ISEE-1 AND GEOTAIL OBSERVATIONS OF LOW-FREQUENCY WAVES AT THE MAGNETOPAUSE

Observations of waves at frequencies below similar to 200 Hz obtained near the magnetopause are presented. For one case identified in the IS EE 1 data as a period when steady state reconnection was occurring, th ere were waves below the lower hybrid frequency with amplitudes up to similar to 7 mV/m. Intense low-frequency waves with amplitudes up to s imilar to 20 mV/m at the subsolar magnetopause have also been observed by the Geotail electric field instrument. In some cases, large spiky fields were embedded in the waves. The waves observed by ISEE 1 and Ge otail were large enough to provide the dissipation required for reconn ection to occur.