Ionospheric total electron content and critical frequencies over Europe at solar minimum
The paper presents results obtained by analyzing high-resolution ionospheric vertical total electron content (vTEC) data set evaluated from a chain of European ground-based Global Positioning System (GPS) stations and its equivalent slab thickness, as well as the F2-layer critical frequency foF2 and propagation factor M(3000)F2 from nearby ionosonde stations over the period 2006-2007. The study covers data within an area between 36°N and 68°N geographic latitude, and 7°W and 21°E geographic longitude during these last two years of minimum solar activity in the 23rd solar cycle. It reveals 15 extraordinary events, all of which exhibited some form of large short-lived vTEC and foF2 enhancements of the duration of small-magnitude solar-terrestrial events. The results clearly show a well-defined vTEC and foF2 storm-like disturbance patterns developed under these conditions. They prove that there are still some open questions related to the large electron density variations during weak disturbances that require additional study for both their relevance to different Global Navigation Satellite Systems (GNSS) applications and their role in the formation and evolution of the daytime ionosphere at middle latitudes.
Bibliogr. 14 poz.
- Beutler, G., M. Rothacher, S. Schaer, T.A. Springer, J. Kouba, and R.E. Neilan (1999), The International GPS Service (IGS): An interdisciplinary service in support of earth sciences, Adv. Space Res. 23, 4, 631-635.
- Bourdillon, A., Lj.R. Cander, and B. Zolesi (2009), COST 296 MIERS: Mitigation of Ionospheric Effects on Radio Systems, Final Report: COST296.
- Cander, Lj.R. (2008), Ionospheric research and space weather services, J. Atmos. Sol.-Terr. Phys. 70.
- Cander, Lj.R., and S.J. Mihajlovic (2005), Ionospheric spatial and temporal variations during the 29-31 October 2003 storm, J. Atmos. Sol.-Terr. Phys. 67, 12, 1118-1128.
- Ciraolo, L. (1993), Evaluation of GPS L2-L1 biases and related daily TEC profiles. In: Proc. GPS/Ionosphere Workshop, Neustrelitz, 90-97.
- Foster, J.C., and W. Rideout (2005), Midlatitude TEC enhancements during the October 2003 superstorm, Geophys. Res. Lett. 32, L12S04.
- Heelis, R.A., J.J. Sojka, M. David, and R.W. Schunk (2009), Storm time density enhancements in the middle-latitude dayside ionosphere, J. Geophys. Res. 114, A03315.
- Lee, C.C., B.W. Reinisch, S.-Y. Su, and W.S. Chen (2008), Quiet-time variations of F2-layer parameters at Jicamarca and comparison with IRI-2001 during solar minimum, J. Atmos. Sol.-Terr. Phys. 70, 184-192.
- Mendillo, M. (2006), Storms in the ionosphere: Patterns and processes for total elektron content, Rev. Geophys. 44, RG4001.
- Mendillo, M., and J.A. Klobuchar (2006), Total electron content: Synthesis of past storm studies and needed future work, Radio Sci. 41, RS5S02.
- Prolss, G.W. (1995), Ionospheric F-region storms. In: H. Volland (ed.), Handbook of Atmospheric Electrodynamics, CRC Press, Boca Raton, FL.
- Skone, S., R. Yousuf, and A. Coster (2004), Performance evaluation of the Wide Area Augmentation System for ionospheric storm events, J. Global Positioning Systems 3, 1-2, 251-258.
- Tsurutani, B.T., D.L Judge, F.L. Guarnieri, P. Gangopadhyay, A.R. Jones, J. Nuttall, G. Zambon, A.L. Didkovsky, A.J. Mannucci, B. Iijima, R.R. Meier, T.J. Immel, T.N. Woods, S. Prasad, L. Floyd, J. Huba, S.C. Solomon, P. Straus, and R. Viereck (2005), The October 28, 2003 extreme EUV solar flare and resultant extreme ionospheric effects: Comparison to other Halloween events and the Bastille Day event, Geophys. Res. Lett. 32, L03S09.
- Zolesi, B., and Lj.R. Cander (2004), COST 271 Action – Effects of the upper atmosphere on terrestrial and Earth-space communications, Final Report, Ann. Geophys. 47, 2/3, 1-385, supplement.