Relative Tropospheric Photolysis Rates of HCHO and HCDO Measured at the European Photoreactor Facility
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- 作者：Karen L. Feilberg ; Matthew S. Johnson ; Asan Bacak ; Thomas Rö ; ckmann ; Claus J. Nielsen
- 刊名：Journal of Physical Chemistry A
- 出版年：2007
- 出版时间：September 20, 2007
- 年：2007
- 卷：111
- 期：37
- 页码：9034 - 9046
- 全文大小：229K
- 年卷期：v.111,no.37(September 20, 2007)
- ISSN：1520-5215
文摘
The relative photolysis rates of HCHO and HCDO have been studied in May 2004 at the European PhotoreactorFacility (EUPHORE) in Valencia, Spain. The photolytic loss of HCDO was measured relative to HCHO bylong path FT-IR and DOAS detection during the course of the experiment. The isotopic composition of thereaction product H2 was determined by isotope ratio mass spectrometry (IRMS) on air samples taken duringthe photolysis experiments. The relative photolysis rate obtained by FTIR is jHCHO/jHCDO = 1.58 ± 0.03. Theratios of the photolysis rates for the molecular and the radical channels obtained from the IRMS data, incombination with the quantum yield of the molecular channel in the photolysis of HCHO, HCHOH2+CO (JPLPublication 06-2), are jHCHOH2+CO/jHCDOHD+CO = 1.82 ± 0.07 and jHCHOH+HCO/(jHCDOH+DCO + jHCDOD+HCO)= 1.10 ± 0.06. The atmospheric implications of the large isotope effect in the relative rate of photolysis andquantum yield of the formaldehyde isotopologues are discussed in relation to the global hydrogen budget.