The Dual Nature of Solar Wind Structuring: Resonant Standing Waves and Laval Nozzle Dynamics in Coronal Streamers

TL;DR

This paper reveals that coronal streamers act as dual systems with resonant standing waves and Laval nozzle dynamics, explaining the formation and persistence of periodic density structures in the solar wind.

Contribution

It introduces a dual-mechanism model combining MHD resonances and nozzle oscillations to explain solar wind structuring, a novel approach in solar physics.

Findings

Resonant standing waves dominate PDS formation across 85% of streamers.

Laval nozzle oscillations occur in 35% of streamers, influencing vortex formation.

PDS persist to 1 AU with minimal energy loss, indicating their global significance.

Abstract

Periodic Density Structures (PDS) observed in white-light coronagraphs represent a fundamental challenge to conventional solar wind paradigms. Through systematic analysis of multi-instrument observations and theoretical modeling, we demonstrate that coronal streamers operate as dual-nature systems: magnetohydrodynamic resonators that establish global periodicity through standing waves (122, 61, 41 minutes) and Laval nozzles that generate local flow structures through shock-driven oscillations (93, 47, 31, 23 minutes). The resonant mechanism dominates PDS formation, explaining their universal occurrence across 85\% of streamers, coherence over 10+ cycles, and persistence to 1 AU with only 0.1\% energy loss. Nozzle oscillations, while limited to 35\% of overexpanded streamers and maintaining only 1-2 cycle coherence, play crucial secondary roles in vortex formation and provide the essential converging-diverging geometry for supersonic solar wind acceleration. This dual-mechanism framework resolves longstanding puzzles in solar wind structuring while revealing the hierarchical organization of standing-wave and flow processes in astrophysical plasmas.