Structure and growth of the mixing layer over the Amazonian rain forest

Fluxes of sensible and latent heat were measured at the top of the canopy, and measurements of temperature, moisture, and horizontal wind were made in and above the mixed layer by means of a tethered balloon, rawinsonde, and aircraft. The mixing layer grows rapidly at 5-8 cm s ^-1 soon after sunrise to a mean maximum height of 1200 m by 1300 local standard time (LST). No horizontal inhomogeneities in the mixed layer structure of depth were found over large distances, suggesting that point measurements under undisturbed conditions can be used to obtain estimates of mixed layer structure and fluxes over large areas of the Amazon basin. Budget calculations using the averaged mixed layer depths and surface fluxes are made, which provide estimates of the entrainment flux of moisture across the mixed layer top of the order of 600 W m ^-2 . -from Authors