Escape of O+ through the distant tail plasma sheet

In February 2007, the STEREO-B spacecraft encountered the magnetosheath, plasma sheet and plasma sheet boundary layer from about 200 R-E to 300 R-E downtail. This time period was during solar minimum, and there was no storm activity during this month. Using data from the PLASTIC instrument, we find that even during quiet times, O+ is a constant feature of the deep magnetotail, with an O+ density of about 15% of the O+ density in the near-earth plasma sheet for similar conditions. The tailward flux of the O+ is similar to the flux of O+ beams that have been observed in the lobe/mantle region of the deep tail. The total outflow rate of the O+ down the plasma sheet is 1.1 x 10(24) ions/s, which is 10% of the total outflow rate of 1 x 10(25) ions/s, and of the same order as the estimated loss from dayside transport. Citation: Kistler, L. M., et al. (2010), Escape of O+ through the distant tail plasma sheet, Geophys. Res. Lett., 37, L21101, doi:10.1029/2010GL045075.