@article{cd3029d42465429bb5792cc63eb96b39,
title = "High-Resolution Measurements of the Cross-Shock Potential, Ion Reflection, and Electron Heating at an Interplanetary Shock by MMS",
abstract = "The Magnetospheric Multiscale (MMS) spacecraft obtained unprecedented high-time resolution multipoint particle and field measurements of an interplanetary shock event on 8 January 2018. The spacecraft encountered the supercritical forward shock of a forward/reverse shock pair in the pristine solar wind upstream of the bow shock near the subsolar point as they neared apogee at ~25 RE. The high-time resolution measurements from the four spacecraft, separated by only ~20 km, allowed direct measurement of particle distributions revealing evidence of electron heating and near specularly reflected ions. The cross-shock potential is calculated directly from 3-D electric field measurements. This is the first reported direct high temporal resolution (<1 s) observation at an interplanetary shock of near specularly reflected ions. Calculation of the cross-shock potential yields a potential jump significant enough to reflect at least some of the protons from the incident solar wind beam. The cross-shock potential calculated here is consistent with previous estimations based on particle measurements and numerical/analytical simulations. The ambipolar contribution to the cross-shock potential calculated from the four-spacecraft divergence of the electron pressure tensor is somewhat higher than that inferred form the Liouville-mapped electron energy gain across the shock. Furthermore, the high-time-resolution 3-D electric field measurements reported here reveal small-scale nonlinear structures embedded in the shock layer that contribute to the nonmonotonic shock transition.",
keywords = "MMS, interplanetary shock, particle acceleration, shock potential",
author = "Cohen, {Ian J.} and Schwartz, {Steven J.} and Goodrich, {Katherine A.} and Narges Ahmadi and Ergun, {Robert E.} and Fuselier, {Stephen A.} and Desai, {Mihir I.} and Christian, {Eric R.} and McComas, {David J.} and Zank, {Gary P.} and Shuster, {Jason R.} and Vines, {Sarah K.} and Mauk, {Barry H.} and Decker, {Robert B.} and Anderson, {Brian J.} and Westlake, {Joseph H.} and {Le Contel}, Olivier and Hugo Breuillard and Giles, {Barbara L.} and Torbert, {Roy B.} and Burch, {James L.}",
note = "Funding Information: The authors are grateful to the dedicated scientists and engineers of the MMS Science, Instrument, and Operations Teams. This work was supported by the Magnetospheric Multiscale (MMS) mission of NASA's Science Directorate Heliophysics Division via subcontract to the Southwest Research Institute (NNG04EB99C). All MMS data presented here are level 2 and can be retrieved from the MMS Science Data Center (at https://lasp.colorado.edu/ mms/sdc/). OMNI and WIND data can be retrieved from the NASA Coordinated Data Analysis Web (CDAWeb) service (at https://cdaweb. sci.gsfc.nasa.gov). Additional thanks are extended to Vassilis Angelopoulos, Eric Grimes, and the teams at UCLA and Berkeley for their development and support of the Space Physics Environment Data Analysis Software (SPEDAS) IDL framework (Angelopoulos et al., 2019) together with the development team for the QSAS Science Analysis System (https:// sourceforge.net/projects/qsas/) used for much of the analysis presented here. S. J. S. and K. A. G. are grateful for the hospitality and support provided by ISSI, Bern. Funding Information: The authors are grateful to the dedicated scientists and engineers of the MMS Science, Instrument, and Operations Teams. This work was supported by the Magnetospheric Multiscale (MMS) mission of NASA's Science Directorate Heliophysics Division via subcontract to the Southwest Research Institute (NNG04EB99C). All MMS data presented here are level 2 and can be retrieved from the MMS Science Data Center (at https://lasp.colorado.edu/mms/sdc/). OMNI and WIND data can be retrieved from the NASA Coordinated Data Analysis Web (CDAWeb) service (at https://cdaweb.sci.gsfc.nasa.gov). Additional thanks are extended to Vassilis Angelopoulos, Eric Grimes, and the teams at UCLA and Berkeley for their development and support of the Space Physics Environment Data Analysis Software (SPEDAS) IDL framework (Angelopoulos et al.,) together with the development team for the QSAS Science Analysis System (https://sourceforge.net/projects/qsas/) used for much of the analysis presented here. S. J. S. and K. A. G. are grateful for the hospitality and support provided by ISSI, Bern. Publisher Copyright: {\textcopyright}2019. Johns Hopkins University Applied Physics Laboratory.",
year = "2019",
month = jun,
doi = "10.1029/2018JA026197",
language = "English (US)",
volume = "124",
pages = "3961--3978",
journal = "Journal of Geophysical Research: Space Physics",
issn = "2169-9402",
number = "6",
}