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

The properties of a solar wind stream are determined by its source region andby transport effects. Independently of the solar wind type, the solar windmeasured in situ is always affected by both. We consider the proton-protoncollisional age as an ordering parameter for the solar wind at 1AU and exploreits relation to the solar wind classification scheme developed by Xu & Borovsky(2015). We use this to show that explicit magnetic field information is notrequired for this solar wind classification. Based on the observation that thethree basic solar wind types from this categorization cover different regimesin terms of proton-proton collisional age $a_{col,p-p}$ , we propose asimplified solar wind classification scheme that is only based on theproton-proton collisional age. The resulting so-called PAC solar windclassifier is an alternative to the full Xu & Borovsky (2015) solar windclassification scheme and leads to a classification that is very similar to thefull Xu & Borovsky (2015) scheme. The solar wind is well ordered by theproton-proton collisional age. This implies underlying intrinsic relationshipsbetween the plasma properties, in particular, proton temperature and magneticfield strength in each plasma regime. We argue that sector-reversal plasma is acombination of particularly slow and dense solar wind and most streaminteraction boundaries. Most solar wind parameters (e.g., the magnetic fieldstrength, B, and the oxygen charge state ratio $n_{O^{7+}}$ /$n_{O^{6+}}$)change with the solar activity cycle. Thus, all solar wind categorizationschemes based on threshold values need to be adapted to the solar activitycycle as well.

Proton-proton collisional age to order solar wind types