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Salby & Callaghan 2006
Salby, M.L. and Callaghan, P.F. (2006). Relationship of the quasi-biennial oscillation to the stratospheric signature of the solar cycle. Journal of Geophysical Research 111: doi: 10.1029/2005JD006012. issn: 0148-0227.

Records of analyzed dynamical structure indicate a correlation with the 11-year variation of solar flux Fs. In the monthly record, anomalous temperature maximizes in the stratosphere, with symmetry about the equator. However, even there, the signature is weak and scarcely significant. Sampling the same record around solstice and during extremal phases of the QBO sharply enhances the strength, significance, and symmetry of the solar signature. In the tropics the solar signature follows from a decadal modulation in the frequency of the quasi-biennial oscillation (QBO). In instantaneous power spectra the modulation is manifested to either side of the QBO's mean frequency, in two spectral peaks where the QBO dwells: one at (24 months)-1, reflecting a biennial oscillation (BO), and another at (36 months)-1. Intrinsic to the QBO, those peaks are separated from its mean frequency by ~11 yr-1. The decadal modulation produces a strong correlation to Fs and, through the residual circulation of the QBO, symmetry about the equator. Augmenting this high-frequency contribution is a low-frequency contribution to the solar signature, one that simply tracks the 11-year variation of Fs. Characterized by broad symmetry about the equator, it reflects the involvement of the Brewer-Dobson circulation. Accompanying anomalous temperature in the subtropics is a stronger signature over the winter pole, where interannual variance is large. Discovered by Labitzke and van Loon (1988), that solar signature reflects anomalous downwelling of the Brewer-Dobson circulation. As strong as the RMS interannual variation, it is accounted for entirely by the high-frequency contribution associated with the QBO. The extratropical signature is shown to follow through the BO, which is transmitted poleward by planetary waves. Salient features of the observed behavior are reproduced by a simple model of the QBO's modulation and its interaction with the extratropical circulation.

BACKGROUND DATA FILES

Abstract

Keywords
Atmospheric Processes, Climate change and variability (1616, 1635, 3309, 4215, 4513), Atmospheric Processes, Middle atmosphere dynamics (0341, 0342), Geomagnetism and Paleomagnetism, Time variations, diurnal to decadal, Global Change, Solar variability
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
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