Quasi-biennial oscillation signal detected in the stratospheric zonal wind at 55–65°N

Abstract

AbstractTo investigate the impacts of the quasi-biennial oscillation (QBO) on high-latitude circulation and the Arctic vortex, stratospheric zonal wind at 55–65°N is analyzed. The seasonal cycle, solar cycle, and linear trend in the zonal wind at these latitudes are analyzed and removed, and the QBO signal is retrieved from the monthly zonal wind for the period 1979–2014. The zonal wind has a strong decreasing trend in winter, with a maximum decrease (less than −0.35 m s−1 yr−1) occurring within 70–100°E. The zonal wind has an in-phase response of 1.6 m s−1 to the solar cycle, with a maximum within 100–140°E. A clear QBO signal is detected in the zonal wind during the period 1979–2014, with an amplitude of 2.5 m s−1 and a period of 30 months. The latitudinal distribution of the QBO signal is inhomogeneous, with a maximum within 120–180°E and a minimum within 25–45°E.