The 30 cm radio flux as a solar proxy for thermosphere density modelling
LPC2E, CNRS and University of Orléans, 3A avenue de la Recherche Scientifique, 45071
Orléans Cedex 2, France
2 CNES, Department of Terrestrial and Planetary Geodesy, 18 avenue E. Belin, 31401 Toulouse Cedex 4, France
* Corresponding author: email@example.com
Accepted: 15 February 2017 Revised: 10 February 2017
The 10.7 cm radio flux (F10.7) is widely used as a proxy for solar UV forcing of the upper atmosphere. However, radio emissions at other centimetric wavelengths have been routinely monitored since the 1950 s, thereby offering prospects for building proxies that may be better tailored to space weather needs. Here we advocate the 30 cm flux (F30) as a proxy that is more sensitive than F10.7 to longer wavelengths in the UV and show that it improves the response of the thermospheric density to solar forcing, as modelled with DTM (Drag Temperature Model). In particular, the model bias drops on average by 0–20% when replacing F10.7 by F30; it is also more stable (the standard deviation of the bias is 15–40% smaller) and the density variation at the the solar rotation period is reproduced with a 35–50% smaller error. We compare F30 to other solar proxies and discuss its assets and limitations.
Key words: Thermosphere density / Solar proxies / Solar radio emissions
© T. Dudok de Wit and S. Bruinsma, Published by EDP Sciences 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.