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

We compared the results from the JSOC pipeline for horizontal flow componentsand the perturbations of the speed of sound at set of depths with equivalentresults from an independently implemented pipeline using a differenttime-distance inversion scheme. Our inversion pipeline allows inversion for allquantities at once while allowing minimisation of the crosstalk between them.This gives us an opportunity to discuss the possible biases present in the JSOCdata products. For the tests we used the subtractive optimally localisedaveraging (SOLA) method with a minimisation of the cross-talk. We comparedthree test inversions for each quantity at each target depth. At first, we usedthe JSOC setup to reproduce the JSOC results. Subsequently, we used theextended pipeline to improve these results by incorporating more independenttravel-time measurements but keeping the JSOC-indicated localisation in theSun. Finally, we inverted for flow components and sound-speed perturbationsusing a localisation kernel with properties advertised in the JSOC metadata. Wesuccessfully reproduced the horizontal flow components. The sound-speedperturbations are strongly affected by the high level of the cross-talk in JSOCproducts. This leads to larger amplitudes in the inversions for the sound-speedperturbations. Different results were obtained when a target function localisedaround the target depth was used. This is a consequence of non-localised JSOCaveraging kernels. We add that our methodology also allows inversion for thevertical flow.

Comparison of time-distance inversion methods applied to SDO/HMI Dopplergrams