| Radio Physics and Radio Astronomy |
Vol. 9, 2004, No.2, June, p.130 |
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Magnetic Field Variations in Antarctica and the Conjugate Region (New England) Stimulated by Cyclone Activity
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Yu.M. Yampolski, A.V. Zalizovski, L.M. Lytvynenko, G.V. Lizunov1, K. Groves2 and M. Moldwin3
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Institute of Radio Astronomy of NAS of Ukraine, 4, Krasnoznamennaya St., 61002, Kharkov, Ukraine, E-mail: yampol@rian.kharkov.ua 1Киевский национальный университет имени Тараса Шевченко, Украина, 03022, г. Киев, пр. Глушкова, 6 2Air Force Research Laboratory, 29 Randolph Road Hanscom AFB MA 01731 – 3000 USA 3University of California – Los Angeles, 595 Charles Young Drive East, Box 951567 Los Angeles, CA 90095 – 1567 USA
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Long-term synchronous records of surface pressure and geomagnetic field variations at the Ukrainian Antarctic station “Akademik Vernadsky” are analyzed. Excitation of atmospheric gravity waves (AGW) by powerful atmospheric fronts above the Antarctic Peninsula has been found, and their projection to ionospheric and magnetospheric altitudes. The most probable period of the AGW reaching the dynamo-region of the ionosphere, equals 1.5 hours. A distinctive feature of the wave processes is the half-hour delay of the magnetic field variations with respect to such of the surface pressure. Similar magnetic field variations were detected near the conjugate region in the Northern hemisphere (New England, USA).
A physical model of atmospheric disturbance transportation to ionospheric altitudes has been developed, emphasizing modulation of transverse plasma conductivities and the dynamo current. Excitation mechanisms of the magnetic field variations in Antarctica and at the conjugate region are considered. |
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