Atmospheric boundary layer growth during LBA/TRMM experiment

The knowledge of the atmospheric boundary layer (ABL) is very important as the ABL links the surface and the free atmosphere above. During the LBA/TRMM experiment (wet season 1999 in Rondonia - Amazonia/Brazil) an extensive set of rawinsounding (30 days) were realesed in a pasture and forest representative sites at 8, 11, 14 and 17 Local Time. An intercomparison of the upper air profiles made by 2 different systems (viz and Vaisala equipments) was done and the results shows a difference of less that 0.5 C for temperature and around 10% for humidity. The height of the ABL was computed using potential temperature and specific humidity profiles. The time evolution of the growth is 90 m (8LT), 470 m (11 LT), 750 m (14 LT) and 930 m (17 LT) for the pasture and 130 m (8 LT), 480 m (11 LT), 800 m (14 LT) and 1000 m (17 LT). The results has shown that the growth of the ABL are quite similar, with a final height of the convective boundary layer around 1000 m at both pasture and forest sites. The estimates using temperature and specific humidity agree very well. These results differs the one obtained for the same sites during the dry season (RBLE experiment) which the pasture ABL is almost 1000 m deeper that forest.