Scale factor mitigating non-compliance of double-frequency altimeter measurements of the ionospheric electron content over the oceans with GPS-TEC mapsReport as inadecuate




Scale factor mitigating non-compliance of double-frequency altimeter measurements of the ionospheric electron content over the oceans with GPS-TEC maps - Download this document for free, or read online. Document in PDF available to download.

Earth, Planets and Space

, Volume 61, Issue 9, pp 1103–1109

First Online: 10 November 2009Received: 18 February 2009Revised: 31 March 2009Accepted: 22 June 2009

Abstract

This paper presents results from a study of GPS total electron content TEC grid maps and ionospheric electron content IEC over the oceans delivered by the TOPEX-Jason satellites during half a solar cycle July 2001 to December 2008. The IEC data are averaged and binned at latitudes from 60°S to 60°N in steps of 5°±2.5°, at longitudes from 180°W to 180°E in steps of 15°±7.5°, and for 0–23 h UT in steps of 1±0.5 h UT. The ratio of monthly averaged TEC-IEC over the oceans from the observations was compared to the reference model ratio of TECm-IECm obtained using the plasmaspheric model augmented with the International Reference Ionosphere. By definition, TEC should exceed IEC by the plasmaspheric electron content PEC contribution at the altitude range from 1336 km TOPEX orbit to 20,200 km GPS orbit. However, as solar activity tends to the minimum, we found that IEC estimates systematically exceed those of GPS TEC. An empirical scale factor was derived in terms of the smoothed sunspot number, and this factor reduced the systematic excess of the TOPEX-Jason-derived IEC over the GPS TEC by a factor of 1.5 towards the solar minimum. This factor was tested with observations made at the solar minimum and revealed that the plasmaspheric electron content to be a residual of the GPS TEC and modified TOPEX-Jason IEC.

Key-wordsIonosphere plasmasphere GPS TOPEX-Jason total electron content  Download to read the full article text



Author: T. L. Gulyaeva - F. Arikan - S. H. Delay

Source: https://link.springer.com/



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