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Air Atlas–Estimated Atmospheric Deposition

Estimated annual average atmospheric wet deposition for the 2008–2012 time period are shown on the map below:

  • Ammonium (NH4), nitrate (NO3), and nitrogen (N) wet deposition
  • Sulfate (SO4) and sulfur (S) wet deposition

Click the map legend to turn parks, monitors, or atmospheric deposition layers on and off. Click on parks on the map to find park specific estimates. Atmospheric deposition estimates for 2008–2012 are also avaiable in table form (pdf, 584 KB). Wet deposition estimates are based on air quality data from monitors in the National Atmospheric Deposition Program (NADP) network.

What is Atmospheric Deposition?

Deposition is any air pollutant that "deposits" to the earth. It occurs by wet and dry processes. Wet deposition occurs via rain, snow, and fog. Dry deposition occurs by settling and other complex processes. The map above shows only wet deposition. The NPS is concerned about the deposition of nitrogen (N) and sulfur (S) compounds because it can cause fertilization and acidification of natural ecosystems. Research to determine critical loads of deposition that protect sensitive ecosystems in national parks is underway.
N & S depostion effects »

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Last Updated: June 21, 2016