INTERDEPENDENCE OF THE TROPICAL AND EXTRATROPICAL QBO - RELATIONSHIP TO THE SOLAR-CYCLE VERSUS A BIENNIAL OSCILLATION IN THE STRATOSPHERE

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.