Solar Wind Helium Abundance Heralds Solar Cycle Onset
| Autor: | Justin C. Kasper, Benjamin L. Alterman, Robert J. Leamon, Scott W. McIntosh |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010504 meteorology & atmospheric sciences
Abundance (chemistry) High Energy Physics::Lattice chemistry.chemical_element Flux FOS: Physical sciences Context (language use) Astrophysics 01 natural sciences 7. Clean energy Physics - Space Physics 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Helium Solar and Stellar Astrophysics (astro-ph.SR) 0105 earth and related environmental sciences Condensed Matter::Quantum Gases Physics Photosphere Order (ring theory) Astronomy and Astrophysics Physics - Plasma Physics Space Physics (physics.space-ph) Solar cycle Plasma Physics (physics.plasm-ph) Solar wind Astrophysics - Solar and Stellar Astrophysics chemistry 13. Climate action Space and Planetary Science Physics::Space Physics Astrophysics::Earth and Planetary Astrophysics |
| DOI: | 10.48550/arxiv.2006.04669 |
| Popis: | We study the solar wind helium-to-hydrogen abundance's ($A_\mathrm{He}$) relationship to solar cycle onset. Using OMNI/Lo data, we show that $A_\mathrm{He}$ increases prior to sunspot number (SSN) minima. We also identify a rapid depletion and recovery in $A_\mathrm{He}$ that occurs directly prior to cycle onset. This $A_\mathrm{He}$ Shutoff happens at approximately the same time across solar wind speeds ($v_\mathrm{sw}$), implying that it is formed by a mechanism distinct from the one that drives $A_\mathrm{He}$'s solar cycle scale variation and $v_\mathrm{sw}$-dependent phase offset with respect to SSN. The time between successive $A_\mathrm{He}$ shutoffs is typically on the order of the corresponding solar cycle length. Using Brightpoint (BP) measurements to provide context, we infer that this shutoff is likely related to the overlap of adjacent solar cycles and the equatorial flux cancelation of the older, extended solar cycle during Solar Minima. Comment: Accepted in Solar Physics |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|