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Highlights
Past Highlights
April 2007
Climate Change Science Program (CCSP) Synthesis and Assessment Product (SAP) 3.2. A first draft of the CCSP SAP 3.2 was completed this month, focusing on the climate impacts of long and short-lived chemical species on air quality. A Division scientist has participated in SAP 3.2 as a co-author, working with Dr. Chip Levy from the NOAA Geophysical Fluid Dynamics Laboratory and Dr. Drew Shindell from the NASA Goddard Institute of Space Studies on this effort. While the primary focus of SAP 3.2 was on global-scale climate simulations (led by Drs. Levy and Shindell), several sections were included on the value of downscaling to address with regional climate issues. Reviews will now be underway at the National Research Council, and the final product will be completed by December 2007. (alice.gilliland@noaa.gov)
Air Quality Forecast Model Development and Testing. Several updated model codes along with updated emissions data sets for 2007 have benn delivered to the National Weather Service for deployment in early May 2007 in the experimental ozone forecast system over the Continental United States. Updates relating to the representation of vertical mixing of pollutants have been made to the CMAQ and PREMAQ codes for use in experimental O3 forecasting over the Continental United States in 2007. Updated emission inputs for use in the forecast modeling system were developed by incorporating available projections (from base year inventory to current year) for various emission source sectors. (jeffrey.young@noaa.gov, rohit.mathur@noaa.gov, jonathan.pleim@noaa.gov, george.pouliot@noaa.gov)
Multipollutant version of the Community Multiscale Air Quality (CMAQ) Model. The Division has expanded the Air Toxics version of CMAQ to include mercury. The new 2002 Multipollutant platform model can now predict ozone, PM, mercury, and 38 other hazardous air pollutant concentrations and interactions among them within the same simulation. In the coming year, EPA's Office of Air Quality Planning and Standards (OAQPS) plans to begin to use this version of CMAQ for accountability studies, and regional and local scale studies to help EPA project and assess the potential co-benefits and effectiveness of various control programs such as Clean Air Interstate Rule, Clean Air Mercury Rule, Clean Air Visibility Rule, and various onroad and nonroad mobile source rules. In addition, OAQPS expects to use this platform in its future development of a National Air Pollutant Assessment Study that would be based on a fully integrated toxics and criteria pollutant national emission inventory for the year 2008. (shawn.roselle@noaa.gov, luecken.deborah@epa.gov, hutzell.bill@epa.gov, o.russell.bullock@noaa.gov, and sarwar.golam@epa.gov)
Two-Way Coupling of the Weather Research and Forecasting (WRF) Model and the Community Multiscale Air Quality (CMAQ) Modeling System. The Division has made considerable progress toward the development of the meteorology-chemistry interface module (air quality preparation, or “AQPREP”) for the forthcoming two-way coupled Weather Research and Forecasting (WRF) model and Community Multiscale Air Quality (CMAQ) modeling system. The current output set from CMAQ’s offline Meteorology-Chemistry Interface Processor (MCIP) was examined in detail to identify fields that are required for performing online WRF-CMAQ processing. An analysis of the WRF internal variables was conducted to determine which of the required meteorological and geospatial fields could be filled directly from WRF fields that are available in memory and which fields needed to be computed. Algorithms were then adapted from MCIP, as needed, to compute meteorological and geospatial fields that are needed for biogenic emissions, plume rise calculations, chemistry transport modeling, and grid identification header fields in the “Models 3 Input/Output” (M3IO) data format used by CMAQ. Finally, a draft version of AQPREP was coded in Fortran 90. (tanya.otte@noaa.gov)
The effects of emissions, heterogeneous reaction, and surface photolysis reaction on model performance for nitrous acid.Comparison of model predictions with observed data suggest that the Community Multiscale Air Quality (CMAQ) modeling system underestimates ambient nitrous acid concentrations by a large margin. Photolysis of nitrous acid through the generation of the OH radical plays an important role in atmospheric photochemistry. Recent studies recommend that emissions, heterogeneous reaction, and surface photolysis may produce additional nitrous acid in the atmosphere. These sources have been implemented into the CMAQ modeling system and their effects on nitrous acid predictions are being evaluated. Predicted nitrous acid with and without these sources were compared with observed data in northeast Philadelphia. Preliminary results indicate that the incorporation of these sources can help reduce the model bias for nitrous acid. (sarwar.golam@epa.gov)
