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Applications of COSMIC to Weather and Climate

Applications of COSMIC to Weather and Climate. Bill Kuo UCAR COSMIC and NCAR ESSL/MMM. COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate). 6 Satellites was launched: 01:40 UTC 15 April 2006 Three instruments: GPS receiver, TIP, Tri-band beacon

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Applications of COSMIC to Weather and Climate

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  1. Applications of COSMIC to Weather and Climate Bill Kuo UCAR COSMIC and NCAR ESSL/MMM

  2. COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) • 6 Satellites was launched: • 01:40 UTC 15 April 2006 • Three instruments: • GPS receiver, TIP, Tri-band beacon • Weather + Space Weather data • Global observations of: • Pressure, Temperature, Humidity • Refractivity • Ionospheric Electron Density • Ionospheric Scintillation • Demonstrate quasi-operational GPS limb sounding with global • coverage in near-real time • Climate Monitoring A Joint Taiwan-U.S. Mission FORMOSAT-3 in Taiwan

  3. The velocity of GPS relative to LEO must be estimated to ~0.2 mm/sec (velocity of GPS is ~3 km/sec and velocity of LEO is ~7 km/sec) to determine precise temperature profiles

  4. The velocity of GPS relative to LEO must be estimated to ~0.2 mm/sec (20 ppb) to determine precise temperature profiles

  5. Over 1 Million Profiles in Real Time4/21/06 – 9/28/2008 Neutral Atmosphere Ionosphre 1,333,237 profiles 1,574,947 profiles

  6. Global FORMOSAT-3 / COSMIC Data Users 882 users 48 Countries

  7. Presentation of first results from COSMIC/ FORMOSAT-3 to appear in Bulletin of American Meteorological Society, March 2008 Anthes et al.

  8. ECMWF SH T Forecast Improvements from COSMICAssimilation of bending angles above 4 km Sean Healy, ECMWF

  9. 100 hPa Temperature vs. radiosondes Sean Healy, ECMWF NH tropics SH

  10. NCEP Impact study with COSMIC • 500 hPa geopotential heights anomaly correlation (the higher the better) as a function of forecast day for two different experiments: • PRYnc (assimilation of operational obs ), • PRYc (PRYnc + COSMIC) • Assimilated ~1,000 COSMIC profiles per day • Assimilated operationally at NCEP 1 May 2007 • Assimilating refractivities from rising and setting occultations at all levels (including low level), provided they pass QC • Results with COSMIC “very encouraging” • Lidia Cucurull, JCSDA

  11. UKMO Bias and RMS as function of forecast range mean mean Temp, 250 hPa, SH Wind speed, 100 hPa, SH RMS RMS

  12. Impact of COSMIC on Hurricane Ernesto (2006)

  13. Hurrican Ernesto: Formed: 24 August 2006 Reached Hurricane strength: 27 August Dissipated: 1 September 2006 15:50 UTC 27 August 2006 Picture taken by MODIS, 250 m resolution

  14. Forecast experiments • No GPS: initialized from AVN/GFS analysis at 2006-08-23-06Z • GPS all: assimilate all 15 GPS profiles at 2006-08-23-06Z, followed by a 5-day forecast • GPS 1 : only assimilate 1 GPS profile at 2006-08-23-06Z, followed by a 5-day forecast WRF/DART EnKF system 36-km, 36 member ensemble Use non-local excess phase observation operator

  15. Assimilate this sounding only Low-level moisture change by assimilating GPS GPS all GPS 1

  16. 2006-08-23-12Z (06h forecast) COSMIC data was critical in prediction the formation and track for Hurricane Ernesto (2006) Assimilate a total of 15 soundings over a 6-h period, and assess their impact on prediction of hurricane genesis Sat. IR No GPS With 15 GPS

  17. 2006-08-24-00Z (18h forecast) Sat. IR No GPS GPS all

  18. 2006-08-24-12Z (30h forecast) Sat. IR No GPS GPS all

  19. 2006-08-25-00Z (42h forecast) Sat. IR No GPS GPS all

  20. 2006-08-25-12Z (54h forecast) Sat. IR No GPS GPS all

  21. 2006-08-26-00Z (66h forecast) Sat. IR No GPS GPS all

  22. 2006-08-26-12Z (78h forecast) Sat. IR No GPS GPS all

  23. 2006-08-27-00Z (90h forecast) Sat. IR No GPS GPS all

  24. 2006-08-27-12Z (102h forecast) Sat. IR No GPS GPS all

  25. WRF/DART ensemble assimilation of COSMIC GPSRO soundings • WRF/DART ensemble Kalman filter data assimilation system • 36-km, 36-members, 5-day assimilation • Assimilation of 171 COSMIC GPSRO soundings (with nonlocal obs operator, Sokolovskiey et al) plus satellite cloud-drift winds • Independent verification by ~100 dropsondes. 171 COSMIC GPSRO soundings during 21-25 August 2006

