Parallel Electric Fields and Wave Phenomena Associated with Magnetic Reconnection: The Merged Magnetic Field Product from MMS
Friday, 18 December 2015
Poster Hall (Moscone South)
Kinetic processes associated with magnetic reconnection current structures are able to be resolved for the first time by the instrument suites and small inter-spacecraft separation of MMS. Measurements of the parallel electric fields responsible for electron acceleration, and wave activity associated with reconnection onset and electron scattering require precise knowledge of the magnetic field amplitude and phase. The fluxgate and searchcoil magnetometers on MMS are sensitive to low- and high-frequency field fluctuations, respectively. In the middle frequency range, we optimize sensitivity by merging the two datasets to create a single magnetic field data product. We analyze frequency-dependent amplitude and phase relationships between the two instruments to determine how they should be joined. The result is a product with the time resolution and Nyquist frequency of the searchcoil, but with the fluxgate's ability to measure the DC magnetic field. This dataset provides improved phase information suitable for determining parallel electric fields during magnetic reconnection events. Its enhanced sensitivity also makes it ideal for resolving thin current layers and uncovering low-amplitude wave activity, such as EMIC waves related to substorm injections and Alfven or lower hybrid waves related to reconnection.