“Marine heat waves are relatively unknown to scientists, with research papers on these ocean temperatures starting to appear only in 2013. The phenomenon has since become a key signal of climate change — for decades oceans have absorbed most of the additional heat in the atmosphere, acting like sponges for global warming.”
This sounds suspect to me to me since it is still uncertain just how the greenhouse effect directly affects the ocean’s heat uptake. The penetration depth of Infra-Red (IR) radiation caused by greenhouse gasses in the atmosphere into the ocean surface is limited to the sub-millimeter scale so it could not directly heat the layers beyond the top few micrometers of the ocean surface. The oceans absorb heat directly from the sun and as a result the net energy flux across the ocean/atmosphere interface carries heat from the ocean to the air. The heat (IR radiation) gained by the atmosphere from added greenhouse gasses is not able to penetrate the ocean surface more than a few micrometers so how could the “oceans have absorbed most of the additional heat in the atmosphere, acting like sponges for global warming.” ?
The current theory suggests that since the downward infrared radiation heats the very thin thermal skin layer (TSL) of ocean which has the effect of reducing the flow of heat from the ocean to the air, thus allowing the oceans to retain heat over time. Detractors of this theory point out that the increase in skin temperature would increase evaporation rates and thus tend to cool the skin surface, largely nullifying any warming effect.
I don’t think that the claim that " oceans have absorbed most of the additional heat in the atmosphere, acting like sponges for global warming.” is correct.
A recent SST Anomaly chart shows there are also large regions of “Marine Cold Waves” as well.