【摘 要】
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We analyzed a Pc2 wave event above the He+ cyclotron frequency detected by the four Cluster satellites and multiple ground stations in Antarctica.During the wave event, Cluster satellites were located
【机 构】
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Polar Atmosphere and Space Physics Department, Polar Research Institute of China, Shanghai 200129, C
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We analyzed a Pc2 wave event above the He+ cyclotron frequency detected by the four Cluster satellites and multiple ground stations in Antarctica.During the wave event, Cluster satellites were located sunward from L~13 in the outer magnetosphere to the magnetopause, over 13°-20° magnetic latitude, north of the equator near local magnetic noon.The Poynting flux results show that the wave packet energy propagated dominantly along the geomagnetic field direction and in alternating directions rather than uni-directionally from the equator, implying the wave source was located in a high latitude region away from the equator, where a minimum in the B field is located.The footprint of Cluster was closest to the Zhong Shan and Davis (ZHS/DAV) stations (L~14) in Antarctica.Consequently, the frequency range and the burst-pattern of the dynamic spectra from ZHS and DAV are highly consistent with those seen by Cluster.Although wave packets on Cluster occurred from 0800 UT to 1430 UT, lasting for 6.5 hours, the wave bursts on ZHS and DAV stations were concentrated earlier at 0800-1040 UT.This suggests the azimuthal extent of the wave source may be estimated at 2.6 hours and the wave packets were guided by the field lines from Cluster to ZHS/DAV.The waves at Mawson (L~9) and Casey (L~38.8) are rather weak and the wave burst-patterns appear obviously different from those at ZHS/DAV and Cluster, suggesting the wave energy propagated toward both high and low latitudes via the inonospheric waveguide.
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