Ionospheric Assimilation Model for Space Weather Monitoring and Forecasting

1. Ionospheric Assimilation Model for Space Weather Monitoring and Forecasting I. T. Lee1 (itelee@cwb.gov.tw) W. H. Chen2, T. Matsuo3,4, C. H. Chang2, C. H. Lin2, J. Y. Liu6, W. Wang7, A. D. Richmond7 [1] Meteorological R&D Center, Central Weather Bureau, Taipei, Taiwan. [2] Department of Earth Science, National Cheng Kung University, Tainan, Taiwan. [3] University of Colorado Boulder, Boulder, Colorado, USA. [4] National Oceanic and Atmospheric Administration, Boulder, Colorado, USA. [5] National Space Organization, Hsinchu, Taiwan. [6] Institute of Space Science, National Central University, Jhongli City, Taiwan. [7] High Altitude Observatory, National Center for Atmospheric Research, Boulder, Colorado, USA

2. Content • System overview • Assimilation Results • Validations • Forecasting • Summary

3. Assimilation System Initial Condition Ne, O+, O&O2 ratio, TN, UN, VN Hourly Observations RO NE Profile GPS-TEC EnKF Advanced Condition Forecast Products TEC, foF2, NmF2, NE slices Neutral Density, etc.

4. Background Model Thermosphere Ionosphere Electrodynamic General Circulation Model (TIE-GCM) • A self-consistent and non-linear system. • Solving the three-dimensional momentum, energy and continuity equations for thermosphere and ionosphere. • The standard low-resolution grid: • Latitude: -87.5° to 87.5° • Longitude: -180° to 180° • Lower boundary: ~97 km • Upper boundary: ~500 to ~700 km • Resolution: 5°×5°×0.5lev (75,168 grids)

5. FORMOSAT-3/COSMIC • Profiles from 160 to 450 km • Vertical resolution: 10 km • Assimilation window: 60 min. • Quality control applied

6. Geomagnetic Quiet Time Period Electron Density Profiles Data Assimilation Research Testbed (DART) TIE-GCM Model States (NE,TN, U, V…) Observation Operator H(x) Matsuo and Araujo-Pradere [2011], Lee et al. [2012], and Matsuo et al. [2013] • Period: 2008.04.08 08:00 UT – 04.09 23:00 UT • Assimilation System: NCAR TIE-CGM + DART • Observation range: from 160 to 450 km, 10 km resolution • Observation error: 10% instrument error + Abel inversion error • Localization function: Gaspari-Cohn function • Horizontal distance: 20°x 20°; Vertical distance: 200 km • Assimilation window: 60 minutes • Ensemble members: 90 members • Gaussian perturbation: Solar flux (F10.7), Hemispheric power, Cross-tail potential

7. 24 Hours RMSE Percentage

8. Global NmF2 map Lat-Alt slices at -75E

9. Mid-latitude enhancement Hemispheric asymmetric Evening enhancement Lee et. al. [2011]

10. Geomagnetic Disturbed Condition • Period: 2008.10.11 01:00 – 10.11 23:00 UT • Observation range: from 160 to 450 km with 10 km step • Observation error: 10% instrument error and Abel inversion error • Assimilation window: 60 minutes • Ensemble members: 90 members • Gaussian perturbation: Solar flux (F10.7) [5], Hemispheric power[8], Cross-tail potential[10] • Localization function: Gaspari-Cohn function • Horizontal distance: 20°x 20°; Vertical distance: 200 km

12. From research to operation, Well it good for operation?

13. Validation with Ionosonde (NmF2) Evening enhancement Hemispheric asymmetric

14. Validation with JPL GIM-TEC Receivers Observations Collocated grids

15. Validation for Neutral Density Image reprinted from Matsuo et al. [2012]

16. Future Task Ionospheric Weather Forecasting

17. Possible for Ionospheric Forecasting Assimilatied Period Forecasting Period

18. Not yet! Need more work!

19. Summary • Successful to assimilate the F3/C GOX observations with TIE-GCM to assimilate global 3D electron density structures by using DART. • The validations of the assimilation well agree with independent measurements of ionosonde and JPL GIM as well as neutral density obtained CHAMP data. • Although the RMSE revels possible ability for ionospheric weather forecasting, the validation shows the forecasted results still far away from independent observations.

20. Thanks for your attention~ Wait for FORMOSAT-7 Next Year.