Solar activity, Earth's rotation rate and climate variations in the secular and semi-secular time scales

By applying the wavelet formalism to sudden storm commencements and aa geomagnetic indices and solar total irradiation, as a proxy data for solar sources of climate-forcing, we have searched the signatures of those variables on the Northern Hemisphere surface temperature. We have found that cyclical...

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Publicado: 2006
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14747065_v31_n1-3_p99_Duhau
http://hdl.handle.net/20.500.12110/paper_14747065_v31_n1-3_p99_Duhau
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spelling paper:paper_14747065_v31_n1-3_p99_Duhau2023-06-08T16:17:36Z Solar activity, Earth's rotation rate and climate variations in the secular and semi-secular time scales Climatology Earth rotational variations Geomagnetic secular variation Origin and modelling, of the magnetic field, dynamo theory Atmospheric temperature Geomagnetism Storms Time series analysis Wavelet transforms Dynamo theory Earth rotational variations Geomagnetic secular variation Solar activity Climatology climate forcing climate modeling climate variation climatology Earth rotation Fourier transform geomagnetic storm irradiation Northern Hemisphere solar activity solar radiation time series analysis wavelet analysis By applying the wavelet formalism to sudden storm commencements and aa geomagnetic indices and solar total irradiation, as a proxy data for solar sources of climate-forcing, we have searched the signatures of those variables on the Northern Hemisphere surface temperature. We have found that cyclical behaviour in surface temperature is not clearly related to none of these variables, so we have suggested that besides them surface temperature might be related to Earth's rotation rate variations. Also it has been suggested that in the long-term Earth's rotation rate variations might be excited by geomagnetic storm time variations which, in turn, depends on solar activity. The study of these phenomena and its relationships is addressed in the present paper. With this purpose we perform an analysis of the evolution during the last 350 years of the signals that conform the 11-year sunspot cycle maxima envelope for different time scales. The result is applied to analyze the relationship between long-term variations in sunspot number and excess of length of day; and to unearth the signature in surface temperature of this last from that of sudden storm commencement and aa geomagnetic indices and total solar irradiation. As solar dynamo experiments transient processes in all the time scales from seconds to centuries, Fourier analysis and its requirement for the process to be stationary is likely to produce spurious periodicities. We resort instead to wavelet formalism. By this representation we found that sunspot maxima envelope for the last 350 years may be described by means of the superposition of two cycles - a decadal and a semi-secular one - and a secular trend. And that the changing amplitude and phase of the cycles are well reconstructed using the superposition of two wavelets with nearby periods. The strong temporal changes in amplitude of the cycles facilitate to detect its phase in a given time series. It is found that a strong semi-secular cycle in the sunspot maxima envelope that started during the 1705 chaotic transition having its maximum amplitude at the Dalton minimum, was mapped 94 years later in Earth's rotation rate and simultaneously in surface temperature. Also, there was a decrease (increase) of 0.022 °C for each millisecond of decrease (increase) in the Earth's rotation period for the semi-secular cycle as well as the secular trend. © 2006. 2006 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14747065_v31_n1-3_p99_Duhau http://hdl.handle.net/20.500.12110/paper_14747065_v31_n1-3_p99_Duhau
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Climatology
Earth rotational variations
Geomagnetic secular variation
Origin and modelling, of the magnetic field, dynamo theory
Atmospheric temperature
Geomagnetism
Storms
Time series analysis
Wavelet transforms
Dynamo theory
Earth rotational variations
Geomagnetic secular variation
Solar activity
Climatology
climate forcing
climate modeling
climate variation
climatology
Earth rotation
Fourier transform
geomagnetic storm
irradiation
Northern Hemisphere
solar activity
solar radiation
time series analysis
wavelet analysis
spellingShingle Climatology
Earth rotational variations
Geomagnetic secular variation
Origin and modelling, of the magnetic field, dynamo theory
Atmospheric temperature
Geomagnetism
Storms
Time series analysis
Wavelet transforms
Dynamo theory
Earth rotational variations
Geomagnetic secular variation
Solar activity
Climatology
climate forcing
climate modeling
climate variation
climatology
Earth rotation
Fourier transform
geomagnetic storm
irradiation
Northern Hemisphere
solar activity
solar radiation
time series analysis
wavelet analysis
Solar activity, Earth's rotation rate and climate variations in the secular and semi-secular time scales
topic_facet Climatology
Earth rotational variations
Geomagnetic secular variation
Origin and modelling, of the magnetic field, dynamo theory
Atmospheric temperature
Geomagnetism
Storms
Time series analysis
Wavelet transforms
Dynamo theory
Earth rotational variations
Geomagnetic secular variation
Solar activity
Climatology
climate forcing
climate modeling
climate variation
climatology
Earth rotation
Fourier transform
geomagnetic storm
irradiation
Northern Hemisphere
solar activity
solar radiation
time series analysis
wavelet analysis
description By applying the wavelet formalism to sudden storm commencements and aa geomagnetic indices and solar total irradiation, as a proxy data for solar sources of climate-forcing, we have searched the signatures of those variables on the Northern Hemisphere surface temperature. We have found that cyclical behaviour in surface temperature is not clearly related to none of these variables, so we have suggested that besides them surface temperature might be related to Earth's rotation rate variations. Also it has been suggested that in the long-term Earth's rotation rate variations might be excited by geomagnetic storm time variations which, in turn, depends on solar activity. The study of these phenomena and its relationships is addressed in the present paper. With this purpose we perform an analysis of the evolution during the last 350 years of the signals that conform the 11-year sunspot cycle maxima envelope for different time scales. The result is applied to analyze the relationship between long-term variations in sunspot number and excess of length of day; and to unearth the signature in surface temperature of this last from that of sudden storm commencement and aa geomagnetic indices and total solar irradiation. As solar dynamo experiments transient processes in all the time scales from seconds to centuries, Fourier analysis and its requirement for the process to be stationary is likely to produce spurious periodicities. We resort instead to wavelet formalism. By this representation we found that sunspot maxima envelope for the last 350 years may be described by means of the superposition of two cycles - a decadal and a semi-secular one - and a secular trend. And that the changing amplitude and phase of the cycles are well reconstructed using the superposition of two wavelets with nearby periods. The strong temporal changes in amplitude of the cycles facilitate to detect its phase in a given time series. It is found that a strong semi-secular cycle in the sunspot maxima envelope that started during the 1705 chaotic transition having its maximum amplitude at the Dalton minimum, was mapped 94 years later in Earth's rotation rate and simultaneously in surface temperature. Also, there was a decrease (increase) of 0.022 °C for each millisecond of decrease (increase) in the Earth's rotation period for the semi-secular cycle as well as the secular trend. © 2006.
title Solar activity, Earth's rotation rate and climate variations in the secular and semi-secular time scales
title_short Solar activity, Earth's rotation rate and climate variations in the secular and semi-secular time scales
title_full Solar activity, Earth's rotation rate and climate variations in the secular and semi-secular time scales
title_fullStr Solar activity, Earth's rotation rate and climate variations in the secular and semi-secular time scales
title_full_unstemmed Solar activity, Earth's rotation rate and climate variations in the secular and semi-secular time scales
title_sort solar activity, earth's rotation rate and climate variations in the secular and semi-secular time scales
publishDate 2006
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14747065_v31_n1-3_p99_Duhau
http://hdl.handle.net/20.500.12110/paper_14747065_v31_n1-3_p99_Duhau
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