Effects of variation in background mixing ratios of N&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;, O&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;, and Ar on the measurement of &amp;lt;i&amp;gt;δ&amp;lt;/i&amp;gt;&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;O–H&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O and &amp;lt;i&amp;gt;δ&amp;lt;/i&amp;gt;&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;H–H&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O values by cavity ring-down spectroscopy
Atmospheric measurement techniques