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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>M.W. Williams</dc:contributor>
  <dc:contributor>K. Campbell</dc:contributor>
  <dc:contributor>E.M. Elliott</dc:contributor>
  <dc:contributor>C. Kendall</dc:contributor>
  <dc:creator>L. Nanus</dc:creator>
  <dc:date>2008</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;In the Rocky Mountains, there is uncertainty about the source areas and emission types that contribute to nitrate (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) deposition, which can adversely affect sensitive aquatic habitats of high-elevation watersheds. Regional patterns in NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt; deposition sources were evaluated using NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt; isotopes in five National Parks, including 37 lakes and 7 precipitation sites. Results indicate that lake NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt; ranged from detection limit to 38 μeq/L, δ&lt;/span&gt;&lt;sup&gt;18&lt;/sup&gt;&lt;span&gt;O (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) ranged from −5.7 to +21.3‰, and δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) ranged from −6.6 to +4.6‰. δ&lt;/span&gt;&lt;sup&gt;18&lt;/sup&gt;&lt;span&gt;O (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) in precipitation ranged from +71 to +78‰. δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) in precipitation and lakes overlap; however, δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) in precipitation is more depleted than δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) in lakes, ranging from −5.5 to −2.0‰. δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) values are significantly related (&lt;/span&gt;&lt;i&gt;p&lt;/i&gt;&lt;span&gt; &amp;lt; 0.05) to wet deposition of inorganic N, sulfate, and acidity, suggesting that spatial variability of δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) over the Rocky Mountains may be related to source areas of these solutes. Regional patterns show that NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt; and δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) are more enriched in lakes and precipitation from the southern Rockies and at higher elevations compared to the northern Rockies. The correspondence of high NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt; and enriched δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) in precipitation with high NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;and enriched δ&lt;/span&gt;&lt;sup&gt;15&lt;/sup&gt;&lt;span&gt;N (NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) in lakes, suggests that deposition of inorganic N in wetfall may affect the amount of NO&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt; in lakes through a combination of direct and indirect processes such as enhanced nitrification.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1021/es800739e</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>ACS Publications</dc:publisher>
  <dc:title>Evaluating regional patterns in nitrate sources to watersheds in national parks of the Rocky Mountains using nitrate isotopes</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>