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USC/JPL GAIM Validation:. GPS & UV Assimilations. Brian Wilson, JPL *. George Hajj, JPL, USC. Chunming Wang, USC. Xiaoqing Pi, JPL, USC. Gary Rosen, USC. GAIM MURI Semi-Annual Review, Park City, Utah, March 11-12, 2002. Band-limited Kalman runs (10/03/2000) Input GPS TEC only
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USC/JPL GAIM Validation: GPS & UV Assimilations Brian Wilson, JPL * George Hajj, JPL, USC Chunming Wang, USC Xiaoqing Pi, JPL, USC Gary Rosen, USC GAIM MURI Semi-Annual Review, Park City, Utah, March 11-12, 2002
Band-limited Kalman runs (10/03/2000) Input GPS TEC only Input UV radiance only Input GPS TEC and UV radiance Validation techniques GAIM vertical TEC versus GIM (2D shell maps of TEC) GAIM density versus NRL retrieval (2D slice) GAIM profiles versus NRL retrieval using Chapman profiles TOPEX vertical TEC comparisons Conclusions Outline
GPS only Assimilation: Is the global GPS Assim. good on this day (as usual) as assessed by postfit residuals and GIM & TOPEX comparisons? Does GAIM 2D density slice agree with NRL EUV retrieval? UV only Assimilation: Are UV data being used effectively? Does GAIM density slice agree with NRL Chapman retrieval? GPS and UV Assimilation: Are GPS & UV data consistent with each other? Are UV data still used effectively when combined with GPS? Motivating Questions
Ingest data from: GPS slant TEC from ground receivers GPS relative TEC from space links ARGOS UV imaging & limb scans Ionosonde data: FoF2, HmF2, etc. DMSP in situ densities & fields C/NOFS datatypes Etc. . . . GAIM Assimilation Runs
For Climate or Assimilation model runs Compare electron density profiles to: IRI95 model ISR data Ionosonde data (foF2, hmF2, & bottomside profiles) 2D density retrievals from UV limb scans Compare vertical TEC to: TOPEX observations GIM maps Compare slant TEC predictions to independent GPS data GAIM Validation Techniques
GAIM assimilation run: Using band-limited Kalman filter Date: 2000/10/03 Input “real” slant TEC from 97 GPS sites (global) 13,107 Grid cells determined by 166,000 TEC obs. (5-min data over 24 hours) Input radiance from UV limb scans (135.6 nm) Partial night-side only Each scan takes ~93 seconds Validation of GAIM Assimilation Results
GPS Ground Network for 00/10/03 (10 degree elevation mask; 450 km shell height)
GAIM vertical TEC versus GIM GAIM density versus NRL UV retrieval GAIM profiles versus UV Chapmans GAIM TEC versus TOPEX vertical TEC 1st Validation Technique
GAIM Climate versus GIM VTEC GAIM Climate on 00/10/03: Ap=30, F10.7=192.1
GAIM Assimilation versus GIM VTEC Assimilating ground GPS TEC on 00/10/03
GAIM vertical TEC versus GIM GAIM density versus NRL UV retrieval GAIM profiles versus UV Chapmans GAIM TEC versus TOPEX vertical TEC 2nd Validation Technique
2D EUV Retrieval Using Chapman Profiles 00/10/03: 1st orbit, 10scans, 30 Chapman parameters.
NRL UV Retrieval versus GAIM Climate NRL 2D Retrieval GAIM Climate GAIM Climate very different from EUV on this day. Difference
NRL UV Retrieval versus GAIM with GPS NRL 2D Retrieval GAIM Assim. of GPS GPS Assim. often different from EUV. Difference
NRL UV Retrieval versus GAIM NRL 2D Retrieval GAIM Climate GAIM w/ GPS GAIM w/ UV But GAIM UV Assim. is much closer to Chapman retrieval.
NRL UV Retrieval versus GAIM NRL 2D Retrieval GAIM Climate GAIM w/ GPS + UV GAIM w/ UV
NRL UV Retrieval Using Chapman Profiles 00/10/03: 11th orbit, 18 scans
NRL UV Retrieval versus GAIM NRL 2D Retrieval GAIM Climate GAIM w/ GPS GAIM w/ UV
NRL UV Retrieval versus GAIM with GPS NRL 2D Retrieval GAIM Assim. of GPS NmF2 & HmF2 both higher than UV retrieval. Difference
NRL UV Retrieval versus GAIM with EUV NRL 2D Retrieval GAIM Assim. of UV NmF2 closer but HmF2 higher than UV. Difference
NRL UV Retrieval versus GAIM NRL 2D Retrieval GAIM Climate GAIM w/ GPS GAIM w/ UV
NRL UV Retrieval versus GAIM NRL 2D Retrieval GAIM Climate GAIM w/ GPS + UV GAIM w/ UV
GAIM vertical TEC versus GIM GAIM density versus NRL UV retrieval GAIM profiles versus UV Chapmans GAIM TEC versus TOPEX vertical TEC 3rd Validation Technique
GAIM vertical TEC versus GIM GAIM density versus 2D EUV retrieval GAIM profile versus EUV Chapmans GAIM TEC versus TOPEX vertical TEC 4th Validation Technique
TOPEX vertical TEC obs 1330km altitude, 110 min. orbit -66 to +66 deg. latitude coverage 1-sec. points smoothed to 12 sec. TOPEX may be biased high by 2-3 TECU Editor removes bad TOPEX points GAIM Validation Using TOPEX
USC/JPL GAIM model can now assimilate (combine) ground & space GPS and UV radiance using a band-limited Kalman filter. NRL UV Retrievals in general show somewhat lower densities and peak height than the GAIM assimilations. But first validation results show reasonable behavior. Need ISR & ionosonde density profiles as a third vote. Validation infrastructure in place: GAIM vertical TEC versus GIM GAIM density versus Ionosonde NmF2 and NRL 2D Retrieval GAIM slant TEC prediction accuracy GAIM TEC versus TOPEX vertical TEC Conclusions