  26. No COSMIC With COSMIC 06/8/21 12Z 06/8/22 12Z 06/8/23 12Z 06/8/24 12Z 06/8/25 12Z Genesis of Hurricane Ernesto (2006) Continuous data assimilation during genesis stage with WRF EnKF system

  27. Verification of WRF/DART analysis by about 100 dropsondes during the Ernesto genesis stage.

  28. 06/8/21 12Z 06/8/22 12Z 06/8/23 12Z Analysis increment in Q (water vapor) due to the assimilation of COSMIC GPSRO data. 06/8/24 12Z 06/8/25 12Z

  29. No COSMIC With COSMIC 06/8/21 12Z 06/8/22 12Z 06/8/23 12Z 06/8/24 12Z 06/8/25 12Z Genesis of Hurricane Ernesto (2006) Cloud and Rain water Continuous data assimilation during genesis stage with WRF EnKF system

  30. Prediction of Typhoon with a High-Resolution Mesoscale Model Typhoon Jangmi (2008)

  31. Super Typhoon Jangmi (2008)

  32. Radar and Rainfall Obervations

  33. WRF 1.33 km Movable GridInitialized with NCEP GFS analysis Initial Condition: 1200 UTC 27 September 2008

  34. WRF 1.33 km Movable GridInitialized with NCEP GSF analysis Accumulated Rain + SLP Surface wind speed and directions

  35. A COSMIC Sounding during Jangmi

  36. A COSMIC Sounding during Jangmi

  37. COSMIC RO sounding locations (June 8, 2007)

  38. Assimilation Experiments To examine impact of RO data on analysis of the subtropical anti-cyclone over Western Pacific and prediction of a heavy rainfall event over Taiwan  DART/WRF ensemble data assimilation at 36km resolution continuously for June 1-14, 2007 over East Asia • Analyses are produced 6-hourly GPS run: Assimilate radiosonde, satellite cloud-motion winds, cloud-free AIRS temperature + RO refractivity •NoGPS run: The same as GPS run but without RO refractivity

  39. Effect of RO data on 850 hPa Water Vapor Flux Analysis GPS Analysis June 1-14 PV 850 mb RO data Enhances flux from Western Pacific toward Asia Difference of GPS - NoGPS

  40. Effect of RO data on 850 hPa Water Vapor Flux Analysis GPS Analysis June 8-9, 2007 PV 850 mb Difference of GPS - NoGPS GPS RO shows enhanced flux from South & East to Taiwan

  41. Heavy rainfall Caseover Taiwan (June 6-9, 2007) Accumulated gauge precipitation from Pilot SoWMEX Rainfall > 200mm/day on June 7 & 8, 2007

  42. Effect of RO data on 24-hour Prediction of Rainfall (00Z 8 - 00Z 9 June, 2007, unit: mm) GPS Forecast RO data increases forecast rainfall over Taiwan consistent with gauge observations NoGPS Forecast PV 850 mb Difference of GPS - NoGPS

  43. Climate Applications

  44. Precision of COSMIC Profiles • Collocated COSMIC soundings (FM3 - FM4) • 2006.150-2006.300 • Tangent point separation (TPS) < 10 km • Precision of Refractivity (N) < 0.2% between 10 and 20 km altitude • For TPS < 5 km, N precision ~0.1% (~0.25oC precision for temperature) • For TPS< 1 km, N precision ~0.02% (~0.05oC precision for temperature) • Post-Processed products more precise than real-time products • Schreiner, W., C. Rocken, S. Sokolovskiy, S. Syndergaard and D. Hunt, 2007: Estimates of the precision of GPS radio occultations from the COSMIC/FORMOSAT-3 mission. Geophys. Res. Lett., 34, L04808, doi:10.1029/2006GL027557.

  45. Compare GPS RO synthetic BT with NOAA SNO calibrated MSU BT Mean bias CHAMP-COSMIC temp from 500mb to 5 mb =-0.021K 2002/09 2006/09 COSMIC (launched in 2006) vs. CHAMP (launched in 2000) atm tmp

  46. Precision of COSMIC RO Data With 0.02-0.05 K precision at all vertical levels, COSMIC data are useful to inter-calibrate measurements from other satellites Dry temperature difference between 2 nearby COSMIC Satellites Within 10 km

  47. a b c COSMIC data to calibrate AMSU on NOAA satellites

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