SH24A-03
Modeling SEPs and Their Variability in the Inner Heliosphere
Tuesday, 15 December 2015: 16:50
2011 (Moscone West)
M. Leila Mays1,2, Janet G Luhmann3, Dusan Odstrcil2, Nathan Schwadron4, Matt Gorby4, Hazel M Bain3, Richard A Mewaldt5 and Robert E Gold6, (1)Catholic University of America, Washington, DC, United States, (2)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (3)University of California Berkeley, Berkeley, CA, United States, (4)University of New Hampshire Main Campus, Space Science Center, Durham, NH, United States, (5)California Institute of Technology, Pasadena, CA, United States, (6)Applied Physics Laboratory Johns Hopkins, Laurel, MD, United States
Abstract:
In preparation for Solar Probe Plus and Solar Orbiter we consider a series of SEP modeling experiments based on the global MHD WSA-ENLIL model. The models include the Solar Energetic Particle Model (SEPMOD) (Luhmann et al., 2007; 2010) and the Earth-Moon-Mars Radiation Environment Module (EMMREM) (Schwadron et al., 2010)). WSA-ENLIL provides a time-dependent background heliospheric description including CME-like clouds which can generate shocks during their propagation. SEPMOD makes use of the ENLIL-provided magnetic topologies of observer-connected magnetic field lines and all plasma and shock properties along those field lines. The model injects protons onto a sequence observer field lines at intensities dependent on the connected shock source strength which are then integrated at the observer to approximate the proton flux. EMMREM couples with MHD models such as ENLIL and computes energetic particle distributions based on the focused transport equation along a Lagrangian grid of nodes that propagate out with the solar wind. In this presentation we compare SEP modeling results with data, and consider SEP variability in longitude and latitude. Additionally we study the relative importance of observer-connectivity to the solar source and shock locations, as derived from ENLIL. We evaluate the shock geometry and compare model-derived shock parameters with those observed. Finally, we test the effect of the seed population on the resulting profiles.
