Improvement of SAMI2 with Comprehensive Photochemistry at Mid-Latitudes and a Preliminary Comparison with Ionosonde Data

Abstract

Photochemistry can significantly affect the ionospheric status. Adopting a comprehensive photochemical scheme with 60 reactions, primarily based on the recent systematic study of ion chemistry by Richards in 2011, we revised the open-source SAMI2 (Sami2 is another model of the ionosphere) model to SAMI2−ph. The scheme includes both ground state and metastable/vibrational excited compositions (e.g., N(2D), N2(ν), and O2(ν)) and associated reactions, which can remarkably affect the ionospheric electron density. The model accuracy is tested using the most widely used ionospheric data foF2 derived from mid-latitude ionosonde stations. The correlation coefficients are larger for SAMI2−ph than for SAMI2. In addition, the linear slope k is significantly closer to 1 than the default run for the NmF2 comparisons. The smaller RMSE and b indicate that the modified model provides a reasonably good match with the ionosonde NmF2 measurements. The above results demonstrate that the model with the chosen photochemical scheme performs better than the original SAMI2 at mid-latitude.

Keywords

• ionosphere model
• photochemistry
• improvement