattle, WA@ University of Utah, Salt Lake City+ University of Colorado / CIRES

  2. Motivation • MM5’s BMPs have been thoroughly verified and published for one IMPROVE IOP (13-14 DEC). What about other cases? • General improvement of BMPs will likely require microphysical analysis using other field data (IPEX, PACJET, CALJET, ….). • There have been no WRF verification of IMPROVE IOPs.

  3. 3250 3000 2750 2500 2250 2000 1750 1500 Elevation (m) 50 km COMPARISON OF IMPROVE-2 WITH RESULTS FROM IPEX NOAA P3 Leg 1 Leg 4 Leg 3 IPEX IOP3: 12-13 February 2000 Leg 2 Great Leg 5 x KMTX Great Salt Lake Desert Cascade Range NOAA P3 Stacks Salt Lake Wasatch Range SLC IMPROVE-2: 4-5 December 2001 Oquirrh Mts Stansbury Mts

  4. 4-5 Dec Simulation • Same setup as Garvert et al. (2005a). • HOWEVER NO FDDA -> using FDDA (GDAS analyses) degraded the forecast … too warm at low-levels, and too convective… • There is low-level wind sensitivity to PBL parameterization. Eta-PBL better. • Since NOFDDA was run, a comparison with WRF could be completed (using Hong et al. 2004 BMP for now, is exmoisg available??).

  5. NCEP 850mb analysis 00 UTC 05 Dec 2001 Model 850mb forecast 00 UTC 05 Dec 2001 (12 hr forecast)

  6. IR IMAGERY 23 UTC 04 Dec 2001

  7. UW Sounding Comparison at 0100 UTC 5 Dec (model green, obs orange) MM5-MRF (winds too weak, too warm near surface) MM5-Eta (winds better) WRF-MRF

  8. P-3 legs 2&3 (4km green, 1.33km orange) – Eta better wind speeds, 1.33km good vertical velocities MM5-MRF MM5-ETA leg3 leg2

  9. WRF

  10. MM5-MRF MM5-Eta has better qualitative precip structure agreement during flight Spol (0100 UTC 5 Dec) MM5-Eta

  11. Model 12-h precip (in mm) for 8-20 h MM5-MRF WRF-MRF MM5-Eta

  12. MM5-Eta THE CLASSIC OVERPREDICTION NEAR CREST PROBLEMModel Percent of Observed Precipitation (8-20 h) WRF-MRF

  13. Assumes all P-3 particles are graupel (upper-bound for P-3), dry snow ~50% as much MM5-ETA MM5-WRF leg2 leg3

  14. IPEX: 1800 UTC 12 February 2000 Observed surface winds 1.33-km MM5 (sfc T and winds, 6 h) Colle et al. 2005 MWR in press

  15. KMTX (2260 m, 1830 UTC) 1.33-km MM5 (2260 m) B A 6 5 4 3 2 1 km MSL A B

  16. IPEX: 1800-0000 UTC Precipitation 1.33-km (6-12 h pcp in mm) 1.33-km % of observed

  17. Model Cross Section and two P-3 legs at 1900 UTC -11 oC -5 oC Snow, graupel, and cloud water

  18. Model vs. Observed (NOAA P-3) at 3800 m Simulated Cloud water (g kg-1) Observed Snow (g kg-1) Cross-barrier wind speed (m s-1) Vertical motion (cm s-1) WEST Crest EAST

  19. Model vs. Observed (NOAA P-3) at 2800 m Simulated Cloud water (g kg-1) Observed Snow (g kg-1) Cross-barrier wind speed (m s-1) Vertical motion (cm s-1) EAST WEST

  20. Summary • Preliminary analysis of 4-5 Dec IMPROVE-2 suggests similar problems to the 13-14 Dec IOP. There is precip overprediction near the crest associated with an overprediction of snow and graupel aloft. • Unlike 13-14 December, the exmoisg underpredicts cloud water over lower windward slope. • IPEX results are different than IMPROVE-2. Model underpredicted snow aloft and overpredicted cloud water. Why?? (CCN?, colder temps in IPEX?, …). IPEX results suggests need to confirm IMPROVE results in other regions.

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