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Really like what you have done with a home based computer.

Once upon a time far in the distant past I was an Oceanographer, so I can appreciate how much time and effort you have put into completing this task.

 

Watching the SST closely and awaiting the results from Rapid's latest sail.

Interesting and uncertain times ahead.

 

Indeed!..... will look forward to your professional take on this.

 

It's a long way ahead but the JAMSTEC (Japanese ocean research institute) modelling, for next summer, has not read the script about Atlantic cold anomalies dissipating. That's still a big cold pool in situ and it appears the effects are being seen across more of the adjacent land area temperatures.

 

l2968na.gif   82jEhre.gif

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So, have you ever wondered how exactly would N Atlantic look like if you would pump out all the water? Well, its one big mountain range (MAR - Mid Atlantic Ridge). It gives you a feeling and a differe

Yeah, I think that's quite a disingenuous chart (no reflection on yourself , of course!).   If we look at the months used in that chart, and the 9 months leading up to them, we get the following:  

The 13 hours later this arrived..   Many thanks for your enquiry regarding North Atlantic sea surface temperatures. I have spoken to the relevant scientists within the Met Office Hadley Centre who h

Posted Images

Indeed!..... will look forward to your professional take on this.

 

It's a long way ahead but the JAMSTEC (Japanese ocean research institute) modelling, for next summer, has not read the script about Atlantic cold anomalies dissipating. That's still a big cold pool in situ and it appears the effects are being seen across more of the adjacent land area temperatures.

  

 

Very interesting Nouska. So JAMSTEC are forecasting that (like this year) the SST anomaly of the cold pool remains negative through the summer months. And the land temps suggest (again like this year) that the UK monthly mean temps are likely to be below the CET throughout the summer months. If these conditions do indeed continue through a second year, to me it starts to hint that the slow-down of the AMOC could be starting to impact regional climate?

 

As moorlander said above, "interesting and uncertain times ahead".

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Very interesting Nouska. So JAMSTEC are forecasting that (like this year) the SST anomaly of the cold pool remains negative through the summer months. And the land temps suggest (again like this year) that the UK monthly mean temps are likely to be below the CET throughout the summer months. If these conditions do indeed continue through a second year, to me it starts to hint that the slow-down of the AMOC could be starting to impact regional climate?

 

As moorlander said above, "interesting and uncertain times ahead".

 

While the new RAPID data for the past 18 months will certainly be interesting, at this point too much is being read into the current figures.

As the RAPID team point out - When a time-series is too short, it is not possible to distinguish between a long-term trend and decadal variablity - periodic fluctuations that occur over time scales of decades. The RAPID time-series of AMOC flow is not long enough yet to make this distinction

The MOCHA site suggests 30% reduction as occurred in 2009/10 was within the expected modeled interdecadal variation - it was largely due to anomalous Ekman transport i.e. the atmosphere leading the ocean.

Then has been pointed out by a few here, this is at 26°N, not that this is insignificant but this is within the subtropical gyre whilst the cool pool is in the subpolar gyre and the links between the two are complex and the effects different - this point and the short timeseries are both acknowledged by Rahmstorf et al. -

Recent oceanographic measurements from the RAPID array at 26°N in the Atlantic suggest that the AMOC has been weakening again since these measurements started in 2004 (ref. 39), although we cannot conclude to what extent this temporary decrease signals a progressive trend, and the connection between subtropical and subpolar overturning, especially on shorter timescales, is not clear

In both regions the effect of gyre transport - again atmosphere led - has an affect over longer interdecadal time scales. Warming/cooling of the north Atlantic gyre subpolar mode water (SPMW) has been linked to gyre strength - recent warming occurred with a weakened gyre with reduced deep water formation and thus subsequently reduced overturning. The cooling occurs with a strengthened gyre modulated largely by more cold Labrador water deep convection, influenced by NAO and East Atlantic patterns.

Edited by Interitus
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While the new RAPID data for the past 18 months will certainly be interesting, at this point too much is being read into the current figures.

