Bremen 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
UP: Fachverband Umweltphysik
UP 6: Methoden - Fernerkundung
UP 6.4: Vortrag
Mittwoch, 15. März 2017, 09:30–09:45, GW2 B3009
Impact of ambient conditions on the DOAS retrival of NOVAC data — •Elsa Wilken1, Florian Dinger1,2, Simon Warnach1,2, Nicole Bobrowski1,3, and Ulrich Platt1 — 1IUP, University of Heidelberg — 2MPI Chemistry, Mainz — 3University of Mainz
The measurement of magnitude and composition of volcanic gas emissions allow insights in magmatic processes as well as the impact of volcanoes on the atmospheric chemistry. Therefore the Network for Observation of Volcanic and Atmospheric Change (NOVAC) has been installed for monitoring the SO2 and BrO emissions of 30 volcanoes using scanning UV-spectrometers. The volcanic gas emissions are retrieved from the recorded spectra by applying Differential Optical Absorption Spectroscopy (DOAS). While NOVAC records an outstanding amount of gas emission data, the drawback of this automatically operating network is a limited accuracy and precision compared to manual measurements. For accurate retrievals, it is mandatory to find a Fraunhofer reference spectrum (FRS) which is free of volcanic gas and was recorded under similar conditions (e.g., instrument temperature, atmospheric conditions). We present an analysis of the impact of different external parameters on the DOAS fit quality when evaluating spectra using a FRS recorded, for example, on a different day. Based on our findings, an algorithm is introduced which automatically recommends for each plume spectrum a recorded FRS which optimises the accuracy. We show previous data from Tungurahua (Ecuador) and compare them to data created with the FRS with optimised accuracy.