Journal of Geodesy

, Volume 91, Issue 5, pp 485–502 | Cite as

Temporal and spatial variations of global ionospheric total electron content under various solar conditions

  • Jingbin Liu
  • Manuel Hernandez-Pajares
  • Xinlian Liang
  • Jiachun An
  • Zemin Wang
  • Ruizhi Chen
  • Wei Sun
  • Juha Hyyppä
Original Article


By utilizing the numerical technique of principal component analysis (PCA), this work analyses temporal and spatial variations of the ionosphere under various solar conditions during the period 1999–2013. Applying the PCA technique to the time series of the global ionospheric total electron content (TEC) maps provides an efficient method for analyzing the main ionospheric variability on a global scale that is able to decompose periodic variations (e.g., annual and semiannual oscillations) while retaining the asymmetry in the temporal and spatial domains (e.g., seasonal and equator anomalies). The TEC series of different local times are processed separately at two time scales: (1) the whole 15 years of the period of study and (2) the individual years. In contrast with previous studies, the analysis of the dataset of the 15 years shows that dawn (e.g., LT4–6) and late morning (LT10–12) are the more remarkable characteristic times for ionospheric variability. This study also reveals a cyclic trend of the variability with respect to local times. The first two modes, which contain 80–90% of the total variance, represent spatial distributions and temporal variations with respect to the different stages of the solar cycle and local times. Annual and semiannual variations are demodulated from the first two modes, and the results show that these variations evidently have distinct trends for daytime and nighttime. An exception is that, under active solar conditions, extremely strong solar irradiance during the daytime has a residual effect on the variability of the nighttime.


Global ionosphere GNSS Principal component analysis Total electron content Atmosphere monitoring with geodetic techniques Ionospheric variability Ionospheric dynamics Numerical methods 



The CODE GIM dataset used in this study was downloaded from CODE’s data archive server (, and the solar and geomagnetic indices were downloaded from the National Geophysical Data Center ( The Mg II index was downloaded from the data archive of the Institute of Environmental Physics at the University of Bremen in Germany ( This work was supported in part by the Finnish Centre of Excellence in Laser Scanning Research (Grant Number 272195) of the Academy of Finland, by the National Key Research Development Program of China with project No. 2016YFB0502204, and by the National Natural Science Foundation of China (Grant Nos. 41231064 and 41174029).