As the RAPID team point out - When a time-series is too short, it is not possible to distinguish between a long-term trend and decadal variablity - periodic fluctuations that occur over time scales of decades. The RAPID time-series of AMOC flow is not long enough yet to make this distinction

The MOCHA site suggests 30% reduction as occurred in 2009/10 was within the expected modeled interdecadal variation - it was largely due to anomalous Ekman transport i.e. the atmosphere leading the ocean.

Then has been pointed out by a few here, this is at 26°N, not that this is insignificant but this is within the subtropical gyre whilst the cool pool is in the subpolar gyre and the links between the two are complex and the effects different - this point and the short timeseries are both acknowledged by Rahmstorf et al. -

Recent oceanographic measurements from the RAPID array at 26°N in the Atlantic suggest that the AMOC has been weakening again since these measurements started in 2004 (ref. 39), although we cannot conclude to what extent this temporary decrease signals a progressive trend, and the connection between subtropical and subpolar overturning, especially on shorter timescales, is not clear

In both regions the effect of gyre transport - again atmosphere led - has an affect over longer interdecadal time scales. Warming/cooling of the north Atlantic gyre subpolar mode water (SMW) has been linked to gyre strength - recent warming occurred with a weakened gyre with reduced deep water formation and thus subsequently reduced overturning. The cooling occurs with a strengthened gyre modulated largely by more cold Labrador water deep convection, influenced by NAO and East Atlantic patterns.

 

I linked this paper further back - longer time series in the SPG. Don't know if you looked but some stuff way above my capabilities of comprehension.

 

http://onlinelibrary.wiley.com/doi/10.1002/2015JC010762/full

 

 

Abstract

The Extended Ellett Line (EEL) hydrographic section extends from Scotland to Iceland crossing the Rockall Trough, Hatton-Rockall Basin, and Iceland Basin. With 61 full-depth stations at a horizontal resolution of 10–50 km, the EEL samples the upper limb of the Atlantic Meridional Overturning Circulation flowing across the Iceland-Scotland Ridge into the Nordic Seas. The Rockall Trough has been sampled nearly four times per year from 1975 to 1996, and the full section annually since 1996. The EEL is an exceptionally long-time series of deep ocean temperatures and salinities. This study extends prior work in the Rockall Trough, and examines for the first time 18 year records in the Iceland and Hatton-Rockall Basins. We quantify errors in the time series from two sources: observational errors and aliasing. The data quality and annual sampling are suitable for observing interannual to decadal variability because the variability exceeds our error estimates. The upper waters of all three basins are cooler/fresher from 1997 to 2001, warmer/more saline 2001–2006, and cooler/fresher from 2006 to 2014. A reference level for geostrophic shear is developed heuristically and by comparison with sea-surface altimetry. The mean northward transport in the upper waters is 6.7 ± 3.7 Sv and there is a 6.1 ± 2.5 Sv southward flow below the thermocline. Although the magnitude of the Iceland Basin overturning circulation (4.3 ± 1.9 Sv) is greater than in the Rockall Trough (3.0 ± 3.7 Sv), the variability is greater in the Rockall Trough. We discuss the results in the context of our understanding of drivers of variability.

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While the new RAPID data for the past 18 months will certainly be interesting, at this point too much is being read into the current figures.

As the RAPID team point out - When a time-series is too short, it is not possible to distinguish between a long-term trend and decadal variablity - periodic fluctuations that occur over time scales of decades. The RAPID time-series of AMOC flow is not long enough yet to make this distinction

The MOCHA site suggests 30% reduction as occurred in 2009/10 was within the expected modeled interdecadal variation - it was largely due to anomalous Ekman transport i.e. the atmosphere leading the ocean.

