Ambient Air Concentration Maps
This page includes maps showing annual average ambient air concentrations of particles and gas measured at CASTNET sites.
Click on the map thumbnails to open the full size maps. Once the full size maps are open, right click on the map and click "save as" to save the maps to your computer.
| Year | Sulfur Dioxide | Particulate Sulfate | Particulate Ammonium | Total Nitrate (Nitric Acid + Nitrate) | Nitric Acid | Particulate Nitrate |
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| 2021-2023 |  |
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| 2000-2002 |  |
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| 2023 |  |
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| 2022 |  |
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| 2021 |  |
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| 2020 |  |
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| 2019 |  |
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| 2018 |  |
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| 2017 |  |
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| 2016 |  |
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| 2015 |  |
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| 2014 |  |
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| 2013 |  |
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| 2012 |  |
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| 2011 |  |
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| 2010 |  |
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| 2009 |  |
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| 2008 |  |
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| 2007 |  |
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| 2006 |  |
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| 2006 | |
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| 2006 | |
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| 2005 |  |
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| 2004 |  |
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| 2003 |  |
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| 2002 |  |
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| 2001 |  |
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| 2000 |  |
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