Impact/Purpose:

This task objective is the development and improvement of state-of-the-science meteorology models and contributing process parameterizations for use in advanced air quality simulation model systems such as the Community Multi-scale Air Quality (CMAQ) modeling system and for other modeling studies and situations involving transport and dispersion of pollutants. Components of this work include: (a) improved meteorological and transport modeling, (b) improved meteorological modeling physics, (c) physical modeling of flows- building wakes, complex terrain, urban canyons, (d) modeling of transport and dispersion of specialized situations and (e) develop AERMOD (AMS/EPA Regulatory MODel).

Description:

Advanced air quality simulation models, such as CMAQ, as well as other transport and dispersion models, require accurate and detailed meteorology fields. These meteorology fields include primary 3-dimensional dynamical and thermodynamical variables (e.g., winds, temperature, moisture, cloud and rain water, and pressure), as well as an extensive set of 2-dimensional fields (e.g., surface turbulent fluxes, land-use parameters, radiation fields, and planetary boundary layer (PBL) depth). By design, even the most sophisticated mesoscale meteorology models (e.g., MM5) cannot fully account for sub-grid scale processes. Thus, model forecasts tend to decrease in skill through the simulation period. Yet, to support air quality modeling, meteorological models are typically run retrospectively for a longer simulation than general forecasting applications, so it becomes particularly important to control the error through the duration of the run. It is also more difficult to effectively apply the model at finer spatial scales where local effects (e.g., small-scale terrain and land-use variations, coastal processes) become more important and where routine observations cannot adequately capture the meteorological characteristics in the region of interest. The failure of the meteorological model to capture local phenomena will adversely impact the predictions of air quality and dispersion models. As air quality modeling studies move to higher resolutions (e.g., 1-12 km), the work with the meteorology model will be focused on these resolutions and improving the simulation of local phenomena. Improvements to the meteorology models are proposed in three primary areas: model initialization, model physics, and data assimilation. Improvements to dispersion models for local scale situations are also undertaken. Evaluation of new techniques in the meteorological model and their subsequent impact on the air quality model will be addressed in Task 3874.

This task utilizes high performance computing and scientific visualization resources provided by EPA's National Environmental Scientific Computing Center (NESC2).

Record Details:

Record Type:PROJECT

Start Date:07/01/1998

Completion Date:09/30/2002

Record ID: 15866

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Project Information:

Progress :MM5 Version 3 was upgraded to Release 4 and tailored with EPA modifications for air-quality modeling simulations. (FY-01)
(A) MM5 was tested and evaluated on new serial and parallel hardware platforms including EPA's NESC IBM SP2 and Cray T3E. (FY-01) (A)
Initial meteorological fields based on MM5 were generated for the SOS-1999 field study domains. (FY-01) (A)
Otte, T.L., N.L. Seaman, and D.R. Stauffer, 2001: A heuristic study on the importance of anisotropic error distributions in data assimilation. Monthly Weather Review, 129, 766?783. (A)
Workshop Paper: "Using MM5v3 with Eta Analyses for Air-Quality Modeling at the EPA" by Tanya L. Otte. Presented at the Tenth PSU/NCAR Mesoscale Model User's Workshop, June 21-22, 2000, in Boulder, CO. (A)
An urban canopy parameterization was implemented in MM5 for fine-scale (~1 km) applications. (FY-01) (B)
Otte, T.L., and A. Lacser, 2001. Implementation of an urban canopy parameterization in MM5 for meso-gamma-scale air quality modeling applications. Preprints, AMS Ninth Conf. on Mesoscale Processes. Ft. Lauderdale, FL. 78-81. (B)
The PX Land Surface Model has been added to NCAR?s community MM5 system as a second LSM option. It was included in MM5 version 3.4, released in November 2000 by NCAR. (B)
Pleim, J.E., A. Xiu, P.L. Finkelstein, and T.L. Otte, 2001: A coupled land-surface and dry deposition model and comparison to field measurements of surface heat, moisture, and ozone fluxes. Water, Air, and Soil Pollution (in press) (B)
Xiu, A. and J.E. Pleim, 2001: Development of a land-surface model. Part I: Application in a mesoscale meteorology model. J. Appl. Meteorol., 40, 192-209. (B)
Pleim, J.E. and A. Xiu, 2001: Updates and evaluation of the PX-LSM in MM5. Paper presented at the Eleventh PSU/NCAR Mesoscale Model User's Workshop, June 25-27, 2001, Boulder, CO. (B)

Xiu, A. and J.E. Pleim, 2001: The Pleim-Xiu Land Surface Model. Presentation at the 2001 WRF/LSM Workshop, August 16-17, 2001, Boulder, CO (B)

Workshop Paper: "A New Land-Surface Model in MM5" by Jonathan Pleim and Aijun Xiu. Presented at the Tenth PSU/NCAR Mesoscale Model User's Workshop, June 21-22, 2000 in Boulder, CO. (B)

Pleim, J.A., and Byun, D.W. "Application of a new land-surface, dry deposition, and PBL model in the Models-3 community multi-scale air quality (CMAQ) model system." Paper presented at Millennium NATO/CCMS International Technical Meeting, Boulder, CO, May 16-19, 2000. (B)

Work continues on an internal grant entitled "Improved tools for estimating the dispersion of toxic air pollutants in a convective boundary layer." Experiments on puff dispersion in calm-wind convective conditions are being analyzed and interpreted as part of a overall development effort for a buoyant puff dispersion model. Experiments in the EPA?s convection tank show indication of 15% difference in the depth of the mixed layer when (traditionally) based on temperature profile measurements as compared to the true mixing depth as determined by concentration measurements within the tank. This information will have important implications in future model development. Two journal articles describing the capabilities of the EPA's convection tank facility have been accepted for publication in Boundary Layer Meteorology. (C)

Under a second internal grant entitled "Research into the mechanics of resuspension: modeling of PM10 and PM2.5 from soil and vegetative surfaces" experiments in EPA's calibration wind tunnel have helped to quantify threshold velocities for resuspension of PM10 particles previously deposited on wheat grass. (C)

Journal Article - Snyder, W. H., R. E. Lawson, M. S. Shipman, J. Lu, 2001: Fluid Modeling of Atmospheric Dispersion in the Convective Boundary Layer. accepted for publication in Boundary Layer Meteorology. (C)

Journal Article - Weil, J. C., W. H. Snyder, R. E. Lawson, M. S. Shipman, 2001: Experiments on Buoy

Relevance :Advanced models for meteorology and transport that operate at a spectrum of temporal and spatial scales provide the basis for driving a "one atmosphere" local to regional scale state-of-the-science atmospheric modeling system. Improved parametric formulations of meteorology and transport processes are needed as fundamental building blocks for Models-3/CMAQ. These state of science models serve various communities and clients ranging from those in basic research to regulatory and policy to those involved with specialized applications. It is intended that this task provide a basis for meteorological input for air quality models and a building block for use in exposure models

Clients :Joseph Tikvart, David Mobley - OAR/OAQPS, OPPT

Project IDs:

ID Code :3871

Project type :OMIS