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Posted
  • Location: Truro, Cornwall
  • Weather Preferences: Winter - Heavy Snow Summer - Hot with Night time Thunderstorms
  • Location: Truro, Cornwall

    Those very warm sst's are stronger than the strength of the cold pool so could it work to cancel out some Of the cold pool if currents and winds move it towards the cold pool (although the cold pool is large). :)

    Edited by Costa Del Fal
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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

    Posted
  • Location: High Wycombe
  • Weather Preferences: Snow and Cold.
  • Location: High Wycombe

    The strength of the El Nino is impressive to look at. And the eastern seaboard looks like it could be nice for a dip with those temps lol.

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    Posted
  • Location: Yatton, South of Bristol
  • Location: Yatton, South of Bristol

    Those very warm sst's are stronger than the strength of the cold pool so could it work to cancel out some Of the cold pool if currents and winds move it towards the cold pool (although the cold pool is large). :)

    Indeed the warm could win out, but its not going to get warmer in that region due to the time of year. But the question is, what is feeding that cold pool?

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    Posted
  • Location: Now moved to tropical Bradford on Avon
  • Weather Preferences: Cold, snow and summer heatwaves.
  • Location: Now moved to tropical Bradford on Avon

    Indeed the warm could win out, but its not going to get warmer in that region due to the time of year. But the question is, what is feeding that cold pool?

     

    Or maybe it is more a case of warm currents that normally feed the north Atlantic in that area are weaker? 

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    Posted
  • Location: Bramley, Hampshire, 70m asl
  • Location: Bramley, Hampshire, 70m asl

    Or maybe it is more a case of warm currents that normally feed the north Atlantic in that area are weaker? 

    Yes this would seem the more likely cause to me

    ....north atlantic drift slows down leaving warmer waters closer to the gulf ie; along the eastern atlantic seaboard of US (warm anomaly). Meanwhile the north atlantic is getting much less warm water fed up to it and consequently cools down (cold anomaly).

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    Posted
  • Location: Exile from Argyll
  • Location: Exile from Argyll

    Yes this would seem the more likely cause to me

    ....north atlantic drift slows down leaving warmer waters closer to the gulf ie; along the eastern atlantic seaboard of US (warm anomaly). Meanwhile the north atlantic is getting much less warm water fed up to it and consequently cools down (cold anomaly).

    There's a post on real climate about this.  http://www.realclimate.org/index.php/archives/2015/03/a-hypothesis-about-the-cold-winter-in-eastern-north-america/

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    Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers!
  • Location: Hadleigh, Suffolk

    An interesting paper has just been published (15 Sept) that suggests the solar cycle has an impact on the North Atlantic winter climate through the interaction between ocean and atmosphere and that this effects the North Atlantic Oscillation (NOA), Artic Oscillation (AO) and sea surface temperatures (SSTs).
     

    If I’ve read the paper correctly, the interaction sequence seems to be:

    Level of solar irradiance (solar cycle) > impacts modulation of the polar-night jet & stratospheric meridional overturning circulation  > impacts NAO/AO > impacts SST & mid-latitude winds  > amplification of initial signal through feedback mechanisms.

     

    There is a lag of up to 3 years with the impact and it is interesting that the diagram of the N. Atlantic SSTs shown in Fig.1f - 1g within the paper has many similarities to the current SST anomaly we’ve been discussing in this forum, suggesting we are currently somewhere in the +1 to +3 year lag phase. 

     

    The authors suggest that the SST pattern shown in their Figure 1 is a tripole anomaly and a consequence of a positive phase of the NAO. (This would suggest a wet and windy winter more likely for Northern Europe).

