Monitoring Greenhouse Gases in the Open Atmosphere by the Fourier Spectroscopy Method.

The problem of global climate change has become one of the most important challenges to humanity in the 21^st century. The main reason is the appearance in the atmosphere of an excessive concentration of greenhouse gases, which absorb the thermal radiation of the Earth and partially return it to the Earth's surface. The accumulation of greenhouse gases in the atmosphere leads to a rapid increase in the global average air temperature and, as a result, climate change. It is well known that greenhouse gases have a high transparency in the visible spectral range and high absorption in the infrared range. In this paper, we propose a new technique for recording the CO₂ and CH₄ spectra. An experimental setup based on dynamic Fourier spectrometer is developed. It allows to record IR absorption spectra in the wavelength range of 1.0 to 1.7 μm with a 10 cm^–1 spectral resolution. Long-term recording of the atmospheric transmittance in the conditions of urban development is carried out. Based on the obtained data, the CO₂ and CH₄ integral and volumetric concentrations are monitored. It is shown that the carbon dioxide and methane volumetric concentrations time dependences accurately reflects the traffic congestion degree on that day. Reduction of volume concentrations in the evening hours is explained by the increase of the optical path and the additional capture of air masses outside the heavy traffic area. [ABSTRACT FROM AUTHOR]