Abstract
In the present work we model the global ionospheric total electron content (TEC) with the analysis of empirical orthogonal functions (EOF). The obtained statistical eigen modes, which makeup the modeled TEC, consist of two factors: the eigen vectors mapping TEC patterns at latitude and longitude (or local time LT), and the corresponding coefficients displaying the TEC variations in different time scales, i.e., the solar cycle, the yearly (annual and semiannual) and the diurnal universal time variations. It is found that the EOF analysis can separate the TEC variations into chief processes and the first two modes illustrate the most of the ionospheric climate properties. The first mode contains both the semiannual component which shows the semiannual ionospheric anomaly and the annual component which shows the annual or non-seasonal ionospheric anomaly. The second mode contains mainly the annual component and shows the normal seasonal ionospheric variation at most latitudes and local time sectors. The annual component in the second mode also manifests seasonal anomaly of the ionosphere at higher mid-latitudes around noontime. It is concluded that the EOF analysis, as a statistical eigen mode method, is resultful in analyzing the ionospheric climatology hence can be used to construct the empirical model for the ionospheric climatology.
Similar content being viewed by others
References
Schunk R W, Sojka J J, Schunk R W. Ionospheric Models. In: Kohl H, Ruester R, Schlegel K, eds. Modern Ionospheric Science. European Geophysical Society, 1996. 181–215
Cander L R, Leitinger R, Levy M F. Ionospheric Models Including the Auroral Environment. Workshop on Space Weather. The Netherlands: European Space Agency, 1999. 135–142
Bilitza D. Ionospheric Models for Radio Propagation Studies. The Review of Radio Science. Piscataway: IEEE Press, 2002. 625–679
Bent R B, Llewellyn S K, Walloch M K. Description and Evaluation of the Bent Ionospheric Model, Space & Missile Systems Organization. Report SAMSO TR-72-239, Los Angeles, California, 1972
Bent R B, Llewellyn S K, Nesterczuk G, et al. The Development of a Highly Successful Worldwide Empirical Ionosphere Model and Its Use in Certain Aspects of Space Communications and World-Wide Total Electron Content Investigations. In: Goodman J M, ed. Effects of the Ionosphere on Space Systems and Communications. Springfield: National Technical Information Service, 1975. 13–28
Rawer K, Ramakrishnan S, Bilitza D. International Reference Ionosphere 1978. Brussels: International Union of Radio Science, 1978
Rawer K, Lincoln J V, Conkright R O, eds. International Reference Ionosphere IRI-79. Report UAG-82, Boulder, Colorado, World Data Center A for Solar-Terrestrial Physics, 1981
Bilitza D. International Reference Ionosphere 1990. NSSDC Report 90-22. National Space Science Data Center, Greenbelt, USA, 1990
Bilitza D. International Reference Ionosphere 2000. Radio Sci, 2001, 36: 261–275
Hochegger G, Nava B, Radicella S, et al. A Family of Ionospheric Models for Different Uses. Physics and Chemistry of the Earth, Part C, 2000, 25: 307–310
Radicella S M, Leitinger R. The Evolution of the DGR Approach to Model Electron Density Profiles. Adv Space Res, 2001, 27: 35–40
Leitinger R, Radicella S, Hochegger G, et al. Diffusive Equilibrium Models for the Height Region above the F2 Peak. Adv Space Res, 2002, 29: 809–814
Klobuchar J A. Ionospheric Time Delay Algorithm for Single Frequency GPS Users. IEEE T Aeros Electron Syst, 1987, 23: 325–331
Brown L D, Daniel R E, Fox M W, et al. Evaluation of six ionospheric models as predictors of total electron content. Radio Sci, 1991, 26: 1007–1015
Coïsson P, Radicell S M, Leitinger R, et al. Are models predicting a realistic picture of vertical, total electron content. Radio Sci, 2004, 39: RS1S14, doi:10.1029/2002RS002823
Poulter E M, Hargreaves J K. A harmonic analysis of ATS-6 electron content observation at Lancaster, UK, during 1975–6. Ann Geophys, 1981, 37: 405–415
Baruah S, Bhuyan P K, Tyagi T R. Modeling of ionospheric electron content over Lunping-An empirical approach. Indian J Radio Space Phys, 1993, 22: 325–330
Jain S, Vijay S K, Gwal A K. An empirical model for IEC over Lunping. Adv Space Res, 1996, 18: 263–266
Bradley P. PRIME (Prediction and Retrospective Ionospheric Modelling over Europe), Action 238, Final Report, Rutherford Appleton Laboratory, Chilton Didcot, UK, European Cooperation in the field of Scientific and Technical Research (COST), 1999
Hanbaba R. Improved Quality of Services in Ionospheric Telecommunication Systems Planning and Operation, Action 251, Final Report, Warsaw, Poland, Space Research Centre, European Cooperation in the field of Scientific and Technical Research (COST), 1999
Gulyaeva T L. Regional Analytical Model of Ionospheric Total Electron Content: Monthly Mean and Standard Deviation. Radio Science, 1999, 34: 1507–1512
