SH049-0009
Searching for Weak Stream Interactions in the Inner Heliosphere Using the Parker Solar Probe

Wednesday, 16 December 2020
Poster
Christopher Mark Bert1, Justin Christophe Kasper1, Anthony W Case2, Kelly E Korreck2, Davin E Larson3, Roberto Livi4, Michael Louis Stevens2, Phyllis L Whittlesey4, Stuart D Bale5, Marc Pulupa4, Robert J MacDowall6, Robert Colby Allen7 and Jia Huang1, (1)University of Michigan, Climate and Space Sciences and Engineering, Ann Arbor, MI, United States, (2)Smithsonian Astrophysical Observatory, Cambridge, MA, United States, (3)Space Sciences Laboratory, Berkeley, CA, United States, (4)Space Sciences Laboratory, University of California Berkeley, Berkeley, CA, United States, (5)University of California Berkeley, Space Sciences Laboratory, Berkeley, CA, United States, (6)NASA/Goddard Space Flight Center, Greenbelt, United States, (7)Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States
Abstract:
We present a statistical examination of local gradients in solar wind speed observed by the Parker Solar Probe (PSP) Faraday Cup (SPC) during its first encounters. Calculating radial gradients of speed across many observed timescales and in an Eulerian frame – as opposed to evaluating the acceleration through space of a particular parcel of plasma – provides a means to determine the extent of each parcel’s change in volume along its propagation path through the inner heliosphere. This systematic discrimination between compressions and rarefactions of varying magnitude forms the basis of a spherical shells model of the solar wind and reveals scales at which temperature and density are adiabatically coupled to volume. We use this analysis to search for weak stream interactions and corresponding trends in temperature and density, characterizing their impact as an additional driver of solar wind variability. Finally, we compare to similar analysis of observations by the Wind spacecraft at L1.
<< Previous Abstract | Next Abstract >>