  1. Afraimovich EL, Astafyeva EI, Oinats AV, Yasukevich YV, Zhivetiev IV (2008) Global electron content: a new conception to track solar activity. Ann Geophys 26:335–344. doi: 10.5194/angeo-26-335-2008 CrossRefGoogle Scholar
  2. Ahn B-H, Moon G-H, Sun W, Akasofu S-I, Chen GX, Park YD (2002) Universal time variation of the Dst index and the relationship between the cumulative AL and Dst indices during geomagnetic storms. J Geophys Res 107(A11):1409. doi: 10.1029/2002JA009257 CrossRefGoogle Scholar
  3. Araujo-Pradere EA, Fuller-Rowell TJ, Codrescu MV (2005) Characteristics of the ionospheric variability as a function of season, latitude, local time and geomagnetic activity. Radio Sci 40:RS5009. doi: 10.1029/2004RS003179
  4. Astafyeva EI, Afraimovich EL, Oinats AV, Yasukevich YuV, Zhivetiev IV (2007) Dynamics of global electron content in 1998–2005 derived from global GPS data and IRI modeling. Adv Space Res 42(1):763–769. doi: 10.1016/j.asr.2007.11.007 Google Scholar
  5. Chapman S (1931) The absorption and dissociative or ionizing effect of monochromatic radiation in atmosphere on a rotating earth. Proc Phys Soc 43:483–501CrossRefGoogle Scholar
  6. Chen Z, Zhang S-R, Coster AJ, Fang G (2015) EOF analysis and modeling of GPS TEC climatology over North America. J Geophys Res Space Phys 120:3118–3129. doi: 10.1002/2014JA020837 CrossRefGoogle Scholar
  7. Dow JM, Neilan RE, Rizos C (2009) The International GNSS Service in a changing landscape of Global Navigation Satellite Systems. J Geod 83:191–198. doi: 10.1007/s00190-008-0300-3 CrossRefGoogle Scholar
  8. Ercha A, Zhang D, Ridley AJ, Xiao Z, Hao Y (2012) A global model: empirical orthogonal function analysis of total electron content 1999–2009 data. J Geophys Res 117:A03328. doi: 10.1029/2011JA017238
  9. García-Rigo A, Hernández-Pajares M, Orús-Pérez R (2014) UPC contributions to GNSS monitoring of ionosphere in the frame of the IGS Iono-WG, IGS Workshop 2014, June 23–27. Pasadena, CaliforniaGoogle Scholar
  10. Hernández-Pajares M, Aragón-Ángel À, Defraigne P, Bergeot N, Prieto-Cerdeira R et al (2014) Distribution and mitigation of higher-order ionospheric effects on precise GNSS processing. J Geophys Res Solid Earth 119:3823–3837. doi: 10.1002/2013JB010568 CrossRefGoogle Scholar
  11. Hernández-Pajares M, Juan JM, Sanz J, Orus R, Garcia-Rigo A et al (2009) The IGS VTEC maps: a reliable source of ionospheric information since 1998. J Geod 83:263–275. doi: 10.1007/s00190-008-0266-1 CrossRefGoogle Scholar
  12. Hocke K (2008) Oscillations of global mean TEC. J Geophys Res 113:A04302. doi: 10.1029/2007JA012798 Google Scholar
  13. Laštovička J (2013) Trends in the upper atmosphere and ionosphere: recent progress. J Geophys Res Space Phys 118:3924–3935. doi: 10.1002/jgra.50341 CrossRefGoogle Scholar
  14. Le G, Wang Y, Slavin JA, Strangeway RJ (2009) Space Technology 5 multipoint observations of temporal and spatial variability of field-aligned currents. J Geophys Res 114:A08206. doi: 10.1029/2009JA014081 Google Scholar
  15. Lean JL, Emmert JT, Picone JM, Meier RR (2011a) Global and regional trends in ionospheric total electron content. J Geophys Res 116:A00H04. doi: 10.1029/2010JA016378
  16. Lean JL, Meier RR, Picone JM, Emmert JT (2011b) Ionospheric total electron content: global and hemispheric climatology. J Geophys Res 116:A10318. doi: 10.1029/2011JA016567 Google Scholar
  17. Liu J, Chen R, An J, Wang Z, Hyyppä J (2014a) Spherical cap harmonic analysis of the Arctic ionospheric TEC for one solar cycle. J Geophys Res Space Phys 119. doi: 10.1002/2013JA019501
  18. Liu J, Chen R, Wang Z, Zhang H (2011) Spherical cap harmonic model for mapping and predicting regional TEC. GPS Solut 15:109–119CrossRefGoogle Scholar
  19. Liu J, Chen R, Wang Z, An J, Hyyppa J (2014b) Long-term prediction of the Arctic ionospheric TEC based on time-varying periodograms. PLoS One 9(11):e111497. doi: 10.1371/journal.pone.0111497 CrossRefGoogle Scholar
  20. Liu L, Wan W, Ning B, Zhang ML (2009) Climatology of the mean total electron content derived from GPS global ionospheric maps. J Geophys Res A06308. doi: 10.1029/2009JA014244
  21. Maslennikova YuS, Bochkarev VV (2014) Principal component analysis of global maps of the total electronic content. Geomagnet Aeron 54(2):216–223. doi: 10.1134/S0016793214020133 CrossRefGoogle Scholar
  22. Meza A, Natali MP, Fernández LI (2012) Analysis of the winter and semiannual ionospheric anomalies in 1999–2009 based on GPS global International GNSS Service maps. J Geophys Res 117:A01319. doi: 10.1029/2011JA016882 CrossRefGoogle Scholar
