An overview of the WETAMC/LBA - January and February 1999

The Large-Scale Biosphere-Atmosphere Experiment in Amazonia ( LBA ) is an international research enterprise led by Brazil. The LBA is designed to generate new knowledge, essential to the understanding of the processes within the ecology, hydrology, biogeochemistry and climatology of Amazonia , the impacts of the different land uses on these proceses and the interactions between the Amazonia and the global biogeophysical system of the planet. The LBA is anchored in two fundamental questions that will receive a multidisciplinary approach. · How does the Amazonia operate as a regional entity, at the present? · How will the changes in the soil usage affect the biological, chemical and physical modus operandum of Amazonia, including its own sustainability and its influence on the global climate? The Wet Season Atmospheric Mesoscale Campaign - WETAMC - has a focus on the local effects of deforestation, with its different impacts, as well as on the regional response to the larger scale forcing, within the lines of the LBA. The WETAMC scientists (including Brazilians and Europeans) joined forces with the NASA/TRMM scientists , whereby a major ground validation program within the TRMM, known as TRMM/LBA, was collocated with the WETAMC. The field phase of this campaign took place in the Rondonia state of Brazil ( Southwest side of Amazonia) during January and February 1999. TRMM/LBA had a focus on the dynamical, microphysical, electrical and diabatic heating characteristics of tropical convection in the Amazon region. Together, the WETAMC and TRMM/LBA campaigns represent an opportunity to study tropical convection in Amazonia and its relation to the underlying forested and deforested regions. The field campaign design included: § four radiosonde sites performing 6-8 soundings per day, § three tethered balloon sites; § 1 forest 60 m micrometeorological tower instrumented with 3 levels of eddy correlation measurements and vertical profiles of radiation, temperature, humidity and windspeed; § 1 forest 54 m tower instrumented for atmospheric chemistry measurements, including CO2 flux; § forest and pasture arrays for temperature and soil moisture and set of rings for soil respiration. § 1 tethered ballon for atmospheric chemistry measurements, § 2 pasture towers with profiles, and eddy correlation measurements including CO2 flux, § 1 pasture tower for atmospheric chemistry measurements, § 2 wind profiler sodar, § network of complete AWS; § a four-station lightning detection network, a network of flat plate antennas, § a dense raingauge and disdrometer network, § two Doppler radars (including the S-pol and the TOGA radar), § a dual-wavelength profiler from the NOAA/Aeronomy Lab § U. of North Dakota Citation II Learjet for in-situ sampling of microphysical variables § the high altitude NASA ER- carrying the EDOP radar (ER-2 Doppler, X band radar) and AMPR (Airborne Microwave Profiling Radiometer), a multi-frequency radiometer similar to the SMI instrument on TRMM. The aircraft operations required also the functioning of a weather forecasting office at Ji-Paraná with access to NWP from CPTEC/INPE and from USP (RAMS 20 km resolution model) used in conjuction with high resolution GOES and airport data.