RT Journal Article
T1 Intra-seasonal variability of extreme boreal stratospheric polar vortex events and their precursors
A1 Díaz Durán, Adelaida
A1 Serrano Mendoza, Encarnación
A1 Ayarzagüena Porras, Blanca
A1 Ábalos Álvarez, Marta
A1 De La Cámara Illescas, Álvaro
AB The dynamical variability of the boreal stratospheric polar vortex has been usually analysed considering the extended winter as a whole or only focusing on December, January and February. Yet recent studies have found intra-seasonal differences in the boreal stratospheric dynamics. In this study, the intra-seasonal variability of anomalous wave activity preceding polar vortex extremes in the Northern Hemisphere is examined using ERA-Interim reanalysis data. Weak (WPV) and strong (SPV) polar vortex events are grouped into early, mid- or late winter sub-periods depending on the onset date. Overall, the strongest (weakest) wave-activity anomalies preceding polar vortex extremes are found in mid- (early) winter. Most of WPV (SPV) events in early winter occur under the influence of east (west) phase of the Quasi-Biennial Oscillation (QBO) and an enhancement (inhibition) of wavenumber-1 wave activity (WN1). Mid- and late winter WPV events are preceded by a strong vortex and an enhancement of WN1 and WN2, but the spatial structure of the anomalous wave activity and the phase of the QBO are different. Prior to mid-winter WPVs the enhancement of WN2 is related to the predominance of La Nia and linked to blockings over Siberia. Mid-winter SPV events show a negative phase of the Pacific-North America pattern that inhibits WN1 injected into the stratosphere. This study suggests that dynamical features preceding extreme polar vortex events in mid-winter should not be generalized to other winter sub-periods.
PB Springer
SN 0930-7575
YR 2017
FD 2017-01-20
LK https://hdl.handle.net/20.500.14352/108342
UL https://hdl.handle.net/20.500.14352/108342
LA eng
NO Díaz-Durán, A., Serrano, E., Ayarzagüena, B., Abalos, M., & de la Cámara, A. (2017). Intra-seasonal variability of extreme boreal stratospheric polar vortex events and their precursors. Climate Dynamics, 49, 3473-3491.
NO Atmospheric Chemistry Modeling and Analysis Program (ACMAP) NASA
NO Ministerio de Economia y Competitividad (España)
NO Natural Environment Research Council (UK)
NO National Aeronautics and Space Administration (US)
DS Docta Complutense
RD 22 mar 2026