کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8140027 1523613 2015 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
First results of the high-resolution multibeam ULF wave experiment at the Ekaterinburg SuperDARN radar: Ionospheric signatures of coupled poloidal Alfvén and drift-compressional modes
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فیزیک زمین (ژئو فیزیک)
پیش نمایش صفحه اول مقاله
First results of the high-resolution multibeam ULF wave experiment at the Ekaterinburg SuperDARN radar: Ionospheric signatures of coupled poloidal Alfvén and drift-compressional modes
چکیده انگلیسی
The first ULF wave events observed in the experiment and presented here occurred on 14 December 2013 and 2 January 2014 in the nightside magnetosphere during two geomagnetic disturbances classified as small magnetic storms and associated with high speed streams from coronal holes. Both the ULF events occurred after substorm-like auroral disturbances. The ULF waves observed during these events are classified as Pc5 geomagnetic pulsations. Two oscillation branches were observed, the higher and the lower frequency ones. As the azimuthal wave numbers m increase, the branches converge and merge into a single oscillation branch at some critical azimuthal wave number value m⋆. This ω(m) dependence is characteristic of the coupled Alfvén and drift-compressional waves which according to theory merge if the azimuthal wave number exceeds some critical value. This merged single oscillation branch represents an unstable drift ballooning coupling mode. Thus, the following interpretation of the observed events can be suggested; at mm⋆ the single branch can be identified with the drift ballooning coupling mode.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Atmospheric and Solar-Terrestrial Physics - Volumes 130–131, August 2015, Pages 112-126
نویسندگان
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