Cooler Atlantic

[northwestsnow]

Anyone have any thoughts on the Atlantic sst pattern for May? I believe ukmo factor this in for their winter thoughts..

[Mike Poole]

4 hours ago, northwestsnow said:

Anyone have any thoughts on the Atlantic sst pattern for May? I believe ukmo factor this in for their winter thoughts..

UKMO say in their contingency planners forecast for May-July:

'Meanwhile, in the North Atlantic Ocean, the current pattern of sea surface temperatures (SSTs) moderately increases the chances of higher-than-average pressure across Northern Europe. During spring and early summer, high pressure is usually associated with warmer than-average conditions. In addition, SSTs close to the UK are currently higher than normal, which also increases the chances of above-average temperatures.'

Current SST anomaly:

I think we just need the after effects of the stratosphere final warming to dissipate, and then this influence should become stronger.

[JeffC]

14 hours ago, northwestsnow said:

Anyone have any thoughts on the Atlantic sst pattern for May? I believe ukmo factor this in for their winter thoughts..

Looking at this, doesn't look like a triple, all looks averagely cool with some warmer areas. Not convinced by the contingency planners report...not that much warmer anomaly wise...

https://earth.nullschool.net/#current/ocean/primary/waves/overlay=sea_surface_temp_anomaly/orthographic=-359.33,62.45,1068

 

 

[Catacol]

Seems like the right thread for this musing...

Tropical atlantic SSTs have gone cold at the moment around the western edge of Africa. 

In many years on this forum and others I have rarely seen much discussion of the impact of tropical atlantic temperatures. Is there anyone out there with papers or thoughts as to potential impacts in the north atlantic basin? 

[karyo]

On 24/06/2019 at 22:12, Catacol said:

Seems like the right thread for this musing...

Tropical atlantic SSTs have gone cold at the moment around the western edge of Africa. 

In many years on this forum and others I have rarely seen much discussion of the impact of tropical atlantic temperatures. Is there anyone out there with papers or thoughts as to potential impacts in the north atlantic basin? 

This cold anomaly can suppress the development of tropical storms and hurricanes 

[weirpig]

On 24/06/2019 at 22:12, Catacol said:

Seems like the right thread for this musing...

Tropical atlantic SSTs have gone cold at the moment around the western edge of Africa. 

In many years on this forum and others I have rarely seen much discussion of the impact of tropical atlantic temperatures. Is there anyone out there with papers or thoughts as to potential impacts in the north atlantic basin? 

Dont know if this helps   howver it is interesting

69914.pdf

[Catacol]

12 hours ago, weirpig said:

Dont know if this helps   howver it is interesting

69914.pdf 1.29 MB · 7 downloads

Thanks - yes - interesting. Not quite sure how well reviewed that paper is, but if the conclusions are correct then it would certainly lend support to the high pressure dominated summer at the moment over western and central Europe. Less impact directly over the UK, but if the monsoon tracks north then the sub tropical high tracks north with it - and that means a predisposition to warm and dry weather. Fans of hot and dry summer weather won't be sad therefore to see the Gulf of Guinea cold.

Will watch this through the summer - interesting observational exercise.

[Blessed Weather]

On 24/06/2019 at 22:12, Catacol said:

Seems like the right thread for this musing...

Tropical atlantic SSTs have gone cold at the moment around the western edge of Africa. 

In many years on this forum and others I have rarely seen much discussion of the impact of tropical atlantic temperatures. Is there anyone out there with papers or thoughts as to potential impacts in the north atlantic basin? 

Looking at some of the papers in the Netweather Research library, the SST pattern you show indicates that the Atlantic Meridional Mode (AMM) and the Atlantic Meridional Oscillation (AMO), influenced by the ENSO state and strength of the Atlantic Meridional Overturning Circulation (AMOC), may be behind the changes to Tropical Atlantic SST. Probably the best read is the 2016 paper Is There Evidence of Changes in Tropical Atlantic Variability Modes under AMO Phases in the Observational Record? Interestingly, the AMO, after being positive since 1995, has recently slipped slightly negative and is currently bouncing along close to neutral.

