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

Flow vorticity is a fundamental property of turbulent convection in rotatingsystems. Solar supergranules exhibit a preferred sense of rotation, whichdepends on the hemisphere. This is due to the Coriolis force acting on thediverging horizontal flows. We aim to spatially resolve the vertical flowvorticity of the average supergranule at different latitudes, both for outflowand inflow regions. To measure the vertical vorticity, we use two independenttechniques: time-distance helioseismology (TD) and local correlation trackingof granules in intensity images (LCT) using data from the Helioseismic andMagnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). Both mapsare corrected for center-to-limb systematic errors. We find that 8-h TD and LCTmaps of vertical vorticity are highly correlated at large spatial scales.Associated with the average supergranule outflow, we find tangential (vortical)flows that reach about 10 m/s in the clockwise direction at 40{\deg} latitude.In average inflow regions, the tangential flow reaches the same magnitude, butin the anti-clockwise direction. These tangential velocities are much smallerthan the radial (diverging) flow component (300 m/s for the average outflow and200 m/s for the average inflow). The results for TD and LCT as measured fromHMI are in excellent agreement for latitudes between $-$60{\deg} and 60{\deg}.From HMI LCT, we measure the vorticity peak of the average supergranule to havea full width at half maximum of about 13 Mm for outflows and 8 Mm for inflows.This is larger than the spatial resolution of the LCT measurements (about 3Mm). On the other hand, the vorticity peak in outflows is about half the valuemeasured at inflows (e.g. 4/(10^6 s) clockwise compared to 8/(10^6 s)anti-clockwise at 40{\deg} latitude). Results from MDI/SOHO obtained in 2010are biased compared to the HMI/SDO results for the same period.

Spatially resolved vertical vorticity in solar supergranulation using helioseismology and local correlation tracking