Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Cooler Atlantic


Recommended Posts

Posted
  • Location: Solihull, West Midlands. - 131 m asl
  • Weather Preferences: Sun, Snow and Storms
  • Location: Solihull, West Midlands. - 131 m asl

One I think the AMO is losing/flipping.

 

Two this is going to be impossible to fathom until around 2075 -2100 due to the impacts of solar on the stratosphere.

 

Limited dataset ( 11 years) only held on the deep THC is insufficient to envelope even a solar cycle analog, let alone solar plus unique ENSO. Data and analog influences therefore new builds and learnings will be created this season.

 

Remember the influence on the forecast is how well the ocean sea parametrization exist in the NWP.

 

Fascinating.

 

Lorenzo..

 

My 1-5 years timescales are for just knowing whether the AMO has indeed flipped.

Not read  yours above yet.

It will be later on today.

 

It is extremely interesting.

 

MIA

Link to comment
Share on other sites

Posted
  • Location: West Belgium
  • Weather Preferences: Snow, Thunderstorms
  • Location: West Belgium

Hello, i have some questions... 

 

1)

 

1972 was the 3rd coldest year for the AMO, and the 2nd coldest for the May to September period and the coldest on record for June.

 

ewcDE0D.png

 

How is it possible to make cards with NCEP Reanalysis, (i've seen them a couple of times in this topic, i want to make them too.

 

2) I've seen a graphic about the decreasing AMOC in the last years. How is it possible that we didn't see the effects from the AMOC on our weather? Is it possible that the warming factors are more overwhelming than the cooling factors. Or is there another reason? Or is the decreasing not 'that exceptional', or is it still coming?

 

3) Will the cold pool in the At. Ocean have an effect on our weather, and not only for the UK but also for Scandinavia or where i live Belgium? Or is it just local? What are the effects for the winter. Does the cold pool stimulate high pressure or au contraire low pressure?

 

4) Is there certainty that the cold pool is a result of the ice water in Greenland? Will the cold pool be more significant in the future? Is there a possibility that there is a new Younger Dryas event or a 8.2 ka event or a small 8.2 ka event is coming? Or are the quantities of ice water that are released not great enough (or not fast enough) to have an impact on our regional climate?

  • Like 2
Link to comment
Share on other sites

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

This project and its output is one we need to watch closely. It's called UK-OSNAP (Overturning in the Subpolar North Atlantic Programme) and it’s a multi-party collaboration led by the National Oceanography Centre, 2 UK Universities and the Scottish Association of Marine Science.

 

It’s basically doing a RAPID (monitoring the AMOC), but instead of an array of monitoring instruments at 26°N, its focussing on the North Atlantic subpolar region between roughly 45°N and 65°N. The array will stretch from Newfoundland, past the tip of Greenland and over to the West coast of Scotland.

 

RAPID and OSNAP arrays post-20040-0-94880100-1443645051_thumb.j  OSNAP array in detail post-20040-0-36208700-1443645076_thumb.j

 

The project started monitoring in 2014 and is set to run to at least 2018. Results are already coming in and the first 4 papers will be published over the next 6 months.

 

Their website is worth a look, particularly the Project Information page with a good overview of how the subpolar gyre works and the what, why and how of the project. http://www.ukosnap.org/

  • Like 5
Link to comment
Share on other sites

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

Hello, i have some questions... 

 

1)

 

 

How is it possible to make cards with NCEP Reanalysis, (i've seen them a couple of times in this topic, i want to make them too.

 

2) I've seen a graphic about the decreasing AMOC in the last years. How is it possible that we didn't see the effects from the AMOC on our weather? Is it possible that the warming factors are more overwhelming than the cooling factors. Or is there another reason? Or is the decreasing not 'that exceptional', or is it still coming?

 

3) Will the cold pool in the At. Ocean have an effect on our weather, and not only for the UK but also for Scandinavia or where i live Belgium? Or is it just local? What are the effects for the winter. Does the cold pool stimulate high pressure or au contraire low pressure?

 

4) Is there certainty that the cold pool is a result of the ice water in Greenland? Will the cold pool be more significant in the future? Is there a possibility that there is a new Younger Dryas event or a 8.2 ka event or a small 8.2 ka event is coming? Or are the quantities of ice water that are released not great enough (or not fast enough) to have an impact on our regional climate?

 

 

Re: 1) To make your own charts, you can use the tool found here:

 

http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl?var=SST%20%28NCEP%20Reanalysis%20Model%29;level=1000mb;mon1=0;mon2=11;iy=1972;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;ipos%5B1%5D=;ipos%5B2%5D=;ineg%5B1%5D=;ineg%5B2%5D=;timefile0=;tstype=0;timefile1=;value=;typeval=1;compval=1;lag=0;labelc=Color;labels=Shaded;type=2;scale=100;labelcon=1;switch=0;cint=0.5;lowr=-3;highr=3;proj=Northern%20Hemisphere;xlat1=0;xlat2=90;xlon1=0;xlon2=360;custproj=Northern%20Hemisphere%20Polar%20Stereographic;level1=1000mb;level2=10mb;Submit=Create%20Plot

 

(The example is Jan-Dec 1972 SST Anomalies for the Northern Hemisphere. Click Create Plot to view the chart.)

