Investigating the Dependence of Normalized Reconnection Rate on Upstream Plasma Parameters

Abstract We present the results of a multi‐event study of the normalized reconnection rate integrating events spanning the three primary regimes of reconnection observed by the Magnetospheric Multiscale mission. We utilize a new method for determining the normalized reconnection rate with fewer sources of uncertainty by estimating the aspect ratio and spatiotemporal variability of the current sheet with magnetic field gradients. After demonstrating this technique is valid in different regimes we perform a multi‐event analysis and find no dependence of reconnection rate on upstream conditions. The only statistically significant correlation is between spatiotemporal variability in the current sheet aspect ratio and an unsteady reconnecting component of the upstream magnetic field. This analysis suggests that under typical steady magnetospheric conditions the normalized reconnection rate is constant, which may be significant in predicting the terrestrial effects of space weather by providing insight into the efficiency of solar wind‐magnetospheric coupling.