Ozone remote monitoring

In this chapter, the impact of these policy actions on elevated episodic peak ozone levels is assessed over the 1980-2009 period. The annual maximum 8-h average ozone level is the chosen air quality metric, and the focus is mainly on rural and remote monitoring stations as recorded in the EMEP ozone database. 

The origin of these episodic peak ozone levels is unquestionably photochemical ozone formation from man-made NOx and VOC precursors. Efficient long-range transboundary transport ensures that these episodic peak levels are observed at even the most remote monitoring stations in the EMEP monitoring network. Equally well, efficient transboundary transport ensures that responses to reductions in man-made NOx and VOC precursor emissions should be felt across Europe in terms of reductions in episodic peak ozone levels. 

Atmospheric and remote-sensing appHcations of uv—vis spectroscopy have been reviewed (157,158). Many volatile organics absorb in the near-uv, and the vapors exhibit rovibronic stmcture suitable for identification and quantification if interferences can be avoided. Especially suitable for uv monitoring are the strong Huggins (300—370 nm) and Hartley (210—300 nm) bands of O other inorganics such as NO2 and SO2 have been successfully analyzed at kilometer distances (see Ozone). 

With a growing interest in the global atmospheric environment, remote sensing techniques are regarded as a most powerful and efficient way of monitoring stratospheric ozone. Some of the methods described can be applied to tropospheric ozone measurements as well. 

An ozone monitor is an example of a continuous emission sampler based on absorption spectroscopy. A drop in beam intensity is proportional to ozone concentration in the chamber. Absorption spectrometers exist for sulfur and nitrogen oxides. This type of technology is portable and relatively inexpensive to run and can be used under field conditions, for example monitoring in-use emissions of motor vehicles. Absorption spectroscopy is also used in satellite remote sensing and has been adapted to remote sensing devices deployed on the ground to measure vehicular emissions. 

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