Simple models and sensor networks to study flow and energy transport in urban canopies

The physics of flow and energy transport in urban canopies are highly variable and complex. In this study, we use a hybrid methodology to study urban canopy phenomena by coupling field measurements and a numerical urban canopy model. Field measurements are conducted to study flow patterns around a single building, through the Sensor Network Over Princeton (SNOP) project. Sensing instruments in this network include: two standard eddy-covariance (EC) stations, a scintillometer, 12 wireless sensorscope stations, a SODAR/RASS system and other less conventional instruments (thermal/humidity iButtons, IR cameras, etc). We also implement a single-layer urban canopy model (UCM) similar to the one in the Weather Research and Forecasting (WRF) model, further develop and generalize this UCM, and use it offline (i.e. decoupled from the atmospheric model) to study our experimental site. The coupling between the field campaign and the numerical model are two-fold. Data collected from sensor network are used to improve the parameter space and validate the predictions of the numerical model. On the other hand, numerical simulations also provide guidance for design of the sensor network from selecting the deployment locations to measuring the most crucial physical quantities with suitable instruments.