Then has been pointed out by a few here, this is at 26°N, not that this is insignificant but this is within the subtropical gyre whilst the cool pool is in the subpolar gyre and the links between the two are complex and the effects different - this point and the short timeseries are both acknowledged by Rahmstorf et al. -

Recent oceanographic measurements from the RAPID array at 26°N in the Atlantic suggest that the AMOC has been weakening again since these measurements started in 2004 (ref. 39), although we cannot conclude to what extent this temporary decrease signals a progressive trend, and the connection between subtropical and subpolar overturning, especially on shorter timescales, is not clear

In both regions the effect of gyre transport - again atmosphere led - has an affect over longer interdecadal time scales. Warming/cooling of the north Atlantic gyre subpolar mode water (SMW) has been linked to gyre strength - recent warming occurred with a weakened gyre with reduced deep water formation and thus subsequently reduced overturning. The cooling occurs with a strengthened gyre modulated largely by more cold Labrador water deep convection, influenced by NAO and East Atlantic patterns.

 

You are right to caution about reading too much into what is currently happening in the N. Atlantic Interitus. It is nevertheless a very interesting development and clearly an awful lot of academic and scientific research is currently being put into understanding the ‘what’ and ‘why’ better (including the RAPID and possibly more relevant OSNAP surveys).

 

The paper Nouska talks about above is a good read and identifies just how complex the N. Atlantic subpolar gyre is. Of interest is one of the closing paragraphs about the decrease in temperature and salinity in this part of the Atlantic since 2010, as other research papers suggest a decrease in salinity is likely to slow the AMOC and cause temperatures to decrease. I’ve copied some of the relevant sections below, including the schematic of the area and its currents:  

 

The Extended Ellett Line (EEL) hydrographic section extends from Scotland to Iceland crossing the Rockall Trough, Hatton-Rockall Basin, and Iceland Basin. With 61 full-depth stations at a horizontal resolution of 10–50 km, the EEL samples the upper limb of the Atlantic Meridional Overturning Circulation flowing across the Iceland-Scotland Ridge into the Nordic Seas.

 

post-20040-0-93327400-1444937987_thumb.j

 

The international OSNAP project (Overturning in the Subpolar North Atlantic Program) is making direct and continuous measurements of the overturning circulation of the whole subpolar North Atlantic from 2014 to 2018 and will quantify variability on seasonal to interannual time scales.

 

The decrease in potential temperature and salinity after 2010 in all basins provides the first new evidence that the eastern subpolar North Atlantic is once again being influenced by cold, fresh western subpolar water.

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The paper Nouska talks about above is a good read and identifies just how complex the N. Atlantic subpolar gyre is. Of interest is one of the closing paragraphs about the decrease in temperature and salinity in this part of the Atlantic since 2010, as other research papers suggest a decrease in salinity is likely to slow the AMOC and cause temperatures to decrease.....

 

The decrease in potential temperature and salinity after 2010 in all basins provides the first new evidence that the eastern subpolar North Atlantic is once again being influenced by cold, fresh western subpolar water.

Yes, but your interpretation is selective, the paragraph where this quote is from is in agreement with the assessment above that the subpolar gyre strength and atmospheric circulation are controlling features -

 

Recent research has established that the cause of the overall increase in potential temperature and salinity of the upper ocean from the late 1990s to the mid-2000s was a change in the circulation of the subpolar gyre and the inflow of subtropical waters. The subpolar gyre circulation decreased, and at the same time, the subpolar front moved westward and more subtropical water entered the eastern region [Holliday, 2003]. The Hatton-Rockall Basin lies within the region where the subpolar front shifts either northwestward or southeastward which is the likely reason why property extremes are highest there. The mechanisms driving the changes are still being examined, with contributing effects from the NAO, wind stress curl, blocking highs, and transport of anomalies from the subtropics all being proposed [Hakkinen and Rhines, 2004; Hátún et al., 2005; Hakkinen et al., 2011a, 2011bb; Desbruyeres et al., 2013]. The observations presented here are consistent with the present understanding of the basin-scale circulation changes to 2010 [Hughes et al., 2012]. The decrease in potential temperature and salinity after 2010 in all basins provides the first new evidence that the eastern subpolar North Atlantic is once again being influenced by cold, fresh western subpolar water. Whether this implies a sustained expansion of the subpolar gyre into the region remains to be seen.

