We present (1) K–H vortices in direct response to the northward turning of the interplanetary magnetic field (IMF); (2) solar wind transport into the magnetosphere caused by the K–H vortices, involving both ion and electron fluxes; and (3) typical portraits of the ion and electron fluxes in the regions of plasma transport. The unique characteristics may complement existing observations and enhance our understanding of the K–H vortices and transport process.

A new plasma intrusion or preonset aurora scenario of substorm triggering proposed by Nishimura et al. (2010) needs to be tested. To test the scenario, we revisited three of their substorm events in detail, based on THEMIS ground-based all-sky imager data. We list a series of open questions for testing the scenario further in future studies.

Hot flow anomalies (HFAs) at Earth's bow shock were identified in Time History of Events and Macroscale Interactions During Substorms (THEMIS) satellite data from 2007 to 2009. The events were classified as young or mature and regular or spontaneous hot flow anomalies (SHFAs). HFA–SHFA occurrence decreases with distance upstream from the bow shock. HFAs are more prevalent for radial interplanetary magnetic fields and solar wind speeds from 550 to 600 km^s−1.

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.

Magnetic reconnection is a ubiquitous process that drives global-scale dynamics in plasmas. For reconnection to proceed, both ion and electrons must be unfrozen in a localized diffusion region. By analyzing in situ measurements, we show that the non-gyrotropic ion pressure is mainly responsible for breaking the ion frozen-in condition in reconnection. The reported non-gyrotropic ion pressure tensor can specify the reconnection electric field that controls how quickly reconnection proceeds.