Are there any (educated) opinions here about the likely evolution of the
cold blob (in the N Atlantic) in the next say 10-50 years. And likely
impact on UK weather?
--
Order alone is boring; complexity alone is chaos

On Friday, August 25, 2023 at 1:35:01 PM UTC+1, JohnD wrote:
> Are there any (educated) opinions here about the likely evolution of the
> cold blob (in the N Atlantic) in the next say 10-50 years. And likely
> impact on UK weather?
> --
> Order alone is boring; complexity alone is chaos

Confused.com, what cold blob, or am I missing something here :-)

Keith (Sothend)

On 25/08/2023 13:34, JohnD wrote:
> Are there any (educated) opinions here about the likely evolution of the
> cold blob (in the N Atlantic) in the next say 10-50 years. And likely
> impact on UK weather?

I canot find ref now, but I posted here perhaps 8 years ago details.
An academic pdf, having analysed uk headed Atlantic storms , high
correlation with a cold spot south of Greenland, probably not stated by
them as "cold blob" for more/stronger? storms. Also E-W/W-E SST gradient
and readings a month earlier correlations as well. In the end not much
use for predictions of individual storms.

--
Global sea level rise to 2100 from curve-fitted existing altimetry data
<http://diverse.4mg.com/slr.htm>uk landing

It's been in the news again recently, like:

https://phys.org/news/2023-08-north-atlantic-oscillation-contributes-cold.html

Also I noticed a PBS documentary recently posted to YouTube:

https://www.youtube.com/watch?v=4CXZi-gFgX4

On Saturday, 26 August 2023 at 13:17:32 UTC+1, JohnD wrote:
> It's been in the news again recently, like:
>
> https://phys.org/news/2023-08-north-atlantic-oscillation-contributes-cold..html
>
> Also I noticed a PBS documentary recently posted to YouTube:
>
> https://www.youtube.com/watch?v=4CXZi-gFgX4

Looking at https://psl.noaa.gov/map/clim/sst.shtml it seemed to me that the cold blob had gone so I asked the AI bing site:
"Is the north atlantic cold blob still there?"

This is the reply I got:
"Yes, the North Atlantic cold blob is still present. It is a cold temperature anomaly of ocean surface waters, affecting the Atlantic Meridional Overturning Circulation (AMOC) which is part of the thermohaline circulation1. It is possibly related to global warming-induced melting of the Greenland ice sheet1. A recent study published in February 2022 suggests that changes in wind patterns, among other factors, may be contributing to this "cold blob"2. The researchers found that more than half—54 percent—of the observed cooling trend is a result of increased heat loss from the ocean induced by the overlying atmosphere2. Another 38 percent of the trend is explained by strengthened local convection, whereby ocean mixing brings cold water from depth to the surface2. According to the team, storminess increased in the region because the jet stream moved northward2. As a result, there are more frequent and more intense storms in this region2. The increase in storminess creates a stronger heat loss from the ocean and induces stronger convection in winter, leading to cooler temperatures in the region2.

Learn more:
1. en.wikipedia.org
2. phys.org
3. carbonbrief.org
4. psu.edu
5. severe-weather.eu
6. sciencedaily.com
+2 more"

My explanation for the cold blob was it was caused by melting Arctic sea ice, or melting Greenland ice which being fresh water would be lighter than sea water and float on the surface. Bing agreed, but did not point out that with the increase in SSTs, See https://www.bbc.co.uk/news/science-environment-66387537 that perhaps the Greenland ice melt is no longer less denser than North Atlantic sea water.

What do you think?

