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Solar cycle modulation of the Southern Annular Mode
Author(s) -
Kuroda Yuhji,
Kodera Kunihiko
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl022516
Subject(s) - southern hemisphere , troposphere , northern hemisphere , modulation (music) , stratosphere , solar cycle , climatology , atmospheric sciences , oscillation (cell signaling) , environmental science , mode (computer interface) , geology , physics , chemistry , solar wind , plasma , biochemistry , quantum mechanics , computer science , acoustics , operating system
The effect of the 11‐year solar cycle modulation on the Southern Annular Mode (SAM) in the Southern Hemisphere is examined through analysis of observational data from 1968 to 2001. It is found that the year‐to‐year variability of the October–November mean SAM differs significantly according to the solar activity. In high solar activity years, the SAM signal extends to the upper stratosphere during October to December and activity in the troposphere lasts until autumn, whereas in low solar activity years, the SAM signal is confined almost inside the troposphere from October to December and it disappears by January. This situation is very similar to that observed for the modulation of the winter mean North Atlantic Oscillation in the Northern Hemisphere. A possible mechanism of solar cycle modulation of the SAM is also discussed.