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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The Solar Dynamics Observatory (SDO) was launched in February 2010 and is nowproviding an unprecedented view of the solar activity at high spatialresolution and high cadence covering a broad range of temperature layers of theatmosphere. We aim at defining the structure of a polar crown cavity anddescribing its evolution during the erupting process. We use high cadence timeseries of SDO/AIA observations at 304\AA (50000 K) and 171\AA (0.6 MK) todetermine the structure of the polar crown cavity and its associated plasma aswell as the evolution of the cavity during the different phases of theeruption. We report on the observations recorded on 13 June 2010 located on theNorth-West limb. We observe coronal plasma shaped by magnetic field lines witha negative curvature (U-shape) sitting at the bottom of a cavity. The cavity islocated just above the polar crown filament material. We thus observe the innerpart of the cavity above the filament as depicted in the classical three partCoronal Mass Ejection (CME) model composed of a filament, a cavity and a CMEfront. The filament (in this case a polar crown filament) is part of the cavityand makes a continuous structuring from the filament to the CME front depictedby concentric ellipses (in a 2D cartoon). We propose to define a polar crowncavity as a density depletion sitting above denser polar crown filament plasmadrained down the cavity due to gravity. As part of the polar crown filament,plasma at different temperatures (ranging from 50000K to 0.6 MK) is observed atthe same location on the cavity dips and sustained by a competition between thegravity and the curvature of magnetic field lines. The eruption of the polarcrown cavity as a solid body can be decomposed into two phases: a slow rise ata speed of 0.6 km/s, and an acceleration phase at a mean speed of 25 km/s.

A new look at a polar crown cavity as observed by SDO/AIA