Сходство современных изменений фоновых концентраций метана в приповерхностном слое атмосферы на различных широтах

Фундаментальная и прикладная климатология. 2018. Т. 3. С. 82–95.

Semenov S.

Variations in methane concentrations in the surface layer are studied using monthly averages provided by the Global Atmospheric Sampling Laboratory (GASLAB), Australia. Flask measurements have been carried out at the network of monitoring stations of the Commonwealth Scientific and Industrial Research Organization (CSIRO). Mainly data of 1991–2014 are analyzed in this paper. On the yearly time scale, the variations are studied using yearly running averages. Differences between bimestrial running averages and yearly running averages are employed for the analysis of variations on the seasonal time scale. On the yearly scale, after the elimination of systematic differences in CH4 levels, trends became similar at all stations. For the stations of the Southern Hemisphere, respective curves differ by several ppb only. The similarity of variations at all stations was found also on the seasonal scale. The oscillations observed have seasonal cyclicality and the stable shape. Strong correlations are found for different stations. However, the correlations are manifested only after respective time shifts accounting for seasonality have been applied. Methane levels are increased in the cold period of year and decreased in the warm period. Such type of variations supports the following hypothesis: CH4 variations on the seasonal time scale are caused by seasonal changes in hydroxyl burden in the lower atmosphere.

Keywords: similarity, метан, present-day variations, global level, concentrations, surface layer, methane, different latitudes, современные изменения, глобальный уровень, концентрации, приповерхностный слой, сходство, разные широты