Methane in the western part of Eurasian Arctic in late autumn 2023: AMK-93 observations and model simulation

Methane (CH₄) is the second most important greenhouse gas in atmosphere after carbon dioxide (CO₂). Since 2005, according to measurements, there has been a noticeable increase in near-surface methane concentration. This phenomenon is especially strong in Arctic. Unfortunately, data of surface methane concentrations are extremely limited for this region, it makes it difficult to quantify the impact of emissions from the most important regional anthropogenic and biogenic sources. This gap is partially filled by long-term observations at Arctic and subarctic monitoring stations, as well as by measuring companies during expeditions on research vessels.

This paper presents the results of continuous measurements of methane and carbon dioxide concentration, and isotope δ¹³C_CH4 in  atmospheric bottom layer over the waters of Kara and Barents Seas during the 93rd expedition of RV Akademik Mstislav Keldysh (AMK-93), November 08 – December 07, 2023. In addition, data obtained were compared with regional chemical climate model WRF-Chem calculations and model fields of surface methane content for certain regions of the Russian Arctic were shown. Model estimates of methane fluxes from  sea surface have been made for Baydaratskaya Bay area and compared with observations conducted during the expedition.