Comparison of O+ density from ARGOS LORAAS data analysis and SAMI2 model results

Abstract

We report the first results comparing the ionospheric O+ density obtained from the Low Resolution Airglow and Aurora Spectroscopy (LORAAS) experiment aboard the Advanced Research and Global Observation Satellite (ARGOS) with computational modeling results from the NRL ionosphere code "Sami2 is Another Model of the Ionosphere" (SAM12). We also compare the electron density obtained from SAM12 with the International Reference Ionosphere (IRI). The O+ density comparison between the LORAAS data analysis and the SAM12 results is very good considering that the modeled results near the geomagnetic equator are sensitive to the electric field and neutral wind models. For example, we find better agreement with the data using a simple sinusoidal model of the E × B drift instead of the empirical Fejer/Scherliess drift model Scherliess and Fejer [1999]. It is expected that better agreement between data and modeled results will be achieved using more accurate electric field and neutral wind input data. This suggests that the ARGOS data set will be an important test bed to assess the physical processes needed in a comprehensive model of the low- to mid-latitude ionosphere. The comparison of the LORAAS data with the IRI model is also reasonably good, but some details of the ionosphere's morphology is better described by SAM12.