Whistler mode waves near the plasmapause: Results from the IMS VLF experiment at Halley, Antarctica

During the International Magnetospheric Study (IMS) a program of wide band VLF recordings was carried out at Halley (76S, 27W, L=4), coordinated with related observations at other L=4 Antarctic stations, including SEAL, an unmanned automatic observatory deployed specifically for the IMS. Using whistler data from Halley and Siple, plasmapause structures of scale size 0.5L and 30 deg in longitudinal extent were investigated. Two station (Halley-SEAL and Halley-Palmer) direction-finding on whistlers yielded results on whistler mode propagation near the plasmapause, providing evidence of coupling across the plasmapause between whistler ducts, and of non-field-aligned propagation at low altitudes. The properties of magnetospheric line radiation were studied using Halley IMS data.