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 present a method to derive outflow velocities in the solar corona usingdifferent data sets including solar wind mass flux coming from the SWAN/SOHOinstrument, electron density values from LASCO-C2 and interplanetary solar windvelocities derived from ground-based Interplanetary Scintillation Observations(IPS).  In a first step, we combine the LASCO electron densities at 6 solar radii andthe IPS velocities, and compare the product to the SWAN mass fluxes. It isfound that this product represents the actual mass flux at 6 solar radii forthe fast wind, but not for the slow wind. In regions dominated by the slowwind, the fluxes derived from SWAN are systematically smaller. This isinterpreted as a proof that the fast solar wind has reached its terminalvelocity at about 6 solar radii and expands with constant velocity beyond thisdistance. On the contrary, the slow solar wind has reached only half of itsterminal value and is thus accelerated further out.  In a second step, we combine the LASCO-C2 density profiles and the SWAN fluxdata to derive velocity profiles in the corona between 2.5 and 6 solar radii.Such profiles can be used to test models of the acceleration mechanism of thefast solar wind.

Velocity Profiles in the Solar Corona from Multi-Instrument Observations