Temperature, carbon dioxide and methane

Abstract

1) Globally-representative monthly rates of change of atmospheric carbon dioxide and methane are compared with global rates of change of sea ice and with Arctic and Antarctic air temperatures. 2) Carbon dioxide is very strongly correlated with sea ice dynamics, with the carbon dioxide rate at Mauna Loa lagging sea ice extent rate by 7 months. 3) Methane is very strongly correlated with sea ice dynamics, with the global (and Mauna Loa) methane rate lagging sea ice extent rate by 5 months. 4) Sea ice melt rate peaks in very tight synchrony with temperature in each Hemisphere. 5) The very high synchrony of the two gases is most parsimoniously explained by a common causality acting in both Hemispheres. 6) Time lags between variables indicate primary drivers of the gas dynamics are due to solar action on the polar regions, not mid-latitudes as is conventionally believed. 7) Results are consistent with a proposed role of a high-latitude temperature-dependent abiotic variable such as sea ice in the annual cycles of carbon dioxide and methane. 8) If sea ice does not drive the net flux of these gases, it is a highly precise proxy for whatever does. 9) Potential mechanisms should be investigated urgently.

Sea ice and oxygen

“…Changes in ice cover may influence oxygen through other processes: for example it may enable or reduce upwelling and ventilation of deep water rich in nutrients and methane but also depleted of oxygen (Verdy et al 2007;Rysgaard et al 2011;Annett et al 2015;Bushinsky et al 2017Bushinsky et al , 2019Zhang et al 2017;Ouyang et al 2020;Hambler & Henderson 2020b). Sea ice may, however, be a proxy for some other seasonal process such as light availability, temperature of air or sea, wind direction or even terrestrial productivity.…”

“…At Barrow, whilst carbon dioxide has very tight synchrony with Greenland Sea ice (Hambler & Henderson 2020a), oxygen rate leads Greenland Sea ice rates very slightly (Fig. 9) as with methane (Hambler & Henderson 2020b); this suggests various biological and abiotic processes may proceed at different rates as the ice melts, or different Arctic regions are most important for different gases (or that there are different monthly averaging methods). Remote sensing of ice extent may not be detecting some relevant changes in or beneath the sea ice.…”

“…Remote sensing of ice extent may not be detecting some relevant changes in or beneath the sea ice. Other Arctic sea ice regions might have tighter or weaker synchrony with oxygen, as they do with carbon dioxide (Hambler & Henderson 2020a) and methane (Hambler & Henderson 2020b).…”

“…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.…”