Atlantic Meridional Overturning Circulation (AMOC)

[GordMay]

The Atlantic Meridional Overturning Circulation, and the Gulf Stream*, are on the verge of collapsing, climate scientists warn
*That thing that assists or impedes [but, almost always affects] sailing, in Atlantic waters.

In an open letter [1], 44 of the world's leading climate scientists say that key Atlantic Ocean currents - including the Gulf Stream - are on the brink of failure.
The scientists caution that the collapse of the Atlantic Meridional Overturning Circulation (AMOC) could lead to 'devastating and irreversible impacts' which will affect 'the entire world for centuries to come'.

Should the AMOC collapse, the effects would be widespread, devastating, and extremely long-lasting.
Scientists believe that the last time AMOC completely collapsed was during the end of the last Ice Age, around 12,000 years ago, when temperatures, in western Europe, plummeted by up to 10°C (18°F); and it took about 1,000 years to recover, though the past is not a direct analogue, because there is also massive CO2 forcing this time [CO2 is already higher than any time in 15m years].

The collapse would lead to major cooling, and 'unprecedented extreme weather', especially in Nordic countries. This would enlarge and deepen the 'cold blob', of anomalously cold waters, which has already developed, over the eastern North Atlantic, due to the slowdown of heat-carrying currents. This would be particularly bad news for the UK, which is kept warm by currents of warm water, carried by AMOC, northwards from the Gulf of Mexico.

However, not every scientist is in agreement that AMOC will collapse within this century.[2]
Since AMOC was first measured in 2004, scientists have expressed concerns that the current system could be weakening. Yet a number of leading experts argue that these conclusions are far from being definitively established. The main issue is that researchers have had to make some basic assumptions, about how AMOC works, in order to predict how it might change, over time.

Is the AMOC definitely changing?
Direct instrumental measurements of the strength of the AMOC only began in 2004, when the RAPID [3] array was installed across the Atlantic. After nearly 20 years of continuous measurements, the data show a 10-per-cent decrease in its strength, but because the observations show such a lot of change from year to year, we can’t be sure that this is a meaningful, long-term decline.

[1] “Open Letter by Climate Scientists to the Nordic Council of Ministers” [October 2024]
➥ https://en.vedur.is/media/ads_in_hea...tter_Final.pdf

[2] “Future of the Gulf Stream circulation” ~ by the German Marine Research Consortium [KDM]
➥ https://www.deutsches-klima-konsorti...SAAEgI-tfD_BwE

Originally Posted by KDM

“There has been lots of speculation about the Gulf Stream. But what kind of scientific evidence exists? Nine experts summarize this evidence in this brochure.

One of the key messages: The Gulf Stream circulation will not collapse in the near future. But this is not a reason to be complacent...”

[3] “RAPID 26°N array” [RAPID/MOCHA/WBTS]
➥ https://rapid.ac.uk/

The Atlantic Meridional Overturning Circulation (AMOC): What Is It and Why Is It So Important?
Video ➥

https://www.youtube.com/watch?v=KTnhtQ2YtGo

[Pete7]

Makes me wonder if the current slow down is causing the spate of wet winters and dry summers we are experiencing in Europe right now.

If the AMOC does slow or even stop, then presumably the heat in the Caribbean and Gulf won't have an escape route just adding to the problems.

Were doomed

[GordMay]

Originally Posted by Pete7

Makes me wonder ...

Cause and effect can be, inextricably linked, and co-dependent.

The effect is [can be]] as much the cause, of the cause being a cause, as the cause, is the cause of the effect.
If I hit you [cause], and you die [effect]; I am a murderer [consequential effect].
If I hit you, and you don’t die; I am an assaulter [different effect].
What you did, determines what I did; even though I acted first, and 'caused’, whatever you did.

I’ve heard that cataracts, are the fourth leading cause, of blindness.
The first three being: climate change, politics, and religion.

[barcoMeCasa]

Originally Posted by Pete7

Makes me wonder if the current slow down is causing the spate of wet winters and dry summers we are experiencing in Europe right now.

Maybe not.

https://esd.copernicus.org/articles/15/131/2024/

[GordMay]

Originally Posted by Pete7

Makes me wonder if the current slow down is causing the spate of wet winters and dry summers we are experiencing in Europe right now...

