 |
| Titel |
Inorganic iodine in the tropical upper troposphere and lower stratosphere as derived from balloon-borne solar occultation observations |
| VerfasserIn |
A. Butz, M. Dorf, S. Kreycy, L. Kritten, C. Prados, K. Pfeilsticker |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250026652
|
|
|
|
|
|
| Zusammenfassung |
| The budget and photochemistry of iodine is assessed in the tropical Upper Troposphere/
Lower Stratosphere (UT/LS) where the halogen source gases enter the stratosphere and
supply the stratosphere with halogen species. Two stratospheric balloon flights of the
LPMA/DOAS (Limb Profile Monitor of the Atmosphere/Differential Optical Absorption
Spectrometer) payload were performed from a tropical station in north-eastern Brazil (5°S,
43°W) in June 2005 and June 2008. The LPMA/DOAS payload conducted spectroscopic
direct sun measurements in the UV/visible and infrared spectral range during balloon
ascent/descent and in solar occultation geometry. Here we focus on the outcome of the
occultation measurements during sunrise and sunset.
The DOAS observations allow for the retrieval of IO and OIO from their absorption
features in the visible spectral range. Neither species could be detected unambiguously with
detection limits ranging between 0.01 and 0.2 ppt in the UT/LS. Constraining a stratospheric
chemistry model by the inferred detection limits for IO and OIO, yields an upper limit for Iy
of 0.1 to 0.3 ppt. |
|
|
|
|
|
|