Abstract
The Advanced Ensemble electron density (Ne) Assimilation System (AENeAS) is a new data assimilation model of the ionosphere/thermosphere. The background model is provided by the Thermosphere Ionosphere Electrodynamics General Circulation Model (TIE-GCM) and the assimilation uses the local ensemble transform Kalman filter (LETKF). An outline derivation of the LETKF is provided and the equations are presented in a form analogous to the classic Kalman filter. An enhancement to the efficient LETKF implementation to reduce computational cost is also described. In a 3 day test in June 2017, AENeAS exhibits a total electron content (TEC) RMS error of 2.1 TECU compared with 5.5 TECU for NeQuick and 6.8 for TIE-GCM (with an NeQuick topside).
Original language | English |
---|---|
Article number | A30 |
Journal | Journal of Space Weather and Space Climate |
Volume | 9 |
Issue number | 2019 |
DOIs | |
Publication status | Published - 12 Aug 2019 |
Keywords
- data assimilation
- ensemble Kalman filter
- LETKF
- ionosphere
- thermosphere