17O18O and 18O18O in ice core O2 from Greenland: implications to reconstruct past atmospheric photochemistry
Abstract
&lt;p&gt;Abundances of &lt;sup&gt;17&lt;/sup&gt;O&lt;sup&gt;18&lt;/sup&gt;O and &lt;sup&gt;18&lt;/sup&gt;O&lt;sup&gt;18&lt;/sup&gt;O (also called clumped isotopes and denoted by &amp;#916;&lt;sub&gt;35&lt;/sub&gt; and &amp;#916;&lt;sub&gt;36&lt;/sub&gt;) of O&lt;sub&gt;2&lt;/sub&gt;&amp;#160; in firn and ice core air are novel tracers that can be useful to study past changes in atmospheric photochemistry and temperature. We present &amp;#916;&lt;sub&gt;35&lt;/sub&gt; and &amp;#916;&lt;sub&gt;36&lt;/sub&gt; values measured in firn and ice core air O&lt;sub&gt;2&lt;/sub&gt; from North Greenland (NEEM; 77.45&amp;#176;N 51.06&amp;#176;W). The aim is to reconstruct the preindustrial-industrial, Holocene and glacial-interglacial variation in the tropospheric ozone photochemistry and temperature. Measurements of &amp;#916;&lt;sub&gt;35&lt;/sub&gt; and &amp;#916;&lt;sub&gt;36&lt;/sub&gt; are carried out using a high-resolution stable isotope ratio mass spectrometer Thermo Fisher 253 ULTRA[1]. Our measurements of &amp;#916;&lt;sub&gt;35&lt;/sub&gt; and &amp;#916;&lt;sub&gt;36&lt;/sub&gt; &amp;#160;across past air, from archive samples, to the modern-day show significant changes in the atmospheric photochemistry via ozone burdening and stratospheric- tropospheric transport processes. We will present the measurement results along with a detailed discussion on the dominant process using explicit dynamic simulations of &amp;#8710;&lt;sub&gt;36 &lt;/sub&gt;in the AC-GCM EMAC model [2,3,4].&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt; </jats:pSimilar works
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