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Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

Any updates?

With another excessive melt season underway I expect to see those cold anomalies persist if not intensify over the coming weeks and months.

 

Karyo

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Posted
  • Location: Camborne
  • Location: Camborne
1 hour ago, karyo said:

Any updates?

With another excessive melt season underway I expect to see those cold anomalies persist if not intensify over the coming weeks and months.

 

Karyo

That rather depends on where the melt water originates and where it ends up.

Oceanic transport of surface meltwater from the southern Greenland ice sheet

Quote

The Greenland ice sheet has undergone accelerating mass losses during recent decades. Freshwater runoff from ice melt can influence fjord circulation and dynamics1 and the delivery of bioavailable micronutrients to the ocean2. It can also have climate implications, because stratification in the adjacent Labrador Sea may influence deep convection and the strength of the Atlantic meridional overturning circulation3. Yet, the fate of the meltwater in the ocean remains unclear. Here, we use a high-resolution ocean model to show that only 1–15% of the surface meltwater runoff originating from southwest Greenland is transported westwards. In contrast, up to 50–60% of the meltwater runoff originating from southeast Greenland is transported westwards into the northern Labrador Sea, leading to significant salinity and stratification anomalies far from the coast. Doubling meltwater runoff, as predicted in future climate scenarios, results in a more-than-double increase in anomalies offshore that persists further into the winter. Interannual variability in offshore export of meltwater is tightly related to variability in wind forcing. The new insight that meltwaters originating from the west and east coasts have different fates indicates that future changes in mass loss rates and surface runoff will probably impact the ocean differently, depending on their Greenland origins.

http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2708.html

Article

Researchers discover fate of melting glacial ice in Greenland

http://www.eurekalert.org/pub_releases/2016-04/uog-rdf042516.php

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Posted
  • Location: Near King's Lynn 13.68m ASL
  • Weather Preferences: Hoar Frost, Snow, Misty Autumn mornings
  • Location: Near King's Lynn 13.68m ASL

A new paper in Science 'New scrutiny for a slowing Atlantic conveyor'.

http://science.sciencemag.org/content/352/6287/751.full

It's behind a paywall, but there's some info here:

https://news.mongabay.com/2016/05/scientists-concerned-slowing-atlantic-conveyor-warn-abrupt-climate-change/

 

 

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  • 2 weeks later...
Posted
  • Location: Camborne
  • Location: Camborne

A reversal of climatic trends in the North Atlantic since 2005

Quote

In the mid-1990s the North Atlantic subpolar gyre warmed rapidly1, which had important climate impacts such as increased hurricane numbers2 and changes to rainfall over Africa, Europe and North America3, 4. Evidence suggests that the warming was largely due to a strengthening of the ocean circulation, particularly the Atlantic Meridional Overturning Circulation1, 5, 6, 7. Since the mid-1990s direct and indirect measurements have suggested a decline in the strength of the ocean circulation8, 9, which is expected to lead to a reduction in northward heat transport10, 11. Here we show that since 2005 a large volume of the upper North Atlantic Ocean has cooled significantly by approximately 0.45 °C or 1.5 × 1022 J, reversing the previous warming trend. By analysing observations and a state-of-the-art climate model, we show that this cooling is consistent with a reduction in the strength of the ocean circulation and heat transport, linked to record low densities in the deep Labrador Sea9. The low density in the deep Labrador Sea is primarily due to deep ocean warming since 1995, but a long-term freshening also played a role. The observed upper ocean cooling since 2005 is not consistent with the hypothesis that anthropogenic aerosols directly drive Atlantic temperatures12.

http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2727.html

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Posted
  • Location: Surrey and SW France.
  • Location: Surrey and SW France.

Thanks, @knocker

There is a presentation PDF for the above link; gives a bit more info with illustrations.

http://indico.ictp.it/event/a14266/session/96/contribution/530/material/slides/0.pdf

Further cooling expected, I see. This would tie in with the resurfacing of the cold pool anomaly in the seasonal modelling for later in the year. I wonder if the current summer pattern will allow for as much warming out as the models currently suggest.

 

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  • 3 weeks later...
Posted
  • Location: Near King's Lynn 13.68m ASL
  • Weather Preferences: Hoar Frost, Snow, Misty Autumn mornings
  • Location: Near King's Lynn 13.68m ASL

An update of the charts that Nouska posted way back in the thread:

ArgoTimeSeriesTemp59N.GIF

OceanTemp0-800mDepthAt59Nand30-0W.gif

 

The contrast with the world's oceans overall is stark:

World3monthTemperatureSince1955Depth0-70

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Posted
  • Location: Kensington
  • Location: Kensington

There are more and more warnings regarding the cold atlantic blob  and the possible slow down of the gulf stream  all of which point to rising sea levels and colder winters espicially in countries bordering the north atlantic  whatever you believe the climate is changing.

