DOAS measurements of iodine monoxide from satellite [Elektronische Ressource] = DOAS-Messungen des Spurengases Iodmonoxid vom Satelliten aus / vorgelegt von Anja Schönhardt

DOAS measurements of iodine monoxidefrom satelliteDOAS Messungen des Spurengases Iodmonoxidvom Satelliten ausVom Fachbereich Physik und Elektrotechnikder Universität Bremenzur Erlangung des akademischen GradesDoktor der Naturwissenschaften (Dr.rer.nat)genehmigte Dissertationvorgelegt vonDipl. Phys. Anja SchönhardtBremen, 03. September 2009Dissertation eingereicht am: 03.09.2009Tag des Promotionskolloquiums: 09.10.20091. Gutachter: Prof. Dr. John P. Burrows2. Gutachter: Prof. Dr. Lars KaleschkeFor my parentsAnne and RudolfAbstractAtmospheric columns of the trace gas iodine monoxide, IO, have been investigated by means ofspectroscopic measurements in the visible wavelength range. For this purpose, solar radiation scat-tered and reflected by the Earth’s atmosphere and surface is recorded by satellite instrumentationin nadir viewing geometry. These spectra have been analysed for the absorption signal of the IOvibronic absorption lines. Employing the Sciamachy sensor mounted on the ENVISAT satellite,global observations of IO from space become possible for the first time. The importance of iodinein the atmosphere lies in its high potential for destroying ozone as well as in the formation of newparticles which is initiated by condensable iodine oxides and may impact on Earth’s radiation bud-get at least locally.A major challenge in this work is the smallness of the observed IO optical depths with respect tothe instrument’s detection limit.