On 26/08/2023 16:38, Alastair B. McDonald wrote:
> On Saturday, 26 August 2023 at 13:17:32 UTC+1, JohnD wrote:
>> It's been in the news again recently, like:
>>
>> https://phys.org/news/2023-08-north-atlantic-oscillation-contributes-cold..html
>>
>> Also I noticed a PBS documentary recently posted to YouTube:
>>
>> https://www.youtube.com/watch?v=4CXZi-gFgX4
>
> Looking at https://psl.noaa.gov/map/clim/sst.shtml it seemed to me that the cold blob had gone so I asked the AI bing site:
> "Is the north atlantic cold blob still there?"
>
> This is the reply I got:
> "Yes, the North Atlantic cold blob is still present. It is a cold temperature anomaly of ocean surface waters, affecting the Atlantic Meridional Overturning Circulation (AMOC) which is part of the thermohaline circulation1. It is possibly related to global warming-induced melting of the Greenland ice sheet1. A recent study published in February 2022 suggests that changes in wind patterns, among other factors, may be contributing to this "cold blob"2. The researchers found that more than half—54 percent—of the observed cooling trend is a result of increased heat loss from the ocean induced by the overlying atmosphere2. Another 38 percent of the trend is explained by strengthened local convection, whereby ocean mixing brings cold water from depth to the surface2. According to the team, storminess increased in the region because the jet stream moved northward2. As a result, there are more frequent and more intense storms in this region2. The increase in storminess creates a stron
ger heat loss from the ocean and induces stronger convection in winter, leading to cooler temperatures in the region2.
>
> Learn more:
> 1. en.wikipedia.org
> 2. phys.org
> 3. carbonbrief.org
> 4. psu.edu
> 5. severe-weather.eu
> 6. sciencedaily.com
> +2 more"
>
> My explanation for the cold blob was it was caused by melting Arctic sea ice, or melting Greenland ice which being fresh water would be lighter than sea water and float on the surface. Bing agreed, but did not point out that with the increase in SSTs, See https://www.bbc.co.uk/news/science-environment-66387537 that perhaps the Greenland ice melt is no longer less denser than North Atlantic sea water.
>
> What do you think?
>

At least not a story about Mr Blobby having to put on an extra jumper

I would be interested to find its take on what has caused the recent
rise, since about 2020, in mean sea levels around the UK, well above
global sea level rise.
All UK ports are showing vertical displacemets of the tide gauge
readings about 0.15m or so above predictions.
eg for Newlyn , but pick any of the UK ports and much the same
https://ntslf.org/storm-surges/latest-surge-forecast?port=Newlyn&chrt=3
the red line should on average track the blue line.

None of the academic experts on mean sea level have got back to me with
any sort of redponse. It would be easy to say the uderlying tide-curve
predictions are wrong, but 2 other independent tide-curve analyses agree
with this displacement of about 0.15m

--
Global sea level rise to 2100 from curve-fitted existing altimetry data
<http://diverse.4mg.com/slr.htm>

> I would be interested to find its take on what has caused the recent
rise, since about 2020, in mean sea levels around the UK, well above
global sea level rise.

I think that is its own topic, not obviously related to the cold blob
(is it???), and really needs its own thread.

The cold blob is interesting to me at least, as apparently the only area
of the world's oceans to show consistent cooling over in recent years.
And, given its relative proximity to the UK, presumably it will have
some impact on UK weather, despite global warming in general.

The main theory nowadays for the cold blob seems to be a slowing of AMOC
rather than Greenland icecap melt. But whatever the cause it does seem
to be an interesting and relevant phenomenon to UK weather.

On 26/08/2023 19:28, JohnD wrote:
> > I would be interested to find its take on what has caused the recent
> rise, since about 2020, in mean sea levels around the UK, well above
> global sea level rise.
>
>
> I think that is its own topic, not obviously related to the cold blob
> (is it???), and really needs its own thread.
>
> The cold blob is interesting to me at least, as apparently the only area
> of the world's oceans to show consistent cooling over in recent years.
> And, given its relative proximity to the UK, presumably it will have
> some impact on UK weather, despite global warming in general.
>
> The main theory nowadays for the cold blob seems to be a slowing of AMOC
> rather than Greenland icecap melt. But whatever the cause it does seem
> to be an interesting and relevant phenomenon to UK weather.