Originally Posted by barcoMeCasa

Maybe not.
https://esd.copernicus.org/articles/15/131/2024/

barcoMeCasa, and I, may be reading his citation, very differently.

Contrary to barcoMeCasa's assertion, the authors, of his cited article*, attribute the summer 2022 western–central European soil drought “to human-induced climate change”.

* “Detecting the human fingerprint in the summer 2022 western–central European soil drough” ~ by Dominik L. Schumacher et al
➥ https://esd.copernicus.org/articles/15/131/2024/

“... 4.2.1
... Overall, these results indicate that an event such as the 2022 summer drought in WCE has become far more likely due to our warming climate...
4.2.2 ...
... This indicates that such a hot summer would have been virtually impossible without climate change, and ...

... 6 Conclusions

Extending our rapid attribution analysis (Schumacher et al., 2022), we find evidence for a global warming-induced summer root zone soil moisture decline in western–central Europe, and several observation-driven soil moisture estimates agree on a downward trend since at least 1980. Our analysis suggests that the large uncertainties, also due to a lack of in situ root zone soil moisture observations except for a few hundred stations, make it difficult to communicate precise numbers. Nevertheless, the synthesized probability ratio for a 2022-like summer drought in western–central Europe is likely larger than 1 and amounts to about 5 (2.8 when using 1850–2022 model data, and 8.8 for 1950–2022). In other words, combining observation-driven and model evidence, we find that anthropogenic climate change has made such an event more probable...”

[jeanathon]

Seemed to be chugging along nicely when I rode it up earlier this summer, but I guess if it collapses it will make it easier for cruisers to hop from South Florida to the Bahamas!
https://youtu.be/3DXyRsOQ9Is

[GordMay]

jeanathon is an optimist.
An optimist says, “the glass is half full.”
A pessimist says, “the glass is half empty.”
An optometrist says, “you both need glasses.”

[newhaul]

Originally Posted by GordMay

The Atlantic Meridional Overturning Circulation, and the Gulf Stream*, are on the verge of collapsing, climate scientists warn
*That thing that assists or impedes [but, almost always affects] sailing, in Atlantic waters.

In an open letter [1], 44 of the world's leading climate scientists say that key Atlantic Ocean currents - including the Gulf Stream - are on the brink of failure.
The scientists caution that the collapse of the Atlantic Meridional Overturning Circulation (AMOC) could lead to 'devastating and irreversible impacts' which will affect 'the entire world for centuries to come'.

Should the AMOC collapse, the effects would be widespread, devastating, and extremely long-lasting.
Scientists believe that the last time AMOC completely collapsed was during the end of the last Ice Age, around 12,000 years ago, when temperatures, in western Europe, plummeted by up to 10°C (18°F); and it took about 1,000 years to recover, though the past is not a direct analogue, because there is also massive CO2 forcing this time [CO2 is already higher than any time in 15m years].

The collapse would lead to major cooling, and 'unprecedented extreme weather', especially in Nordic countries. This would enlarge and deepen the 'cold blob', of anomalously cold waters, which has already developed, over the eastern North Atlantic, due to the slowdown of heat-carrying currents. This would be particularly bad news for the UK, which is kept warm by currents of warm water, carried by AMOC, northwards from the Gulf of Mexico.

However, not every scientist is in agreement that AMOC will collapse within this century.[2]
Since AMOC was first measured in 2004, scientists have expressed concerns that the current system could be weakening. Yet a number of leading experts argue that these conclusions are far from being definitively established. The main issue is that researchers have had to make some basic assumptions, about how AMOC works, in order to predict how it might change, over time.

Is the AMOC definitely changing?
Direct instrumental measurements of the strength of the AMOC only began in 2004, when the RAPID [3] array was installed across the Atlantic. After nearly 20 years of continuous measurements, the data show a 10-per-cent decrease in its strength, but because the observations show such a lot of change from year to year, we can’t be sure that this is a meaningful, long-term decline.