 

What it is not saying is that we are seeing extensive freshwater hosing leading to a mooted AMOC shutdown which basically appears to be the undercurrent of this thread.

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Yes, but your interpretation is selective, the paragraph where this quote is from is in agreement with the assessment above that the subpolar gyre strength and atmospheric circulation are controlling features -

 

Recent research has established that the cause of the overall increase in potential temperature and salinity of the upper ocean from the late 1990s to the mid-2000s was a change in the circulation of the subpolar gyre and the inflow of subtropical waters. The subpolar gyre circulation decreased, and at the same time, the subpolar front moved westward and more subtropical water entered the eastern region [Holliday, 2003]. The Hatton-Rockall Basin lies within the region where the subpolar front shifts either northwestward or southeastward which is the likely reason why property extremes are highest there. The mechanisms driving the changes are still being examined, with contributing effects from the NAO, wind stress curl, blocking highs, and transport of anomalies from the subtropics all being proposed [Hakkinen and Rhines, 2004; Hátún et al., 2005; Hakkinen et al., 2011a, 2011bb; Desbruyeres et al., 2013]. The observations presented here are consistent with the present understanding of the basin-scale circulation changes to 2010 [Hughes et al., 2012]. The decrease in potential temperature and salinity after 2010 in all basins provides the first new evidence that the eastern subpolar North Atlantic is once again being influenced by cold, fresh western subpolar water. Whether this implies a sustained expansion of the subpolar gyre into the region remains to be seen.

 

What it is not saying is that we are seeing extensive freshwater hosing leading to a mooted AMOC shutdown which basically appears to be the undercurrent of this thread.

 

I see what you did there.  :)

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Oceanographers will hate this: The AMO and AMOC are only an atmospherically driven phenomenon

 

 

The Atlantic Multidecadal Oscillation without a role for ocean circulation

The Atlantic Multidecadal Oscillation (AMO) is a major mode of climate variability with important societal impacts. Most previous explanations identify the driver of the AMO as the ocean circulation, specifically the Atlantic Meridional Overturning Circulation (AMOC). Here we show that the main features of the observed AMO are reproduced in models where the ocean heat transport is prescribed and thus cannot be the driver. Allowing the ocean circulation to interact with the atmosphere does not significantly alter the characteristics of the AMO in the current generation of climate models. These results suggest that the AMO is the response to stochastic forcing from the mid-latitude atmospheric circulation, with thermal coupling playing a role in the tropics. In this view, the AMOC and other ocean circulation changes would be largely a response to, not a cause of, the AMO.

 

http://www.sciencemag.org/content/350/6258/320.full

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if you consider thet north usa and north atlantic have had a string of very cold winters autumns and spring!

 

could this run of recent colder seasons brought about by a very intense vortex!

 

could this have cooled the surface water?

 

and is only at the surface that this cold anomaly in the atlantic  is..

 

down deep under the cold anomaly everything might be fine.

and ive not seen any evidence to support this is fresh water mixing.

 

ok so I went back a page and see the paper on fresh water mixing but as knocker has posted up it seems to be driven but atmospheric changes perhaps intense vortex and extreme cold in the states and in and around Greenland plus the recent la nina and as it switched to el nino this forced the movement of the atlantic cold anomaly.

Edited by emotional rollercoaster
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It is possible but the fact it mirrors the surface graph BFTV posted leads me to believe it is accurate. The deeper transect to 2000 metres also shows a very changed profile in the last few years. The data starts from 2004 so presume this is all part of the same monitoring as on the RAPID-MOC website.

 

Jn3tbSc.gif

 

 

Just how big of a pool this Atlantic cold pool really is? Well, it actually goes pretty deep and you could actually say that its a pool. :D This is a cross-section through the 50N lat line, versus the climatology and versus last year. Data is from Glosea5 analysis (FOAM).

