Numerical Simulations of a Summer 2010 Heat Wave in New York City using WRF's Building Energy Parameterization

The Weather Research and Forecasting (WRF) model is coupled to a multi-layer urban canopy model that considers thermal and mechanical effects of the urban environment including a building energy model to account for anthropogenic heat contributions due to air conditioning systems (Martilli et al.). This new urban parameterization is used to evaluate the evolution and the resulting urban heat island formation associated to a 3-day heat wave in New York City (NYC) during the summer of 2010. High resolution (250 m.) urban canopy parameters (UCPs) from the National Urban Database were employed to initialize the multi-layer urban parameterization. The precision of the numerical simulations is evaluated using a range of observations. Data from a dense network of surface weather stations, wind profilers and Lidar measurements are compared to model outputs over Manhattan and its surroundings during the 3-days event. The thermal and drag effects of buildings represented in the multilayer urban canopy model improves simulations over urban regions giving better estimates of the surface temperature and wind speed. An accurate representation of the nocturnal urban heat island registered over NYC in the event was obtained from the improved model. The accuracy of the simulation is further assessed against more simplified urban parameterizations models with positive results with new approach. Results are further used to quantify the energy consumption of the buildings during the heat wave.

Keywords: uWRF mesoscale meteorological model, urban canopy parameterization, urban heat island, heat wave, energy demands.