M. Salby et al., INTERDEPENDENCE OF THE TROPICAL AND EXTRATROPICAL QBO - RELATIONSHIP TO THE SOLAR-CYCLE VERSUS A BIENNIAL OSCILLATION IN THE STRATOSPHERE, J GEO RES-A, 102(D25), 1997, pp. 29789-29798
Interannual variations in the tropical and polar stratosphere are inve
stigated in monthly mean records of north polar temperature and equato
rial zonal wind. The spectrum of polar temperature possesses discrete
components associated with the tropical quasi-biennial oscillation (QB
O), as well as with a biennial oscillation (BO) that figures prominent
ly in the record of north-polar temperature. The BO, in fact, accounts
for as much temperature variance as the QBO. The running correlation
between equatorial zonal wind and polar temperature oscillates on a de
cadal timescale, resembling the Ii-year sunspot cycle [Kodera, 1993].
This oscillation is shown to follow from an interaction between the QB
O and the BO. Interaction between the QBO and BO also figures in Labit
zke and van Loon's [1988] evidence of the solar cycle, which results w
hen data are stratified according to the QBO. Both apparent signatures
of solar cycle influence therefore revolve about the interpretation o
f the BO.