https://iopscience.iop.org/article/10.1088/1748-9326/ab0385
The upper stratospheric zonal wind anomaly on the initial date plays a role in the winter prediction of the NAO/AO. Around 22% of the 19-year period winter NAO variability can be explained by the initial upper stratospheric zonal wind anomaly in November.
An initial westerly anomaly in the stratospheric pole in November propagates downward to the troposphere in December, inducing a poleward shift of the tropospheric mid-latitude jet. Then the anomalous poleward jet shift persists well into January and February, which finally results in the positive phase of NAO/AO. The reverse happens for easterly initial anomalies.
The resulting surface response resembles the NAO and AO in SLP and has an amplitude of 1–2 hPa.
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Laatste EC46 dus niet goed voor negatieve NAO. Een bouwsteen lijkt tegen te werken.
