The magnetopause: Part 2: Magnetopause position and the reconnection problem

OGO-5 magnetic field data were used to locate the magnetopause, while HEOS-1 (or sometimes Explorer 33) plasma data were used to measure the solar wind dynamic pressure and to study the actual response of the magnetosphere (through the location of the magnetopause) to different solar wind pressures. The OGO-5 magnetopause positions were divided into two groups, one relating to observations close to the ecliptic plane, the other having a sun-earth-satellite angle greater than 56.5 deg. Results show that not only is the interplanetary magnetic field latitude important for the magnetopause position (and therefore for the reconnection process) but also the presence or absence of magnetosheath turbulence and the proton number density are important.