Progress Report
Acid Deposition
Acid deposition, commonly known as "acid rain," is a broad term referring to the mixture of wet and dry deposition from the atmosphere containing higher than normal amounts of sulfur and nitrogen-containing acidic pollutants. The precursors of acid deposition are primarily the result of emissions of sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) from fossil fuel combustion; however, natural sources, such as volcanoes and decaying vegetation, also contribute a small amount.
Acid Deposition Figures
![Three-Year Average of Total Sulfur Deposition](img/acid_deposition_f1_small.png)
![Three-Year Average of Total Nitrogen Deposition](img/acid_deposition_f2_small.png)
![Regional Trends in Deposition](img/acid_deposition_f3_small.png)