Fig. 2.

Variations along the AI of (A) land surface temperatures, (B) surface absorption of solar (red) and downwelling longwave radiation (blue), (C) water limitation factor defined as the ratio of actual to potential evaporation, (D) cloud area fraction (%), (E) turbulent fluxes estimated at maximum power (black dotted line), turbulent fluxes derived from CERES observations (black solid line), partitioned fluxes into sensible (red) and latent heat (blue), and (F) difference between the source and sink temperature of the conceptualized heat engine. Note that the surface temperature is representative of the source, while the radiative temperature of the atmosphere is representative of the sink temperature.