 

votemper-in-meto-glo-phy.png votemper-in-meto-glo-phy.png

 

 

if you consider thet north usa and north atlantic have had a string of very cold winters autumns and spring!

 

could this run of recent colder seasons brought about by a very intense vortex!

 

could this have cooled the surface water?

 

and is only at the surface that this cold anomaly in the atlantic  is..

 

down deep under the cold anomaly everything might be fine.

and ive not seen any evidence to support this is fresh water mixing.

 

ok so I went back a page and see the paper on fresh water mixing but as knocker has posted up it seems to be driven but atmospheric changes perhaps intense vortex and extreme cold in the states and in and around Greenland plus the recent la nina and as it switched to el nino this forced the movement of the atlantic cold anomaly.

 

 

Read the whole thread and your answers will be found there. I've just quoted two examples from Nouska and Recretos, but there are many more. 

Edited by Yarmy
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if you consider thet north usa and north atlantic have had a string of very cold winters autumns and spring!

 

could this run of recent colder seasons brought about by a very intense vortex!

 

could this have cooled the surface water?

 

<snipped>

 

There's certainly an element of that in the cooling cycle - described in this recent presentation.

 

ftp://ftp.noc.soton.ac.uk/pub/rma/iugg-1737_marsh_final.pdf

 

As Yarmy states, a lot of new research in this thread, some of it conflicting. Seems to me that there is evidence of a change in the deeper layers prior to the last two winters - the atmospheric turbulence may have hastened the upwelling and surface cooling.

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I haven't been following this all that closely, but looking at the latest images it seems this cold pool has weakened significantly since I last looked- not a lot of discussion about that in here though.

 

There now also appear to be other perhaps more significant cold pools developing in other parts of the globe, notably around Japan.

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if you consider thet north usa and north atlantic have had a string of very cold winters autumns and spring!

 

could this run of recent colder seasons brought about by a very intense vortex!

 

could this have cooled the surface water?

 

and is only at the surface that this cold anomaly in the atlantic  is..

 

down deep under the cold anomaly everything might be fine.

and ive not seen any evidence to support this is fresh water mixing.

 

ok so I went back a page and see the paper on fresh water mixing but as knocker has posted up it seems to be driven but atmospheric changes perhaps intense vortex and extreme cold in the states and in and around Greenland plus the recent la nina and as it switched to el nino this forced the movement of the atlantic cold anomaly.

 

Atmosphere conditions have unquestionably cooled the surface and it would probably be more worrying if this didn't extend to some depth because this would mean that there was a halocline in place with fresh water at the surface maintaining the density stratification and preventing mixing.

The formation of Labrador Sea Water (LSW) through surface cooling leading to deep convection - actual overturning in action - extended below 1700 metres in winter 2013/4, one of the deepest observed in recent years as reported in NOAA's State of the Climate report (linked by Nouska in climate section https://forum.netweather.tv/topic/83555-the-weakening-of-the-north-atlantic-circulation/page-2#entry3265046) and published here http://www.researchgate.net/profile/Igor_Yashayaev/publication/270345227_Studies_of_Labrador_Sea_Water_formation_and_variability_in_the_subpolar_North_Atlantic_in_the_light_of_international_partnership_and_collaboration/links/54c699220cf289f0cecbae22.pdf

 

Winter 2014/5 also saw anomalous deep convection in the Irminger Sea which was the greater than any time in the past 20 years -

 

ANOMALOUSLY DEEP WINTER CONVECTION IN THE IRMINGER SEA IN 2014/15.

