A new model for the low altitude trapped proton environment

We have developed a new model for the low-altitude (250-850 km) trapped radiation environment based on data from the TIROS/NOAA polar orbiting spacecraft. The model is based on a long time series (more than one complete solar cycle) obtained from the TIROS/NOAA data. The model provides the integral flux of protons in three energy channels (>16, >36, and >80 MeV) as a function of position in geomagnetic coordinates and solar radio flux. The model includes a phase lag between the solar activity and the proton flux; the phase lag is a function of energy and position in geomagnetic coordinates. Comparison with the AP8 models shows that the new model predicts fluxes approximately twice as large as AP8. These data have important implications for the development and use of trapped radiation models.