Detection of pollution transport events southeast of Mexico City using ground-based visible spectroscopy measurements of nitrogen dioxide
1Centro de Ciencias de la Atmósfera, Univ. Nacional Autónoma de México, México D.F., México
2Institute for Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Forschungszentrum Karlsruhe GmbH, Garmisch-Partenkirchen, Germany
*now at: Institut für Meteorologie und Klimaforschung, Karlsruhe, Germany
Abstract. This work presents ground based differential optical absorption spectroscopy (DOAS) measurements of nitrogen dioxide (NO2) during the MILAGRO field campaign in March 2006 at the Tenango del Aire research site located to the southeast of Mexico City. The DOAS NO2 column density measurements are used in conjunction with ceilometer, meteorological and surface nitrogen oxides (NOx) and total reactive nitrogen (NOy) measurements to show a more comprehensive view of air pollution results when a research site has both surface and remote sensing instruments. An in depth analysis of 13 March 2006 demonstrates how DOAS NO2, surface NO2 and ceilometer data can be used to determine the extent of mixing of the pollution layer. In addition, we show the effectiveness of how DOAS measurements can be used to observe pollution sources that may reside above the mixing layer, such as the presence of lightning produced NO2 as seen on 28 March 2006.