 
Abstract:
Using CTDO/ADCP data from the annual summer transatlantic section along 59.5° N along with AR07E data and ERA Interim reanalysis data we analyze anomalously deep winter convection in the Irminger Sea in 2014/15 in context of the history of properties of the North Atlantic intermediate water for the last two decades. Labrador Sea Water (LSW) was defined through the minimum potential vorticity. Oxygen saturation rate was used to separate the newly ventilated LSW from the old one as well as from the LSW advected from the Labrador Sea. Comparative analysis of the LSW properties from 1991 onwards shows that such a deep winter convection (down to 1800 m) with the potential density of the convected water amounting to 27.75 σΘ did not happen in the Irminger Sea during the last twenty years. During a single winter the mean LSW temperature dropped by 0.18°C and became just 0.05° C higher compared to the temperature observed in 2007. It is noteworthy that the LSW core held relatively high salinity (34.893 PSU) after 2008. Average LSW oxygen saturation rate of 94.5% unambiguously testifies its local origin and implies the LSW total renewal during the last winter. LSW filled the entire southern part of the deep Irminger Basin and was not observed in the region of the Western Boundary Current and the Irminger Current in June 2015. Analysis of the circulation reveals that most of LSW was generated outside of the Irminger Gyre. Anomalously deep winter convection can be explained by the anomalously large number of days with north-westerly - westerly winds exceeding 15 m/c which (along with the negative air temperatures over the large area spanning far beyond the vicinity of southern Greenland tip to the Reykjanes Ridge) was responsible for the anomalous cooling of surface ocean layer by extreme air-sea turbulent fluxes.

 

https://agu.confex.com/agu/os16/preliminaryview.cgi/Paper92594.html

This is in the region of the Argo temperature time series at 59°N shown by Nouska and again above by Yarmy which shows the strong recent cooling.

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can someone tell me what the difference is between meltwater from greenland, and meltwater that was released from lakes during the beginning of the younger dryas and 8.2 ka event. Is there a chanche there is a new event in the near future. And will the weakening also impact europe's climate?

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can someone tell me what the difference is between meltwater from greenland, and meltwater that was released from lakes during the beginning of the younger dryas and 8.2 ka event. Is there a chanche there is a new event in the near future. And will the weakening also impact europe's climate?

 

 

In a word, volume. The most popular prevailing theory for the cause of the YD was a sudden outburst draining into the North Atlantic of the colossal glacial Lake Agassiz. Similar outburst floods are associated with other periods of abrupt climate change in Northern Europe. Nothing like that can happen today, but while the Greenland icecap continues to melt a weakening seems plausible.

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Atmosphere conditions have unquestionably cooled the surface and it would probably be more worrying if this didn't extend to some depth because this would mean that there was a halocline in place with fresh water at the surface maintaining the density stratification and preventing mixing.

The formation of Labrador Sea Water (LSW) through surface cooling leading to deep convection - actual overturning in action - extended below 1700 metres in winter 2013/4, one of the deepest observed in recent years as reported in NOAA's State of the Climate report (linked by Nouska in climate section https://forum.netweather.tv/topic/83555-the-weakening-of-the-north-atlantic-circulation/page-2#entry3265046) and published here http://www.researchgate.net/profile/Igor_Yashayaev/publication/270345227_Studies_of_Labrador_Sea_Water_formation_and_variability_in_the_subpolar_North_Atlantic_in_the_light_of_international_partnership_and_collaboration/links/54c699220cf289f0cecbae22.pdf

 

Winter 2014/5 also saw anomalous deep convection in the Irminger Sea which was the greater than any time in the past 20 years -

 

https://agu.confex.com/agu/os16/preliminaryview.cgi/Paper92594.html

This is in the region of the Argo temperature time series at 59°N shown by Nouska and again above by Yarmy which shows the strong recent cooling.

 

I’ve only just found the time to digest the paper that Nouska posted in the Climate thread - thanks for posting the link in this thread. Another very good read and the comment you made in the Climate thread is clearly spot-on:

 

"Atlantic basin-scale SST variability in 2014 was driven primarily by atmospheric forcing. In particular, pronounced atmospheric cooling over much of the subpolar gyre, as I for one suspected.â€

 

The team behind the research featured in the State of the Climate report have recently published an easy-to-understand summary of the impact of the 2013-14 winter. Key extracts:

 

New research has revealed the impact on the North Atlantic of severe ocean surface heat loss during the extreme winter 2013-14.

