are characterizing aerosol optical properties and column water vapor during the
LBA study. Many LBA researchers will be utilizing satellite imagery for
large-scale analysis and therefore will require aerosol optical thickness and
precipitable water amounts for accurate atmospheric correction algorithms. A
year-round network of six ground-based automatic sunphotometers will be
established to emphasize the ecological and remote sensing effects of aerosols.
These instruments will be collocated with LBA-designated tower sites when
feasible. Three additional instruments were purchased by Brazilian researchers
and deployed in a wider distribution near the boundaries of the Amazon region.
This study will build on NASA's existing global AERONET atmospheric
characterization system and the University of São Paulo in-situ aerosol-sampling program. In this manner, comprehensive
climatologies of aerosol and water vapor can be developed that encompass both
burning and non-burning seasons for the entire Amazon basin. We intend to use
this opportunity to investigate the long-term effects of biomass burning on the
vegetation and atmosphere of the Amazon basin and the nature of the atmospheric
aerosol observed on a year-round basis.
LBA site was instrumented with a Cimel automatic sun/sky scanning spectral
radiometer (direct sun and sky radiance measurements), UVB sensor (0.28-0.32
(m), PAR sensor (0.4-0.7 (m), broadband pyranometer (0.28-2.8 m), and satellite
transmission equipment. Automated Cimel sunphotometers make direct sun
measurements at 8 wavelengths approximately every 15 minutes from which aerosol
optical thickness (AOT) at 7 wavelengths, and precipitable water will be
derived. Sky radiance almucantar measurements are also performed automatically
which are inverted to yield aerosol size distributions and phase functions.
We are using this data set to investigate
the long-term effects of biomass burning on the vegetation and atmosphere of the
Amazon basin and the nature of the atmospheric aerosol observed on a year-round
basis. The broadband radiometers will provide irradiance data in wavebands
significant to vegetative production, and allow characterization of aerosol
absorption parameters relevant to remote sensing and climate models. We have
also characterized the direct radiative forcing at the surface for all sites
having the full suite of instrumentation.
intensive field campaigns, one site will also feature an Optronics
spectroradiometer (0.3-0.8 (mm)
to measure spectral irradiance
and a Yankee MFRSR spectral radiometer (diffuse flux component) to further
radiative modeling efforts, and a number of handheld sunphotometers will be
deployed to better characterize the spatial variability of the atmospheric
aerosol. One field campaign is planned next year and will include measurements
during the pre-burning, burning and rainy seasons over the next 3 years.
Training and Education
were used for a Brazilian post doc from the University of São Paulo to do field
work and later, analysis at NASA/GSFC. The focus of the research will be surface
sampling of particulates with an emphasis on modeling of aerosol transport and
their chemical analysis (P, S, K and others) and dynamics, including dry
deposition mechanisms. Local site managers were taught to set up and maintain
instrument suites at each deployment site.
region is already familiar to the authors who operated a network of
sunphotometers successfully in the Amazon from 1993-1995, including the SCAR-B
campaign. Over this period, sites were developed efficiently in the states of
Rondônia, Mato Grosso, Tocantins, and others. Brazilian research aircraft will
be available at no expense during some field campaigns and will allow us to
operate a handheld sun photometer to assess the vertical distribution of
permanent sites are Balbina, Abraços Hill, Rio Branco, Alta Floresta, Cuiabá,
Belterra and Belém. A reference
site was established in São Paulo. Solar
flux sensors are at all sites except Belém and Cuiabá.
planned instruments have been deployed. A
Dry-to-Wet transition season field campaign is planned for ‘02, which will
complement field campaigns from previous years.
updated July 20, 2001