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ARP Meeting Soundings Algorithm Research Panel

ARP Meeting Soundings Algorithm Research Panel. GOES Sounder Products Assimilation of GOES Sounder Clouds Tim Schmit NOAA/NESDIS/ORA/ARAD/ASPT Washington DC April 20, 1999. Presented at COMET Faculty 99 Course by Bob Aune Monday, 7 June 1999. GOES Sounder Products. GOES Sounders

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ARP Meeting Soundings Algorithm Research Panel

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  1. ARP MeetingSoundings Algorithm Research Panel GOES Sounder Products Assimilation of GOES Sounder Clouds Tim Schmit NOAA/NESDIS/ORA/ARAD/ASPT Washington DC April 20, 1999 Presented at COMET Faculty 99 Course by Bob Aune Monday, 7 June 1999

  2. GOES Sounder Products GOES Sounders 18 Infrared Channels 1 Visible Channel Filter Wheel Radiometer Hourly CONUS Coverage (to supplement ASOS observations)

  3. GOES Imager -- Spectral Coverage

  4. GOES Sounder -- Spectral Coverage

  5. GOES Sounder -- Example of all the channels

  6. Longwave Weighting Functions -- Standard Atmosphere

  7. Mid wave Weighting Functions -- Standard Atmosphere

  8. Shortwave Weighting Functions -- Standard Atmosphere

  9. Spatial Coverage of two GOES Sounders

  10. GOES Retrieval Algorithm References: Smith et al., 1985, Advances in Remote Sensing Hayden, 1988, Journal of Applied Meteorology Hayden et al, 1996, Journal of Applied Meteorology Menzel et al., 1998, Bulletin of the AMS Li et al., 1999, Applied Optics Ma et al., 1999, Journal of Applied Meteorology Non-linear, Physical, Simultaneous

  11. Derived Product Images (DPI): Guess TPW + RAOBS Retrieved TPW + RAOBS

  12. GOES-8 retrieval moisture verification The dates range from April 1997 to March 1998 (00 UTC). The match distance is 0.25 degree. The guess is based on the Eta. The bias, root-mean-square (RMS) and root-mean-square error (RMSE) compared to radiosondes (in mm). sigma is the ratio of the pressure over the surface pressure. Sample size is 2363. Guess Retrieval Bias RMS RMSE Bias RMS RMSE Total Water Vapor -1.1 3.4 3.6 -1.5 3.0 3.3 WV1 (Surface to .9 sigma) -0.4 1.5 1.5 -0.5 1.4 1.5 WV2 (0.9 to 0.7 sigma) -0.4 2.0 2.0 -0.6 1.7 1.8 WV3 (0.7 to 0.3 sigma) -0.3 1.2 1.3 -0.4 1.0 1.1

  13. Water Vapor increase seen by both SSM/I and GOES-8

  14. Early Impact Test: Eta Forecast of Moisture Improved A negative RMS Error Difference implies an improved forecast

  15. GOES-8/10 Sounder being used in NWP: Operational • Water vapor winds improve TC trajectories • 4 layers of G-8/10 retrieved moisture used in Eta over CONUS and nearby oceans. • TPW (Total Precipitable Water) used in RUC-2 (Rapid Update Cycle), if surface pressure is more than 900 hPa. • Clear radiances assimilated in NCEP Global model (only G-8 over ocean).

  16. Water Vapor Winds improve TC trajectories GFDL Model Tropical Cyclone Jeanne/Ivan (14 cases) Mean Track Forecast Errors (km) Forecast interval (h):24hr 48hr 72hr Control (NO SATWINDS) 196 278 387 Control + SATWINDS 154 240 348 (including sounder winds)

  17. Sensitivity to the Assimilation Weights Overall, the GOES PW improves 24-36 hour Eta precipitation forecasts.

  18. Clouds Assimilation of GOES Sounder Clouds CRAS RUC-2 Eta

  19. Sounder Cloud Top Pressure DPI: Clear Low Middle High

  20. Review of the CO2 Technique

  21. GOES-8/10 Sounder Cloud Data in NWP: Research • Cloud information used in CIMSS Regional Analysis System (CRAS) over both land and ocean. • RUC-2 is using hourly cloud-top information in continuous real-time cloud analysis experiments. • Experiments with the NCEP Eta system have begun.

