Amazon Forests

Tropical forests are the most productive ecosystems on the Earth, and are undergoing very rapid change due to human land use. Altered cycles of   water, energy, carbon and nutrients, resulting from the changes in Amazonian vegetation cover, are expected to have climatic and environmental consequences at local, regional, and global scales.
To develop better understanding of these consequences, the Brazilian scientific community called for a new multidisciplinary research effort in the early 1990’s. A large number of South American, North American and European research programs, agencies and individual groups have contributed extensive efforts toward defining an integrated research program in Brazil. The program is known as the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA (link not found)), and is constituted as an international research initiative led by Brazil.

We are studying the regional carbon balance of the central Amazon Basin (map (link not found)) using a multiple-constraint approach. We use a numerical model of ecophysiology and isotope biogeochemistry (SiB) coupled to a mesoscale atmospheric model (RAMS). The model is tested against local flux observations collected at three sites in the state of Para, Brazil, near the city of Santarem (see a map). The sites include a primary forest (at km 67 on the Santarem-Cuiaba highway), a forested site that has been selectively logged (at km 83), and a completely deforested pasture site (at km 77).

The coupled SiB-RAMS model, parameterized from satellite imagery of the region,  is used to predict the weather as well as spatially varying fluxes of heat, water, momentum, CO2. Both the concentration and stable isotopic ratio of CO2 are compared against atmospheric measurements made during field campaigns. In addition, we are applying “top-down” inverse methods to estimate regional fluxes at both the mesoscale and the Basin scale which are optimally consistent with local fluxes, satellite imagery, and atmospheric composition.

Data and Model Products:

. USP RAMS Santarem forecast grids (28 km and 7 km) (link not found)

. Santarem mesoscale campaign trajectory forecasting system (link not found)

. Model parameters from satellite imagery

Download Documents:
Original proposal to LBA-Ecology (1997)
. Latest progress report to NASA (2001)
Renewal proposal to LBA-ECO (2002)
Uliasz et al draft manuscript on mesoscale inverse modeling

Download Presentations and Posters:
Rondonia site simulations with SiB (Poster presented in Belem, 2000)
Overview poster presentated at Fall AGU, 2000
Mesoscale inverse modeling presentation at Atlanta 2001 meeting
Stable isotope systematics poster presented at Atlanta, 2001 meeting
Influence of surface water CO2 evasion poster (GEWEX Paris, 2001)
Mesoscale simulations of CO2 evasion (Fall AGU, 2001)
Simulations and observations of CO2 evasion poster (Manaus, 2002)


This research was supported by the United States National Aeronautics and Space Administration under Cooperative Agreement NCC5-284 with Colorado State University.