Environmental drivers constraining the seasonal variability in satellite-observed and modelled methane at northern high latitudes

作者：Ella Kivimäki, Maria Tenkanen, Tuula Aalto, Michael Buchwitz, Kari Luojus, Jouni Pulliainen, Kimmo Rautiainen, Oliver Schneising, Anu‐Maija Sundström, Johanna Tamminen, Aki Tsuruta, Hannakaisa Lindqvist · 发表于：Biogeosciences · 年份：2025 · DOI：10.5194/bg-22-5193-2025 · 被引用次数：4 · 研究领域：Atmospheric and Environmental Gas Dynamics、Methane Hydrates and Related Phenomena、Hydrocarbon exploration and reservoir analysis

Abstract. Methane emissions from Northern Hemisphere high-latitude wetlands are associated with large uncertainties, especially in the rapidly warming climate. Satellite observations of column-averaged methane concentrations (XCH4) in the atmosphere exhibit variability due to time-varying sources and sinks as well as atmospheric transport. In this study, we investigate how environmental variables, such as temperature, soil moisture, snow cover, and the hydroxyl radical (OH) sink of methane, explain the seasonal variability in XCH4 observed from space over Northern Hemisphere high-latitude wetland areas. We use XCH4 data obtained from the TROPOMI instrument aboard the Sentinel-5 Precursor satellite, retrieved using the Weighting Function Modified Differential Optical Absorption Spectroscopy (WFMD) algorithm. In addition, we perform the analysis using two atmospheric inversion model configurations: one based on non-optimized prior fluxes and another using fluxes optimized with in situ atmospheric observations. The aim was to assess the consistency between satellite-based and model-based results and to explore differences in how environmental variables drive the variability in XCH4. Environmental variables are derived primarily from meteorological reanalysis datasets, with satellite-based data used for snow cover and soil freeze–thaw dynamics and modelled data used for the OH sink. Our analysis focuses on five wetland-dominated case study regions over Northern Hemisphere high la...