[1] A model of transient time-dependent magnetic reconnection is used to describe the behavior of nightside flux transfers (NFTEs) in the Earth's magnetotail. On the basis of the analytical approach to reconnection developed by Heyn and Semenov (1996) and Semenov et al. (2004a) we calculate the magnetic field and plasma bulk velocity time series observed by a satellite. The solution for the plasma parameters is given in the form of a convolution integral. The calculation of the reconnection electric field is an ill-posed inverse problem, which we treat in the frame of the theory of regularization. This method is applied to Cluster measurements from 8 September 2002, where a series of earthward propagating 1-min scale magnetic field and plasma flow variations are observed outside of the plasma sheet, which are consistent with the theoretical picture of NFTEs. We analyzed three NFTEs and reconstructed the reconnection electric field. Additionally, the position of the satellite with respect to the reconnection site as well as the Alfvén velocity are estimated because they are necessary input parameters for the model. The reconnection electric field is found to be about 1-2 mV/m, while the reconnection site is located about 29-31 R E in the magnetotail.

[1] We report strong repeated magnetic reconnection pulses that occurred deep inside closed plasma sheet flux tubes at r 14Re. They have been observed with a fortuitous spacecraft constellation during three consecutive turbulent magnetic dipolarizations, accompanied by localized auroral brightenings near the equatorward edge of a wide auroral oval. The reconnection separatrix was mapped to $64°CGLat in the ionosphere, where a very energetic and narrow energy-dispersed ion injection with unusually steep dispersion slope was observed. Reconstruction of the reconnection rate from magnetic waveforms at Cluster provided a reconnection pulse duration ($1 min) and peak strength (E R $ 8 mV/m) consistent with direct observations in the reconnection outflow region. The magnetic activity was rather weak, although the concurrent solar wind flow pressure was above the norm. We suggest that near-Earth reconnection events may be a phenomenon more frequent than generally thought. We also confirm that reconnection and the growth of strong turbulence in the near tail are strongly coupled together in near-Earth reconnection events.

[1] We present a method to determine the location of the reconnection site and the amount of reconnected magnetic flux out of an analytical time-dependent reconnection model and apply this method to disturbances observed on 2 February 2008 at about 0200 and 0815 UT by THEMIS B (P1). During these events, P1 detected two tailward propagating traveling compression regions, associated with typical variations in B z and B x . We find the reconnection site to be located at about À16 R E for the event at 0200 UT and À17.5 R E for the event at 0815 UT. These locations are consistent with simple timing considerations with respect to disturbances detected by the inner THEMIS spacecraft. The amount of reconnected flux in our 2-D model can be found to be in the order of 10 8 nT m for both events. The calculations for the reconnection site's location are done by using two approaches, i.e., by using the B z and the B x signals, yielding consistent results. The reconnected flux can be determined using B z and v z . Also, these results are in good agreement. A comparison between the disturbances detected by P1 and the modeled variations shows that our model describes disturbances in the magnetic field and the background plasma very well.