HR: 11:45h
AN: SM51D-06 INVITED     [PDF]
TI: Numerical modelling of observed cusp characteristics for spatial and temporal variations in magnetopause reconnection rate
AU: * Lockwood, M
EM: m.lockwood@rl.ac.uk
AF: Rutherford Appleton Lab., Space Science Department, Chilton, Oxfordshire, Didcot, OX11 0QX United Kingdom
AU: Morley, S K
EM: skm@phys.soton.ac.uk
AF: University of Southampton, Department of Physics and Astronomy Hampshire, Southampton, SO17 1BJ United Kingdom
AB: Using the Cowley-Lockwood theory of ionospheric flow excitation, a numerical model of the response to generalised variations of the magnetopause reconnection rate, in both space and time, has been developed for times when the Y-component of the IMF is small. This model allows the motion of all reconnected field lines to be monitored and maps of time-elapsed since reconnection can be generated. Because the characteristics of the ion precipitation spectrum can be characterised as a function of this elapsed time and the site of the reconnection, we can use this model to generate time series of maps of parameters such as the sheath ion flux, the mean energy, the low-energy cut-off, and the proton aurora intensity, as well as the convection patterns and maps of the consequent ion heating. Comparison with observations shows very good agreement with observations by the IMAGE spacecraft and the SuperDARN network of HF radars. The model reproduces observed stepped and sawtooth signatures, depending on satellite altitude and pass orientation, as predicted for pulsed reconnection. Using the maintenance of quasi-neutrality, first-order predictions of features produced by sheath electron precipitation can also be modelled. For example, we show how poleward-moving 630 nm auroral transients and patches of enhanced plasma concentration can also result from the pulsed reconnection.
DE: 2704 Auroral phenomena (2407)
DE: 2724 Magnetopause, cusp, and boundary layers
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2760 Plasma convection
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting