ClearSky: development and evaluation of an automated, MM5-CALMET-CALPUFF modeling system providing web-mediated support for management of smoke from agricultural field burning

An agricultural smoke dispersion modeling system, ClearSky was developed and run on an experimental basis in the fall 2002 agricultural field burning season and again with expanded domain in fall, 2003. The ClearSky project was developed as a tool to guide smoke management in northern Idaho and eastern Washington in decision making for agricultural burning. The system features: 1) use of data from state burn permitting programs to locate sources, 2) a web application giving users the ability to posit potential burn scenarios for modeling, and 3) web graphics displaying scenario simulation results. ClearSky is a NW-AIRQUEST (Northwest International Air Quality, Environmental Science and Technology Consortium) project and is being developed in collaboration with the US Forest Service BlueSky/RAINS project for management of prescribed forest burning.

The ClearSky modeling system uses the University of Washington MM5 forecast, at 4-km grid spacing, processed through CALMET to drive CALPUFF to simulate smoke dispersion from agricultural field burning. The emissions are simulated using a buoyant line source to represent an active flame front and a buoyant area source to represent the smoldering portion of a field. Parameters for the emissions and plume-rise modules were obtained from data collected during recent field studies and from sensitivity studies of the plume-rise modules.

ClearSky was operated on a daily basis during the 2002 through 2004 burn seasons. Analysis of the ClearSky system was conducted at the end of the 2002 season by re-running each burn day using actual burn data. Performance of the modeling system was analyzed by comparing 1) observed and MM5 predicted meteorology and 2) observed and ClearSky predicted PM2.5 concentrations at the monitoring stations. A similar evaluation was conducted with the 2003 burn season results.

The paper will present the ClearSky modeling system, including recent enhancements, and review the results of our model evaluation efforts.