1985 - 2019  2017-2019

Source: https://stateoftheocean.osmc.noaa.gov/atm/amo.php

The above paper states:

"During negative AMO, the tropical–extratropical teleconnections are enhanced and the Walker circulation is altered. This, together with the increased equatorial SST variability, could promote the ENSO impacts on Tropical Atlantic Variability."

And includes the following charts:

AMO Positive:  AMO Negative:

And the impacts? There's plenty of research that shows a regional rainfall/drought impact, and as mentioned in previous posts, on levels of Atlantic Hurricane activity. This webpage from NOAA provides a great summary of the impact of AMO modes:

https://www.aoml.noaa.gov/phod/amo_faq.php

Hope that helps.

[Catacol]

13 hours ago, Blessed Weather said:

Looking at some of the papers in the Netweather Research library, the SST pattern you show indicates that the Atlantic Meridional Mode (AMM) and the Atlantic Meridional Oscillation (AMO), influenced by the ENSO state and strength of the Atlantic Meridional Overturning Circulation (AMOC), may be behind the changes to Tropical Atlantic SST. Probably the best read is the 2016 paper Is There Evidence of Changes in Tropical Atlantic Variability Modes under AMO Phases in the Observational Record? Interestingly, the AMO, after being positive since 1995, has recently slipped slightly negative and is currently bouncing along close to neutral.

1985 - 2019  2017-2019

Source: https://stateoftheocean.osmc.noaa.gov/atm/amo.php

The above paper states:

"During negative AMO, the tropical–extratropical teleconnections are enhanced and the Walker circulation is altered. This, together with the increased equatorial SST variability, could promote the ENSO impacts on Tropical Atlantic Variability."

And includes the following charts:

AMO Positive:  AMO Negative:

And the impacts? There's plenty of research that shows a regional rainfall/drought impact, and as mentioned in previous posts, on levels of Atlantic Hurricane activity. This webpage from NOAA provides a great summary of the impact of AMO modes:

https://www.aoml.noaa.gov/phod/amo_faq.php

Hope that helps.

Thanks Malcolm - appreciated. More knowledge to accrue....

 

 

[Midlands Ice Age]

On 24/06/2019 at 22:12, Catacol said:

Seems like the right thread for this musing...

Tropical atlantic SSTs have gone cold at the moment around the western edge of Africa. 

In many years on this forum and others I have rarely seen much discussion of the impact of tropical atlantic temperatures. Is there anyone out there with papers or thoughts as to potential impacts in the north atlantic basin? 

Catacol...

Also in the above chart notice that the Southern Hemisphere SST's have now turned negative, particularly in the Pacific.Todays Climate Reanalyser is still very much the same.

 

This now seems to be pushing the EL Nino very much towards the West.

Latest 3.4 chart is falling very rapidly.

 

 

Probably should have put this post in the ENSO thread, but I was quite surprised by your SST post above.

MIA

Edited June 28, 2019 by Midlands Ice Age

[summer blizzard]

Not quite perfect in the Tropics but the current chart shows a stonker of a -NAO Tripole.

[jules216]

10 hours ago, summer blizzard said:

Not quite perfect in the Tropics but the current chart shows a stonker of a -NAO Tripole.

yes,was reading through some research papers earlier today,might also be a lagged response to solar minimum, lets hope it stays that way for a while https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/grl.50099

[Yarmy]

Ocean circulation causes the largest freshening event for 120 years in

WWW.NATURE.COM

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The Atlantic Ocean overturning circulation is important to the global climate system. Here the authors show that eastern subpolar North Atlantic underwent extreme freshening during 2012 to 2016, with a...

