Towards a better representation of the IRI topside based on ISIS and Alouette data Original Research Article

The current IRI topside model is based on the data compilation and grouping that was used for the Bent model (Bent et al., 1972). The principal data source for Bent were Alouette 1 sounder data from a period of low to medium solar activity. Through a systematic search of the NASA archives, we have established a large data base of topside profiles recorded by the Alouette 1, 2, and ISIS 1, 2 topside sounder instruments. Comparison of IRI with these data reveals shortcomings of the model especially in the upper topside. The largest discrepancies are found at low latitudes and at high solar activities. We will discuss the cause of these model limitations and ways to improve the current model with the help of our data base.