Energetic particle pressure in intense ESP events

[摘要] We study three intense energetic storm particle (ESP) events in which the energetic particle pressure PEPexceeded both the pressure of the background thermal plasma Pthand the pressure of the magnetic field PB. The region upstream of the interplanetary shocks associated with these events was characterized by a depression of the magnetic field strength coincident with the increase of the energetic particle intensities and, when plasma measurements were available, a depleted solar wind density. The general feature of cosmic-ray mediated shocks such as the deceleration of the upstream background medium into which the shock propagates is generally observed. However, for those shocks where plasma parameters are available, pressure balance is not maintained either upstream of or across the shock, which may result from the fact that PEPis not included in the calculation of the shock parameters.

[发布机构] Johns Hopkins University, Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel; MD; 20723, United States^1;NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Greenbelt; MD; 20771, United States^2

[效力级别] 天文学 [学科分类] 天文学(综合)

[关键词] Background medium;Energetic particles;Interplanetary shocks;Magnetic field strengths;Plasma measurement;Pressure balance;Shock parameters;Solar wind density