  22. 3-hour forecast: No Sounder data Coverage: CTP and TPW 3-hour forecast: With Sounder data Observed GOES-9 Sounder Image More realistic moisture forecasts with GOES sounder data.

  23. 3-hour forecast: No Sounder data Coverage: CTP and TPW 3-hour forecast: With Sounder data Observed GOES-9 Sounder Image More realistic moisture forecasts with GOES sounder data.

  24. GOES Sounder-Derived Cloud Product in the RUC 00 UTC 23 March 1999 GOES Sounder- Derived Cloud Top Pressure 900 mb 600 300 Model-Derived Cloud Top Pressure

  25. GOES Sounder-Derived Cloud Product in the RUC 00 UTC 23 March 1999 GOES Sounder-Derived plus Model-Derived Cloud Top Pressure Impact of the GOES Sounder-Derived Cloud Product (Gray to Black indicate cloud added; Yellow to Red indicate cloud removed by GOES data)

  26. High Clouds: Jan. 28, 1999 00 UTC No Sounder Clouds Assimilated into the EDAS Assimilating Sounder Clouds for 5 time periods

  27. High Clouds: Jan. 28 00UTC Satellite Image Clear - White Low - Orange Mid - Yellow High - Blue Low Mid High Clear EDAS Difference (NOSAT-SAT) Red=Removed

  28. Mid-LevelClouds: Jan. 28, 1999 00 UTC No Sounder Clouds Assimilated into the EDAS Assimilating Sounder Clouds for 5 time periods

  29. Jan. 28 00UTC Mid-Level Clouds: Satellite Image Clear - White Low - Orange Mid - Yellow High - Blue Clear Low Mid High EDAS Difference (NOSAT-SAT) Red=Removed

  30. The last entry is the sum of all days. 1998 (Month/Day) Removing the cloud water mass where the Sounder product indicates clear only slightly improves (positive difference) the Eta precipitation forecasts.

  31. Cloud Observations Cloud Physics Cloud Assimilation The use of satellite cloud data may lead to modifications of the Cloud Physics to ensure the model cloud generation and removal terms are consistent with the observations.

  32. GOES Sounder Band Central Frequency Some Uses 1 14.7 Retrieval, Ozone 2 14.4 Retrieval, Ozone 3 14.0 Retrieval, Ozone, Clouds 4 13.7 Retrieval, Ozone, Clouds 5 13.4 Retrieval, Clouds, Cloud-Clearing 6 12.7 Retrieval, Clouds 7 12.0 Retrieval, Clouds, Cloud-Clearing 8 11.0 Retrieval, Winds, Clouds, Snow, Cloud-Clearing 9 9.7 Ozone 10 7.5 Retrieval, Winds 11 7.0 Retrieval, Winds 12 6.5 Retrieval, Ozone 13 4.6 Retrieval, Ozone 14 4.5 Retrieval, Ozone 15 4.4 Retrieval, Ozone 16 4.1 Retrieval, Ozone, Snow 17 4.0 Snow, Cloud-Clearing 18 3.8 Snow

  33. Summary • The GOES Sounders monitor hourly the CONUS earth/atmosphere. • Layers of retrieved moisture from the GOES sounder improve the operational Eta precipitation forecasts. • Retrieval and Cloud information complement each other. • Assimilation of the Cloud information is being investigated in both research and operational models.

  34. Summary • Some of the clear radiances are being used directly in numerical models. • Future GOES retrievals: • 5x5 = 3x3 field-of-view • Discrepancy Principle • Surface Emissivity • The use of GOES Sounder products are also being used in various forecast offices. • More information: • http:// cimss.ssec.wisc.edu/goes.html • http://orbit-net.nesdis.noaa.gov/goes/

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