Hamburg 2009 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

UP: Fachverband Umweltphysik

UP 3: Atmosphäre III

UP 3.2: Talk

Tuesday, March 3, 2009, 16:42–16:54, VMP 9 HS

Longpath-DOAS measurements of BrO and ClO on the westcoast of Ireland — •Joelle Buxmann, Katja Seitz, Denis Pöhler, Jens Tschritter, Tobias Sommer, and Ulrich Platt — Institut für Umweltphysik, Im Neuenheimer Feld 229, 69120 Heidelberg

Reactive halogen species (RHS) are of great importance as the influence of the atmospheres ozone chemistry. The involved processes are not fully understood yet. Two measurement campaigns were undertaken at the west coast of Ireland between August and September 2007. On both campaigns the RHS BrO and ClO were investigated by active Differential Optical Absorption Spectroscopy (DOAS) in the marine boundary layer. Expecting very low concentrations of BrO and ClO, a low detection limit is necessary. By using a special strategy and an optimized configuration of the instruments, noise was significantly reduced. A tropospheric BrO Signal was detected. The peak concentration was estimated on August 7th to (6,9±1,7) ppt. Furthermore there was an ozone depletion event on August 24th down to 10 ppb connected with high IO (evaluated by Katja Seitz) concentrations. On the second campaign the distribution of BrO was measured for 8 days. There was also a BrO signal during 3 nights. An anticorrelation with Ozone concentrations was found. ClO was not detected. The mean detection limit was 40 ppt.