https://news.mongabay.com/2016/05/scientists-concerned-slowing-atlantic-conveyor-warn-abrupt-climate-change/

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Posted
  • Location: Medlock Valley, Oldham, 103 metres/337 feet ASL
  • Weather Preferences: Cold, snow, thunderstorms, warm summers not too hot.
  • Location: Medlock Valley, Oldham, 103 metres/337 feet ASL
5 hours ago, weirpig said:

There are more and more warnings regarding the cold atlantic blob  and the possible slow down of the gulf stream  all of which point to rising sea levels and colder winters espicially in countries bordering the north atlantic  whatever you believe the climate is changing.

https://news.mongabay.com/2016/05/scientists-concerned-slowing-atlantic-conveyor-warn-abrupt-climate-change/

Interesting. That article says we could cool as much as 5C. I'm not an expert on climate change etc but I'm guessing that means a 5C cooling of average temps? if so we could end up slightly colder than New York City in the Winter. But not quite as cold as Chicago. Sort of a Winter blended with both which would be interesting and well....bloody cold at times.

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Posted
  • Location: Nelson, Caerphilly County, 175m ASL
  • Location: Nelson, Caerphilly County, 175m ASL
12 hours ago, Frost HoIIow said:

Interesting. That article says we could cool as much as 5C. I'm not an expert on climate change etc but I'm guessing that means a 5C cooling of average temps? if so we could end up slightly colder than New York City in the Winter. But not quite as cold as Chicago. Sort of a Winter blended with both which would be interesting and well....bloody cold at times.

The most extreme impact of a large scale NAD slowdown wouldn't necessarily be the drop in average temperatures (although that would be very significant): it would be how much snowier our winters would become, possibly akin to Hokkaido or Newfoundland, given that while a weakened NAD would bring less heat to our shores, it wouldn't impact on available moisture.

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Posted
  • Location: Ouse Valley, N. Bedfordshire. 48m asl.
  • Location: Ouse Valley, N. Bedfordshire. 48m asl.

Would it really though? We'd still get predominately west and south west winds, and the average air temps that feeds from will still be higher. 

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Posted
  • Location: Nelson, Caerphilly County, 175m ASL
  • Location: Nelson, Caerphilly County, 175m ASL

Well, possibly. It's all conjecture at this stage, but current climate knowledge (and logic!) would suggest that a weaker or diverted NAD would increase likelihood of blocking and, as we've seen in the last three winters (mostly in the north and west), an increased potential for PM outbreaks. Perhaps I was using hyperbole with my Newfoundland/Hokkaido comparison but given the predominantly cool and wet winters we normally experience, it wouldn't take much of a temperature drop to turn "cool and wet" into "cold and snowy". 

Conversely, our winters could become stormier: two of the last three, I think we'll all agree, have been rather on the stormy side, and these have coincided with the pronounced cooling of the North Atlantic.

We're at such an early stage in our understanding of AMOC that all we can do at the moment is hypothesise, similar (in a separate but related (in terms how of they affect our climate) example) to our understanding of sunspot activity.

Edited by Jackfrost
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Posted
  • Location: Yorkshire Puddin' aka Kirkham, Lancashire, England, United Kingdom
  • Weather Preferences: cold winters, cold springs, cold summers and cold autumns
  • Location: Yorkshire Puddin' aka Kirkham, Lancashire, England, United Kingdom

It depends on what landmass is most affected by the cooling Atlantic.  Because the cold pool is nearer to Greenland, the Polar Vortex and cold air has been confined to Greenland which in turn has made our winters milder and stormier than ever before.  However if the Atlantic cold pool displaces or extends towards Scandinavia, the Polar Vortex and cold air will centre over there which will make our winters colder and snowy.

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Posted
  • Location: Medlock Valley, Oldham, 103 metres/337 feet ASL
  • Weather Preferences: Cold, snow, thunderstorms, warm summers not too hot.
  • Location: Medlock Valley, Oldham, 103 metres/337 feet ASL
12 hours ago, Jackfrost said:

The most extreme impact of a large scale NAD slowdown wouldn't necessarily be the drop in average temperatures (although that would be very significant): it would be how much snowier our winters would become, possibly akin to Hokkaido or Newfoundland, given that while a weakened NAD would bring less heat to our shores, it wouldn't impact on available moisture.

Thanks for the reply, sounds pretty good. As we have seen in the past & more recently in 2009/2010 etc the seas around us can be good snow making machines giving those fantastic snow streamers.

Edited by Frost HoIIow
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Posted
  • Location: Surrey and SW France.
  • Location: Surrey and SW France.

