Evaluating WRF model atmospheric boundary layer simulations for a coastal region in Southeast Texas

Air quality forecasting requires atmospheric models to generate reliable and accurate meteorological conditions, one of which is the development of the atmospheric boundary layer (ABL) height. ABL height development is a determining factor in the extent and location of pollution upset events, so having accurate ABL height development is essential to accurate pollution predictions. However, ABL height parameterization stems from complex interactions including those for radiation, land usage, atmospheric turbulence and mixing, and cloud conditions. A previous study focused on evaluating a “best fit” of the four parameters listed above for the 5th generation Penn State/NCAR Mesoscale Model (PSU-NCAR MM5) ABL height in and around the city of Houston, Texas. In this study, we will attempt to reproduce the study for the Weather Research and Forecasting (WRF) Model for selected periods in summer 2006 over a coastal prairie south of Houston, where the interactions between the land/sea breeze circulation and point-source pollutants from the metropolitan area contribute to the conditions of the area. Data collected during the Second Texas Air Quality Study (TexAQS-II), including flux (sensible, latent, and soil heat flux and momentum flux), radiation (incoming/outgoing long- and short-wave radiation), and standard atmospheric (pressure, relative humidity, temperature, wind speed, and wind direction) measurements are used to initialize the WRF model. The simulated output is then compared to daytime radiosondes and nighttime tethersondes that documented the development of the ABL height over this time period. An analysis of the biases—their values, conditions for expression, and possible causes—will be conducted, and a potential “best fit” scheme will be examined.