Multi-satellite simultaneous observations of magnetopause and atmospheric losses of radiation belt electrons during an intense solar wind dynamic pressure pulse
- 1Department of Space Physics, School of Electronic Information, Wuhan University, Wuhan, Hubei, China
- 2State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing, China
- 3National Space Weather Monitoring and Warning Center, China Meteorological Administration, Beijing, China
- 4Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado, USA
- 5Institute for the Study of Earth, Oceans, and Space and Department of Physics, University of New Hampshire, Durham, New Hampshire, USA
- 6Space Science and Applications Group, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
Abstract. Radiation belt electron flux dropouts are a kind of drastic variation in the Earth's magnetosphere, understanding of which is of both scientific and societal importance. Using electron flux data from a group of 14 satellites, we report multi-satellite simultaneous observations of magnetopause and atmospheric losses of radiation belt electrons during an event of intense solar wind dynamic pressure pulse. When the pulse occurred, magnetopause and atmospheric loss could take effect concurrently contributing to the electron flux dropout. Losses through the magnetopause were observed to be efficient and significant at L ≳ 5, owing to the magnetopause intrusion into L ∼ 6 and outward radial diffusion associated with sharp negative gradient in electron phase space density. Losses to the atmosphere were directly identified from the precipitating electron flux observations, for which pitch angle scattering by plasma waves could be mainly responsible. While the convection and substorm injections strongly enhanced the energetic electron fluxes up to hundreds of keV, they could delay other than avoid the occurrence of electron flux dropout at these energies. It is demonstrated that the pulse-time radiation belt electron flux dropout depends strongly on the specific interplanetary and magnetospheric conditions and that losses through the magnetopause and to the atmosphere and enhancements of substorm injection play an essential role in combination, which should be incorporated as a whole into future simulations for comprehending the nature of radiation belt electron flux dropouts.