Sea ice, argon and carbon dioxide

Abstract

1) Atmospheric argon on Earth and Mars cycles on a seasonal basis and abiotic factors will be particularly important drivers of this noble gas. 2) It is predicted and confirmed that there is similarity in the seasonality of sea ice and argon, with atmospheric argon in a Hemisphere often increasing fastest when sea ice in that Hemisphere is declining fastest. 3) There is some visual similarity between the detailed phenology of Greenland Sea ice extent and argon in some Northern Hemisphere sites, but formal analysis is required. 4) Argon monthly rates of change are inversely correlated with those of Antarctic sea ice and carbon dioxide for at least one Southern Hemisphere site (Palmer Station). 5) If causal, the mechanism is unclear but could involve argon bubble formation during freezing and bubble release in the spring melt. 6) Other variables with very similar phenology to sea ice, including high-latitude sea temperatures, should be investigated as potential drivers. 7) Cycling of argon by sea ice would strengthen the argument that seasonal cycling of carbon dioxide is in part driven abiotically, and also necessitate revision of oxygen flux estimates. 8) The general absence of lags between argon and carbon dioxide cycles suggests the dominant seasonal fluxes of both gases are in high latitudes and marine. 9) Failure to explore the causality of the highly similar time-series of argon, oxygen, methane and carbon dioxide could be extremely costly and scientifically remarkable.

Sea ice and oxygen

“…However, there is evidence that the role of sea ice may have been neglected and indeed may dominate the cycles of atmospheric carbon dioxide (Nelson & Nelson 2016;Hambler & Henderson 2020a, of methane (Hambler & Henderson 2020b and of argon (Hambler 2023). I therefore predict that sea ice extent changes will be strongly inversely correlated with oxygen flux within a year, at least at high latitudes.…”

“…I predict seasonal cycles of oxygen will be pronounced where those of carbon dioxide are pronounced, particularly the Northern Hemisphere high-latitude recording sites. I therefore examine Alert, Canada, and Point Barrow, Alaska ('Barrow') where gas dynamics have been considered in detail and compared to other sites (Peterson et al 1987;Semiletov et al 2004Semiletov et al , 2007Keeling et al 2005;Graven et al 2013;Barlow et al 2015;Hambler & Henderson 2020a,b, 2022.…”

“…Carbon dioxide is measured in flasks in parts per million (ppm). I consider rates of change of atmospheric gases more informative for the purposes of identifying flux locations than are the raw data on the levels of these gases (Hambler & Henderson 2020a. Two data sets are available from the Scripps O2 Program: a) The 'bimonthly' set, where intervals between samples of oxygen and carbon dioxide at the Scripps sites are nominally 'bimonthly' (approximately twice per month) but approximately weekly at Mauna Loa.…”

“…Understanding the oxygen cycle will require understanding the carbon cycle and involve disentangling biotic and abiotic fluxes. Potential abiotic fluxes of oxygen may also be explored by comparisons with seasonal cycles of argon which are widely accepted to be caused by abiotic marine fluxes (Cassar et al 2008;Hambler 2023).…”

“…Oxygen flux is partly decoupled from photosynthetic carbon dioxide flux through processes such as abiotic and biotic calcium carbonate production (Rysgaard et al 2007(Rysgaard et al , 2011(Rysgaard et al , 2013Fransson et al 2011;Geilfus et al 2013Geilfus et al , 2015Papakyriakou & Miller 2011;Keeling & Manning 2014;Hambler & Henderson 2020a;Keeling & Graven 2021). Carbon dioxide availability may limit some phytoplankton in some regions (Rivero-Calle et al 2015).…”