- Open Access
GPS observations of post-storm TEC enhancements at low latitudes
Earth, Planets and Space volume 58, pages 1479–1486 (2006)
In a previous work (J. Geophys. Res., 110(A01308), 1–11, 2005), the authors developed an original approach to the processing of total electron content (TEC) data obtained by GPS signals from the Japan receiver network. This approach includes removing the diurnal and seasonal variation carried by 27-day medians and the solar rotation periodicity. The relative deviations of TEC from the median—from all measured locations at a given hour—were then approximated by a regression line along the main prolongation of the Japan islands, between latitudes 24° and 45°N. The two variables of the regression line, the average value at the center and the slope were obtained as a time series, and their behavior during geomagnetic storms in the period 2000–2002 were analyzed. One interesting result was the observed enhancement of TEC at the end of the recovery phase of the storms. The slope variations clearly showed that this enhancement started from the south and was interpreted as a poleward expansion of equatorial crest. In the present paper we further analyze this post-storm phenomenon, adding foF2 data from Japanese Kokubunji and Okinawa ionosondes. We also show the latitude extension of the poleward expansion by using lat/UT contour plots. The results confirm that most of the post-storm TEC enhancements are part of the equatorial crest region which extends poleward during nighttime. In some cases, the enhanced TEC structures develop by separating from the crest region. Daytime TEC enhancements were also observed. Their structures are not confined to the equatorial crests region, but occupy the whole latitude range considered in this study. TEC post-storm enhancements were generally found to be in agreement with foF2 variations.
Codrescu, M., T. J. Fuller-Rowell, and I. Kutiev, Modeling the F-layer During Specific Geomagnetic Storms, J. Geophys. Res., 102, 14315–14320, 1997.
Eccles, J. V., N. Maynard, and G. Wilson, Study of the evening plasma drift vortex in the low-latitude ionosphere using San Marco electric field measurements, J. Geophys. Res., 104, 28133–18145, 1999.
Fejer, B. G. and L. Scherliess, Empirical models of storm time equatorial zonal electric fields, J. Geophys. Res., 102, A11, 24047–24056, 1997.
Field, R. P. and H. Rishbet, The response of the ionospheric F2-layer to geomagnetic activity: an analysis of worldwide data, J. Atmos. Solar-Terr. Phys., 59(2), 163–180, 1997.
Heelis, R. A., Electrodynamics in the low and mid latitude ionosphere: a tutorial, J. Atmos. Solar Terr. Phys., 66, 825–838, 2004.
Kelley, M. C, M. N. Vlasov, J. C. Foster, and A. J. Coster, A quantitative explanation for the phenomenon known as storm-enhanced density, Geophys. Res. Lett., 31, L19809, doi:10.1029/2004GL020875, 2004.
Kutiev, I., P. Muhtarov, and P. Bradley, Penetration of ionospheric disturbances into the European region during geomagnetic storms, Adv. Space Res., 22(6), 865–867, 1998.
Kutiev, I., S. Watanabe, Y. Otsuka, and A. Saito, Total electron content behavior over Japan during geomagnetic storms, J. Geophys. Res., 110(A1), A01308, doi:10.1029/2004JA010586, 2005.
Lin, C. H., A. D. Richmond, J. Y. Liu, H. C. Yeh, L. J. Paxton, G. Lu, H. F. Tsai, and S.-Y Su, Large-scale variations of the low-latitude ionosphere during the October-November 2003 superstorm: Observational results, J. Geophys. Res., 110, A09S28, doi:10.1029/2004JA010900, 2005.
Liu, L., W. Wan, B. Ning, H. Yuan, and J. Y Liu, Low latitude ionospheric effects near 120° E during the great geomagnetic strom of July 2000, Sci. China (series A), 45 (suppl.), 148–155, 2002.
Liu, L., W Wan, C. C. Lee, B. Ning, and J. Y. Liu, The low latitude ionospheric effects of the April 2000 magnetic storm near 120° E, Earth Planets Space, 56, 607–612, 2004.
Muhtarov, P. and I. Kutiev, Empirical modelling of ionospheric storms at midlatitudes, Adv. Space Res., 22, 6, 829, 1998.
Muhtarov, P., I. Kutiev, and L. Cander, Geomagnetically correlated au-toregression model for short-term prediction of ionospheric parameters, Inverse Problems, 18(1), 49–65, 2002.
Namgaladze, A. A. and M. Förster, Analysis of the positive ionospheric response to a moderate geomagnetic storm using a global numerical model, Ann. Geophys., 18, 4, 461–477, 2000.
Otsuka, Y, T. Ogawa, A. Saito, T. Tsugawa, S. Fukao, and S. Miyazaki, A new technique for mapping of total electron content using GPS network in Japan, Earth Planets Space, 54, 63–70, 2002.
Tsugawa, T., A. Saito, and Y. Otsuka, A statistical study of large-scale traveling ionospheric disturbances using the GPS network in Japan, J. Geophys. Res., 109, A06302, doi:10.1029/2003JA010302, 2004.
Vlasov, M., M. C. Kelley, and H. Kil, Analysis of ground-based and satellite observations of F region behavior during the great magnetic storm of July 15, 2000, J. Atmos. Solar Terr. Phys., 65, 1223–1234, 2003.
About this article
Cite this article
Kutiev, I., Otsuka, Y., Saito, A. et al. GPS observations of post-storm TEC enhancements at low latitudes. Earth Planet Sp 58, 1479–1486 (2006). https://doi.org/10.1186/BF03352647
- Low latitude ionosphere
- GPS derived Total Electron Content (TEC)
- low latitude TEC enhancement
- equatorial anomaly crests