Phobos 2/ASPERA data revisited: Planetary ion escape rate from Mars near the 1989 solar maximum



[1] Insights about the near-Mars space environment from Mars Express observations have motivated a revisit of the Phobos 2/ASPERA ion data from 1989. We have expanded the analysis to now include all usable heavy ion (O+, Oinline image, COinline image) measurements from the circular orbits of Phobos 2. Phobos 2/ASPERA ion fluxes in the Martian tail are compared with previous results obtained by the instruments on Phobos 2. Further validation of the measurement results is obtained by comparing IMP-8 and Phobos 2/ASPERA solar wind ion fluxes, taking into account the time lag between Earth and Mars. Heavy ion flux measurements from 18 circular equatorial orbits around Mars are bin-averaged to a grid, using the MSE (electric field) frame of reference. The binned data are subsequently integrated to determine the total escape rate of planetary ions. From this we derive a total planetary heavy ion escape rate of (2–3) × 1025 s−1 from Mars for the 1989 solar maximum.