Fig. 6.

Vertical profiles of temperature change (A) and enhancement of surface cooling at high elevations (B). Vertical temperature profiles were calculated by using standard meteorological formulae and a surface relative humidity of 80%. (A) Temperature change is the difference from the 26°C surface temperature vertical profile. [Average tropical Atlantic surface temperature and humidity are 26°C and 80%, respectively (31)]. The temperature altitude gradient is enhanced for cooler sea level temperatures such as those predicted for the LIA. (B) The cooling enhancement is the magnitude of the temperature change at a given altitude divided by the temperature change at sea level. Cooling enhancement is independent of the magnitude of the temperature change (overlapping curves in B are for the −0.5 to −2.0°C temperatures changes plotted in A).