Reconnection Magnetic Fields, Expectations and Preliminary Magnetic Field Measurements from Magnetospheric Multiscale

Strangeway, Robert

Reconnection Magnetic Fields, Expectations and Preliminary Magnetic Field Measurements from Magnetospheric Multiscale

Friday, October 2, 2015: 11:00 AM

Robert J Strangeway¹, Christopher T Russell¹, James L Burch², Roy B Torbert^3,4, Werner Magnes⁵, Brian J Anderson⁶, Hannes Karl Leinweber¹, Kenneth R Bromund⁷, Guan Le⁷, Larry Kepko⁷, Wolfgang Baumjohann⁵, Rumi Nakamura⁵, Ferdinand Plaschke⁵, David Fischer⁵, Olivier Le Contel⁸, James A Slavin⁹, Matthew R Argall³, Mark Chutter³, Ivan Dors³ and David Rau³, (1)University of California Los Angeles, IGPP/EPSS, Los Angeles, CA, United States, (2)Southwest Research Institute San Antonio, San Antonio, TX, United States, (3)University of New Hampshire, Durham, NH, United States, (4)Southwest Research Institute Durham, Durham, NH, United States, (5)Space Research Institute, Austrian Academy of Sciences, Graz, Austria, (6)The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States, (7)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (8)Laboratoire de Physique des Plasmas (UMR7648), CNRS/Ecole Polytechnique/UPMC/Univ. Paris Sud/Obs. de Paris, Paris, France, (9)University of Michigan, Atmospheric, Oceanic and Space Sciences, Ann Arbor, MI, United States

Abstract:

The instrument complement of the Magnetospheric Multiscale (MMS) Mission includes redundant analog (AFG) and digital (DFG) fluxgate magnetometers, and search coil magnetometers (SCM). Measurements acquired during the magnetometer boom deployment showed that the spacecraft had a weak magnetic field with less than 1 nT at the deployed sensor location. This can be attributed to the efforts of the spacecraft and instrument teams in reducing potential sources of magnetic interference, and the comprehensive pro-active magnetic cleanliness program. By flying two fluxgate magnetometers it was also possible to immediately determine that the pre-launch testing and calibration activities had resulted in very high quality magnetic field measurements. In particular, while additional in-flight calibration has been and continues to be performed, the data fidelity was sufficiently good that some preliminary inter-spacecraft comparisons were possible as soon as magnetometer data were available.

At launch the MMS orbit initially had apogee at ~ 4 MLT. By September 1, 2015 apogee will have passed through midnight and be around dusk. At that time the first dayside science phase will begin. Nevertheless, while still in commissioning phase, the magnetometer data are of science grade quality, and we will review some of the magnetic field measurements and associated phenomena that will be described in more detail in other presentations at this conference. These include observations of the magnetopause during the strong magnetospheric compression that occurred during the March 17-18 geomagnetic storm, observations of current sheet thinning and recovery, dipolarization fronts and flux bundles, and magnetospheric wave phenomena. We also discuss our expectations for the magnetic field measurements associated with reconnection.