Sea ice and methane

TL;DR

This study reveals that Antarctic sea ice dynamics significantly influence the global annual cycle of atmospheric methane, suggesting a need to reassess carbon cycle models and their parameters.

Contribution

It identifies Antarctic sea ice as a primary driver of atmospheric methane cycles and highlights the importance of sea ice processes in methane flux modeling.

Findings

Antarctic sea ice extent correlates strongly with atmospheric methane cycles.

Sea ice freeze and temperature-dependent solubility dominate methane fluxes.

Results suggest current carbon cycle models need reevaluation.

Abstract

1) The annual cycle of atmospheric methane in southern high latitudes is extremely highly correlated with Antarctic sea ice extent. 2) The annual cycle of atmospheric methane in the Arctic is highly correlated with Antarctic or Arctic plus Antarctic sea ice extent. 3) We propose the global annual cycle of atmospheric methane is largely driven by Antarctic sea ice dynamics, with relatively stronger influence from other fluxes (probably the biota) in the Northern Hemisphere. 4) We propose degassing during sea ice freeze and temperature dependent solubility in the ocean dominate the annual methane cycle. 5) Results provide evidence that carbon cycle pathways, parameters and predictions must be reassessed.