Relationship between In-Lake Sulfate Concentration and Estimates of Atmospheric Sulfur Deposition for Subregions of the Eastern Lake Survey.

摘要

Estimated amounts of the total sulfur deposition at each of the 1798 lakes in the US Environmental Protection Agency's Eastern Lake Survey, obtained by using the ASTRAP model, were compared with the survey measurements of in-lake sulfate concentration on a subregional basis. In general, the sample median in-lake sulfate concentration was qualitatively correlated with the sample median estimated total sulfur deposition, with in-lake concentration increasing with increased estimated deposition. Two subregions, 3A (southern Blue Ridge) and 3B (Florida), however, did not fit this relationship. In-lake sulfate concentrations were higher than expected in Florida and lower than expected in the southern Blue Ridge. Comparison of our modeled total sulfur deposition with estimated amounts of wet-only sulfate deposition were in good agreement in terms of subregional rank order. More detailed comparison of the magnitudes of the estimates was not done because others reported deposition in terms of the estimated population medians, obtained by using a weighting procedure based on alkalinity map class, instead of as sample medians and also used the weighting procedure to estimate the subregional median in-lake sulfate concentration. 7 refs., 3 figs., 1 tab. (ERA citation 14:025270)