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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

The solar wind in the inner heliosphere has been observed by Parker SolarProbe (PSP) to exhibit abundant wave activities. The cyclotron wave modes inthe sense of ions or electrons are among the most crucial wave components.However, their origin and evolution in the inner heliosphere close to the Sunremain mysteries. Specifically, it remains unknown whether it is an emittedsignal from the solar atmosphere or an eigenmode growing locally in theheliosphere due to plasma instability. To address and resolve this controversy,we must investigate the key quantity of the energy change rate of the wavemode. We develop a new technique to measure the energy change rate of plasmawaves, and apply this technique to the wave electromagnetic fields measured byPSP. We provide the wave Poynting flux in the solar wind frame, identify thewave nature to be the outward propagating fast-magnetosonic/whistler wave modeinstead of the sunward propagating waves. We provide the first evidence forgrowth of the fast-magnetosonic/whistler wave mode in the inner heliospherebased on the derived spectra of the real and imaginary parts of the wavefrequencies. The energy change rate rises and stays at a positive level in thesame wavenumber range as the bumps of the electromagnetic field power spectraldensities, clearly manifesting that the observed fast-magnetosonic/whistlerwaves are locally growing to a large amplitude.

Growth of Outward Propagating Fast-Magnetosonic/Whistler Waves in the Inner Heliosphere Observed by Parker Solar Probe