English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Recent Magnetosphere Multiscale (MMS) observations found 238 high energy (>40 keV) electron "leaking" events in the the magnetosheath [Cohen et al.,2017]. While several sources have been proposed, the dominant mechanism ororigin of these particles is not well understood. We have analyzed MMSlocations during these these events and found that most of these electronleaking events were observed close to the southern high-altitude cusp andassociated boundaries, so these events may have a high-latitude source. Here wepresent a new case study of observations of a MMS encounter of southernmagnetospheric cusp boundaries. In the magnetosheath side of the southern cusp,MMS observes both parallel streaming energetic ions, as well as a populationwith 90 degree pitch angles. Subsequently, MMS detects plasma flows andmagnetic field rotation consistent with magnetic reconnection (operating aboveand dawn-ward of the MMS spacecraft), finally entering a depressed magneticfield region with nearly stagnant flow. The depressed field region is occupiedby high-fluxes of trapped high-energy electrons and protons, which resemble theCluster observations of cusp diamagnetic cavities at the northern hemisphere[Nykyri et al., 2011a]. However, the local magnetic field geometry during theprevailing IMF orientation is not favorable for magnetic reconnection todirectly create a cavity in this location. We show that the plasma flows thatwere observed prior to cavity observation satisfy the onset condition for theKelvin-Helmholtz instability for 50 percent of all available k-vectordirections.

Magnetospheric Multi-Scale Observations of High-Energy Electrons and Protons in the Vicinity of Southern High-Altitude Cusp Boundaries