Using the local ensemble Transform Kalman Filter for upper atmospheric modelling
Space Environment and Radio Engineering, University of Birmingham, Birmingham B15 2TT, UK
* Corresponding author: email@example.com
Accepted: 19 April 2019
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).
Key words: data assimilation / ensemble Kalman filter / LETKF / ionosphere / thermosphere
© S. Elvidge & M.J. Angling, Published by EDP Sciences 2015
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