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Titel |
Iodine monoxide in the north subtropical free troposphere |
VerfasserIn |
O. Puentedura, M. Gil, A. Saiz-Lopez, T. Hay, M. Navarro-Comas, A. Gomez-Pelaez, E. Cuevas, J. Iglesias, L. Gomez |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 11 ; Nr. 12, no. 11 (2012-06-06), S.4909-4921 |
Datensatznummer |
250011220
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Publikation (Nr.) |
copernicus.org/acp-12-4909-2012.pdf |
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Zusammenfassung |
Iodine monoxide (IO) differential slant column densities (DSCD) have been
retrieved from a new multi-axis differential optical absorption spectroscopy
(MAX-DOAS) instrument deployed at the Izaña subtropical observatory as
part of the Network for the Detection of Atmospheric Composition Change
(NDACC) programme. The station is located at 2370 m a.s.l., well above the
trade wind inversion that limits the top of the marine boundary layer, and
hence is representative of the free troposphere. We report daily
observations from May to August 2010 at different viewing angles. During
this period, the spectral signature of IO was unequivocally detected on
every day of measurement. A mean IO DSCD of
1.52×1013 molecules cm−2 was observed at the
5° instrument elevation angle (IEA) on clear days using a
single zenith reference for the reported period, with a
day-to-day variability of 33% at one standard deviation. Based on the
simulation of the DSCDs using radiative transfer calculations with five
different hypothesized IO profiles, the IO mixing ratio is estimated to
range between 0.2 and 0.4 pptv in the free troposphere. Episodes of Saharan
dust outbreaks were also observed, with large increases in the DSCDs at
higher IEA, suggesting an enhancement of IO inside the dust cloud. |
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