TY - JOUR

T1 - Long lasting energetic proton precipitation in the inner magnetosphere after substorms.

AU - Gvozdevsky, BB

AU - Sergeev, VA

AU - Mursula, K

PY - 1997/11/1

Y1 - 1997/11/1

N2 - Data of polar-orbiting low-altitude NOAA spacecraft are used to study the precipitation of energetic (30-80 keV) protons, several degrees equatorward of the energetic proton isotropic boundary. This precipitation, to be called low-latitude proton precipitation (LLPP), is observed at all local time sectors. The LLPP precipitating flux is found to be generally smaller than the trapped flux. The LLPP particle flux significantly increases during intense substorms and then decays with a long characteristic timescale of about 9 hours. Therefore, it may also be found during very quiet times. The long decay and the observed loss cone anisotropy imply a moderate pitch angle diffusion of energetic protons. During quiet magnetic conditions following the disturbance the latitudinal position of the LLPP region moves slowly to higher latitudes. The equatorial boundary of the precipitation is found to be at lower latitudes in the night sector than in the dayside sector Mapping to the equatorial plane along magnetic field lines showed that the equatorial boundary of the precipitation at the nightside is situated on a closer drift shell than that at the dayside.

AB - Data of polar-orbiting low-altitude NOAA spacecraft are used to study the precipitation of energetic (30-80 keV) protons, several degrees equatorward of the energetic proton isotropic boundary. This precipitation, to be called low-latitude proton precipitation (LLPP), is observed at all local time sectors. The LLPP precipitating flux is found to be generally smaller than the trapped flux. The LLPP particle flux significantly increases during intense substorms and then decays with a long characteristic timescale of about 9 hours. Therefore, it may also be found during very quiet times. The long decay and the observed loss cone anisotropy imply a moderate pitch angle diffusion of energetic protons. During quiet magnetic conditions following the disturbance the latitudinal position of the LLPP region moves slowly to higher latitudes. The equatorial boundary of the precipitation is found to be at lower latitudes in the night sector than in the dayside sector Mapping to the equatorial plane along magnetic field lines showed that the equatorial boundary of the precipitation at the nightside is situated on a closer drift shell than that at the dayside.

KW - RADIATION BELT PROTONS

KW - RING CURRENT

KW - CONFIGURATION

KW - PLASMAPAUSE

KW - MAGNETOTAIL

KW - DIFFUSION

KW - BOUNDARY

KW - WAVES

U2 - 10.1029/97JA02062

DO - 10.1029/97JA02062

M3 - статья

VL - 102

SP - 24333

EP - 24338

JO - Journal of Geophysical Research: Biogeosciences

JF - Journal of Geophysical Research: Biogeosciences

SN - 0148-0227

IS - A11

ER -