  23. Millward GH, Rishbeth H, Fuller-Rowell TJ, Aylward AD, Quegan S, Moffett RJ (1996) Ionospheric F2 layer seasonal and semiannual variation. J Geophys Res 101:5149–5156. doi: 10.1029/95JA03343 CrossRefGoogle Scholar
  24. Natali MP, Meza A (2010) Annual and semiannual VTEC effects at low solar activity based on GPS observations at different geomagnetic latitudes. J Geophys Res 115:D18106. doi: 10.1029/2010JD014267 CrossRefGoogle Scholar
  25. Natali MP, Meza A (2011) Annual and semiannual variations of vertical total electron content during high solar activity based on GPS observations. Ann Geophys 29(865–873):2011. doi: 10.5194/angeo-29-865-2011 Google Scholar
  26. Pearson K (1901) On lines and planes of closest fit to systems of points in space. Philos Mag 2:559–572CrossRefGoogle Scholar
  27. Preisendorfer R (1988) Principal component analysis in meteorology and oceanography. In: The series of developments in atmospheric sciences. Elsevier Science Ltd, New YorkGoogle Scholar
  28. Qian L, Burns AG, Solomon SC, Wang W (2013) Annual/semiannual variation of the ionosphere. Geophys Res Lett 40:1928–1933. doi: 10.1002/grl.50448 CrossRefGoogle Scholar
  29. Rishbeth H, Setty CSGK (1961) The F-layer at sunrise. J Atmos Solar Terr Phys 21:263–276CrossRefGoogle Scholar
  30. Rishbeth H, Muller-Wodarg ICF, Zou L, Fuller-Rowell TJ, Millward GH, Moffett RJ, Idenden DW, Aylward AD (2000) Annual and semiannual variations in the ionospheric F2-layer: II. Phys Discuss Ann Geophys 18:945–956. doi: 10.1007/s00585-000-0945-6 CrossRefGoogle Scholar
  31. Rishbeth H, Müller-Wodarg ICF (2006) Why is there more ionosphere in January and in July? The annual asymmetry in the F2 layer. Ann Geophys 24:3293–3311. doi: 10.5194/angeo-24-3293-2006 CrossRefGoogle Scholar
  32. Schaer S (1999) Mapping and predicting the earth’s ionosphere using the global positioning system. Dissertation, University of BernGoogle Scholar
  33. Schaer S, Gurtner W, Feltens J, Feltens J (1998) IONEX: the IONosphere map exchange format version 1. Accessed 21 July 2014
  34. Snow M, Weber M, Machol J, Viereck R, Richard E (2014) Comparison of Magnesium II core-to-wing ratio observations during solar minimum 23/24. J Space Weather Space Clim 4:A04. doi: 10.1051/swsc/2014001 CrossRefGoogle Scholar
  35. Storch H, Zwiers FW (1999) Statistical analysis in climate research. Cambridge Univ. Press, CambridgeCrossRefGoogle Scholar
  36. Torr MR, Torr DG (1973) The seasonal behavior of the F2-layer of the ionosphere. J Atmos Sol Terr Phys 35:2237–2251CrossRefGoogle Scholar
  37. Verhulst T, Stankov SM (2015) Ionospheric specification with analytical profilers: evidences of non-Chapman electron density distribution in the upper ionosphere. Adv Space Res 55(8):0273–1177. ISSN 2058–2069. doi: 10.1016/j.asr.2014.10.017
  38. Wan W, Ding F, Ren Z, Zhang M, Liu L, Ning B (2012) Modeling the global ionospheric total electron content with empirical orthogonal function analysis. Sci China Technol Sci 55:1161–1168Google Scholar
  39. Weber M, Burrows JP, Cebula RP (1998) GOME solar UV/VIS irradiance measurements between 1995 and 1997—first results on proxy solar activity studies. Sol Phys 177:63–77Google Scholar
  40. Zhang S-R, Chen Z, Coster AJ, Erickson PJ, Foster JC (2013) Ionospheric symmetry caused by geomagnetic declination over North America. Geophys Res Lett 40:5350–5354. doi: 10.1002/2013GL057933 CrossRefGoogle Scholar
  41. Zhao B, Wan W, Liu L, Mao T, Ren Z, Wang M, Christensen AB (2007) Features of annual and semiannual variations derived from the global ionospheric maps of total electron content. Ann Geophys 25:2513–2527CrossRefGoogle Scholar
  42. Zou L, Rishbeth H, Müller-Wodarg ICF, Aylward AD, Millward GH, Fuller-Rowell TJ, Idenden DW, Moffettt RJ (2000) Annual and semiannual variations in the ionospheric F2-layer. I. Modelling Ann Geophys 18:927–944CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Jingbin Liu
    • 1
    • 2
  • Manuel Hernandez-Pajares
    • 3
  • Xinlian Liang
    • 2
  • Jiachun An
    • 4
  • Zemin Wang
    • 4
  • Ruizhi Chen
    • 1
  • Wei Sun
    • 5
  • Juha Hyyppä
    • 2
  1. 1.State Key Laboratory of Information Engineering in Surveying, Mapping and Remote SensingWuhan UniversityWuhanChina
  2. 2.Department of Remote Sensing and Photogrammetry, Center of Excellence in Laser Scanning ResearchFinnish Geospatial Research InstituteMasalaFinland
  3. 3.Department of Applied Mathematics IVTechnical University of Catalonia, UPC-IonSATBarcelonaSpain
  4. 4.Chinese Antarctic Center of Surveying and MappingWuhan UniversityWuhanChina
  5. 5.Wuhan Geomatics InstituteWuhanChina

Personalised recommendations