Ground-based and OMI-TROPOMI NO2 measurements at El Arenosillo observatory: Unexpected upward trends.

Ground-based and OMI-TROPOMI NO2 measurements at El Arenosillo observatory: Unexpected upward trends. Environ Pollut. 2020 Sep;264:114771 Authors: Adame JA, Gutierrez-Alvarez I, Bolivar JP, Yela M Abstract Eleven years, January 2008 to June 2019, of hourly nitrogen dioxide (NO2) levels recorded at El Arenosillo observatory (Southwestern Europe) were analyzed. Annual averages ranged between 4 μg m-3 and 6 μg m-3 with peaks exceeding 40 μg m-3. A slight monthly variation was observed with maximum and minimum values in the cold (∼6 μg m-3) and warm (∼4 μg m-3) seasons respectively. A diurnal pattern was found with a weak amplitude (∼3 μg m-3). The monthly trends were investigated using surface observations and OMI (Ozone Monitoring instrument) satellite measurements. An unexpected upward trend was obtained in the last five years. The periods with elevated NO2 concentrations in the last years were analyzed, showing an increase in its frequency and concentrations, linked with the upward trend observed. The weather conditions in these NO2 peaks were studied using local surface meteorology, mean sea level pressure and wind fields from the data reanalysis of ERA5. The transport of NO2 was explored using TROPOMI (Tropospheric Monitoring Instrument) measurements. The events occurred under conditions governed by high-pressure systems, which induced weak synoptic airflows or the development of mesoscale processes. Four sc...
Source: Environmental Pollution - Category: Environmental Health Authors: Tags: Environ Pollut Source Type: research