Research Spotlight: Connections between climate patterns of the stratosphere and troposphere

Roughly every 28 months, the zonal winds in the stratosphere at the equator cycle from easterly to westerly and then back to easterly. Known to atmospheric scientists as the quasibiennial oscillation (QBO), these shifting wind patterns result when the energy from perturbations in the troposphere ripples through the stratosphere. However, QBO patterns are known not to be regular—the shift in wind patterns can be weak or strong and does not occur at precise intervals.