RE: Record Marine Heatwave Hits Mediterranean Sea

RE: Record Marine Heatwave Hits Mediterranean Sea

Two comments:

RE “The warmer air along with shifting ocean currents and a stable sea surface have warmed coastal Mediterranean waters several degrees Celsius beyond the average temperature of 24°C to 26°C for this time of year.”

Although the warmer air does have a minor effect, the main cause of the rising SST in the western Mediterranean was a prolonged period of clear skies and light wind which allowed the sea to absorb more solar energy while limiting mixing.

RE: “Scientists have known that oceans have absorbed 93% of heat captured by greenhouse gasses since the 1970s”.

Scientists have known that the penetration depth of IR radiation (added heat from greenhouse gasses) in water is only a few micrometers and therefore does not directly heat the layers beyond the top submillimeter of the ocean surface so is not heating the upper 700 meters of the ocean. The global mean SST is about 16.1 °C (60.9 °F) while the global mean surface air temperature is 14°C (57°F) so the net global heat flux is from the ocean to the air. Since the surface air temperature has been rising faster than the sea surface temperature the temperature difference between air and sea has decreased and thus the rate of heat flux from ocean to air has decreased allowing the ocean to gain heat overall.

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