Abstract
Total electron content (TEC) observations can provide insights into
electron density variations in the ionosphere. Such variations are
associated with many aspects of ionospheric dynamics, including
traveling ionospheric disturbances. In the present work we assimilate
observations of TEC and horizontal TEC gradients into the SAMI3 (SAMI3
is Another Model of the Ionosphere 3D) ionosphere model. Assimilation
into SAMI3 is accomplished using an ensemble Kalman filter implemented
within LightDA, an extensible data assimilation library. Our TEC
gradient observations are obtained from the Very Large Array Low-band
Ionosphere and Transient Experiment (VLITE) and the TEC measurements are
derived from GNSS receiver data. VLITE provides high precision and high
spatial resolution TEC gradient observations over a small area, while
GNSS observations supplement these with global coverage. By leveraging
TEC observations in a physics-based model through data assimilation, we
aim to improve our understanding of ionospheric processes and develop
tools for improved ionospheric forecasting capabilities.