Fig. S2.

Monthly mean tropical potential temperature at seven pressure levels from near surface to lower stratosphere, averaged during the period from 1979 to 2014 using the ERA-Interim global reanalysis dataset. Mean potential temperature in (Left) February and (Middle) September; (Right) difference between February and September. Over the Amazon, the wet season is generally cooler than the dry season near the surface and the tropopause but warmer in the free troposphere, consistent with observation (Fig. 1).