 

The extreme winter left a cold imprint on the ocean surface over the North Atlantic, to the west of the UK. Changes in the ocean surface temperature are important because they have the potential to influence atmospheric temperature and weather systems.

Analysis of this cooling event, led by Dr Jeremy Grist from the NOC, has revealed that it was driven by cold, dry airflows originating from North America and the Nordic Seas. These airflows cooled the surface waters as they blew over the North Atlantic.

 

Dr Grist said “Extreme ocean surface cooling of this magnitude is very unusual in the datasets we used in this study and has left a major imprint on ocean properties both at the surface and at depthâ€.

 

His colleague, Prof Simon Josey has highlighted the significance of the extreme winter 2013/14 for the wider North Atlantic including the Labrador Sea in an article for the 2014 State of the Climate report.

 

Prof Josey, also from the NOC, said “As well as the cooling of the ocean surface found in our study, this winter has resulted in the first significant formation of dense water (exceeding depths of 1700 m) in the Labrador Sea for nearly a decade observed by our international colleagues. Overall, winter 2013-14 was remarkable for impacts across the mid-high latitude North Atlantic.â€

 

Above paper: http://noc.ac.uk/new...-winter-cooling

 

If I may also briefly mention the AMOC findings contained in the Nouska paper. Now we know these developments are not the cause of the recent cold pool, maybe the watching brief should be are they contributing in any way? e.g. by exerting less moderation of the cold pool due to reduced strength and heat transport.

 

AMOC strength: research from 3 surveys at 16°N, 26°N and 41°N (page 78) showed:

  • at 26°N the now decade-long (2004–March 2014) findings from the trans-basin instrument array shows there was a decrease in transport of −4.2 ± 2.5 Sv over the decade. The median value of the AMOC over this period was 17 Sv. The report notes “a statistically significant downward trend in MOC transport from 2004 to 2012, particularly starting in 2008.â€
  • at 16°N and 41°N there was no significant trend.

Next looking at the Meridional Heat Transport (MHT - linked to the AMOC) the report (page 81) finds a significant decreasing trend in northern latitudes:

  • −0.19 ± 0.09 PW decade at 41°N.
  • −0.27 ± 0.19 PW decade at 26°N.

Note: The median MHT value over the decade is 1.2 ± 0.4 PW. 1PW = (1015 W).

 

It will be interesting to see what the latest findings are from the RAPID AMOC 'data gathering' cruise that's just set sail to recover the last 18 months of observations. They'll be made available in January 2016.

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I’ve only just found the time to digest the paper that Nouska posted in the Climate thread - thanks for posting the link in this thread. Another very good read and the comment you made in the Climate thread is clearly spot-on:

 

"Atlantic basin-scale SST variability in 2014 was driven primarily by atmospheric forcing. In particular, pronounced atmospheric cooling over much of the subpolar gyre, as I for one suspected.â€

 

The team behind the research featured in the State of the Climate report have recently published an easy-to-understand summary of the impact of the 2013-14 winter. Key extracts:

 

New research has revealed the impact on the North Atlantic of severe ocean surface heat loss during the extreme winter 2013-14.

 

The extreme winter left a cold imprint on the ocean surface over the North Atlantic, to the west of the UK. Changes in the ocean surface temperature are important because they have the potential to influence atmospheric temperature and weather systems.

Analysis of this cooling event, led by Dr Jeremy Grist from the NOC, has revealed that it was driven by cold, dry airflows originating from North America and the Nordic Seas. These airflows cooled the surface waters as they blew over the North Atlantic.

 

Dr Grist said “Extreme ocean surface cooling of this magnitude is very unusual in the datasets we used in this study and has left a major imprint on ocean properties both at the surface and at depthâ€.

