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The system is specifically designed to provide uninterrupted
monitoring of momentum, heat, water vapor, and carbon dioxide fluxes. Walker
Branch watershed flux studies have recently been extended in an exploration of
the flux contributions of the forest floor and the trees themselves. Experience
gained in this effort will be important for anticipated surface-layer model
testing and evaluation studies (under NOAA/GEWEX/GCIP). At Research Triangle
Park, and in cooperation with Oak Ridge, a separate portable flux-measuring
system was developed, this time designed for direct measurement of trace gas
fluxes but relying on measurement of the standard micrometeorological quantities
for quality assurance. The system provides for direct eddy correlation
measurements of sulfur dioxide, ozone, and carbon dioxide fluxes, and of nitric
acid by filter pack gradient analysis, as well as the important components of
the surface energy budget.
The Mobile Flux Platform, and GPS. Ron Dobosy (dobosy@atdd.noaa.gov)
During 1994, the use of new Global Positioning System (GPS) technology was
evaluated, and the newest available GPS systems were adopted. The systems
developed for aircraft eddy flux use have now been fitted to one of NOAA's two
Twin Otter aircraft. Large-Area Exchange Tim Crawford (crawford@atdd.noaa.gov)
The Oak Ridge group has frequently deployed both tower and aircraft eddy
correlation systems during studies of areal fluxes over a heterogenous surfaces,
in real-world studies of how well flat-earth formulations apply in real
situations. Analysis of tower eddy correlation fluxes of heat and moisture
displayed differences in the fluxes among alfalfa, corn, and wheat crops; during
daytime, transpiration rates differed by 20% to 50%. Measurements of momentum,
heat, and moisture fluxes from the ATDD Long-EZ research airplane were analyzed
to quantify spatial variabilities in the fluxes. Carbon Dioxide.
Tilden Meyers (meyers@atdd.noaa.gov)
Continuous eddy correlation measurement of CO2 flux over the Walker Branch (Oak
Ridge) forest have continued since 1993. The eddy flux measurement of CO2
exchange is now a mature technology. (See discussion above -- Tower Studies.)
Air-surface exchange has been studied extensively in classical investigations
that focus on revealing the processes involved. Winston Luke (winston.luke@noaa.gov)
The importance of accurate air-surface flux formulation in numerical models is
now widely acknowledged. Atmospheric Loadings to Coastal Ecosystems Regulatory
strategies that fail to recognize that part of the problem arises from
atmospheric deposition will not work as expected. The ARL Role Measurement and
modeling of atmospheric deposition are long-standing ARL specialties. east
coast, from Maine to Florida.
ARL is leading a large part of the integrated
research effort focusing on this issue. Leadership of the Chesapeake Bay Air
Subcommittee Contact -- richard.valigura@noaa.gov The Chesapeake Bay Program (CBP)
is a multi-agency program of targeted scientific research and integrated
assessment, which has been instrumental in alerting policy makers to the need to
couple air and water issues in their decision-making processes. Characterizing
the East and Gulf Coast Atmospheric Resource Contact -- bruce.hicks@noaa.gov It
is clear that emissions from the airshed that serves as a regional origin of air
pollutants affecting the Chesapeake Bay also influence other coastal ecosystems.
east coast estuarine and coastal ecosystems would benefit as well. Research
Grade Monitoring of Deposition in the Coastal Zone Contact -- richard.artz@noaa.gov
The atmospheric deposition that affects east coast ecosystems is very poorly
measured. For dry deposition, there are very few data points.
The NOAA
Atmospheric Integrated Research Monitoring Network (AIRMoN) has constituted a
framework for exploring methods for quantifying the actual deposition loadings
to the Chesapeake Bay watershed. ARL is currently operating several AIRMoN
stations in the watershed -- State College, PA, is a long-term site where both
wet and dry deposition are being studied. Modeling Deposition to the Coastal
Zone at Regional Scales Contact -- rdennis@hpcc.epa.gov The Regional Acid
Deposition Model (RADM) has been adopted as the modeling workhorse of the east
coast estuarine regulatory community. The results indicate that grid sizes *2 km
may be necessary to resolve the effects of the Bay on atmospheric dry deposition
(but not wet).
Estimating Air-Water Exchange of Nitric Acid in Coastal Areas
Contact -- richard.valigura@noaa.gov A project was successfully undertaken
which, i) developed and evaluated an iterative bulk exchange model to estimate
air-water exchange of heat, water and momentum from buoy data, and ii) used the
model outputs to estimate air-water transfer rates of nitric acid (HNO3).
Natural emissions of Oxidant precursors: Validation of techniques and Assessment
(NOVA) Contact -- winston.luke@noaa.gov Historically, NOx emissions from soils
have been estimated using chamber, or enclosure, techniques, whereby the
measured rate of increase of [NO] within the chamber used to derive an estimate
of the NO emission flux from the underlying soil surface.
Mercury Deposition
Contact -- meyers@atdd.noaa.gov ARL researchers at Oak Ridge (a collaboration
between ATDD and Oak Ridge National Laboratory) have been working on techniques
to measure the deposition of mercury directly. More recently, field studies have
been conducted in southern Florida, where mercury originating from sugar farming
practices is suspected to be affecting coastal ecosystem viability. Research
Plans Linkages within NOAA The ARL coastal studies program is strongly linked
with the NOAA Chesapeake Bay Office of the National Marine Fisheries Service.
The work is also tied to the NOAA Coastal Ocean Program, and to coastal
activities of the National Ocean Service. The Chesapeake Bay Air Subcommittee
(led by ARL) serves as an interface with all federal agencies involved in
related research (EPA, DOD, DOE, DOI, DOA, NASA, Smithsonian) as well as with
the air and water environmental components of each of the states in the
Chesapeake Bay region (Delaware, New York, Pennsylvania, Maryland, Virginia,
District of Columbia, West Virginia). Describing statutory authorities which
help the NPS protect air resources. In 1983, barely a half dozen parks were
using air quality information in interpretive/educational programs.
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