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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We use helioseismic holography to study the association of shallow flows withsolar flare activity in about 250 large sunspot groups observed between 2010and 2014 with the Helioseismic and Magnetic Imager on the Solar DynamicsObservatory. Four basic flow parameters: horizontal speed, horizontal componentof divergence, vertical component of vorticity, and a vertical kinetic helicityproxy, are mapped for each active region during its passage across the solardisk. Flow indices are derived representing the mean and standard deviation ofthese parameters over magnetic masks and compared with contemporary measures offlare X-ray flux. A correlation exists for several of the flow indices,especially those based on the speed and the standard deviation of all flowparameters. However, their correlation with X-ray flux is similar to thatobserved with the mean unsigned magnetic flux density over the same masks. Thetemporal variation of the flow indices are studied, and a superposed epochanalysis with respect to the occurrence to 70 M and X-class flares is made.While flows evolve with the passage of the active regions across the disk, nodiscernible precursors or other temporal changes specifically associated withflares are detected.

A Helioseismic Survey of Near-surface Flows Around Active Regions and their Association with Flares