Remote monitoring of methane in the Earth's atmosphere based on a lidar with a powerful optical amplif er

Abstract

Issues of global control of greenhouse gases are highlighted, and an overview of satellite, airborne and ground-based monitoring methods is given. It is shown that it is inappropriate to use satellite and aircraft methods to measure the concentrations of local methane emissions due to the low horizontal resolution. It is proposed to determine local methane emissions from natural or anthropogenic sources by ground control methods using a mobile laboratory equipped with a remote lidar. Local path measurements of the background methane concentration in the northeast of the Moscow Region were carried out using
a lidar operating at a wavelength of ~1650 nm with a powerful radiation source based on a Raman amplifi er. The length of the tracks ranged from ~0.6 km to ~3.15 km. The highest background concentration of methane was observed over a livestock farm and over a highway with a solid waste landfi ll, which confi rms the fact of increased gas emission over these facilities. On the highway with gasifi ed houses and a highway with heavy traffi c, there was also an increased background of methane content, which indicates a possible increase in the number of vehicles using methane as a fuel and a possible leak of natural gas from pipelines that provide houses with natural gas. The measurement results are compared with the results of other works. The estimation of errors of the made measurements is carried out. The coincidence on average of the results of measurements of methane concentration for the European region was revealed, taking into account the gradual increase in the background concentration of gas over the past 10–15 years. The measurement technique and results can be used for environmental monitoring of facilities with increased methane emission, leaks from gas pipelines, as well as to prevent explosive situations.