 

[Kirkcaldy Weather]

Was looking for a thread on the gulf stream and it was linked to this thread so hopefully the best place to discuss this interesting development, this tweet has a thread worth looking at 

And here's the official tweet with the link to the report 

 

[ICE COLD]

39 minutes ago, Kirkcaldy Weather said:

Was looking for a thread on the gulf stream and it was linked to this thread so hopefully the best place to discuss this interesting development, this tweet has a thread worth looking at 

And here's the official tweet with the link to the report 

 

I was just reading the article on it on sky news . Let’s hope the research is right and what they predict for are winters . Extreme winters would be brilliant for the UK and NW Europe

[bluearmy]

On 25/02/2021 at 22:16, ICE COLD said:

I was just reading the article on it on sky news . Let’s hope the research is right and what they predict for are winters . Extreme winters would be brilliant for the UK and NW Europe

That depends what you think is behind the whole thing ?  my take is that this research confirms that the planet will attempt to deal with AGW with its own recovery systems ...... but I worry that if we don’t try and control our input effectively then the planet may pass the tipping point of dealing with it within what we would consider to be ‘reasonable climatic responses’ .....  probably for another thread .......

[ICE COLD]

1 hour ago, bluearmy said:

That depends what you think is behind the whole thing ?  my take is that this research confirms that the planet will attempt to deal with AGW with its own recovery systems ...... but I worry that if we don’t try and control our input effectively then the planet may pass the tipping point of dealing with it within what we would consider to be ‘reasonable climatic responses’ .....  probably for another thread .......

Oh yes absolutely Nick , it’s most probably a GW influence. I just thought it was interesting with the Gulf Stream it’s slowest for 1000 years and the extreme winters for NW Europe bit . Let’s hope the planet does start to deal with GW in its own way ( but it will definitely need a big hand from us humans) . Sad times for a lot of wild life around the world and will most definitely start effecting humans too . (Some it already has) . Obviously I hope GW doesn’t get worse but if it does I just hope we get put in a cycle of having cold winters and not warm ones and most definitely not scorching summers ( can’t stand extreme heat ) .

[Methuselah]

49 minutes ago, ICE COLD said:

Oh yes absolutely Nick , it’s most probably a GW influence. I just thought it was interesting with the Gulf Stream it’s slowest for 1000 years and the extreme winters for NW Europe bit . Let’s hope the planet does start to deal with GW in its own way ( but it will definitely need a big hand from us humans) . Sad times for a lot of wild life around the world and will most definitely start effecting humans too . (Some it already has) . Obviously I hope GW doesn’t get worse but if it does I just hope we get put in a cycle of having cold winters and not warm ones and most definitely not scorching summers ( can’t stand extreme heat ) .

Possibly, IC. But I'm not so sure -- there was no meaningful AGW 120-years' back, and the AMOC takes longer than 120 years to circulate?

Edited February 27, 2021 by General Cluster

[ICE COLD]

39 minutes ago, General Cluster said:

Possibly, IC. But I'm not so sure -- there was no meaningful AGW 120-years' back; and the AMOC takes longer than 120-years to circulate?

Yes I’m just speculating Ed . Just chasing one of them dream winters you’ve lived through ( not saying your old or anything ) . I’ll just keep on waiting , bit like Spurs waiting for a trophy let’s just hope one turns up ( the cold winter that is )

[Don]

2 hours ago, bluearmy said:

That depends what you think is behind the whole thing ?  my take is that this research confirms that the planet will attempt to deal with AGW with its own recovery systems ...... but I worry that if we don’t try and control our input effectively then the planet may pass the tipping point of dealing with it within what we would consider to be ‘reasonable climatic responses’ .....  probably for another thread .......

I think although the Metoffice agree the Gulf stream will weaken/shut down eventually, they currently believe by the time it does, GW will be too far advanced for it to really affect north west Europe?  And yes, Humans need to play their part, no matter what happens!

Edited February 27, 2021 by Don

[pinball wizard]

Interesting reading about the gulf stream changes, this paper here may be of further interest to some:

https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.2907

Web results

The Gulf Stream influence on wintertime North Atlantic jet variability

Edited February 27, 2021 by pinball wizard

[Blessed Weather]

Worrying signs of a possible collapse of the AMOC in a study by the Potsdam Institute for Climate Impact Research, Germany. Extracts from the Guardian article below, but the full story is also available free-to-view on French website FR24 here.

