Polar survey of magnetic field in near tail:: Reconnection rare inside 9 RE -: art. no. L02101

We have examined the magnetic field at the apogee of the Polar spacecraft for three seasons during which time apogee was close to the equatorial plane and within 2 hours of midnight. The magnetic field magnitude in this region is rarely below 5 nT. However, when it is low, the magnetic field is very dynamic, with current sheet thinnings, plasma sheet expansions, and magnetic field dipolarizations. At times of low magnetic field strength we have examined the component normal to the magnetospheric equator for the presence of southward magnetic fields. However, in the period studied only northward fields were present in this region with one brief exception due to a bent current layer and not due to local reconnection. Thus it is very rare that the neutral point is as close as 9 R-E.