High-Resolution Simulation Test Bed for the Urban and Complex Terrain Environment
Abstract
A large fraction of the world s population lives in urban areas, many of them coastal. The U.S. military frequently operates in these urban coastal areas. Current operational forecasting models do not sufficiently account for urban effects. This research is motivated by the need for improved mesoscale prediction at high horizontal resolutions (< 2 km) over urban regions. The focus of the effort is on urban regions in the coastal zone and urban regions in areas of complex topography. The earth s surface is characterized by inhomogeneities due to variations in vegetation types, soil types and moisture, canopy layers, and topography, as well as urban effects. These inhomogeneities all act together but often on different spatial and temporal scales to produce gradients in surface fluxes of momentum, heat, and moisture that drive three-dimensional circulations and significantly alter the lowllow-leveloscale thermodynamic and dynamic structure. The well-recognized urban heat island phenomenon is one of major impacts resulted from these inhomogeneities. Land-surface processes also critically impact aerosols and boundary layer visibility because nearly all aerosol source and sink processes occur on small scales, and most aerosols originate at the surface and pass through the surface and boundary layers at least once during their lifetime. Furthermore, surface aerosol processes such as mobilization, deposition, and re-suspension are highly dependent on surface roughness, vegetation, and soil moisture.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2003
- Accession Number
- ADA628620
Entities
People
- Teddy R. Holt
Organizations
- United States Naval Research Laboratory