Operational generation of urban wind fields to support transport and dispersion modeling

A realistic wind field is a key component to any transport and dispersion model simulation. In the urban environment observing the wind field accurately is complicated by the presence of the building structures themselves. In situ measurements are only representative over a limited area near the point of observation due to the influence of nearby buildings. Winds observed remotely, via radar or lidar, have good spatial resolution, but are limited to making measurements above rooftop.

The Urban Shield project is an emergency response system for hazardous atmospheric releases in Arlington County Virginia. To provide building aware wind fields over a 100 square kilometer area for transport and dispersion modeling we use a combined approach of remotely sensed wind observations and very high resolution, ~10 meters, diagnostic wind modeling. In brief, the system uses 3-D wind analyses from Doppler radar and lidar as input to Los Alamos National Laboratory's QUIC-Urb empirical wind model. An overview of the system and results will be presented.