What’s causing the extremely warm temperatures in the North Atlantic?
By Paul Homewood
Judith Curry and Jim Johnstone have written a detailed analysis of what is causing the extremely warm sea temperatures in the Atlantic:
Essentially it really revolves around atmospheric circulation patterns and extremely low NAO values, as they explain:
June atmospheric conditions over the North Atlantic are also highly unusual, as indicated by a North Atlantic Oscillation (NAO) index anomaly nearly 3 standard deviations below the monthly average. The NAO is defined by the subtropical – subpolar difference in atmospheric sea-level pressure (SLP) anomalies, and approximately reflects the intensity of the low-level atmospheric circulation over the North Atlantic basin. Extreme low NAO values in June are consistent with a very weak subtropical high (Bermuda High) and relatively stagnant surface winds, involving weakness of the midlatitude westerly flow and the tropical-subtropical easterly trade winds.
Summary
The extreme North Atlantic conditions that developed in recent months are likely due to a combination of dynamical factors, including stochastic weather anomalies, regional positive feedbacks and global-scale changes. The high rate of recent Arc warming is particularly noticeable due to the extreme SST anomalies it produced; however comparable warming over periods of ~4 to 6 months occurred previously in late winter to spring seasons of 1983, 1987, 1989 and 2010 (Figure 2), which preceded a wide range of late summer hurricane anomalies.
The dominant cause of the warm SSTs is dynamical (atmospheric circulations) that modify surface wind speeds (evaporation; apparently the largest factor) and clouds (solar radiation). Minor non-cloud radiative impacts: Hunga-Tonga is a global effect, sulfate ship tracks is local ocean effect primarily in northern hemisphere, wildfire impact on oceans is relatively rare and event driven, and African dust is a regular summer feature that is characterized by discrete events. Cloud variability in most locations will dominate over aerosol forcing in terms of impacts on sea surface temperatures. Some minor Atlantic Ocean cooling can be expected with Canadian smoke and Saharan dust.
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NOT A LOT OF PEOPLE KNOW THAT 
If you project the 1982-2010 trend the new “extreme” warming is right on track, hence not extreme. One could ask why the pause instead. Also the time series is so short that this could all be part of a long term natural cycle. Including a chaotic cycle in ocean circulation.
A lot of possible factors are mentioned, with more in the comments (also at WUWT), so I do not see an actual explanation. The climate system is delightfully complex.
And yet was are told that the science is ‘settled’ and therefore we know everything…..until we get another of those ‘scientists has discovered….’ moments.
‘Anomalies’ presents a very odd view of water temps (and why should we get worked up over 1°C above average temperature; why is is categorized as ‘extremely warm?).
As displayed on the Weather Channel this AM, the Atlantic off southern Morocco is 77°F. Off southern Senegal below it, it is 86°F.
In the first chart above, titled “SST Anomalies 06 27 2023,” it is all BLOOD RED off the coast of north Africa. 77 and 86 are blood read.
Curry appears to be an excitable girl.
the chart is not temperature
it’s “temperature anomalies”
ie if the temp is 1C different what the expected, it’s dark red.
The Atlantic isn’t warm in fact the amount of energy to heat it up isn’t available unless an undersea volcano erupts.