[1] “Open Letter by Climate Scientists to the Nordic Council of Ministers” [October 2024]
➥ https://en.vedur.is/media/ads_in_hea...tter_Final.pdf

[2] “Future of the Gulf Stream circulation” ~ by the German Marine Research Consortium [KDM]
➥ https://www.deutsches-klima-konsorti...SAAEgI-tfD_BwE


[3] “RAPID 26°N array” [RAPID/MOCHA/WBTS]
➥ https://rapid.ac.uk/

The Atlantic Meridional Overturning Circulation (AMOC): What Is It and Why Is It So Important?
Video ➥

Interesting very interesting.
Didn't I tell you this 6 or 8 years ago?
Remember what I was labeled as?
One bright spot slowing of the currents will make the run from Florida to the Bahamas easier

[GordMay]

Originally Posted by newhaul

Interesting very interesting.
Didn't I tell you this 6 or 8 years ago?
Remember what I was labeled as? ...

Pray tell us. [both]

I DO remember you telling us, back then, that the Modern Grand Solar Minimum [solar sunspot cycle], would lead to terrestrial cooling, within a year, or two, as espoused by Valentina Zharkova.
How's that going?

Grand Solar Minima happen, when the peaks of several solar cycles, in a row, show less than average intensity, experiencing many fewer sunspots, and giving off less energy.
The last time this happened, it coincided with a period called the "Little Ice Age" from 1650 to 1715, in the Northern Hemisphere, when a combination of cooling from volcanic aerosols, and low solar activity, produced lower surface temperatures.

Solar maximum refers to the highest rate of solar activity, during the sun's approximately 11-year solar cycle. It is indicated by the intensity, and frequency of sunspots, visible on the surface.

On Oct. 15, 2024, representatives from NASA and the National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center (SWPC) announced that the sun has entered its solar maximum period which could continue for another year.

[newhaul]

Originally Posted by GordMay

Pray tell us. [both]

I DO remember you telling us, back then, that the Modern Grand Solar Minimum [solar sunspot cycle], would lead to terrestrial cooling, within a year, or two, as espoused by Valentina Zharkova.
How's that going?

Grand Solar Minima happen, when the peaks of several solar cycles, in a row, show less than average intensity, experiencing many fewer sunspots, and giving off less energy.
The last time this happened, it coincided with a period called the "Little Ice Age" from 1650 to 1715, in the Northern Hemisphere, when a combination of cooling from volcanic aerosols, and low solar activity, produced lower surface temperatures.

Solar maximum refers to the highest rate of solar activity, during the sun's approximately 11-year solar cycle. It is indicated by the intensity, and frequency of sunspots, visible on the surface.

On Oct. 15, 2024, representatives from NASA and the National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center (SWPC) announced that the sun has entered its solar maximum period which could continue for another year.

Did not say within a year . But I digress and yes it is cooling down. As the rate of warming per decade has dropped from .18°C per decade to now it is .16°C per decade but you must remember that is averaged over the last 40 years.
I'm just waiting for the dump from the Beaufort Gyre actually hope it happens slowly over several years so as to not seriously affect the salinity of the north Atlantic Meridional Overturning Circulation to fresh and well conveyor slows or even possibly stops in the northern finger. Of it.
The current won't stop but it will slow and move south toward Spain Portugal and gibraltar

[Viking Sailor]

Originally Posted by Pete7

Were doomed

Thank GOD!!!

[grantmc]

Originally Posted by Viking Sailor

Thank GOD!!!

Which god?

[GordMay]

Originally Posted by newhaul

...
I'm just waiting for the dump from the Beaufort Gyre actually hope it happens slowly over several years so as to not seriously affect the salinity of the north Atlantic Meridional Overturning Circulation to fresh and well conveyor slows or even possibly stops in the northern finger. Of it.
The current won't stop but it will slow and move south toward Spain Portugal and gibraltar

A 2023 study [1] provides the first observational evidence, of the stabilization of the anti-cyclonic Beaufort Gyre, which is the dominant circulation, of the Canada Basin, and the largest freshwater reservoir, in the Arctic Ocean.

Previous observations, and modeling, that relied on earlier dynamic ocean topography data, up to 2014, have documented that the gyre has strengthened, and increased its freshwater content, by 40%, compared with 1970s climatology.

Stabilization of the gyre could be a precursor of a huge freshwater release, which could have significant ramifications, including impacting the Atlantic Meridional Overturning Circulation [AMOC], a key component of global climate.
With the gyre being the Arctic Ocean’s largest freshwater reservoir, if that freshwater gets released, and ends up spreading into the North Atlantic, it could impact the overturning circulation, and, in an extreme case, disrupt it.
has maintained its excess freshwater storage.

