Abstract ID: 307

Estimates of the height of the boundary layer using SODAR and rawinsoundings in Amazonia

During the RACCi-LBA Dry-to-Wet campaign hold in Rondonia in 2002, simultaneous measurements were made of the boundary layer using different instruments (rawinsoundings and SODAR) at the ABRACOS pasture site (Fazenda Nossa Senhora Aparecida). The profiles of potential temperature, humidity and winds were used to estimates the height of the convective boundary layer using 3 different techniques (Parcel´s Method, Profile´s Method and Richardson Number´s Method). Also, additional measurements by a SODAR (PA2 Remtech, French) were made in order to compare with the estimates of the soundings (RS80-15G, Vaisalay Oy, Finland). The results from Profile and Richardson number´s Methods are almost the same as the potential temperature gradient is the key factor for both methods. The Parcel´s Method overestimates the heights derived by Profile and Richardson number by 15% at early morning and by 30 % at late morning and afternoon period. The SODAR´s measurements did not capture the shallow morning boundary layer observed by the profiles but showed heights that agreed reasonable well with Profile and Richardson Number´s methods.

Session:  Feedbacks to Climate - Effects of deforestation on regional and global climate.

Presentation Type:  Poster