Fig. 4: Long-term trends of 500hPa geopotential height in each pacemaker experiment using GRIMs.
From: Indian Ocean warming as key driver of long-term positive trend of Arctic Oscillation

The linear trends of 500hPa geopotential height (Z500) (shading) in (a) IO, (b) WP, (c) EP, and (d) AT runs with the climatological (1958–2017) Z500 (contour, unit: meter). The black hatched regions indicate statistically significant regions at a 95% confidence level. The red arrow in Fig. 4a indicates stationary wave anomalies from the northern Indian continent to Arctic region.