Journal article
Development of the ClearSky smoke dispersion forecast system for agricultural field burning in the Pacific Northwest
Atmospheric environment (1994), Vol.41(32), pp.6745-6761
2007
Handle:
https://hdl.handle.net/2376/108790
Abstract
The post-harvest burning of agricultural fields is commonly used to dispose of crop residue and provide other desired services such as pest control. Despite careful regulation of burning, smoke plumes from field burning in the Pacific Northwest commonly degrade air quality, particularly for rural populations. In this paper, ClearSky, a numerical smoke dispersion forecast system for agricultural field burning that was developed to support smoke management in the Inland Pacific Northwest, is described. ClearSky began operation during the summer through fall burn season of 2002 and continues to the present. ClearSky utilizes Mesoscale Meteorological Model version 5 (MM5v3) forecasts from the University of Washington, data on agricultural fields, a web-based user interface for defining burn scenarios, the Lagrangian CALPUFF dispersion model and web-served animations of plume forecasts. The ClearSky system employs a unique hybrid source configuration, which treats the flaming portion of a field as a buoyant line source and the smoldering portion of the field as a buoyant area source. Limited field observations show that this hybrid approach yields reasonable plume rise estimates using source parameters derived from recent field burning emission field studies. The performance of this modeling system was evaluated for 2003 by comparing forecast meteorology against meteorological observations, and comparing model-predicted hourly averaged PM
2.5 concentrations against observations. Examples from this evaluation illustrate that while the ClearSky system can accurately predict PM
2.5 surface concentrations due to field burning, the overall model performance depends strongly on meteorological forecast error. Statistical evaluation of the meteorological forecast at seven surface stations indicates a strong relationship between topographical complexity near the station and absolute wind direction error with wind direction errors increasing from approximately 20° for sites in open areas to 70° or more for sites in very complex terrain. The analysis also showed some days with good forecast meteorology with absolute mean error in wind direction less than 30° when ClearSky correctly predicted PM
2.5 surface concentrations at receptors affected by field burns. On several other days with similar levels of wind direction error the model did not predict apparent plume impacts. In most of these cases, there were no reported burns in the vicinity of the monitor and, thus, it appeared that other, non-reported burns were responsible for the apparent plume impact at the monitoring site. These cases do not provide information on the performance of the model, but rather indicate that further work is needed to identify all burns and to improve burn reports in an accurate and timely manner. There were also a number of days with wind direction errors exceeding 70° when the forecast system did not correctly predict plume behavior.
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Details
- Title
- Development of the ClearSky smoke dispersion forecast system for agricultural field burning in the Pacific Northwest
- Creators
- Rahul Jain - Golder Associates, Calgary, BC, CanadaJoseph Vaughan - Laboratory for Atmospheric Research, Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164-2910, USAKyle Heitkamp - Geomatrix, Inc., 19203 36th Avenue West, Suite 101, Lynnwood, WA 98036-5772, USACharleston Ramos - Laboratory for Atmospheric Research, Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164-2910, USACandis Claiborn - Laboratory for Atmospheric Research, Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164-2910, USAMaarten Schreuder - Air Sciences, Inc., 421 SW 6th Avenue, Suite 1400, Portland, OR 97204, USAMark Schaaf - Air Sciences, Inc., 421 SW 6th Avenue, Suite 1400, Portland, OR 97204, USABrian Lamb - Laboratory for Atmospheric Research, Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164-2910, USA
- Publication Details
- Atmospheric environment (1994), Vol.41(32), pp.6745-6761
- Academic Unit
- Civil and Environmental Engineering, Department of
- Publisher
- Elsevier Ltd
- Identifiers
- 99900547277101842
- Language
- English
- Resource Type
- Journal article