The origin and the impact of high NO2 vertical tropospheric column densities (VTCs) observed from the Global Ozone Monitoring Experiment (GOME) instrument within and above an extended cloud cover are studied using air mass trajectories and ground-based in-situ measurements. A frontal system is found to advect near ground pollution to higher tropospheric levels. The NO2 source is located by means of backward trajectories arriving in the GOME columns to be in middle Germany, the Ruhr area and adjacent parts of Netherlands and Belgium in this case. The highly polluted air masses are traced with forward trajectories starting from the GOME columns to move further to the Alpine region. Their impact on the air quality there is confirmed by ground measurements and a simple transport model based on trajectories and the GOME NO2 VTCs. The result confirms that for the investigated case, 50 to 100 % of the NO2 peak mixing ratios measured at remote sites during the frontal passage can be attributed to transboundary transport.
A transboundary transport episode of nitrogen dioxide as observed from GOME and its impact in the Alpine region
2005
Abstract
The origin and the impact of high NO2 vertical tropospheric column densities (VTCs) observed from the Global Ozone Monitoring Experiment (GOME) instrument within and above an extended cloud cover are studied using air mass trajectories and ground-based in-situ measurements. A frontal system is found to advect near ground pollution to higher tropospheric levels. The NO2 source is located by means of backward trajectories arriving in the GOME columns to be in middle Germany, the Ruhr area and adjacent parts of Netherlands and Belgium in this case. The highly polluted air masses are traced with forward trajectories starting from the GOME columns to move further to the Alpine region. Their impact on the air quality there is confirmed by ground measurements and a simple transport model based on trajectories and the GOME NO2 VTCs. The result confirms that for the investigated case, 50 to 100 % of the NO2 peak mixing ratios measured at remote sites during the frontal passage can be attributed to transboundary transport.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
