HELIUM ESCAPE FROM THE TERRESTRIAL ATMOSPHERE - THE ION OUTFLOW MECHANISM

We have computed global He+ escape fluxes for a range and a variety of diurnal, seasonal, universal time, and solar activity geophysical con ditions. We average over the short-term variables and compute the glob ally averaged escape flux for a range of cutoff latitudes, which separ ate regions of open and closed field lines, during one solar cycle. Th e global escape flux averaged over a solar cycle was computed, and we find that a cutoff latitude of about 60 degrees or lower is sufficient to balance the outgassing from the Earth's crust.