Fig. 4: Signal-to-noise ratio of the Walker circulation change in response to CO2 forcing at different tropospheric levels in the abrupt4×CO2 experiment.
From: Early emergence and determinants of human-induced Walker circulation weakening
a–b Spatial distribution of the signal-to-noise ratio of sea level pressure (SLP) for the first 10 years and the last 50 years. Shown are the multimodel ensemble mean. White slant hatchings denote areas where more than 80% of the models agree on the sign of changes. c–f are the same as (a–b) but for vertical velocity at 500 hPa (W500) and velocity potential at 200 hPa (VP200), respectively. Boxes indicate regions used to define the Walker circulation intensity indices.
