Solar cycle dependence of the geomagnetically trapped anomalous cosmic rays

Solar cycle variations in the intensity of geomagnetically trapped anomalou s cosmic ray (ACR) oxygen are demonstrated by similar to 7 years of data fr om the SAMPEX satellite. They correspond to similar variations in the inter planetary ACR. source. Trapped particle losses during the approach to solar maximum are not associated with geomagnetic activity and may be consistent with atmospheric energy degradation. The average trapped particle pitch an gle distribution and energy spectra support this interpretation in which bo th source and loss rates are proportional to atmospheric density.