کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8140573 1523635 2013 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A comparative study of TEC response for the African equatorial and mid-latitudes during storm conditions
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فیزیک زمین (ژئو فیزیک)
پیش نمایش صفحه اول مقاله
A comparative study of TEC response for the African equatorial and mid-latitudes during storm conditions
چکیده انگلیسی
The solar wind effects on the Earth's environment are studied for their basic scientific values and crucial practical impacts on technological systems. This paper reports results of Total Electron Content (TEC) changes during two successive ionospheric storms of 7-12 November 2004 using GPS data derived from dual frequency receivers located at African equatorial and midlatitudes. In the geographic coordinate system, equatorial TEC variability is considered over Libreville (0.36°N, 9.67°E), Gabon and Mbarara (0.60°S, 30.74°E), Uganda. TEC over midlatitude stations Sutherland (32.38°S, 20.81°E) and Springbok (29.67°S, 17.88°E), South Africa are analysed. The analysis of the storm time ionospheric variability over South Africa was undertaken by comparing the critical frequency of the F2 layer (foF2) and the peak height of the F2 layer (hmF2) values obtained from Grahamstown (33.30°S, 26.53°E) and Madimbo (22.4°S, 30.9°E) ionosonde measurements. During the analysed storm period it is observed that GPS TEC for midlatitudes was depleted significantly with a corresponding depletion in foF2, due to the reduction in GUVI O/N2 ratio as observed from its global maps. Over the equatorial latitudes, positive storm effects are more dominant especially during the storm main phase. Negative storm effects are observed over both mid and equatorial latitudes during the recovery phase. A shift in equatorial TEC enhancement (from one GPS station to another) is observed during magnetic storms and has been partially attributed to passage of Travelling Ionospheric Disturbances (TIDs). Magnetometer data over the International Real-time Magnetic Observatory Network (intermagnet) station, Addis Ababa, AAE (9.03°N, 38.77°E) has been used to help with the explanation of possible causes of equatorial ionospheric TEC dynamics during the analysed magnetic storm period.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Atmospheric and Solar-Terrestrial Physics - Volume 102, September 2013, Pages 105-114
نویسندگان
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