Extracting Exospheric Temperature From Daytime Ionospheric Electron Density Profiles

Given that the ionosphere is strongly determined by the thermosphere and its state depends on thermospheric parameters, we propose a new method to extract exospheric temperature (T-ex) from electron density (Ne) profiles based on the relationship between the variations in T-ex and Ne profiles established through simulation. Ne profiles and corresponding T-ex from the Millstone Hill incoherent scatter radar (ISR) observations are used to test the method. ISR Ne profiles are used for T-ex retrieval and ISR T-ex is used to make a comparison with T-ex calculated by model and retrieved T-ex. The results show that the retrieved T-ex effectively captures diurnal, anomalous and short-period variations. The relative deviation between the retrieved-observed T-ex is approximately 2%, which is significantly improved compared with the Mass Spectrometer Incoherent Scatter model, especially under disturbed conditions. This result confirms that thermospheric temperature variation can be deduced from ionospheric profiles and our method can be considered a useful tool to obtain T-ex from Ne profiles.

Automated summary

Given the strong dependence of the ionosphere on the thermosphere and the determination of its state by thermospheric parameters, we propose a new method to extract exospheric temperature (T-ex) from electron density (Ne) profiles based on a simulated relationship between T-ex and Ne profiles. The method is tested using Ne profiles and corresponding T-ex from the Millstone Hill incoherent scatter radar (ISR) observations. The results show that the retrieved T-ex effectively captures various variations and outperforms the Mass Spectrometer Incoherent Scatter model, especially under disturbed conditions. This confirms the possibility of deducing thermospheric temperature variation from ionospheric profiles and highlights the usefulness of our method in obtaining T-ex from Ne profiles.