{"id":337048,"date":"2024-07-20T14:34:40","date_gmt":"2024-07-20T12:34:40","guid":{"rendered":"https:\/\/climatescience.press\/?p=337048"},"modified":"2024-07-20T14:34:42","modified_gmt":"2024-07-20T12:34:42","slug":"amocs-cold-blob-has-gone-missing","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=337048","title":{"rendered":"AMOC\u2019s \u201cCold Blob\u201d Has Gone Missing"},"content":{"rendered":"\n
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From Watts Up With That?<\/a><\/p>\n\n\n\n

Links to the previous rounds: <\/em>1<\/em><\/a>, 2<\/a> and <\/em>3<\/em><\/a>.<\/em><\/p>\n\n\n\n

Gabriel Oxenstierna<\/p>\n\n\n\n

The battle of climate hypotheses, Round 4:
The Green-house Gas Forcer <\/em>vs. The<\/em> Winter Gatekeeper<\/em><\/strong><\/strong><\/em><\/p>\n\n\n\n

For the first time, the IPCC\u2019s doctrine of CO2<\/sub> as a \u2018control knob\u2019 in our climate faces a serious challenger in the form of a comprehensive hypothesis about what drives climate and its shifts. \u2013 This article is the fourth in a series evaluating this new hypothesis of natural climate variability, the so-called Winter Gate-keeper Hypothesis [WGH]. The basic concept of WGH is that natural variations in the polewards meridional transport of heat and moisture controls climate change.[1][2]<\/em><\/p>\n\n\n\n

Alarmists, including the IPCC, love to speculate about tipping points. One of their favourites is that the Atlantic meridional overturning circulation (AMOC), will shut down due to our emissions of greenhouse gases.[3][4]<\/p>\n\n\n\n

The AMOC is an essential part of the global heat transport system. This is how bitterly cold the climate could get in parts of the North if it collapsed:[5]<\/p>\n\n\n\n

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Figure 1: Simulated outcome of an AMOC shutdown. Everything warms up significantly, except the North Atlantic and Northern Europe. Source: [7]<\/em><\/figcaption><\/figure>\n\n\n\n

A collapsed AMOC would also lead to a host of knock-on effects due to \u2018tele-connections\u2019.We are warned that a weakening of AMOC would have severe impacts and increase the risk of \u201ccascading problems\u201d for other major Earth systems, \u201csuch as the Antarctic ice sheet, tropical monsoon systems and Amazon rainforest\u201d.[6] Climate crise effects would occur in many other areas as well. Stormier weather, more floods, collapsed plankton production, and widespread oxygen death in the oceans (anoxia) are forecast, says the IPCC.[3] The issue of AMOC\u2019s whereabouts is therefore of great interest.<\/p>\n\n\n\n

The cold blob<\/strong><\/p>\n\n\n\n

The AMOC is like a giant conveyor belt of energy. It is primarily driven by the Denmark Strait overflow<\/a>: warm and salty water from the northward extension of the Gulf Stream meets the cold ocean currents off south-east Greenland. There they sink to the bottom as a huge \u2018waterfall\u2019, with a drop of more than 3 000 meters (at the threshold of the Denmark Strait). The heavy, cold bottom water then flows south to the Southern Ocean, before turning north again.<\/p>\n\n\n\n

A key part of the AMOC is the convection zone south of Iceland and Greenland, where we find the subpolar Atlantic gyre. The ocean current rotates counterclockwise around the so-called cold blob<\/em>:<\/p>\n\n\n\n

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Figure 2. The thermohaline circulation in the North Atlantic together with the surface water temperature trend from 1993 to 2021. Surrounding the cold spot with deep convection, the AMOC flows counterclockwise.<\/em><\/figcaption><\/figure>\n\n\n\n

The cold blob is not only present at the surface but goes way down to the depths:[8]<\/p>\n\n\n\n

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Figure 3. Change in ocean heat for the top 2000 meters, from 1958-2023, [4] adapted from [8, fig 7]<\/em><\/figcaption><\/figure>\n\n\n\n

The hypothesis that the AMOC is weakening is based on the existence of the cold blob as a long-term climate phenomenon in the North Atlantic, as the AMOC strength is strongly positively correlated with the cold blob temperature. A colder cold blob corresponds to a slower AMOC.[9][10]<\/p>\n\n\n\n

The cold blob disappears!<\/strong><\/p>\n\n\n\n

However, it now appears that the feared slowdown of the AMOC isn\u2019t happening at all. Deep-sea flow data show stable flows over the past 24 years. This was described in an article on WUWT, here<\/a>.<\/p>\n\n\n\n

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