Satellite-based analysis of thermosphere response to extreme solar flares

Abstract. We present a refined algorithm to calculate pseudo solar indices, which enable the reproduction of a solar flare impact on the upper Earth's atmosphere for the empirical thermosphere model Jacchia-Bowman 2008. In a first step we compare the estimates of the new algorithm with those from a previous study by analysing an extreme X17.2 flare in 2003 using TIMED/SEE EUV observations. In a second step we adapt the method to use SOHO/SEM measurements within the algorithm and compare the findings with the previous results. Furthermore, the latter procedure is validated by means of GRACE density measurements during a X2.0 solar flare in November 2004. In each of the cases also a comparison with theoretical thermosphere models is performed, which shows a good agreement and suggests that the algorithm can support theoretical evolution studies in case no in situ density measurements during extreme solar events are available.