Mercury Modeling. EPA’s Office of Air Quality Protocols and Standards (OAQPS) requested guidance regarding unrealistic mercury species concentrations in their simulations using a version of CMAQ incorporating ozone, PM, sulfur, nitrogen, various air toxics and mercury that was recently developed by the Division. Unlike the previous version of the CMAQ mercury model that was used to support the Clean Air Mercury Rule, this multi-pollutant version of CMAQ simulates dry deposition of elemental mercury gas. In order to avoid an artificial depletion of elemental mercury gas in model simulations, all sources of its emissions to air must also be treated. The lack of dry deposition of elemental mercury gas in the previous version was cited as a weakness by the CMAQ peer review in May 2005. However, that previous version also did not treat the re-emission of mercury from recent deposition. This re-emission would be in the form of elemental mercury gas. By omission, the previous versions treated dry deposition and re-emission of elemental mercury gas as being in balance, always and everywhere. Recent versions of the CMAQ model employed for mercury simulation require that re-emissions of mercury be accounted for, something that OAQPS has not considered in their recent testing of the multi-pollutant model. It appears that they also made some simple units conversion errors in their model results analysis for reactive gaseous mercury (oxidized mercury gas) and for particulate mercury, as their results for these species show air concentrations three order of magnitude higher than expected. (o.russell.bullock@noaa.gov)
Surface Exchange of Ammonia. Several members of the Division are collaborating with scientists from EPA’s National Risk Management Research Laboratory (NRMRL), NOAA/ARL’s Atmospheric Turbulence and Diffusion Division (ATTD), NOAA/ARL’s Headquarters (HQ), North Carolina State University, and the University of Maryland to study the surface exchange of ammonia and to improve bidirectional surface exchange modeling capabilities. A field study is underway in Lillington, North Carolina, where extensive meteorological, soil chemistry, leaf chemistry and atmospheric chemistry and flux measurements are being taken over a corn field from pre-planting (early April) through senescence (September). In addition to the instrumentation provided by U.S. institutions, an Ammonia Measurement by ANnular Denuder sampling with Analysis (AMANDA) system has been loaned to the study by the Centre for Ecology and Hydrology (CEH) in Edinburgh, Scotland. Deployment of this system is being overseen by Division’s post-doc Matt Jones. This is the first time that the AMANDA system has been field-tested outside of Northern Europe, and operational deployment has proved challenging in the heat and humidity of the southeastern United States. Routine measurements are ongoing and an intensive experiment is planned for late May. (donna.schwede@noaa.gov)
Wind Tunnel Modeling of Near-Road Flow and Dispersion. As part of the Near-Road and School Infiltration Research Initiative, Division scientists have used wind-tunnel measurements to examine the concentration distributions for several major highway configurations. The four cases completed to date include the following: (1) a flat roadway with no surrounding obstacles (base case); (2) an upwind sound barrier; (3) an upwind and downwind sound barrier; and, (4) an upwind porous barrier intended to simulate a single row of vegetation. Preliminary results show that the solid sound barriers near roadways can have a substantial effect on downwind concentrations by decreasing ground-level concentrations immediately downwind of the road. For a single upwind barrier, downwind concentrations (near the edge of the roadway) decreases by a factor of four compared to the base case. By adding a second solid barrier on the downwind edge of the roadway, the downwind concentration decreases by a factor of six compared to the base case. Experiments are continuing on three configurations of depressed roadways (road cuts) configurations and one elevated roadway configuration. It is anticipated that these physical modeling results will be used to improve dispersion parameterizations in near-roadway air quality and exposure models. (steven.perry@noaa.gov, david.heist@noaa.gov)
ANNOUNCEMENT
The Journal of Service Climatology. The on-line Journal of Service Climatology publishes peer reviewed research articles in applied and service climatology, including but not limited to agricultural and forest climatology, climate data quality and instrumentation, environmental climatology (including air and water quality), hydroclimatology, human dimensions of climate risk and socioeconomic impact assessments, and climate services administration. The research articles must include the relevance of the research to the decision making of the user. The Journal also publishes review articles on the use of climate information in decision-making, reviews of climate service tools (web-based or stand-alone programs), data sets with detailed meta-data, notes, comments to the editor and invited commentaries. A Division scientist has been appointed as an editor of this new journal. The inaugural issue is scheduled for release June, 2007. (ellen.cooter@noaa.gov)
