> 3. Research Capability - Environmental Monitoring Branch
3. Research Capability
SMCD's Branches exploit a number of science and technology areas in fulfilling
its broad mission of transforming raw satellite observations into the accurate,
quantitative information that is needed to predict weather, monitor climate,
and detect environmental hazards. The science and technology area of each of
SMCD's branches are described here.
Environmental Monitoring Branch
As numerical weather prediction models become more sophisticated and improve
their treatment of surface atmosphere interactions, the need for good measurements
of surface conditions - snow cover, ice cover, vegetation conditions, surface
radiation budget, and precipitation - is accelerating. One of the major
uncertainties in projections of climate change is the role of atmospheric aerosols,
and data are urgently needed on their global distribution, characteristics, and
time trends.
Surface condition products, Earth Radiation Budget, and aerosol products are
the responsibility of the Environmental Monitoring Branch. The Branch faces the
challenge of developing high quality products to meet these challenging demands
as well as others in an ever-increasing range of applications for its weather,
climate, and hazards products. The Environmental Monitoring Branch also faces
the challenge - as does the rest of SMCD - of preparing for the entirely new
suite of instruments on NPOESS.
Vegetation Products
Surface vegetation conditions are important for monitoring drought, providing
boundary conditions for weather prediction models, forecasting agricultural yields,
monitoring land surface changes, and understanding the global carbon cycle. Over
the last few decades, SMCD researchers have led the development and application
of vegetation products, primarily from the AVHRR instrument.
Among the products developed by SMCD scientists are the: Normalized Difference
Vegetation Index (NDVI), the two channel AVHRR "greenness" index that serves as
the basis for all other vegetation products; green vegetation fraction, defined as
the fractional area of active vegetation per unit horizontal area; Vegetation Condition
Index (VCI), a measure of drought conditions; and FR, a fire risk index.
Earth Radiation Budget and Aerosols
The Earth's radiation budget (ERB) represents the balance between incoming energy
from the Sun and outgoing longwave (OLR) and reflected (shortwave) energy from the
Earth (planetary albedo). Changes in the radiative energy balance of the Earth-atmosphere
system (caused, for example, by increasing amounts of carbon dioxide and aerosols)
can cause long-term changes in climate. Satellites orbiting above the atmosphere
are ideal for measuring the radiative energy streams into and out of Earth-atmosphere
system. Over the years they have contributed to narrowing the uncertainty in the
planetary albedo and outgoing longwave radiation, and improved our understanding of
the energy budget.
SMCD scientists developed the original algorithm for estimating OLR from POES IR
imagers back in the early 1970s. The OLR data set is now over three decades long,
and has played a crucial role in both real-time monitoring and retrospective studies
of El Nino Southern Oscillation (ENSO) events. SMCD personnel are actively involved
in deriving traditional and new ERB parameters, and in improving the algorithms used
to estimate them.
The important role of aerosols in shaping the environment and climate is now
well recognized as well as the fact that current estimates of aerosol radiative
forcing represent one of the largest uncertainties in assessing global climate
change. This recognition is reflected in various research plans, such as the
2001 US Climate Change Research Initiative, which identified the "Development of
reliable representations of climate forcing resulting from atmospheric aerosol"
as one of its top priority goals. Atmospheric aerosols affect the radiation budget
by either reflecting solar radiation back to space, absorbing long-wave radiation,
or affecting cloud properties - which would also influence the ERB. In addition,
increased levels of aerosols adversely affect human health. Monitoring also
provides information, among others, for visibility analysis, validation of aerosol
transport models and for aerosol-correction of sea surface temperature.
Satellite-derived aerosol data should also improve regional and global
assessment and forecast of air quality.
SMCD scientists developed the AVHRR aerosol product that has been used to monitor
global aerosol distributions and the dust ejected into the atmosphere by intense
volcanic eruptions, such as Mount Pinatubo in 1991. They continue to improve our
capability to measure aerosols from satellite observations.
Dept. of Commerce • NOAA • NESDIS • STAR • Last revised: June 15, 2010
3. Research Capability
Surface vegetation conditions are important for monitoring drought, providing
boundary conditions for weather prediction models, forecasting agricultural yields,
monitoring land surface changes, and understanding the global carbon cycle. Over
the last few decades, SMCD researchers have led the development and application
of vegetation products, primarily from the AVHRR instrument.
The Earth's radiation budget (ERB) represents the balance between incoming energy
from the Sun and outgoing longwave (OLR) and reflected (shortwave) energy from the
Earth (planetary albedo). Changes in the radiative energy balance of the Earth-atmosphere
system (caused, for example, by increasing amounts of carbon dioxide and aerosols)
can cause long-term changes in climate. Satellites orbiting above the atmosphere
are ideal for measuring the radiative energy streams into and out of Earth-atmosphere
system. Over the years they have contributed to narrowing the uncertainty in the
planetary albedo and outgoing longwave radiation, and improved our understanding of
the energy budget.
The important role of aerosols in shaping the environment and climate is now
well recognized as well as the fact that current estimates of aerosol radiative
forcing represent one of the largest uncertainties in assessing global climate
change. This recognition is reflected in various research plans, such as the
2001 US Climate Change Research Initiative, which identified the "Development of
reliable representations of climate forcing resulting from atmospheric aerosol"
as one of its top priority goals. Atmospheric aerosols affect the radiation budget
by either reflecting solar radiation back to space, absorbing long-wave radiation,
or affecting cloud properties - which would also influence the ERB. In addition,
increased levels of aerosols adversely affect human health. Monitoring also
provides information, among others, for visibility analysis, validation of aerosol
transport models and for aerosol-correction of sea surface temperature.
Satellite-derived aerosol data should also improve regional and global
assessment and forecast of air quality.