EUV-TEC proxy to describe ionospheric variability using satellite-borne solar EUV measurements

An updated version of a proxy, termed EUV-TEC, describing the global total primary photoionisation is calculated from satellite-borne EUV measurements assuming a model atmosphere consisting of four major atmospheric constituents. Regional number densities of the background atmosphere are taken from the NRLMSISE-00 climatology. For calculation the Lambert-Beer law is used to describe the decrease of the radiation along their way through the atmosphere. The EUV-TEC proxy thus describes the ionospheric response to solar EUV radiation and its variability. EUV-TEC is compared against the global mean total electron content (TEC), a fundamental ionospheric parameter created from vertical TEC maps derived from GPS data. Strong correlation between these indices is found on different time scales. Results show that the EUV-TEC proxy represents the ionsopheric variability better than the conventional solar index F10.7 does, especially during high and moderate solar activity

EUV-TEC - an index to describe ionospheric variability using satellite-borne solar EUV measurements: first results

Primary ionisation of major ionospheric constituents is calculated from satellite-borne solar EUV measurements. Number densities of the background atmosphere are taken from the NRLMSISE-00 climatology. From the calculated ionisation rates, an index termed EUV-TEC, which is based on the global total ionisation is calculated, and describes the ionospheric response to solar EUV and its variability. The index is compared against global mean ionospheric total electron content (TEC) derived from GPS data. Results show that the EUV-TEC index provides a better overall representation of global TEC than conventional solar indices like F10.7 do. The EUV-TEC index may be used for scientific research, and to describe the ionospheric effects on radio communication and navigation systems

Proxies to describe ionospheric variability and heating rates of the upper atmosphere: current progress

An updated version of the EUV-TEC proxy, describing the total primary ionisation of the upper atmosphere, is calculated from satellite-borne EUV measurements. Regional number densities of the background model atmosphere consisting of four major constituents are taken from the NRLMSISE-00 climatology. Furthermore, a first estimate of a global thermospheric heating rate is calculated from the absorbed energy. For the calculations the Lambert-Beer law is used to describe the decrease of the radiation along their way through the atmosphere. The EUV-TEC proxy is compared against the global mean total electron content (TEC), obtained from vertical TEC maps derived from GPS data. Strong correlations between these indices are found on different time scales. Results show that the EUV-TEC proxy describes the ionospheric variability better than the conventional solar index F10.7, especially at short time scales of days to weeks

Solar activity and ionospheric response as seen from combined SolACES and SDO-EVE solar EUV spectra

Ionospheric response to solar EUV variability during late 2012 through mid 2013 is shown by the EUV-TEC proxy based on combined SolACES and SDO/EVE solar spectra. The results are compared with global TEC analyses. We found that EUV-TEC describes TEC variability better than the conventional F107 index, especially during periods of strong solar flare activity