Chen Y, Wan W, Liu L, et al. A statistical TEC model based on the observation at Wuhan Ionospheric Observatory. Chin J Space Sci, 2002, 34: 27–35
Unnikrishnan K, Balachandran R, Venugopal C. Harmonic analysis and an empirical model for TEC over Palehua. J Atmos Sol Terr Phys, 2002, 64: 1833–1840
Mao T, Wan W, Liu L. An EOF based empirical model of TEC over Wuhan. Chin J Geophys, 2005, 48: 827
Mao T, Wan W, Yue X, et al. An empirical orthogonal function model of total electron content over China. Radio Sci, 2008, 43, RS2009, doi:10.1029/2007RS003629
Mannucci A J, Wilson B D, Yuan D N, et al. A global mapping technique for GPS-derived ionospheric total electron content measurements. Radio Sci, 1998, 33: 565–582
Orús R, Hernández-Pajares M, Juan J M, et al. Performance of different TEC models to provide GPS ionospheric corrections. J Atmos Sol Terr Phys, 2002, 64: 2055–2062
Orús R, Herna’ndez-Pajares M, Juan J M, et al. Improvement of global ionospheric VTEC maps by using Kriging interpolation technique. J Atmos Sol Terr Phys, 2005, 67: 1598–1609
Storch H V, Zwiers F W. Statistical Analysis in Climate Research. Cambridge University Press, 2002
Zhao B, Wan W, Liu L, et al. Statistical characteristics of the total ion density in the topside ionosphere during the period 1996–2004 using empirical orthogonal function (EOF) analysis. Ann Geophy, 2005, 23: 3615–3631
Liu C, Zhang M L, Wan W, et al. Modeling M(3000)F2 based on empirical orthogonal function analysis method. Radio Sci, 2008, 43: RS1003, doi:10.1029/2007RS003694
Zhang M L, Liu C, Wan W, et al. A global model of the ionospheric F2 peak height based on EOF analysis. Ann Geophys, 2009, 27: 3203–3212
Zhang M L, Liu C, Wan W, et al. Evaluation of global modeling of M(3000)F2 and hmF2 based on alternative empirical orthogonal function expansions. Adv Space Res, 2010, 46: 1024–1031
Hernández-Pajares M. Performance of IGS Ionosphere TEC Maps. IGS IONO WG Report, Research Group of Astronomy and Geomatics, Barcelona Technical University of Catalonia (gAGE/UPC), Spain, 2003
Iijima B A, Harris I L, Ho C M, et al. Automated daily process for global ionospheric total electron content maps and satellite ocean altimeter ionospheric calibration based on Global Positioning System data. J Atmos Sol Terr Phys, 1999, 61: 1205
Afraimovich E L, Astafyeva E I, Zhivetiev I V. Solar activity and global electron content. Doklady Earth Sci, 2006, 409: 921–924
She C, Wan W, Xu G. Climatological analysis and modeling of the ionospheric global electron content. Chin Sci Bull, 2008, 53: 282–288
Rishbeth H, Muller-Wodar I C F, Zou L, et al. Annual and semiannual variations in the ionospheric F2-layer: II. Physical discussion. Ann Geophys, 2000, 18: 945–956
Rishbeth H, Muller-Wodarg I C F. Why is there more ionosphere in January than in July? The annual asymmetry in the F2-layer. Ann Geophys, 2006, 24: 3293–3311
Zou L, Rishbeth H, Muller-Wodarg I C F, et al. Annual and semiannual variations in the ionospheric F2-layer: I. Modelling. Ann Geophys, 2000, 18: 927–944
Yu T, Wan W, Liu L, et al. Global scale annual and semi-annual variations of daytime NmF2 in the high solar activity years. J Atmosph Solar-Terr Phys, 2004, 66: 1691–1701
Liu L, Zhao B, Wan W, et al. Seasonal variations of the ionospheric electron densities retrieved from Constellation Observing System for Meteorology. Ionosphere, and Climate mission radio occultation measurements. J Geophy Res, 2009, 114, doi:10.1029/2008JA013819
Codrescu M V, Palo S E, Zhang X, et al. TEC climatology derived from TOPEX/POSEIDON measurements. J Atmos Sol Terr Phys, 1999, 61: 281–298
Codrescu M V, Beierle K L, Fuller-Rowell T J, et al. More total electron content climatology from TOPEX/Poseidon measurements. Radio Sci, 2001, 36: 325–333
Jee G, Schunk R W, Scherliess L. Analysis of TEC data from the TOPEX/Poseidon mission. J Geophys Res, 2004, 109: A01301, doi:10.1029/2003JA010058
Mendillo M, Huang C L, Pi X, et al. The global ionospheric asymmetry in total electron content. J Atmos Sol Terr Phys, 2005, 67: 1377–1387
Rishbeth H. How the thermospheric circulation affects the ionospheric F2-layer. J Atmos Sol Terr Phys, 1998, 60 (14): 1385–1402
Fuller-Rowell T J. The “thermospheric spoon”: A mechanism for the semiannual density variation. J Geophys Res, 1998, 103: 3951–3956
Zeng Z, Burns A, Wang W, et al. Ionospheric annual asymmetry observed by the COSMIC radio occultation measurements and simulated by the TIEGCM. J Geophys Res, 2008, 113: A07305, doi: 10.1029/2007JA012897
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Wan, W., Ding, F., Ren, Z. et al. Modeling the global ionospheric total electron content with empirical orthogonal function analysis. Sci. China Technol. Sci. 55, 1161–1168 (2012). https://doi.org/10.1007/s11431-012-4823-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11431-012-4823-8