Solar Wind Helium Abundance Heralds the Onset of Solar Cycle 25
Abstract
We study the solar wind helium-to-hydrogen abundance's (Ahe) relationship to solar cycle onset. We identify a rapid depletion and recovery in Ahe immediately prior to sunspot number (SSN) minima. This depletion happens at approximately the same time across solar wind speeds, implying that it is formed by a mechanism distinct from the one that drives Ahe's solar cycle scale variation and speed-dependent phase offset with respect to SSN. As Ahe's rapid depletion and recovery have already occurred and Ahe is now increasing as it has following previous solar minima, we infer that solar cycle 25 has already begun.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMSH053..01A
- Keywords:
-
- 7524 Magnetic fields;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7536 Solar activity cycle;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7537 Solar and stellar variability;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7544 Stellar interiors and dynamo theory;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY