VARIABILITY OF IONOSPHERIC TEC AT LOW LATITUDE STATION,HYDERABAD DURING MEDIUM SOLAR ACTIVITY
Abstract and keywords
Abstract (English):
The successful operation of communicational and navigational applications requires knowledgeof state and behaviour of ionosphere as well as spatial and temporal changes taking place init. With this view, we have studied the variability and changes in the low latitude ionosphereby considering a low latitude Indian station Hyderabad (17.41∘N, 78.55∘E). The variabilityis studied during the year 2014, by using the space borne Global Positioning System (GPS)observations. From GPS observations an important parameter; Total Electron Content (TEC)is obtained, which represents the integral electron density of the ionosphere and is widely usedin studies concerning ionospheric variability. We have studied how the ionospheric conditionsat Hyderabad change from hour to hour, day to day, month to month and season to season. Wefound that ionosphere over Hyderabad exhibits significant, interesting and regular variability.Although, the trends followed by the ionospheric changes are similar, but the magnitude ofpeak values differ on different time scales. Finally we have compared the variability of observedor actual values of TEC with the corresponding values predicted by International ReferenceIonosphere (IRI) model-2016 and found good agreement between hourly values, while IRImodel overestimates or underestimates the daily values.

Keywords:
Ionospheric variability, Total Electron Content, International Reference Ionosphere-2016 model
References

1. Abdu, M. A., T. K. Ramkumar, I. S. Batista, et al. (2006), Planetary wave signatures in the equatorial atmosphere-ionosphere system, and mesosphere- 𝐸- and 𝐹 -region coupling, J. Atmos. Sol. Terr. Phys., 68, 509-522

2. Bilitza, D. (2001), International Reference Ionosphere 2000, Radio Sci., 36, 261-275

3. Bilitza, D., B. W. Reinisch (2008), International Reference Ionosphere 2007: Improvements and new parameters, Adv. Space Res., 42, No. 4, 599-609

4. Bilitza, D., D. Altadill, Y. Zhang, et al. (2014), The International Reference Ionosphere 2012 - a model of international collaboration, Space Weather Space Clim., 4, No. A07, 1-12

5. Chaitanya, P. P., A. K. Patra, et al. (2015), Ionospheric variations over Indian low latitudes close to the equator and comparison with IRI2012, Ann. Geophys., 33, 997-1006

6. Chakraborty, S. K., R. Hajra (2009), Electrojet control of ambient ionization near the crest of the equatorial anomaly in the Indian zone, Ann. Geophys., 27, No. 1, 93-105

7. Chandra, H., R. K. Misra, R. G. Rastogi (1971), Equatorial ionospheric drift and the electrojet, Planetary and Space Science, 19, No. 11, 1497- 1503

8. Chau, J. L., L. P. Goncharenko, et al. (2012), Equatorial and low latitude ionospheric effects during sudden stratospheric warming events ionospheric effects during SSW events, Space. Sci. Rev., 168, 385-417

9. Kuverova, V. V., S. O. Adamson, A. A. Berlin, et al. (2019), Chemical physics of 𝐷 and 𝐸 layers of the ionosphere, Advances in Space Research, 64, 1876-1886

10. Limberger, M., W. Liang, M. Schmidt, et al. (2013), Regional representation of 𝐹 2 Chapman parameters based on electron density profiles, Ann. Geophys., 31, 2215-2227

11. Pancheva, D. V., P. J. Mukhtarov, M. G. Shepherd, et al. (2006), Two-day wave coupling of the low-latitude atmosphere-ionosphere system, J. Geophys. Res., 111, A07313

12. Panda, S. K., S. S. Gedam, S. Jin (2015), Ionospheric TEC Variations at Low Latitude Indian Region, Satellite Positioning - Methods, Models and Applications, Intech Open, 8, 149- 174

13. Rastogi, R. G. (1989), The equatorial electrojet, Geomagn. Acad. Press, 3, 461-525

14. Rathore, V. S., S. Kumar, A. K. Singh (2015), A statistical comparison of IRI TEC prediction with GPS TEC measurement over Varanasi, India, J. Atmos. Sol. Terr. Phys., 124, 1-9

15. Rees, M. H. (1989), Physics and Chemistry of the Upper Atmosphere, Cambridge Univ. Press, NY

16. Tariku, Y. A. (2015), Patterns of GPS-TEC variation over low-latitude region (African sector) 435 during the deep solar minimum (2008 to 2009) and solar maximum (2012 to 2013) phases, Earth Planets Space, 67, 35

17. Trivedi, R., A. Jain, et al. (2011), Study of TEC changes during geomagnetic storms occurred near the crest of the equatorial ionospheric ionization anomaly in the Indian sector, Adv. Space Res., 48, No. 10, 1617-1630

18. Wan, Q., G. Ma, J. Li, et al. (2016), A comparison of GPS-TEC with IRI-TEC at low latitudes in Chinain 2006, Adv. Space Res., 60, No. 2, 250-256

Login or Create
* Forgot password?