Global gridded ionospheric electron density derivation during 2006-2016 by assimilating COSMIC TEC and its validation

In the current work, a global monthly mean three-dimensional (3-D) ionospheric electron density product has been obtained during one solar cycle from 2006 to 2016. Specifically, an accurate 3-D product is reconstructed monthly by assimilating the Constellation Observing System for Meteorology, Ionosphere and Climate slant total electron content (TEC) into an empirical background model via the Kalman filter data assimilation algorithm.

The outputs of the results have spatial resolutions of 2 degrees in latitude, 5 degrees in longitude, and 20 km in height, and temporal resolution of 1 hr in universal time. The accuracy and reliability of the results are systematically validated by the critical frequency at the F2 layer from global ionosonde stations, the in situ electron density from the CHAllenging Minisatellite Payload Planar Langmuir Probe, the TEC from the Massachusetts Institute of Technology, and Gravity Recovery and Climate Experiment.