Estimation of Seasonal and Annual Acidic Deposition through Aggregation of Three-Day Episodic Periods

摘要

A method for aggregating episodic deposition estimates has been developed and used to identify which meteorological situations merit simulation by RADM based on their likelihood of producing sulfate (SO4(-2)) wet deposition at multiple locations across eastern North America, their frequency of occurrence, and their seasonality. The aggregation technique has been performed using four years (1982 - 1985) of precipitation chemistry data from the Utility Acid Precipitation Sampling Program (UAPSP). The method developed during the project improves upon random selection. It is based on the stratification of three-day periods into categories of similar 850 mb wind flow across eastern North America. The aggregation project has provided the RADM project with a list of simulation periods which represent the range of meteorological patterns over eastern North America. The selection of storm types was based on their likelihood of producing SO4(-2) wet deposition at multiple locations across eastern North America, their frequency of occurrence, and their seasonality. The project has also provided the RADM project with scaling factors for use in weighing episodic simulation results to seasonal and annual deposition.