Longitude-Time Pattern for Quiet-Time Midlatitude Electron Precipitation
Abstract
During geomagnetically quiet times, particle precipitation at midlatitudes (2 < or = L < or = 4) results from a combination of pitch angle diffusion into the bounce loss cone and the opening of the bounce loss cone in the direction of drift to a maximum value which defines the drift loss cone. The geographical distribution of precipitation can thus be determined from geomagnetic field models which give the rate of change of the bounce loss cone size provided that an assumption is made about the spatial distribution of the source region where particles are scattered in the drift loss cone. Some observations indicate that the pitch angle scattering of kilovolt electrons occurs preferentially in the 0600-1200 LT quadrant of the magnetosphere. If the source of drift loss cone electrons is localized, precipitation into the midlatitude atmosphere will depend on both longitude and time of day. A simple model, in which the morning source is represented by a delta function at 0800 LT, leads to a qualitative picture of the morphology of precipitation in both Northern and Southern Hemispheres. The predictions of this model are consistent with some observations of 29 and 59 keV electrons from the low altitude satellite 1972-76B.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 10, 1977
- Accession Number
- ADA040470
Entities
People
- Alfred L. Vampola
- Janet G. Luhmann
Organizations
- The Aerospace Corporation