The slowing of AMOC , build up of water in the NE Atlantic unable to
return at depth southwards, is the theory I was going with to explain
the anomalous UK MSL rise.
Others are increased local SLR due to increased isostatic land sink, due to
increased weight of water around the UK from ordinary SLR, perhaps
evidensed by less anomalous MSL around Scotland.
Delayed response to abstraction of oil from the North Sea causing land
sink again.
Unfortunately despite the much trumpeted dGPS , perhaps not reliable for
c0.1m z-axis measurement.
Increased temp at depth so steric rise in sea level .

--
Global sea level rise to 2100 from curve-fitted existing altimetry data
<http://diverse.4mg.com/slr.htm

On 26/08/2023 09:34, N_Cook wrote:
> On 25/08/2023 13:34, JohnD wrote:
>> Are there any (educated) opinions here about the likely evolution of the
>> cold blob (in the N Atlantic) in the next say 10-50 years. And likely
>> impact on UK weather?
>
> I canot find ref now, but I posted here perhaps 8 years ago details.
> An academic pdf, having analysed uk headed Atlantic storms , high
> correlation with a cold spot south of Greenland, probably not stated by
> them as "cold blob" for more/stronger? storms. Also E-W/W-E SST gradient
> and readings a month earlier correlations as well. In the end not much
> use for predictions of individual storms.
>
>

that paper is

<https://www.researchgate.net/profile/Conor_Graham/publication/253247101_Storminess_and_Surges_in_the_South-Western_Approaches_Eastern_Atlantic_the_Synoptic_Climatology_of_Recent_Extreme_Coastal_Storms/links/57975d4d08aec89db7b99f64/Storminess-and-Surges-in-the-South-Western-Approaches-Eastern-Atlantic-the-Synoptic-Climatology-of-Recent-Extreme-Coastal-Storms.pdf>

--
Global sea level rise to 2100 from curve-fitted existing altimetry data
<http://diverse.4mg.com/slr.htm>

On 26/08/2023 21:24, N_Cook wrote:
> The slowing of AMOC , build up of water in the NE Atlantic unable to
> return at depth southwards, is the theory I was going with to explain
> the anomalous UK MSL rise.
> Others are increased local SLR due to increased isostatic land sink, due to
> increased weight of water around the UK from ordinary SLR, perhaps
> evidensed by less anomalous MSL around Scotland.
> Delayed response to abstraction of oil from the North Sea causing land
> sink again.
> Unfortunately despite the much trumpeted dGPS , perhaps not reliable for
> c0.1m z-axis measurement.
> Increased temp at depth so steric rise in sea level .

the other is change in surface currents near the UK, relating to AMOC
slow down

--
Global sea level rise to 2100 from curve-fitted existing altimetry data
<http://diverse.4mg.com/slr.htm>

On 25/08/2023 13:34, JohnD wrote:
> Are there any (educated) opinions here about the likely evolution of the
> cold blob (in the N Atlantic) in the next say 10-50 years. And likely
> impact on UK weather?

some useful stuff on
https://www.realclimate.org/index.php/archives/2023/08/the-amoc-tipping-this-century-or-not/

--
Global sea level rise to 2100 from curve-fitted existing altimetry data
<http://diverse.4mg.com/slr.htm>

On Wednesday, 30 August 2023 at 14:55:00 UTC+1, N_Cook wrote:
> On 25/08/2023 13:34, JohnD wrote:
> > Are there any (educated) opinions here about the likely evolution of the
> > cold blob (in the N Atlantic) in the next say 10-50 years. And likely
> > impact on UK weather?
> some useful stuff on
> https://www.realclimate.org/index.php/archives/2023/08/the-amoc-tipping-this-century-or-not/
> --
> Global sea level rise to 2100 from curve-fitted existing altimetry data
> <http://diverse.4mg.com/slr.htm>
There is another long read here https://www.geochemicalperspectives.org/wp-content/uploads/GPv1n2.pdf byWally Broecker, the oceanographer who first proposed that the AMOC switches. In the section CRYING WOLF, p. 283 he says “As time went on it became ever clearer that global warming would lead to a conveyor shutdown was quite small.” He writes that Denton has the same idea as me. That it is large changes in the area of Arctic sea ice which affect north western European climate.