Under a strengthened wind stress curl, the gyre has continuously intensified, even though it has contracted, and it has maintained its excess freshwater storage, the article notes.


[1] “Recent state transition of the Arctic Ocean’s Beaufort Gyre” ~ by Peigen Lin et al
➥ https://www.nature.com/articles/s41561-023-01184-5

See also:
[2] “On the Release and Renewal of Freshwater in the Beaufort Gyre of the Arctic Ocean” ~ by Qiang Wang
➥ https://journals.ametsoc.org/view/jo...-23-0184.1.xml

“... Cyclonic wind perturbation associated with a negative Beaufort high sea level pressure anomaly triggers freshwater release from the Beaufort Gyre, with freshwater export and renewal dependent on wind-perturbation locations and time scales. While some released Beaufort Gyre freshwater exits the Arctic Ocean through the Davis and Fram Straits, a considerable portion could remain within the Arctic Ocean for many years under specific conditions. Wind perturbation associated with the positive Arctic Oscillation enhances the Arctic export of Beaufort Gyre freshwater, mainly through the Fram Strait. The Arctic export of total freshwater and the Arctic export of the portion originating from the Beaufort Gyre have different time scales and magnitudes. Hence, it is essential to collectively examine different freshwater components in order to assess the role of Arctic export in the climate system...”

[GordMay]

Originally Posted by newhaul

Did not say within a year . But I digress and yes it is cooling down. As the rate of warming per decade has dropped from .18°C per decade to now it is .16°C per decade but you must remember that is averaged over the last 40 years.

The 10 warmest years, in the historical record, have all occurred in the past decade [2014-2023].

Despite 2021 and 2022 not ranking among the five warmest years [they’re among the 10 warmest], on record, the global annual temperature increased, at an average rate of 0.06°C [0.11°F], per decade, since 1850, and more than three times that rate [0.20°C / 0.36°F], since 1982.
Unlike 2021 and 2022, which were in a cold phase El Niño Southern Oscillation (ENSO) episode [AKA: La Niña]; 2023 quickly moved into ENSO neutral territory, transitioning to a warm phase episode, El Niño, by June.

2023 was the warmest year, since global records began, in 1850, by a wide margin.
2023 was 2.12 °F [1.18 °C] above the 20th-century average of 57.0°F [13.9°C].
It was 2.43 °F [1.35 °C] above the pre-industrial average (1850-1900).
You say "it's cooling; but admit it's warming.


The 10 warmest years, in the historical record, have all occurred in the past decade [2014-2023].

Despite 2021 and 2022 not ranking among the five warmest years [they’re among the 10 warmest], on record, the global annual temperature increased, at an average rate of 0.06°C [0.11°F], per decade, since 1850, and more than three times that rate [0.20°C / 0.36°F], since 1982.
Unlike 2021 and 2022, which were in a cold phase El Niño Southern Oscillation (ENSO) episode [AKA: La Niña]; 2023 quickly moved into ENSO neutral territory, transitioning to a warm phase episode, El Niño, by June.

2023 was the warmest year, since global records began, in 1850, by a wide margin.
2023 was 2.12 °F [1.18 °C] above the 20th-century average of 57.0°F [13.9°C].
It was 2.43 °F [1.35 °C] above the pre-industrial average [1850-1900].



This year [2024] is almost certain, surpass 2023, as the warmest year on record. This is true, even if the last six months, in 2024, are below the records, set in 2023.
The first six months of 2024 have each set new temperature records, extending an already remarkable streak of 13 consecutive record-breaking months dating back to 2023.
On 22 July, the world experienced its highest absolute global daily temperature on record, reaching a scorching 17.15C.
However, with El Niño fading, and modest La Niña conditions [potentially] developing, later this year, it is unlikely that the extreme monthly temperature records, set in the second half of 2023, will be surpassed in 2024.


So, NO - it's not cooling.

[Bowdrie]

Originally Posted by GordMay

jeanathon is an optimist.
An optimist says, “the glass is half full.”
A pessimist says, “the glass is half empty.”
An optometrist says, “you both need glasses.”

An engineer says that both the pessimist and the optimist have glasses that are too large and heavy for their intended purposes.
A physiatrist says they're all nuts, and hands out pills to make them see reality better.