The solar wind helium abundance: Variation with wind speed and the solar cycle

Abstract We study the solar wind helium-to-hydrogen abundance's ( A He ) relationship to solar cycle onset. Using OMNI/Lo data, we show that A He increases prior to sunspot number (SSN) minima. We also identify a rapid depletion and recovery in A He that occurs directly prior to cycle onset. This A He Shutoff happens at approximately the same time across solar wind speeds ( v sw ) and the time between successive A He shutoffs is typically on the order of the corresponding solar cycle length. In contrast to A He 's v sw -dependent phase lag with respect to SSN (Alterman and Kasper, 2019), A He Shutoff's concurrence across v sw likely implies it is independent of solar wind acceleration and driven by a mechanism near or below the photosphere. 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.

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On solar wind speed distribution and geomagnetic activity during solar cycle 23 and the early ascending phase of solar cycle 24

International Journal of the Physical Sciences ◽

10.5897/ijps2015.4401 ◽

2015 ◽

Vol 10 (21) ◽

pp. 562-567

Author(s):

Louis Zerbo Jean ◽

Ouattara Fr eacute d eacute ric ◽

Nan eacute ma Emmanuel

Keyword(s):

Solar Wind ◽

Solar Cycle ◽

Wind Speed ◽

Geomagnetic Activity ◽

Solar Wind Speed ◽

Speed Distribution ◽

Wind Speed Distribution ◽

Solar Cycle 23 ◽

Solar Cycle 24 ◽

Cycle 24

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Correlations between ULF wave power, solar wind speed, and relativistic electron flux in the magnetosphere: solar cycle dependence

Journal of Atmospheric and Solar-Terrestrial Physics ◽

10.1016/j.jastp.2003.10.002 ◽

2004 ◽

Vol 66 (2) ◽

pp. 187-198 ◽

Cited By ~ 80

Author(s):

I.R. Mann ◽

T.P. O'Brien ◽

D.K. Milling

Keyword(s):

Solar Wind ◽

Solar Cycle ◽

Wind Speed ◽

Relativistic Electron ◽

Electron Flux ◽

Solar Wind Speed ◽

Wave Power ◽

Ulf Wave ◽

Cycle Dependence

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The solar cycle variation of the solar wind helium abundance

Journal of Geophysical Research Atmospheres ◽

10.1029/ja079i031p04595 ◽

1974 ◽

Vol 79 (31) ◽

pp. 4595-4602 ◽

Cited By ~ 46

Author(s):

K. W. Ogilvie ◽

J. Hirshberg

Keyword(s):

Solar Wind ◽

Solar Cycle ◽

Helium Abundance ◽

Solar Cycle Variation ◽

Cycle Variation

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Solar wind, mass and momentum losses during the solar cycle

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311017960 ◽

2010 ◽

Vol 6 (S271) ◽

pp. 395-396

Author(s):

R. Pinto ◽

S. Brun ◽

L. Jouve ◽

R. Grappin

Keyword(s):

Solar Wind ◽

Solar Cycle ◽

Wind Speed ◽

Mass Flux ◽

Solar Minimum ◽

Momentum Flux ◽

Loss Rate ◽

Convection Zone ◽

Mass Loss Rate ◽

Good Agreement

AbstractWe study the connections between the sun's convection zone evolution and the dynamics of the solar wind and corona. We input the magnetic fields generated by a 2.5D axisymmetric kinematic dynamo code (STELEM) into a 2.5D axisymmetric coronal MHD code (DIP). The computations were carried out for an 11 year cycle. We show that the solar wind's velocity and mass flux vary in latitude and in time in good agreement with the well known time-latitude assymptotic wind speed diagram. Overall sun's mass loss rate, momentum flux and magnetic breaking torque are maximal near the solar minimum.

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