Through the study of moist static energy profiles, Herbert Riehl and Joanne Malkus determined in 1958 that hot towers, small cores of convection approximately wide that extend from the planetary boundary layer to the tropopause, were the primary mechanism that transported energy out of the tropics to the middle latitudes.
22.
The urban environment has two atmosphere layers, besides the planetary boundary layer outside and extending well above the city : ( 1 ) The urban boundary layer is due to the spatially integrated heat and moisture exchanges between the city and its overlying air . ( 2 ) The surface of the city corresponds to the level of the urban canopy layer.