    It's not the easiest paper to read so I've tried to pull out some relevant extracts:

     

    Solar forcing synchronizes decadal North Atlantic climate variability

    • There is increasing evidence that variations in solar irradiance at different time scales are an important source of regional climate variability.
    • In the North Atlantic region, a link between the 11-year solar cycle and the winter phase of patterns resembling the North Atlantic oscillation (NAO) or Arctic oscillation (AO) has been found by observational and modelling studies.
    • Recently, analysis of long-term SLP and sea surface temperature observations suggest that the surface climate response to the 11-year solar cycle maximizes with a lag of a few years.
    • These findings….. indicate that the lagged response of the NAO arises from ocean–atmosphere coupling mechanisms. Atmospheric circulation changes associated with the NAO affect the underlying Atlantic Ocean by modulating surface air temperature, atmosphere-ocean heat fluxes, as well as mid-latitude wind stress. This induces a typical sea surface temperature tripolar pattern anomaly that can persist from one winter to the next and amplify the initial atmospheric solar signal over the subsequent years through positive feedbacks onto the atmosphere.
    • ….the ocean-atmosphere feedback mechanism….. remains highly misrepresented by climate models.

     

    North Atlantic climate response to the 11-year solar cycle

    • In winter (December to February), SLP composite differences between solar maximum and solar minimum phases at lag 0 years (Fig. 1a)…. show a statistically significant decrease of 2 hPa over the Arctic region, and a statistically significant increase of 1 hPa in mid-latitudes with maxima in the Euro-Atlantic region and Pacific basin, corresponding to the positive phase of the AO.
    • At lag +1 year (Fig. 1b), the mid-latitude positive SLP anomaly strengthens in the Euro-Atlantic region up to 1.5 hPa and weakens in the Pacific basin resulting in a positive NAO-like pattern. The positive NAO signature still persists at lags +2 and +3 years (Fig. 1c, 1d) in the Atlantic basin.
    • ….a maximum response at a lag of +3 years. The corresponding sea surface temperature anomalies (Fig. 1e – h) evolve coherently with the lagged SLP NAO-like response to solar variability. Together with a cold tongue in the southern North Atlantic, a cold anomaly develops in the Labrador Sea (southwest of Greenland) at lag 0 years before intensifying and extending eastwards into the Atlantic at lags +1 and +2 years (Fig. 1f, 1g). Simultaneously, a warm anomaly strengthens and extends progressively eastward from the middle West Atlantic.
    • ….the sea surface temperature cold–warm–cold tripolar pattern is a typical North Atlantic response to the positive phase of the NAO. This sea surface temperature anomaly, which persists and strengthens over consecutive years, provides a positive feedback onto the atmosphere leading to the lagged and amplified NAO response.

    Figure 1: Solar signal at the surface in the Northern Hemisphere.

     

    post-20040-0-59043000-1442586439_thumb.j

     

    Full paper: http://www.nature.com/ncomms/2015/150915/ncomms9268/full/ncomms9268.html

     

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    Posted
  • Location: cardiff
  • Weather Preferences: storms snow sun
  • Location: cardiff

    Do the Atlantic being cool mean cold temps the UK when it comes across land .as its warm air normally still learning thanks

    Edited by dragon falls
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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

    Do the Atlantic being cool mean cold temps the UK when it comes across land .as its warm air normally still learning thanks

     

    Polar maritime air will experience reduced modification, but that will likely just mean slightly colder rain.

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    Posted
  • Location: Croydon. South London. 286 ft asl
  • Weather Preferences: Thunderstorms, snow, Ice days, warm sunny days.
  • Location: Croydon. South London. 286 ft asl

    It really depends where the PM air comes from.. if it's from a North Westerly direction more places could get snow rather than cold rain.

     

     Figure-6-Air-masses2_2.jpg

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    Posted
  • Location: Stockport
  • Location: Stockport

    Polar maritime air will experience reduced modification, but that will likely just mean slightly colder rain.

    I'm not sure, depends where you are I suppose. I got a few good snowfalls last winter from PM air, and that's with the SST cold anomomly a bit warmer than it could be this Winter.

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    Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.

    My GUESS is that any PM incursion we get, such as were nearly all on the carp-side of marginal, last winter, might be on the other side of marginal, this year? I hope! :D

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    Posted
  • Location: @scotlandwx
  • Weather Preferences: Crystal Clear High Pressure & Blue Skies
  • Location: @scotlandwx

    Look at July 2015 for clues to how that cold pool got there, an exceptional month on many fronts.

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    Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers!
  • Location: Hadleigh, Suffolk

    Look at July 2015 for clues to how that cold pool got there, an exceptional month on many fronts.

