Climate.gov provides an updated on ocean heat in the Climate Change: Ocean Heat Content article by Luann Dahlman and Rebecca Lindsey (updated 10/12/2021):
Averaged over Earth’s surface, the 1993–2020 heat-gain rates were 0.37–0.41 Watts per square meter for depths from 0–700 meters (down to 0.4 miles), depending on which research group’s analysis you consult. Meanwhile, heat gain rates were 0.15–0.31 Watts per square meter for depths of 700–2,000 meters (0.4–1.2 miles). For depths between 2000–6000 meters (1.2–3.7 miles), the estimated increase was 0.06 Watts per square meter for the period from June 1992 to July 2011. According to the State of the Climate 2019 report, “Summing the three layers (despite their slightly different time periods as given above), the full-depth ocean heat gain rate ranges from 0.58 to 0.78 W m-2 applied to Earth’s entire surface.”
The article has helpful short summaries on how heat moves and measuring ocean heat. They link to Global Ocean Heat and Salt Content: Seasonal, Yearly, and Pentadal Fields for the data.
