Berlin 2012 – scientific programme
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UP: Fachverband Umweltphysik
UP 14: Atmosphere 2
UP 14.5: Talk
Thursday, March 29, 2012, 15:00–15:15, HFT-FT 131
Automated identification and verification of long-range transport events of NO2 in GOME-2 observations — •Achim Zien, Andreas Hilboll, Andreas Richter, and John P. Burrows — Institute of Environmental Physics, University of Bremen, Germany
Atmospheric long-range transport (LRT) events relocate trace gases from emission to downwind regions on an intercontinental scale, drastically altering the atmospheric chemistry in remote regions. Tropospheric NO2 is a very short-lived, mainly anthropogenic trace gas with strong impact on the ozone chemistry. Emissions are very localized and allow identification of individual LRT events.
This phenomenon is investigated by remote sensing satellite observations which provide the spatial and temporal coverage needed to identify large-scale, multi-day events. The long, continuous time-series of such measurements allows the estimation of regional, seasonal and global statistics of such events.
Based on a non-cloud-filtered GOME-2 dataset of NO2 slant columns, we use a special algorithm to identify LRT candidates and verify them using Lagrangian transport models. We further discuss the problems in the assessment of spatial extent and NO2 content of LRTs, which are often associated with cloud formation.
As results of this study, we present statistics of NO2 LRT events based on a 4-year dataset, showing that NO2 LRT is not a rare phenomenon. We find strong seasonality in frequency and typical routes of such events. Based on simple estimations, we also provide statistics on the transported NO2 mass.