Quiet time magnetospheric proton plasma parameters in the equatorial plane

Magnetospheric plasma parameters in the equatorial plane, during geomagneti cally quiet conditions (AE<100 nT), are studied with proton measurements fr om AMPTE/CCE-CHEM covering energies from similar to 1 keV to similar to 300 keV. In order to obtain a statistically significant database for a high sp atial resolution, data have been averaged over two years (From January 1985 to June 1987). The results provide average images of proton plasma pressur e tensor, proton plasma anisotropy, proton plasma beta, and azimuthal volum e current density. The change of these magnetospheric plasma parameters wit h MLT is discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.