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July
27, 2004 -- By Gretchen Cook-Anderson & Krishna Ramanujan, NASA
Researchers from around the
globe participating in the world's largest environmental science
experiment, the Large-Scale Biosphere Atmosphere Experiment in Amazonia
(LBA), will, fittingly, convene in Brazil this week.
From July 27-29, some 800 researchers will attend the Third
International Scientific Conference of the LBA in Brasilia, Brazil, to
discuss key findings on how the world's largest rainforest impacts the
ecological health of Amazonia and the world. Never before has so much
information about the Amazon been assembled for presentation at once.
LBA is partly funded by NASA. Also, scores of projects that feed the
Amazon experiment depend heavily on NASA's vast expertise in satellite
information, computer modeling, and providing infrastructure for
large-scale field campaigns.
The overall experiment concentrates on how the Amazon forest and land
use changes within the region affect the atmosphere, and regional and
global climate. In turn, LBA also studies how climate changes influence
the biological, chemical and physical functioning of the forest itself.
Topics discussed at the conference will include: the carbon cycle, the
water cycle, human land use, ecosystem processes and human health,
agricultural applications, and other topics relating to the Amazon. The
conference will also allow researchers and Brazilian policy makers to
discuss ways to use LBA results to create public policies for the Amazon
region that foster a healthy environment and provide for sustainable
development.
NASA plays a key role in LBA research. Satellites provide data for
studying land use changes and their impacts on climate. Scientists hope
to learn more about the Amazon forest's role in sequestering carbon from
the atmosphere. Atmospheric carbon dioxide (CO2) traps heat and adds to
global warming. Plant life absorbs CO2 from the air during
photosynthesis and stores it in stems, leaves and roots. In order to
understand regional and global carbon balances, researchers must
quantify how much carbon is taken up by the rainforest as well as how
much is released back to the atmosphere when forests are cleared or
burned.
In the Amazon, deforestation, selective logging, fires and forest
re-growth all play major roles in the carbon balance. In the Brazilian
Amazon region alone, annual clear-cutting and burning of forests cover
about 20,000 square kilometers (7,700 square miles or about the area of
New Jersey). NASA data products from various instruments on the Landsat
series of satellites have documented the history of deforestation in the
Amazon since the 1970s. LBA researchers have found ways to measure both
logging area and logging damage using Landsat and experimental new
sensors on NASA’s EO-1 satellite.
Ecosystem models and NASA’s Moderate Resolution Imaging
Spectroradiometer (MODIS) instrument aboard the Terra and Aqua
satellites have helped scientists understand how the exchange of carbon
between the forest and atmosphere differs over the course of the year.
Also, LBA studies have found forest uptake of CO2 is not enough to keep
pace with carbon that is returned to the atmosphere when forests are
cut.
Burning practices to clear fields for farming often result in fires
spreading to adjacent forests. These large fires create air pollution
and can contribute to respiratory problems in people. Thick smoke has
forced airports to close, and has caused highway accidents. Satellite
retrievals of concentrations of airborne particles from NASA's MODIS
instrument have been used by Brazil's Center for Weather Prediction and
Climate Studies to create models that can predict fire risk and smoke
transport in near-real time.
Satellite data also help scientists study how particles from fires
impact climate and weather. These particles, known as aerosols, can both
heat and cool the air, depending on size, shape and color.
Scheduled to end in 2006, LBA is considered an international scientific
success, with 61 projects completed and 59 in progress. The efforts
include more than 1,000 researchers from institutions in Brazil, the
United States, eight European countries and several other countries of
the Amazon Basin (Venezuela, Peru, Bolivia, Colombia and Ecuador). LBA
is financed by Brazilian funding agencies, NASA and the European Union. (Read More) |
