SH13E-04
Solar wind ion distribution broadening by waves and transients
Monday, 14 December 2015: 14:36
2011 (Moscone West)
Michael Louis Stevens1, Justin Christophe Kasper2, Anthony W Case1, Adam Szabo3, Andriy Koval3 and Douglas Alan Biesecker4, (1)Smithsonian Astrophysical Observatory, Cambridge, MA, United States, (2)University of Michigan Ann Arbor, Ann Arbor, MI, United States, (3)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (4)NOAA Boulder, SWPC, Boulder, CO, United States
Abstract:
Thermal plasma spectra in the solar wind are subject to peak-broadening by plasma waves and small-scale structures at effective frequencies faster than the measurement rate. Under strong turbulence conditions, the non-thermal contribution to proton peak broadening in many commonly-used solar wind measurements becomes comparable to that of the kinetic temperature. The DSCOVR spacecraft, which arrived at the first Earth-Sun Lagrange point in June 2015, bears the PLASMAG Faraday Cup Experiment. That instrument is identical in most respects to the Wind SWE Faraday Cup instrument that has been measuring 92-second proton spectra in the solar wind for the last twenty years. In this paper, the effective proton VDF peak width is compared at 92-second and 1-second resolution as a function of the ambient magnetic fluctuation amplitude on relevant timescales. This work will enable a more accurate understanding of the energy partition in the solar wind plasma.
