A GCM study of the influence of equatorial winds on the timing of sudden stratospheric warmings

Peer Reviewed

Pascoe CL, Gray LJ, & Scaife AA

Geophysical Research Letters 33, Issue 6, pages L06825, 2006, 10.1029/2005GL024715.

A full troposphere-stratosphere-mesosphere global circulation model is used in a set of idealised experiments to investigate the sensitivity of the Northern Hemisphere winter stratospheric flow to improvements in the equatorial zonal winds. The model shows significant sensitivity to variability in the upper equatorial stratosphere, the imposition of SAO and QBO like variability in this region advances the timing of midwinter sudden warmings by about one month. Perturbations to the lower equatorial stratosphere are mainly found to influence early winter polar variability. These results suggest that it is important to pay attention to the capability of models to simulate realistic variability in the upper equatorial stratosphere.

Keywords: Northern Hemisphere winter, Stratospheric flow, QBO, Quasi-Biennial Oscillation
Categories: Arctic, Natural Science