The North Atlantic “Cold Spot”.

NEWS | February 6, 2019. 2018 fourth warmest year in continued warming trend, according to NASA, NOAA

The latest scary map from NOAA and NASA showing the earth glowing red hot from Climate Change. You can click here to see it as a movie and read the blurb.

The trouble is the North Atlantic cooled considerably over this four year period. No reason is given for this weird behaviour. Perhaps there was a lack of CO2 in this vicinity in 2018, which is strange because weather patterns usually ensure atmospheric gases are well mixed.

There is another explanation: this part of the ocean was warmer in 2014 than in 2018.  Ocean temperature here must be highly variable  for reasons unrelated to CO2 concentration.

The World Ocean Circulation Experiment (WOCE), collected hydrographic data from the world’s oceans between 1990 and 1998. The following map shows the WOCE sections for the North Atlantic:

WOCE Hydrographic Sections of the North Atlantic (© 2011 International WOCE Office)

Section A25 from the tip of Greenland to Portugal crosses the cool region in the NASA-NOAA map. Here is a plot showing potential temperature along this section. (Potential temperature is measured temperature corrected for pressure. Black shows the ocean floor. It looks spiky because the horizontal scale is so contracted.)

Potential temperature along WOCE Section A25. © 2011 International WOCE Office

Salinity shows an even more confused picture:

Salinity along WOCE section A25. © 2011 International WOCE Office

Compared with most oceanographic sections these sections are poorly stratified particularly at the left-hand side, south of Greenland. The perturbations occur down to the ocean floor and near the Mid-Atlantic Ridge (the double black spike on the left) implying they are of volcanic, hydrothermal origin. The MAR is particularly active at its northern end.

The “cold spot” in the North Atlantic cannot be accounted for in terms of the greenhouse effect. It can be readily accounted for in terms of variable volcanic heating of the ocean. Why is this ignored by NOAA and NASA?

By the same argument the “hot spot” to the north of Greenland can be accounted for by more recent hydrothermal activity on the Gakkel Ridge. In both cases the temperature difference is 4 deg C – the difference between the temperature of ice formation and the temperature of the deep ocean. Volcanic heating does not itself cause the observed temperature variations. It acts indirectly by changing the pattern of circulation and intermittently bringing deep ocean water to the surface.

5 Replies to “The North Atlantic “Cold Spot”.”

  1. To quote from TFC #6 page144: “Climate modellers ignore the effect of subaqueous volcanic activity on ocean circulation despite that fact that 85 percent of volcanic activity occurs beneath the ocean and that heating from a major oceanic eruption would dwarf all other ocean processes. This aspect of ocean circulation and climate has not simply been forgotten; it is conscientiously avoided. It is the elephant in the room. (Chapter~13)”

    1. Thanks for the TFC quote!

      I was in the back 40 yesterday looking at the latest effect of changes to the landscape on the flow of water coming down the hill. I was glad to see that a recent upslope fill and grading effort doesn’t seem to have affected things much. Give or take 140 years ago a parker water ditch was installed up there that slows the runoff of a bit when the rains get intense.

      1. Are you in California? Here in Australia we thought you were having a drought! It happens here too. When the drought breaks you get floods.

        Re TFC quote: the full section is quoted in PAGES/”Climate Change”

    2. This is very interesting. The left side in particular at around 32w and 37w having vertical contours in both graphs. Further west is also different. I wonder if the water pressure causes intermittent gassing over long cycles. Then there would also be a more steady thermal draught effect, I’m guessing. Plenty of mixing. It would be interesting to see the concentration of some other elements that might give a volcanic signature.

      1. RobK. The best tracer for volcanic heating is delta 3He. Unfortunately this is not available for this North Atlantic section. It may be for some of the others. Have a look yourself. Google “woce atlantic atlas” and poke around. See page 117 of TFC.

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