Fig. 6: Composite patterns due to AO+ and PNA+.

a Z500 (mb), b surface temperature (C), c 15-day running mean precipitation (mm/day), d period of drought for the 2001–2016 interval. e is the PFIv2. f–j is the same as a–e but for coincident AO+ and PNA. Gray regions in e and f indicate sparse or absent vegetation.