Iodine Isotopes (127I and 129I) in Aerosols at High Altitude Alp Stations

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• 作者：Tania Jabbar ; Peter Steier ; Gabriele Wallner ; Alfred Priller ; Norbert Kandler ; August Kaiser
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：August 21, 2012
• 年：2012
• 卷：46
• 期：16
• 页码：8637-8644
• 全文大小：376K
• 年卷期：v.46,no.16(August 21, 2012)
• ISSN：1520-5851

文摘

Concentrations of gases and particulate matter have been proven to be affected by meteorological and geographical variables from urban locations to high mountain clean air sites. Following our previous research in Vienna, we summarize here new findings about concentration levels of iodine isotopes in aerosols collected at two Alpine meteorological stations, Sonnblick (Austria) and Zugspitze (Germany) during 2001. The present study mainly focuses on the effect of altitude on the anthropogenic concentration of ¹²⁹I and on the isotopic ratio ¹²⁹I/¹²⁷I. Iodine was separated from matrix elements by using either an anion exchange method or solvent extraction, and was analyzed by ICP-MS and AMS. Over the altitude change from Vienna to Zugspitze and Sonnblick (202 m to 2962 m and 3106 m above sea level), stable iodine level decreased from an average of 0.94 ng m^鈥? to 0.52 ng m^鈥? and 0.62 ng m^鈥?, respectively. Similarly, ¹²⁹I concentrations at both Alpine stations were about 1 order of magnitude lower (10⁴ atoms m^鈥?) than values obtained for Vienna (10⁵ atoms m^鈥?) and reveal a strong vertical concentration gradient of ¹²⁹I. A high degree of variability is observed, which is due to wide variation in the origin of air masses. Furthermore, air trajectory analysis demonstrates the importance of large scale air transport mostly from southeast Europe for influencing Sonnblick whereas influence from northwest Europe is strong at Zugspitze. In contrast to ¹²⁹I, a higher concentration of ⁷Be was found at higher altitude stations compared to Vienna which probably results from its production in the upper atmosphere.