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

This letter describes a new phenomenon on the Parker Solar Probe of recurringplasma density enhancements that have $\Delta$n/n ~10% and that occur at arepetition rate of ~5 Hz. They were observed sporadically for about five hoursbetween 14 and 15 solar radii on Parker Solar Probe orbit 12 and they were alsoseen in the same radial range on both the inbound and outbound orbits 11. Theirapparently steady-state existence suggests that their pressure gradient wasbalanced by the electric field. The EX electric field component produced fromthis requirement is in good agreement with that measured. This provides strongevidence for the measurement accuracy of the density fluctuations and the X-and Y-components of the electric field (the Z-component was not measured). Theelectrostatic density waves were accompanied by an electromagnetic lowfrequency wave which occurred with the electrostatic harmonics. The amplitudesof these electrostatic and electromagnetic waves at $\ge$ 1 Hz were greaterthan the amplitude of the Alfvenic turbulence in their vicinity so they can beimportant for the heating, scattering, and acceleration of the plasma. Theexistence of this pair of waves is consistent with the observed plasmadistributions and is explained by a magneto-acoustic wave theory that producesa low frequency electromagnetic wave and electrostatic harmonics.

Density Enhancement Streams in The Solar Wind