A pan-Eurasian pattern of Northern Hemisphere wintertime sea level pressure variability
Linear regression and compositing techniques are used in conjunction with the standardized expansion coefficient time series associated with EOT3 of SLP to investigate its signature in other climatological fields, how the pattern relates to climatological mean features, and the impacts of variability associated with the pattern on time scales of days to months. The pattern's positive (negative) polarity is associated with an expansion (contraction) of the Siberian High on its western flank, accompanied by cold (warm) surface air temperature anomalies and decreased (increased) storminess across the northern tier of the continent. The pattern's influence is discernible on shorter time scales from Europe to southern China, particularly as it affects the frequency of cold air outbreaks.
The pan-Eurasian pattern is most extensive during wintertime, but exhibits two peaks in the fraction of hemispherically-integrated SLP variance it explains, one in autumn and one in spring. During autumn it is the leading pattern of NH SLP variability.