Radiation Belt Response to Driving by Comples ICMEs

Pulkkinen, Tuija

Radiation Belt Response to Driving by Comples ICMEs

Wednesday, 13 February 2019

Fountain III/IV (Westin Pasadena)

Tuija I Pulkkinen^1,2, K Emilia J Kilpua³, Milla Kalliokoski³, Minna Palmroth^3,4, Drew L Turner⁵, Seth G Claudepierre^6,7, Allison N Jaynes⁸, Heli Hietala^9,10, Rami O Vainio⁹, Adnane Osmane^11,12 and Daniel N Baker¹³, (1)University of Michigan, Department of Climate and Space Sciences and Engineering, Ann Arbor, United States, (2)Aalto University, Department of Electronics and Nanoengineering, Espoo, Finland, (3)University of Helsinki, Department of Physics, Helsinki, Finland, (4)Finnish Meteorological Institute, Helsinki, Finland, (5)The Aerospace Corporation, El Segundo, CA, United States, (6)The Aerospace Corporation, Santa Monica, CA, United States, (7)UCLA, Department of Atmospheric and Oceanic Sciences, Los Angeles, CA, United States, (8)University of Iowa, Department of Physics and Astronomy, Iowa City, IA, United States, (9)University of Turku, Department of Physics and Astronomy, Turku, Finland, (10)UCLA, Dept. of Earth, Planetary, and Space Sciences, Los Angeles, CA, United States, (11)University of Oxford, Department of Physics, Oxford, United Kingdom, (12)Aalto University, Department of Electronics and Nanoengineering, Aalto, Finland, (13)University of Colorado, Laboratory for Atmospheric and Space Physics, Boulder, CO, United States

Abstract:

One of the key challenges in space weather predictions is the multitude of responses any driver causes, and the complexity of the drivers often consisting of more than one geoeffective solar wind structure. Here we examine the combined effects of multiple or complex ICMEs on the outer radiation belt during major geomagnetic storms. We do that by addressing each of the drivers and each of the responses separately using observations from the solar wind (OMNI database), magnetosphere (Van Allen Probes and GOES), and ground (geomagnetic indices). We examine the properties of the ICME shock, sheath, and cloud proper at 1 AU, and their effects in the outer magnetosphere and its boundaries, in the inner magnetosphere, and in the ionosphere. The Van Allen Probes and GOES data are used to examine the electron responses over the full energy range from the source (tens of keV) and seed (hundreds of keV) to core (MeV) electrons. The processes leading to the losses and enhancements of the electron fluxes are examined using the Van Allen Probes wave measurements in the ULF Pc5, EMIC, and chorus frequencies as well as the solar wind data and model magnetic fields providing the magnetopause position and inner magnetosphere field configuration. A global MHD simulation is used to complement and verify the conclusions. Using these methods, we create a timeline, which clearly illustrates the combined effects of loss and acceleration processes that lead to the observed electron fluxes. While such detailed observations are not always available during any given storm, our study demonstrates that given sufficient understanding of the processes, reliable nowcasts and forecasts of the electron fluxes are indeed viable.