Total precipitating energy and alpha are anticorrelated. The values for alpha can reach below 20 keV, especially for medium activity, though they are between 20 and 30 keV on average. The plots below show the derived total precipitating energy patterns for medium energy protons. The patterns are displayed versus magnetic local time and magnetic latitude. The perimeter latitude is 54 o magnetic North, and the dotted constant latitude circles are 4 o apart.
Magnetic midnight is at the top.
The trough in energy deposition is in the pre-noon sector, in agreement with the westward curvature drift for protons. The pattern covers lower magnetic latitudes in the midnight and pre-dawn sectors, while the peak energy deposition is less than for electrons. The next graph shows the estimated occurrence for each of the 10 activity levels, in percent of time. The estimate is based on the average of the yearly statistics. Note that for short periods of time, the graph may be quite different.