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Impact of COSMIC on Hurricanes and High-Impact Weather. Hurricane Ernesto (2006). Impact of COSMIC on Hurricane Ernesto (2006) Forecast. With COSMIC. Without COSMIC. 6-h data assimilation at 0600 UTC 23 August 2006, followed by 66 h forecast. Results from Liu et al., NCAR.
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Impact of COSMIC on HurricaneErnesto (2006) Forecast With COSMIC Without COSMIC 6-h data assimilation at 0600 UTC 23 August 2006, followed by 66 h forecast Results from Liu et al., NCAR
Impact of COSMIC on HurricaneErnesto (2006) Forecast With COSMIC GOES Image GOES Image from Tim Schmitt, SSEC
Continuous assimilation of COSMIC data during hurricane genesis stage
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
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
Verification of WRF/DART analysis by about 100 dropsondes during the Ernesto genesis stage.
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
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
Atmospheric River case: Nov 6-8, 2006 From Ma et al. (2008)
Observed Daily Precipitation 24-h precipitation ending at 1200 UTC 7 November 2006 Flooding and debris flow on White River, Oregon
Assimilation of GPS RO data for an Atmospheric River Event • Use NCEP Regional GSI • 36-km resolution, with both local refractivity and nonlocal excess phase observation operator (Sokolovskiy et al. 2005). • Continuous assimilation from 0000 UTC 3 November through 1800 UTC 9 November (with Regional GSI plus WRF-ARW). • 24-h forecast experiments conducted based on analysis at 1200 UTC 6 November 2006.
Assimilation of GPS RO data for an Atmospheric River Event • Total of 370 COSMIC plus 63 CHAMP GPSRO soundings. • All other operational data used by NCEP are assimilated, in additon to GPSRO data.
Analysis of PW from Nonlocal Experiment at 1200 UTC 7 November 2006
Local - CNTL Nonlocal - CNTL Differences in PW at 1200 UTC 7 November 2006 Impact of GPS RO assimilation: Use of Nonlocal excess phase operator produced more significant changes
RMS differences mean Verification of 0-24h forecast (1200 UTC 6 - 1200 UTC 7 November 2006) against GPSRO observations in terms of excess phase
24-h accumulated precipitation ending at 1200 UTC 7 November 2006 OBS CNTL Non-Local Local
Summary and Conclusions • Assimilation of GPSRO soundings with NCEP Regional GSI and WRF-ARW improved the moisture analysis and precipitation forecasts. • The use of nonlocal excess phase observation operator produces larger analysis increments and further improves the precipitation forecasts.