Measurements of nitrous acid, nitrate radicals, formaldehyde, and nitrogen dioxide for the Southern California Air Quality Study by differential optical absorption spectroscopy

1991 ◽  
Author(s):  
Arthur M. Winer ◽  
Heinz W. Biermann
Keyword(s):  
Air Quality ◽  
Optical Absorption ◽  
Nitrogen Dioxide ◽  
Absorption Spectroscopy ◽  
Nitrous Acid ◽  
Southern California ◽  
Differential Optical Absorption Spectroscopy ◽  
Optical Absorption Spectroscopy ◽  
Nitrate Radicals ◽  
Quality Study

scholarly journals Spatially resolved measurements of nitrogen dioxide in an urban environment using concurrent multi-axis differential optical absorption spectroscopy

2006 ◽  
Vol 6 (6) ◽  
pp. 12671-12700
Author(s):  
R. J. Leigh ◽  
G. K. Corlett ◽  
U. Frieß ◽  
P. S. Monks
Keyword(s):  
Remote Sensing ◽  
Optical Absorption ◽  
Nitrogen Dioxide ◽  
Urban Environment ◽  
Absorption Spectroscopy ◽  
Differential Optical Absorption Spectroscopy ◽  
Optical Absorption Spectroscopy ◽  
High Time Resolution ◽  
In Situ Techniques

Abstract. A novel system using the technique of concurrent multi-axis differential optical absorption spectroscopy system has been developed and applied to the measurement of nitrogen dioxide in an urban environment. Using five fixed telescopes, slant columns of nitrogen dioxide, ozone, water vapour, and the oxygen dimer, O4, are simultaneously retrieved in five vertically separated viewing directions. The application of this remote sensing technique in the urban environment is explored. Through, the application of several simplifying assumptions a tropospheric concentration of NO2 is derived and compared with an urban background in-situ chemiluminescence detector. The remote sensing and in-situ techniques show good agreement. Owing to the high time resolution of the measurements, the ability to image and quantify plumes within the urban environment is demonstrated. The CMAX-DOAS measurements provide a useful measure of overall NO2 concentrations on a city-wide scale.

scholarly journals Two-dimensional monitoring of air pollution in Madrid using a Multi-AXis Differential Optical Absorption Spectroscopy two-dimensional (MAXDOAS-2D) instrument

2021 ◽  
Vol 14 (4) ◽  
pp. 2941-2955
Author(s):  
David Garcia-Nieto ◽  
Nuria Benavent ◽  
Rafael Borge ◽  
Alfonso Saiz-Lopez
Keyword(s):  
Air Quality ◽  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Urban Areas ◽  
Spatial Information ◽  
Differential Optical Absorption Spectroscopy ◽  
Optical Absorption Spectroscopy ◽  
Two Dimensional ◽  
Inversion Algorithm ◽  
The City

Abstract. Trace gases play a key role in the chemistry of urban atmospheres. Therefore, knowledge about their spatial distribution is needed to fully characterize air quality in urban areas. Using a new Multi-AXis Differential Optical Absorption Spectroscopy two-dimensional (MAXDOAS-2D) instrument, along with an inversion algorithm (bePRO), we report the first two-dimensional maps of nitrogen dioxide (NO2) and nitrous acid (HONO) concentrations in the city of Madrid, Spain. Measurements were made during 2 months (6 May–5 July 2019), and peak mixing ratios of 12 and 0.7 ppbv (parts per billion by volume) for NO2 and HONO, respectively, were observed in the early morning in the southern part of the downtown area. We found good general agreement between the MAXDOAS-2D mesoscale observations – which provide a typical spatial range of a few kilometers – and the in situ measurements provided by Madrid's air quality monitoring stations. In addition to vertical profiles, we studied the horizontal gradients of NO2 in the surface layer by applying the different horizontal light path lengths in the two spectral regions included in the NO2 spectral analysis: ultraviolet (UV, at 360 nm) and visible (VIS, 477 nm). We also investigate the sensitivity of the instrument to infer vertically distributed information on aerosol extinction coefficients and discuss possible future ways to improve the retrievals. The retrieval of two-dimensional distributions of trace gas concentrations reported here provides valuable spatial information for the study of air quality in the city of Madrid.

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