Annales Geophysicae
Annales Geophysicae
ANGEO
Articles | Volume 33, issue 1
Articles | Volume 33, issue 1
https://doi.org/10.5194/angeo-33-93-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/angeo-33-93-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Articles | Volume 33, issue 1
Regular paper
 | 
16 Jan 2015
Regular paper |  | 16 Jan 2015

Observations and modeling of UHF-band scintillation occurrence probability over the low-latitude region of China during the maximum activity of solar cycle 24

H. Zhang, Y. Liu, J. Wu, T. Xu, and D. Sheng

Abstract. The climatological characteristics of UHF-band scintillations over the low-latitude region of China were investigated by analyzing the observations recorded at three stations of our regional network of satellite-beacon-based scintillation monitoring in 2013. The three stations are Hainan (geographic 20.0° N, 110.3° E; geomagnetic 10.1° N, 177.4° W, dip 28.2°), Guangzhou (geographic 23.0° N, 113.0° E; geomagnetic 13.1° N, 174.8° W, dip 33.9°) and Kunming (geographic 25.6° N, 103.7° E; geomagnetic 15.7° N, 176.4° E, dip 39.0°), located at low latitudes of China. The variations of UHF-band scintillation occurrence with latitude, time and season are presented in detail to understand the morphology and climatology of ionospheric scintillations over the low-latitude region of China. An equinoctial asymmetry in the occurrences of scintillation and an obvious difference of the onset time of scintillations between Hainan and Kunming is noted in this data set. Subsequently, the ionosonde data are utilized to study the possible causes of the asymmetry between two equinoxes. The observations suggest that the mean critical frequency (foF2) at 20:00 LT (12:00 UT) in the autumnal equinoctial months (September and October) and the vernal equinoctial months (March and April) has a similar asymmetry. The ratio of the mean foF2 between two equinoxes is proportional to the ratio between the maximum scintillation occurrence in the autumnal equinox and in the vernal equinox. Therefore, this ratio can act as a proxy for the equinoctial asymmetry in the occurrences of scintillation over the low-latitude region of China, and can be used to model the equinoctial asymmetry in our empirical climatological model of scintillation occurrence probability (CMSOP). The CMSOP can provide the predictions of the occurrences of scintillation over the low-latitude region of China and was validated in this study.

How to cite. Zhang, H., Liu, Y., Wu, J., Xu, T., and Sheng, D.: Observations and modeling of UHF-band scintillation occurrence probability over the low-latitude region of China during the maximum activity of solar cycle 24, Ann. Geophys., 33, 93–100, https://doi.org/10.5194/angeo-33-93-2015, 2015.
Received: 20 May 2014 – Revised: 01 Dec 2014 – Accepted: 04 Dec 2014 – Published: 16 Jan 2015
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Short summary
Variations of UHF-band scintillation occurrence with latitude, time and season over the low-latitude region of China are presented. The ratio of the mean foF2 at 20:00LT between two equinoxes, which could act as a proxy of the equinoctial asymmetry in the occurrences of scintillation, is proportional to the ratio between the maximum scintillation occurrence in the autumn equinox and in the vernal equinox. The empirical climatological model of scintillation occurrence probability was validated.
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