     

    Certainly the 500mb height anomaly shows persistent low pressure in pretty much the same area as the N. Atlantic 'cold pool' during July 2015 with resultant cold air consequently also persistent in that locale. Is this one of the factors in what you refer to as "an exceptional month"?

     

    This anomaly chart produced from the NOAA NCEP plotting page for July: post-20040-0-68488200-1442614387_thumb.g

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    Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers!
  • Location: Hadleigh, Suffolk

    Look at July 2015 for clues to how that cold pool got there, an exceptional month on many fronts.

     

    You'll have to put me out of my inquisitive misery lorenzo! Having slept on this and this morning checked the graph of the monthly SST anomaly figures I produced (post #111 on page 6), I'm wondering if you meant July 2014, as from that month onwards the graph fell steeply and has not recovered since. This year the cold pool anomaly has been bouncing along 'at the bottom' (so to speak) with little movement after July 2015.

     

    To produce the graph I used the coordinates that BFTV uses to monitor the cold pool (post #31 on page 2) and used the NOAA website to obtain the monthly data:

     

    post-20040-0-86720100-1442647456_thumb.j

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    Posted
  • Location: Heckmondwike, West Yorkshire
  • Location: Heckmondwike, West Yorkshire

    You'll have to put me out of my inquisitive misery lorenzo! Having slept on this and this morning checked the graph of the monthly SST anomaly figures I produced (post #111 on page 6), I'm wondering if you meant July 2014, as from that month onwards the graph fell steeply and has not recovered since. This year the cold pool anomaly has been bouncing along 'at the bottom' (so to speak) with little movement after July 2015.

     

    To produce the graph I used the coordinates that BFTV uses to monitor the cold pool (post #31 on page 2) and used the NOAA website to obtain the monthly data:

     

    attachicon.gifMonthly SST Anomaly for NA Cold Pool.jpg

    Lorenzo may be referring the frequent high latitude blocking during July of this year, especially towards Greenland. Maybe he is inferring that this has contributed to that cold pool in the Atlantic.

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

    Great summary, Lorenzo.

     

    Mercator Ocean has a closer view animation of temps, salinity and currents over various depths - unfortunately, no anomalies though.

     

    http://bulletin.mercator-ocean.fr/

     

    The month of July in animation - controls under map.

     

    http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/4/20150701/20150731/1/1

     

    example of view.

     

     

    p0q6E8M.png

    Edited by Nouska
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    Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.

    Looking at those images, with a simplistic broad-brush approach, I'm minded to imagine a similar pattern to 2009-10 but with deeper depressions; however, I fully expect that thought to be nullified by reality...Such is usually the way with any attempt at predicting what'll happen - in four-months' time! :D

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    Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers!
  • Location: Hadleigh, Suffolk

    The atmospheric base state went off the hook in July and continues to rally along at full tilt.

     

    Here are the GLAAM plots for total angular momentum, also alongside the mountain torque plots showing a healthy upward cycle and a huge kick from an EAMT - red line.

     

    Should that pattern repeat then we are going to have an interesting scenario of looking to Asia to see wave one activity perturb the fledgling vortex. Combine this with the advertised HLB over North America/ Canada associated with Nino then this creates another wave 2 pinch on the vortex (albeit dependent on the positioning of the long wave pattern).

     

    attachicon.gifgltotaam.sig.90day.gifattachicon.gifgltaum.90day.gifattachicon.gifgwo_90d.gifattachicon.gifgwo_phase_fig4.jpg

     

    Regarding SSt July reanalysis stuck out looking at Baffin Bay anomalous heat content and spillage of cold South. Loop on that link.

     

    Also this stunning image from NASA Aqua / MODIS paints a better picture than the words..

    attachicon.gifCapture.PNG

    http://neo.sci.gsfc.nasa.gov/view.php?datasetId=MYD28M

     

    Current I notice is getting comparison to 2009, here are the two to make your own conclusions. Still different I think.

    attachicon.gifsst_natl_diff_2009.png attachicon.gifnatl_cdas1_anom.png

     

    Thank you for a comprehensive expansion of your thinking. Hopefully this bodes well for an interesting winter ahead.

