Wintertime Methane Emission From the Barents and Kara Seas and Sea of Okhotsk: Satellite Evidence. ...

• Main Authors: Yurganov, Carroll, Dustin, Pnyushkov, Andrey, Polyakov, Igor, Zhang, Hong
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: Arctic; Okhotsk; arctic methane; Climate change; Sea ice
• Online Access: https://dx.doi.org/10.13016/m26jjd-gnu9; https://mdsoar.org/handle/11603/21422

EGU General Assembly 2021, EGU21-5628, vEGU21: Gather Online,19–30 April 2021 ... : Existence of strong seabed sources of methane, including gas hydrates, in the Arctic and sub-Arctic seas with proven oil/gas deposits is well documented. Enhanced concentrations of dissolved methane in deep layers are widely observed. Many of marine sources are highly sensitive to climate change; however, the Arctic methane sea-to-air flux remains poorly understood: harsh natural conditions prevent in-situ measurements during winter. Satellite remote sensing, based on terrestrial outgoing Thermal IR radiation measurements, provides a novel alternative to those efforts. We present year-round methane data from 3 orbital sounders since 2002. Those data confirm that negligible amounts of methane are fluxed from the seabed to the atmosphere during summer. In summer, the water column is strongly stratified from sea-ice melt and solar warming. As a result, ~90% of dissolved methane is oxidized by bacteria. Conversely, some marine areas are characterized by positive atmospheric methane anomalies that begin in ...