Solar forcing of the semi-annual variation of length-of-day - Archive ouverte HAL Access content directly
Journal Articles Geophysical Research Letters Year : 2010

Solar forcing of the semi-annual variation of length-of-day

(1) , , , (1)
1

Abstract

We study the evolution of the amplitude A of the semi-annual variation of the length-of-day (lod) from 1962 to 2009. We show that A is strongly modulated (up to 30%) by the 11-yr cycle monitored by the sunspot number WN. A and WN are anticorrelated, WN leading A by 1-yr. A is therefore directly correlated with galactic cosmic ray intensity. The main part of the semi-annual variation in lod is due to the variation in mean zonal winds. We conclude that variations in mean zonal winds are modulated by the solar activity cycle through variations in irradiance, solar wind or cosmic ray intensity.
Fichier principal
Vignette du fichier
Geophysical Research Letters - 2010 - Le Mou l - Solar forcing of the semi%u2010annual variation of length%u2010of%u2010day.pdf (355.95 Ko) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-03605302 , version 1 (11-03-2022)

Licence

Public Domain

Identifiers

Cite

Jean-Louis Le Mouël, Elena Blanter, Mikhail Shnirman, Vincent Courtillot. Solar forcing of the semi-annual variation of length-of-day. Geophysical Research Letters, 2010, 37, ⟨10.1029/2010GL043185⟩. ⟨insu-03605302⟩
18 View
9 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More