CONFERENCES, WORKSHOPS AND PRESENTATIONS
Meeting of the National Atmospheric Deposition Program (NADP). A Division scientist attended the meeting of the Critical Loads Ad Hoc Committee (CLAD) in Burlington, Vermont, on April 11-12, 2007. The CLAD has been accepted under the auspices of the National Atmospheric Deposition Program (NADP). There were several interesting presentations on current ongoing critical loads projects in the United States. Of particular interest was the presentation on the New England Governors/Eastern Canadian Premiers Forest Mapping Project, which included an assessment on development and mapping of critical loads due to the effects of acidification. They found that timber extraction had to be included the assessment, because harvesting removes base cations, which can lead to soil acidification. A new project addressing critical loads for sulfur and nitrogen will be starting for the Great Smokey Mountains. A question was raised whether critical loads could be addressed in a more prominent way in the upcoming NAPAP 2009 Assessment report. (robin.dennis@noaa.gov)
Climate Change in New York State. A Division scientist was invited to participate in a meeting on Climate Change in New York State, which was co-sponsored by the New York State Energy Research and Development Authority (NYSERDA), the Environmental Monitoring and Protection (EMEP) Program, and the New York Academy of Sciences (NYAS). This meeting was held April 10, 2007 in New York City. Participants provided comments on a discussion background paper entitled “Climate Change in New York State: Developing a Research Strategy” prior to the meeting, and they participated in two break-out sessions addressing research needs in the areas of “Reducing Emissions of Greenhouse Gases and Aerosols & Mitigating Climate Change Impacts” and “Understanding and Monitoring Impacts and Managing Risks.” The expected outcome from this meeting will be a Climate Change and Variability Research Plan for the state of New York. ellen.cooter@noaa.gov
Meeting of the NARSTO Assessment Writing Team for Ecosystem Effects. A Division scientist participated in the NARSTO meeting on ecosystem effects in Burlington, Vermont, on April 12-13, 2007. The purpose of the meeting was to outline an ecosystem chapter for the NARSTO assessment report on the technical challenges of implementing approaches to accountability relative to human health and ecosystem health effects in a multi-pollutant context. By participating in this meeting and in the development of the NARSTO report, the Division is seeking to learn how to effectively link atmospheric deposition model predictions to ecosystem models. Progress was made on defining important multi-pollutant linkages among deposited chemical species. It was noted that ecosystem protection issues and the salient pollutants can be quite different regionally. Spatial issues were not yet dealt with. An outline is expected sometime in June. (robin.dennis@noaa.gov)
Meeting on the National Urban Database and Access Portal Tools (NUDAPT) Project. Collaborators to the NUDAPT project met in Salt Lake City, Utah, on April 18-20, 2007 to review progress and to plan for completion of this project. The NUDAPT project will provide and demonstrate a community-based database system of urban features and model parameters designed to facilitate the development and utilization of advancing urban meteorological models for air quality, homeland security, and urban planning applications. Efforts are underway to study three cities (Houston, Texas, Atlanta, Georgia, and Phoenix, Arizona) with applications that will illustrate the usefulness of NUDAPT for air quality, transport and dispersion, and urban planning studies. (jason.ching@noaa.gov)
VISITORS
On April 12, 2007, Dr. Zbigniev Kabala of Duke University’s Civil Engineering Department brought his Fluid Dynamics class of 20 undergraduate students for a tour and demonstration at the Fluid Modeling Facility. Discussions included physical modeling techniques and a demonstration of flow visualization from roadway emissions in an urban area.
Tim Gaydos
Engineer
SPARTA, Inc.
Washington, DC
Tim Gaydos visited the Division on April 16, 2007- for a brief orientation. He is deciding whether to accept a postdoctoral research position that will begin this summer. (prakash.bhave@noaa.gov);
Daewon Byun
University of Houston
Houston, Texas
Daewon Byun visited the Division on April 16-17, 2007, and attended a meeting on e-grid work for Air Quality Forecasting. (kenneth.schere@noaa.gov; rohit.mathur@noaa.gov)