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

• Main Authors: C. Unglaub, Ch. Jacobi, G. Schmidtke, B. Nikutowski, R. Brunner
• Format: Article
• Language: deu
• Published: Copernicus Publications 2012-09-01
• Series: Advances in Radio Science
• Online Access: http://www.adv-radio-sci.net/10/259/2012/ars-10-259-2012.pdf

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.