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Extratropical Atmospheric Predictability From the Quasi‐Biennial Oscillation in Subseasonal Forecast Models
Author(s) -
Garfinkel Chaim I.,
Schwartz Chen,
Domeisen Daniela I. V.,
Son SeokWoo,
Butler Amy H.,
White Ian P.
Publication year - 2018
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1029/2018jd028724
Subject(s) - polar vortex , predictability , extratropical cyclone , climatology , quasi biennial oscillation , northern hemisphere , stratosphere , environmental science , troposphere , atmospheric sciences , arctic oscillation , meteorology , geology , geography , physics , quantum mechanics
The effect of the Quasi‐Biennial Oscillation (QBO) on the Northern Hemisphere wintertime stratospheric polar vortex is evaluated in five operational subseasonal forecasting models. Of these five models, the three with the best stratospheric resolution all indicate a weakened vortex during the easterly phase of the QBO relative to its westerly phase, consistent with the Holton‐Tan effect. The magnitude of this effect is well captured for initializations in late October and November in the model with the largest ensemble size. While the QBO appears to modulate the extratropical tropospheric circulation in some of the models as well, the importance of a polar stratospheric pathway, through the Holton‐Tan effect, for the tropospheric anomalies is unclear. Overall, knowledge of the QBO can contribute to enhanced predictability, at least in a probabilistic sense, of the Northern Hemisphere winter climate on subseasonal timescales.