     

    What strikes me with the Sept 2015 SST chart is the stark contrast between the very warm anomaly off the eastern seaboard of the US and the record cold anomaly of the 'cold pool' in the N. Atlantic. To me it smacks of the AMOC declining - it's starting to fail to transport the warmth north so the warm anomaly grows off the seaboard, whilst the 'cold pool' gets colder with insufficient warmth arriving.

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    Posted
  • Location: High Wycombe
  • Weather Preferences: Snow and Cold.
  • Location: High Wycombe

    Thank you for a comprehensive expansion of your thinking. Hopefully this bodes well for an interesting winter ahead.

     

    What strikes me with the Sept 2015 SST chart is the stark contrast between the very warm anomaly off the eastern seaboard of the US and the record cold anomaly of the 'cold pool' in the N. Atlantic. To me it smacks of the AMOC declining - it's starting to fail to transport the warmth north so the warm anomaly grows off the seaboard, whilst the 'cold pool' gets colder with insufficient warmth arriving.

     

    Very interesting read on the AMOC here: http://www.eoearth.org/view/article/150290/  with links to studies / references.   One section discussed the effect of large land based ice sheets breaking off into the ocean.

     

     

     

    Evidence from paleorecords (discussed more completely in subsequent sections) suggests that there have been large, decadal-scale changes in the AMOC, particularly during glacial times. These abrupt change events have had a profound impact on climate, both locally in the Atlantic and in remote locations around the globe. Research suggests that these abrupt events were related to massive discharges of freshwater into the North Atlantic from collapsing land-based ice sheets. Temperature changes of more than 10o C on time scales of a decade or two have been attributed to these abrupt change events.

     

     

    And if I recall, quite recently, the Greenland Glacier (forget the name) shed a huge chunk of ice into the N.Atlantic. Would be interesting to do a comparison of freshwater being released into the Atlantic compared with 30-40 years ago.  Also, not sure if that bit where it says temperatures changes of 10 degrees is an increase or decrease, or if it varies by region.

    Edited by IBringTheHammer
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    Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers!
  • Location: Hadleigh, Suffolk

    Very interesting read on the AMOC here: http://www.eoearth.org/view/article/150290/  with links to studies / references.   One section discussed the effect of large land based ice sheets breaking off into the ocean.

     

     

     

    And if I recall, quite recently, the Greenland Glacier (forget the name) shed a huge chunk of ice into the N.Atlantic. Would be interesting to do a comparison of freshwater being released into the Atlantic compared with 30-40 years ago.  Also, not sure if that bit where it says temperatures changes of 10 degrees is an increase or decrease, or if it varies by region.

     

    As the paper in your link says, what's going on with the AMOC â€œcould have a profound impact on many aspects of the global climate systemâ€.

     

    There’s been an AMOC ‘monitoring system’ deployed for the last decade (2004 – 2014) and latest findings were published in June 2015. Data shows the AMOC has been declining at 0.5Sv (half a million cubic metres per second) per year, 10 times faster than predicted by climate models.

     

    The data for 2009-2010 also showed a totally unexpected dip of 30% and this was accompanied by significant changes in the heat content of the ocean.

     

    More in this paper ‘Observing the Atlantic Meridional Overturning Circulation yields a decade of inevitable surprises’ http://www.sciencemag.org/content/348/6241/1255575.short

     

    Not sure whether you've read it but my post #97 (page 5) discussed a paper showing the role of melt water and increased freshwater in slowing the AMOC. It included a graph of freshwater input from Greenland.

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    Posted
  • Location: High Wycombe
  • Weather Preferences: Snow and Cold.
  • Location: High Wycombe

     

     

    The data for 2009-2010 also showed a totally unexpected dip of 30% and this was accompanied by significant changes in the heat content of the ocean.

     

    That's outrageous. I guess it's no coincidence then that the extreme winters of 09 and 10 coincided with this event.

     

    This winter is going to be interesting what ever happens. The strong El Nino coupled with the cold North Atlantic could really disrupt the jet stream. 

    Edited by IBringTheHammer
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    Posted
  • Location: Horsham, West sussex, 52m asl
  • Location: Horsham, West sussex, 52m asl

    the whole basis of 'The Day After Tomorrow' was the rapid decline of the AMOC...

    just saying...

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