ИСТИНА

We performed the analysis of time series of methane concentrations at the forest remote area since 2006 to 2020 using CCGCRV program. The data had been obtained from the measurements at remote monitoring station Danki in central European Russia more than 50 km far from Moscow. The continuous and regular monitoring of GHG is performed at this Roshydromet station with help of flask air sampling and gas chromatography by IGCE. Mean annual concentrations at this remote statiopn exceeds mean global methane concentration for 5-10%. There are pronounced intra-annual variations supported by CCGCRV analysis results with maximum concentrations in cold season and minimum in mid-summer. An amplitude of seasonal variations is three times higher than variations recorded at the Arctic station Teriberka. There is an evidence of positive trend in CH4 concentrations estimated with help of CCGCRV analysis of about 2 ppb per year since 2006. However, we recognized the observed concentrations in years 2009 and 2010 to be much higher than in previous and further years. After excluding noted years’ values from the analysis, the increasing trend became equals about 6 ppb per year being closer to the reported global trend.