Extended Data Figure 1.
Drivers of the changes in mean bimonthly near-surface air temperature (ΔTa; K) for 0.5 degree latitudinal bands. The change in near-surface air temperature (Ta) due to changes in atmospheric emissivity ε is written as ΔTa|ε. By analogy ΔTa|G is the change in air temperature due to change in the ground heat flux, ΔTa|LE+H due to changes in turbulent fluxes, ΔTa|Rsi due to changes in shortwave incoming radiation (which in this simulation experiment is a proxy for cloud cover), ΔTa|α due to changes in surface albedo, and ΔTa|circ due to changes in atmospheric circulation. Although all the components contribute to the near-surface air temperature, changes in emissivity always result in a cooling and changes in shortwave incoming radiation always result in warming. Consequently, emissivity and incoming shortwave radiation cannot explain the seasonal variation in the changes in near-surface air temperature. The other components are in some months positively correlated with near-surface air temperature whereas they are negatively correlated for other months, excluding them from being the main driver of changes in near-surface air temperature. Suggesting the net effect is the outcome of the interplay between the different components.