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Title: Atmospheric Dispersion at Spatial Resolutions Below Mesoscale for university of Tennessee SimCenter at Chattanooga: Final Report

In Year 1 of this project, items 1.1 and 1.2 were addressed, as well as item 2.2. The baseline parallel computational simulation tool has been refined significantly over the timeline of this project for the purpose of atmospheric dispersion and transport problems; some of these refinements are documented in Chapter 3. The addition of a concentration transport capability (item 1.2) was completed, along with validation and usage in a highly complex urban environment. Multigrid capability (item 2.2) was a primary focus of Year 1 as well, regardless of the fact that it was scheduled for Year 2. It was determined by the authors that due to the very large nature of the meshes required for atmospheric simulations at mesoscale, multigrid was a key enabling technology for the rest of the project to be successful. Therefore, it was addressed early according to the schedule laid out in the original proposal. The technology behind the multigrid capability is discussed in detail in Chapter 5. Also in Year 1, the issue of ground topography specification is addressed. For simulations of pollutant transport in a given region, a key prerequisite is the specification of the detailed ground topography. The local topography must be placed into a form suitable for generating an unstructured grid both on the topography itself and more » the atmospheric volume above it; this effort is documented in Chapter 6. In Year 2 of this project, items 1.3 and 2.1 were addressed. Weather data in the form of wind speeds, relative humidity, and baseline pollution levels may be input into the code in order to improve the real-world fidelity of the solutions. Of course, the computational atmospheric boundary layer (ABL) boundary condition developed in Year 1 may still be used when necessary. Cloud cover may be simulated via the levels of actinic flux allowed in photochemical reactions in the atmospheric chemistry model. The primary focus of Year 2 was the formulation of a multispecies capability with included chemical reactions (item 2.1). This proved to be a very arduous task, taking the vast majority of the time and personnel allocation for Year Two. The addition of this capability and related verification is documented in Chapter 7. A discussion of available tropospheric chemistry models is located in Chapter 8; and, a technology demonstrator for the full multispecies capability is detailed in Chapter 9. Item 2.3 has been partially addressed, in that the computation of sensitivity derivatives have been incorporated in the Tenasi code [7]. However, it has not been utilized in this project in order to compute probability distribution functions for pollutant deposition. In order to completely address the integration of weather and sensor data into the code (item 1.3) and integrate with existing sensor networks (item 3.1), a customizable interface was established. Weather data is most commonly available via a real database, and as such, support for accessing these databases is present in the solver source code. For integration functionality, a method of dynamic code customization was developed in Year 3, which is documented in Chapter 11. « less
Publication Date:
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Technical Report
Research Org:
University of Tennessee at Chattanooga, Chattanooga, TN
Sponsoring Org:
USDOE; USDOE CI Office of Environment and Science (CI-40)
Country of Publication:
United States