Fig. 3: Persistent double jets states.
From: Accelerated western European heatwave trends linked to more-persistent double jets over Eurasia
a Composite of meridional winds at 250hPa (v250) for double jet events exceeding the 90th percentile of double jet persistence (i.e, events lasting more than 11 consecutive days, see Table S1 for the 20 most persistent events and their duration; shading). Contour lines show the v250 July-August climatology for the whole period 1979–2020 (plotted from −5 to 8 m/s every 2 m/s). b, c SOM cluster composites of v250 for persistent double jet events (frequency % of each SOM is shown in parenthesis). d, e Time series of daily similarity index for the two SOMs of v250 winds. The red dashed line shows a linear regression fit, with its slope and p-value plotted on the top left. The continuous red line shows a smoothed LOESS curve fit (span of 0.75). f, g Anomaly composites of (linearly detrended) mean surface temperature for each of the SOM clusters.
