Measurements and data processing of atmospheric CO₂, CH₄, H₂O and δ¹³C_CH4 mixing ratio during the ship campaign in the East Arctic and the Far East seas in autumn 2016

Here we present the results of measurements of the atmospheric methane concentration and its isotope composition (δ¹³C_CH4) in the East Arctic and Far East Seas during the cruise in the autumn 2016 by two different types of analyzers. Open path LI-7700 and LI-7500 analyzers measuring correspondingly methane (CH₄), and carbon dioxide (CO₂) and water vapor (H₂O) have high time resolution (10Hz) that allow to fix instantaneous values of gas concentration. We obtained high CH₄ concentration (more than 8 ppm) at the location of methane bubbles yields from sea water to atmospheric air. However, due to contamination and icing of the mirrors of these analyzers, significant part of data was rejected for analysis. The data sets of contact gas analyzer G2132-i shows good reliability but the peaks of CH₄ concentration obtained by G2132-i are lower (up to 3.7 ppm) and longer due to instrument's slower responding time. For 10-min averaging, data sets of both CH₄ analyzers gives good agreement, the differences between two types measurements of methane values are less then analyzers' accuracy.