Trends in the surface meridional temperature gradient

Given the presence of a meridional temperature gradient (MTG) across midlatitudes, large‐scale eddies transport heat poleward, thereby shaping Earth's climate. Defining an MTG index here as the difference in surface temperature between the 30°–35°N belt and the 50°–55°N belt, we use a temperature record compiled from observations over a 110‐year period to determine a trend in the MTG in the last century. We find a significant decreasing trend in the MTG over this period of 0.4±0.1°C per 100 years, along with indications of substantial multidecadal variability.