Possible Kelvin-Helmholtz waves driven by reconnection accelerated flows

We present new observations of highly steepened magnetic signals within the dayside magnetopause current layer, having a period of about 5 seconds. These signals are embedded within a reconnection region and we suggest they may be Kelvin‐Helmholtz waves driven unstable by the velocity shear associated with reconnection accelerated flows. It is due to the low magnetic field strength and consequent high Alfvén Mach number that the signals are confined to the magnetopause. Our data consist of high time resolution magnetic field and plasma measurements from the AMPTE‐UKS satellite.