DOAS-measurement of the NO<sub>2</sub> formation rate from NO<sub>x</sub> emissions into the atmosphere

Abstract

Abstract. In the present work we deal with emissions originating from combustion processes containing SO 2 , NO and NO 2 , emitted into the atmosphere by a localized source. We present a method for measuring the NO 2 -formation rate (due to conversion of NO to NO 2 ) from measurements of SO 2 -and NO 2 -slant column densities across different plume sections, under the (usually justified) assumption that the SO 2 -flux is constant. The advantages of the proposed method are that the measurements can be performed from an arbitrary location, without explicit reference to the wind speed and direction in the plume. We present results of ground based DOAS-measurements of SO 2 and NO x emissions from an oil refinery located in the northern part of Montevideo Bay and give recommendations for future applications of the method.

Evaluation of tropospheric SO<sub>2</sub> retrieved from MAX-DOAS measurements in Xianghe, China

“…It is based on the measurement of sunlight scattered at multiple elevation angles towards the horizon, thus increasing the sensitivity to absorbers present close to the ground compared to the zenith viewing geometry (Hönninger et al, 2004). MAX-DOAS studies published so far have been mainly focused on the retrieval of NO 2 (e.g., Wittrock et al, 2004;Vlemmix et al, 2010;Frins et al, 2012;Hendrick et al, 2014;Ma et al, 2013;Wang et al, 2014), halogen oxides like BrO and IO (e.g., Frieß et al, 2011;Großmann et al, 2013), formaldehyde (e.g., Heckel et al, 2005;Wagner et al, 2011), and aerosols (e.g., Wagner et al, 2004;Frieß et al, 2006;Clémer et al, 2010). A lot of work has been done on MAX-DOAS measurements of volcanic SO 2 (e.g., Bobrowski et al, 2007;Galle et al, 2010), but so far only a few studies deal with MAX-DOAS observations of this species in polluted areas (e.g., Irie et al, 2011;Lee et al, 2008;Wu et al, 2013), despite the fact that, as for other trace gases like NO 2 , HCHO, and BrO, the combination of both surface concentration and VCD retrievals makes MAX-DOAS a useful technique for validating SO 2 satellite data.…”

Evaluation of tropospheric SO<sub>2</sub> retrieved from MAX-DOAS measurements in Xianghe, China

“…SO 2 fitting windows ranging between 303 and 325 nm have generally been used in previous studies (Bobrowski and Platt, 2007;Lee et al, 2008;Galle et al, 2010;Irie et al, 2011). At wavelengths shorter than 303 nm, the limiting factor is the strong ozone absorption which interferes with SO 2 , leading to lower signal to noise ratio.…”

“…MAX-DOAS studies published so far have been mainly focused on the retrieval of NO 2 (e.g., Wittrock et al, 2004;Vlemmix et al, 2010;Frins et al, 2012;Hendrick et al, 2014;Ma et al, 2013;Wang et al, 2014), halogen oxides like BrO and IO (e.g., Frieß et al, 2011;Großmann et al, 2013), formaldehyde (e.g., Heckel et al, 2005;Wagner et al, 2011), and aerosols (e.g., Wagner et al, 2004;Frieß et al, 2006;Clémer et al, 2010). A lot of work has been done on MAX-DOAS measurements of volcanic SO 2 (e.g., Bobrowski et al, 2007;Galle et al, 2010), but so far only a few studies deal with MAX-DOAS observations of this species in polluted areas (e.g., Irie et al, 2011;Lee et al, 2008;Wu et al, 2013), despite the fact that, as for other trace gases like NO 2 , HCHO, and BrO, the combination of both surface concentration and VCD retrievals makes MAX-DOAS a useful technique for validating SO 2 satellite data.…”

Year-long Concurrent MAX-DOAS Observations of Nitrogen Dioxide and Formaldehyde at Pune: Understanding Diurnal and Seasonal Variation Drivers

“…Being an useful and reliable technique it have been used for measurement of HCHO, NO2, sulfur dioxide (SO2) etc. from both groundbased and satellite-borne instruments (Leue et al, 2001;Hönninger et al, 2004;Beirle et al, 2011;Gonzi et al, 2011;Frins et al, 2012). In this manuscript, simultaneous observations of NO2 and HCHO are being reported in Pune city for the first time, which aims at a better understanding of tropospheric chemistry (including ozone formation) in Pune city.…”