Climate crisis: Scientists spot warning signs of Gulf Stream collapse

Climate scientists have detected warning signs of the collapse of the Gulf Stream, one of the planet’s main potential tipping points.
The currents are already at their slowest point in at least 1,600 years, but the new analysis shows they may be nearing a shutdown.
The complexity of the AMOC system and uncertainty over levels of future global heating make it impossible to forecast the date of any collapse for now. It could be within a decade or two, or several centuries away. But the colossal impact it would have means it must never be allowed to happen, the scientists said.

Source (paywalled): https://www.theguardian.com/environment/2021/aug/05/climate-crisis-scientists-spot-warning-signs-of-gulf-stream-collapse

[Polar.]

I believe I read before that the Gulf stream keeps London 5c warmer during Winter. Anyone have any estimates on how warmer it keeps the UK during Winter?

If it did collapse and was replaced by a cool water current I think we'd be one of the snowiest locations in the world. Like Northern Japan or Newfoundland.

Edited August 5, 2021 by Polar.

[Cheshire Freeze]

How do they expect to stop it from stopping? Probably baked in now and is quite possibly one of the many natural triggers for an ice age.

Edited August 5, 2021 by CreweCold

[Derecho]

48 minutes ago, CreweCold said:

How do they expect to stop it from stopping? Probably baked in now and is quite possibly one of the many natural triggers for an ice age.

Is it natural though? and would it cause a collapse? It's a highly disputed area of research and the other question is that if it does collapse, what sort of timescale would that be? It is IMO the most fascinating area of climate research currently. In terms of how they expect to stop it, well a key contributor is ice melt from the Arctic and Antarctic feeding into the oceans and reducing global salinity.

If the unthinkable were to happen here is what some of the projected temperature changes solely based on this event (so not accounting for greenhouse gases or multidecadal variability):

Which makes sense given a huge conveyer belt of heat is no longer being carried up into mid latitudes of the northern hemisphere anymore. This article covers the topic really well:
 

Guest post: Could the Atlantic Overturning Circulation ‘shut down’? | Carbon Brief

WWW.CARBONBRIEF.ORG

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Generally, we think of climate change as a gradual process: the more greenhouse gases that humans emit, the more the climate will change. But are there any “points of no return” that commit us to irreversible...

 

Some key quotes:

"The figure above illustrates the changes that result in one such experiment. Shutdown of the AMOC results in a cooling (blue shading) of the whole northern hemisphere, particularly the regions closest to the zone of North Atlantic heat loss (the “radiator” of the North Atlantic central heating system). In these regions the cooling exceeds the projected warming due to greenhouse gases, so a complete shutdown in the 21st century, while very unlikely, could result in a net cooling in regions such as western Europe."

"Other impacts include major shifts in rainfall patterns, increases in winter storms over Europe and a sea level rise of up to 50cm around the North Atlantic basin. In many regions these effects would exacerbate the trends due to global warming"

Overall we would be going into a complete unknown given an AMOC shift would occur under a warming climate but we can assume that many northern hemisphere areas would recieve a negative feedback in that warming may be reduced to an extent. In western Europe for example the cooling signal from the collapse of the AMOC would outweigh global temperature increases.

Meanwhile in the southern hemisphere, it would be a positive feedback mechanism, meaning that the warming signal would be enhanced further.

The AMOC is a moderator of global temperatures, it oscillates like an elastic band... but once that band snaps we enter a new climate state where atmospheric circulation is greatly altered.

There would still be an impact from CO2 causing a warming effect, as atmospheric circulation simply represents a distribution of heat. 

I expect the drop in winter temperatures across the northern hemisphere would be staggering if the AMOC went into full blown collapse. It would be catastrophic. Summers I believe could turn even warmer across many areas of the northern hemisphere. Winters and perhaps into much of Autumn and Spring would be far far colder that would far outweigh it, as the moderating influence of the Gulf Stream is taken away. It would be seasonal climate variability on steroids. 

Edited August 5, 2021 by Quicksilver1989