Assessment of Improved WRF-CHEM PM2.5 Characterization via Implementation of an Aerosol Measurement Network

Coupled atmospheric-chemistry models are constrained to using aerosol schemes based on climatic data. An augmentation method of input for the Goddard Chemistry Aerosol Radiation and Transport (GOCART) module is introduced. The large disparity between in-situ particulate matter smaller than 2.5 µm in diameter (PM2.5) number concentrations and Weather Research and Forecasting with Chemistry (WRF-CHEM) output—using GOCART—can be improved using a stream of hourly aerosol observations. Analysis is done on WRF-CHEM output for two sample points near Dayton, Ohio after condensation particle counter (CPC) data is utilized for input modification. Interpolation between data points can be represented over a gridded area using a scaling matrix. Each cell of this matrix is potentially sensitive to land use, time of day (TOD), and present weather conditions, and is therefore variable. After confirmation of improved WRF-CHEM PM2.5 characterization by point-observation initialization and applying an interpolation technique, a method to implement an observation network is suggested: standardized encoding to report PM2.5 number concentration within current METAR framework.