Some brand new research on this very subject.

http://science.sciencemag.org/content/early/2016/06/30/science.aaf5529

An article to go with it as paywalled.

http://www.earthinstitute.columbia.edu/articles/view/3335

This quote is interesting and makes me wonder what the drives the current to slow/almost stop as the scenario described does not seem to allow for an influx of melt water from loss of Arctic ice.

There was a period during the last ice age when temperatures in the Northern Hemisphere went on a rollercoaster ride, plummeting and then rising again every 1,500 years or so. Those abrupt climate changes wreaked havoc on ecosystems, but their cause has been something of a mystery. New evidence published this week in the leading journal Science shows for the first time that the ocean’s overturning circulation slowed during every one of those temperature plunges – at times almost stopping.

 

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Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)
18 minutes ago, bobbydog said:

the cold blob is even closer to our shores...

anomnight.7.7.2016.gif

Has it lost intensity? It only looks slightly below average to me.

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Posted
  • Location: Horsham, West sussex, 52m asl
  • Location: Horsham, West sussex, 52m asl
2 minutes ago, karyo said:

Has it lost intensity? It only looks slightly below average to me.

i think there is a lot of variation in intensity, even day to day. here's two examples from the start and middle of june-

anomnight.6.2.2016.gifanomnight.6.16.2016.gif

however the general area seems to be moving eastwards.

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Posted
  • Location: Camborne
  • Location: Camborne

A Tale of Two Blobs Part II: The cold blob of the North Atlantic

Published on Jun 10, 2016

From 2013 to 2015, the scientific community and the media were enthralled with two anomalous sea surface temperature events, both getting the moniker the “Blob,” although one was warm and one was cold. These events occurred during a period of record-setting global mean surface temperatures. In this webinar, researchers focus on the timing and extent, possible mechanisms, and impacts of these unusual ocean temperature anomalies, and what we might expect in the future as climate changes.

 

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  • 2 weeks later...
Posted
  • Location: 4 miles north of Durham City
  • Location: 4 miles north of Durham City
On 7/9/2016 at 07:53, Lettucing Gutted said:

It depends on what landmass is most affected by the cooling Atlantic.  Because the cold pool is nearer to Greenland, the Polar Vortex and cold air has been confined to Greenland which in turn has made our winters milder and stormier than ever before.  However if the Atlantic cold pool displaces or extends towards Scandinavia, the Polar Vortex and cold air will centre over there which will make our winters colder and snowy.

 

Are the dynamic relationships really that simple? I'm not sure.

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Posted
  • Location: Yorkshire Puddin' aka Kirkham, Lancashire, England, United Kingdom
  • Weather Preferences: cold winters, cold springs, cold summers and cold autumns
  • Location: Yorkshire Puddin' aka Kirkham, Lancashire, England, United Kingdom
On ‎27‎/‎07‎/‎2016 at 11:03, PersianPaladin said:

 

Are the dynamic relationships really that simple? I'm not sure.

I agree that other factors have played a key role in the very mild and stormy yet amplified patterns of 2013 through 2016 such as the Hyper Nino, Positive Pacific North America pattern, Positive Pacific Decadal Oscillation pattern, Arctic Ice melt, Stratospheric Cooling, Westerly QBO phase, and the exceptional European Heatwaves.  However there is a very strong positive correlation between SSTs around southern Greenland/Labrador and the 500 hPa height anomalies over the same locations with cold water driving a powerful Greenland Polar Vortex/Trough and Positive NAO and Positive AO pattern whilst warm waters in the same locations help create or reinforce Northern Blocking over Greenland thus driving a Negative NAO and Negative AO pattern.  Years back I remember Steve Murr and Summer Blizzard discussing at great lengths the links between SSTs and upper level patterns.

Edited by Lettucing Gutted
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  • 1 month later...
Posted
  • Location: Camborne
  • Location: Camborne

Scientists are closely monitoring a key current in the North Atlantic to see if rising sea temperatures and increased freshwater from melting ice are altering the “ocean conveyor belt” — a vast oceanic stream that plays a major role in the global climate system.

Quote

Susan Lozier is having a busy year. From May to September, her oceanographic team is making five research cruises across the North Atlantic, hauling up dozens of moored instruments that track currents far beneath the surface. The data they retrieve will be the first complete set documenting how North Atlantic waters are shifting — and should help solve the mystery of whether there is a long-term slowdown in ocean circulation. “We have a lot of people very interested in the data,” says Lozier, a physical oceanographer at Duke University.

http://e360.yale.edu/feature/will_climate_change_jam_the_global_ocean_conveyor_belt/3030/#.V9AHXUhF_2I.twitter

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Posted
  • Location: Manchester
  • Location: Manchester

I haven't looked for a while but the cold pool certainly seems to have shrunk and fragmented a fair bit recently- here is the latest image. The SSTs immediately around our shores seem to be above average and the main section of the cold pool seems to be further west than before.

 anomnight.9.8.2016.gif

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