An evaluation of the correlation between open solar flux and total solar irradiance
An evaluation of the correlation between open solar flux and total solar irradiance
The correlation between the coronal source flux FS and the total solar irradiance ITS is re-evaluated in the light of an additional 5 years' data from the rising phase of solar cycle 23 and also by using cosmic ray fluxes detected at Earth. Tests on monthly averages show that the correlation with FS deduced from the interplanetary magnetic field (correlation coefficient, r = 0.62) is highly significant (99.999%), but that there is insufficient data for the higher correlation with annual means ( r = 0.80) to be considered significant. Anti-correlations between ITS and cosmic ray fluxes are found in monthly data for all stations and geomagnetic rigidity cut-offs ( r ranging from -0.63 to -0.74) and these have significance levels between 85% and 98%. In all cases, the fit is poorest for the earliest data (i.e., prior to 1982). Excluding these data improves the anticorrelation with cosmic rays to r = -0.93 for one-year running means. Both the interplanetary magnetic field data and the cosmic ray fluxes indicate that the total solar irradiance lags behind the open solar flux with a delay that is estimated to have an optimum value of 2.8 months (and is within the uncertainty range 0.8-8.0 months at the 90% level).
Sun: magnetic fields -- fundamental parameters -- solar-terrestrial relations -- interplanetary medium
678-687
Lockwood, M.
32917473-f7d9-4773-9162-6509baad09fa
2002
Lockwood, M.
32917473-f7d9-4773-9162-6509baad09fa
Lockwood, M.
(2002)
An evaluation of the correlation between open solar flux and total solar irradiance.
Astronomy & Astrophysics, 382, .
(doi:10.1051/0004-6361:20011666).
Abstract
The correlation between the coronal source flux FS and the total solar irradiance ITS is re-evaluated in the light of an additional 5 years' data from the rising phase of solar cycle 23 and also by using cosmic ray fluxes detected at Earth. Tests on monthly averages show that the correlation with FS deduced from the interplanetary magnetic field (correlation coefficient, r = 0.62) is highly significant (99.999%), but that there is insufficient data for the higher correlation with annual means ( r = 0.80) to be considered significant. Anti-correlations between ITS and cosmic ray fluxes are found in monthly data for all stations and geomagnetic rigidity cut-offs ( r ranging from -0.63 to -0.74) and these have significance levels between 85% and 98%. In all cases, the fit is poorest for the earliest data (i.e., prior to 1982). Excluding these data improves the anticorrelation with cosmic rays to r = -0.93 for one-year running means. Both the interplanetary magnetic field data and the cosmic ray fluxes indicate that the total solar irradiance lags behind the open solar flux with a delay that is estimated to have an optimum value of 2.8 months (and is within the uncertainty range 0.8-8.0 months at the 90% level).
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Published date: 2002
Keywords:
Sun: magnetic fields -- fundamental parameters -- solar-terrestrial relations -- interplanetary medium
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Local EPrints ID: 9142
URI: http://eprints.soton.ac.uk/id/eprint/9142
ISSN: 0004-6361
PURE UUID: 8ea47fce-d745-4fde-9857-3ad423e201b6
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Date deposited: 21 Sep 2004
Last modified: 15 Mar 2024 04:55
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Author:
M. Lockwood
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