Heidelberg 2015 – wissenschaftliches Programm
UP 4.14: Poster
Mittwoch, 25. März 2015, 10:45–19:45, G/Foyer
Observations of RHS concentrations and processes at the Dead Sea Valley — •Stefan Schmitt1, Robert Holla1,2, Denis Pöhler1, Udo Frieß1, Ulrich Platt1, Andreas Held3, Katharina Kamilli3, Ulrich Corsmeier5, and Jutta Zingler4 — 1IUP, Heidelberg — 2Deutscher Wetterdienst — 3BayCEER, Bayreuth — 4FTU, Karlsruher Institut für Technologie — 5IMK, Karlsruher Institut für Technologie
The Dead Sea Valley (DSV), located at the border of Israel and Jordan, is a unique place with high activity of reactive halogen species (RHS). Former DOAS measurements revealed high abundances of bromine monoxide (BrO) as well as iodine monoxide (IO) but the processes and sources are still not understood. Therefore we performed intensive LP-DOAS measurements in May 2012. We observed mixing ratios of up to 90 ppt, 5ppt and 60 ppt for BrO, IO and I2 respectively. NO2 mixing ratios dropped from about 6 ppb to below the detection limit of 0,5 ppb during sunrise on every day while significant BrO and IO concentrations were only detected at low NO2 mixing ratios. This supports the assumption that NO2 is consumed by the formation of BrONO2 and IONO2 from released RHS. The data shows several interesting chemical features which are presented.
Further, condensation particle counter (CPC) measurements of particles with sizes of 9-800 nm indicate that significant mixing ratios of IO were observed only at low particle loads while BrO seems to prefer high particle concentrations. This indicates a possible influence of aerosols on the halogen chemistry at the DSV.