 

His colleague, Prof Simon Josey has highlighted the significance of the extreme winter 2013/14 for the wider North Atlantic including the Labrador Sea in an article for the 2014 State of the Climate report.

 

Prof Josey, also from the NOC, said “As well as the cooling of the ocean surface found in our study, this winter has resulted in the first significant formation of dense water (exceeding depths of 1700 m) in the Labrador Sea for nearly a decade observed by our international colleagues. Overall, winter 2013-14 was remarkable for impacts across the mid-high latitude North Atlantic.â€

 

Above paper: http://noc.ac.uk/new...-winter-cooling

 

If I may also briefly mention the AMOC findings contained in the Nouska paper. Now we know these developments are not the cause of the recent cold pool, maybe the watching brief should be are they contributing in any way? e.g. by exerting less moderation of the cold pool due to reduced strength and heat transport.

 

AMOC strength: research from 3 surveys at 16°N, 26°N and 41°N (page 78) showed:

  • at 26°N the now decade-long (2004–March 2014) findings from the trans-basin instrument array shows there was a decrease in transport of −4.2 ± 2.5 Sv over the decade. The median value of the AMOC over this period was 17 Sv. The report notes “a statistically significant downward trend in MOC transport from 2004 to 2012, particularly starting in 2008.â€
  • at 16°N and 41°N there was no significant trend.

Next looking at the Meridional Heat Transport (MHT - linked to the AMOC) the report (page 81) finds a significant decreasing trend in northern latitudes:

  • −0.19 ± 0.09 PW decade at 41°N.
  • −0.27 ± 0.19 PW decade at 26°N.

Note: The median MHT value over the decade is 1.2 ± 0.4 PW. 1PW = (1015 W).

 

 

It will be interesting to see what the latest findings are from the RAPID AMOC 'data gathering' cruise that's just set sail to recover the last 18 months of observations. They'll be made available in January 2016.

 

BW...

Do these reports indicate that the melting of the ice in the Arctic area has contributed little to the setup of this event?

I still think it possible that it may have contributed to the continuation of the cooling, but I guess we will find that out when we hear the results in January.

 

MIA

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http://iceagenow.info/2015/10/greenland-blowing-away-ice-growth-records/

 

Aiding or not.......doesn't seem to be down to excessive ice melt from Greenland

 

BFTP

 

I should be very wary about quoting that blog as the author is an AGW denier par excellence and a complete nutter. Good example of selective quoting to deliberately miss out the calving

 

For an ice sheet that neither grows or shrinks, there is at all points averaged over the year a balance between

  • the amount of snow that falls and is compressed to ice
  • the amount of snow and ice that melts or evaporates (sublimates) and
  • the amount of ice that flows away due to the ice motion

The two first contributions make up the surface mass balance. For the ice sheet as a whole, there is a balance between the surface mass balance and the amount of ice that calves into the ocean as icebergs.

If climate changes, the surface mass balance may change such that it no longer matches the calving and the ice sheet can start to gain or lose mass. This is important to keep track of, since such a mass loss will lead to global sea level rise. As mentioned, satellites measuring the ice sheet mass have observed a loss of around 200 Gt/year over the last decade.

 

http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/

Edited by knocker
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Indeed Knocker its Danish Institute but thanks for the full report.  It seems ok to me and nothing out of the ordinary it would seem overall, and certainly no catastrophic warming/melting or iminent full blown iceage

Seems a decent site to monitor though.

Re being a nutter......same can be said for likes of Gore imo

 

BFTP 

Edited by BLAST FROM THE PAST
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I'm sorry BFTP but i'm not agreeing at all that there is any comparison between Robert W. Felix, and Al Gore who in my opinion is often unjustly maligned by you know who. Felix is an out and out science denier and distorter of the truth. Have a geek at his web site or better still glance at the following.

 

http://rationalwiki.org/wiki/Robert_W._Felix

 

http://www.theguardian.com/environment/2005/may/10/environment.columnists

Edited by knocker
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