Electron energization is an outstanding issue in magnetic reconnection, which is a hot topic in plasma physics and astrophysics. Four different structures have been proposed for electron energization during reconnection. We find that there is no specific sequence of electron energization through the four structures; there is no specific order of electron acceleration efficiency among the four structures, and electron energization occurs in a wide region around X-line.

A possibility of gravity wave propagation from a source region to the airglow layer around the mesopause has been discussed based on the gravity wave blocking diagram taking into account the critical level filtering alone. This paper proposes a new gravity wave transmission diagram in which both the critical level filtering and turning level reflection of gravity waves are considered. It shows a significantly different distribution of gravity wave transmissivity from the blocking diagram.

Adaptive magnetospheric models based on THEMIS magnetic observations made at 6-9Re in the nightside magnetosphere are used to map the magnetically conjugate 30 and 80keV proton isotropy boundaries (IBs) to investigate the value of Kib=Rc/rc (magnetic curvature radius to particle gyroradius) in the neutral sheet at the IB generation place. For the most accurate mapping, the group Kib spread spans from 4 to 32; its median value is ~13, slightly larger than Kib8 expected for current sheet scatter.

The solar wind electric sail (E-sail) is a new way to move in the solar system efficiently without consuming propellant. The E-sail taps momentum from the solar wind by long, charged and centrifugally stretched tethers. Here we develop a new type of simulation for predicting E-sail thrust. The new simulation involves some approximations, but is robust and executes fast on a computer. The results are in good agreement with an earlier theoretical prediction. The E-sail thrust seems strong.

The solar wind plasma interacts with a planetary magnetic field. A magnetohydrodynamic model is used to simulate the interaction and resulting plasma flow. The model uses solar wind inflow parameters as boundary condition. Spacecraft data of the interaction region are compared to the flow model. The solar wind boundary parameters are varied until the model matches the data. With a time-resolution of about 10min, the time-dependent solar wind boundary parameters were reconstructed from the data.