Edited by Yarmy
Link to comment
Share on other sites

Posted
  • Location: Solihull, West Midlands. - 131 m asl
  • Weather Preferences: Sun, Snow and Storms
  • Location: Solihull, West Midlands. - 131 m asl

 

 

 

As it is, I'm not sure how valid the claim this is all just the AMO is acting normally, given that it doesn't appear to follow any clear repeating pattern.

 

7sQdXDm.png

 

There doesn't seem to be much to suggest that the NA cold pool leads the AMO either, not that it acts as a precursor to a phase switch, as far as I can tell at least. In fact, in the 5 years before 1930, the NA cold pool region looked distinctly warm, and in the 5 years before 1964, it was distinctly cool. 

 

Nothing with this is definitive, and so I'm happy to see any evidence to the contrary :)

 

BFTW...

 

Not sure it is to the contrary, but here goes ... it is a very Interesting graph, but where has it come from?.

 

I was not aware of any recording of the AMO going back to 1850.  Is it a reconstruction? Or produced from proxy data?

 

Genuine question as I have seen various articles stating that any AMO measurements only started about 1930. I could be wrong tho.

 

As to the comments after the graph above...

 

1) Where do you get the figures for the 5 years before 1930 from, as you only show the cold pooling from  about 1948?

2) What has 1964 got to do with it? .

 

Oh I understand now - you are looking at the midpoint of the cycles to prove your point about a changing trend at the top or bottom of the cycle?

 

I believe we are at the top of the AMO cycle and we are about to start to fall. You obviously are using the midpoint in the cycle argument to say that the cycle will last until about 2030?.  The midpoint argument states that we will break through into the downward section of the curve by then, but  as I will show you things will probably be changing long before then. Looking at your graph the previous AMO was generally characterised by higher peaks until the maximum  and then decreasing peaks  for the next 30 years to the minimum (including thru the midpoint). (as expected). But notice in the last 5 - 10 years that the peaks are falling quite quickly and we are now definitely seeing a decline..

 

Is this the start of the next downward trend of the AMO?    I submit it could well be.         You are obviously of a different opinion.

 

 

 

 

Why do I think it very well good be the start of change of the AMO?

 

 

Below I produce a graph which is genuine data from HADCRUT4, which has had everything detrended  (ENSO, volcanos,etc,etc) from it apart from the GW signal and what is thought to be the AMO (or some form of proxy for it!). I showed the graph back in March on this forum.

 

Note it is a rate of change of temperature graph and fulfills your aims of being a 30 year period. So 1973 graph cutoff is actually up to 2013.

 

It  more clearly shows a more cyclic oscillation than your AMO chart (it is more sensitive as it shows rate of change rather than actual temps) and even extends back into the 19th century (but with an increasing amplitude over time - probably the GW signal showing its hand).. It clearly shows we are at the top of some form of cycle as shown by the rate of change of world temperatures.

 

 

http://i175.photobucket.com/albums/w152/Mart1n0615/hadcrut30-from%201850_zps4wgxon40.jpg

 

Now if the cycles are correct (they look remarkably similar to your graph), but remember the ones I show  are displaced by 30 years compared to yours, then, it probably is showing the same effect, but by a different route of calculation and display...

 

The thing I note is that the rate of change of temperature preceeds any effect on the world's actual temperature. A bit like a large ship stopping, I guess. After the peak in warming produced by the current ElNino, what is going to happen?

 

I do not know, but to suggest we have to wait another 15 years for any change in AMO is in my mind incorrect and is delaying the obvious.

 

I would expect it to seriously start to have an impact after the El Nino runs its course.

 

As we all agree, these are interesting times.  I am afraid that we will have to wait and see the outcome.

 

MIA

 

Edit I have  just read Lorenzo's report recommended by the Met Office.

 

Can I refer you to pages 10 an 11 (it is all very good by the way!), where it talks about the AMO apparently having changed to an apparently cooler phase in 2004!!!

 

Much the same as my graph above.

Edited by Midlands Ice Age
Link to comment
Share on other sites

Posted
  • Location: Solihull, West Midlands. - 131 m asl
  • Weather Preferences: Sun, Snow and Storms
  • Location: Solihull, West Midlands. - 131 m asl

This project and its output is one we need to watch closely. It's called UK-OSNAP (Overturning in the Subpolar North Atlantic Programme) and it’s a multi-party collaboration led by the National Oceanography Centre, 2 UK Universities and the Scottish Association of Marine Science.

 

It’s basically doing a RAPID (monitoring the AMOC), but instead of an array of monitoring instruments at 26°N, its focussing on the North Atlantic subpolar region between roughly 45°N and 65°N. The array will stretch from Newfoundland, past the tip of Greenland and over to the West coast of Scotland.

 

RAPID and OSNAP arrays attachicon.gifosnap_schematic.jpg  OSNAP array in detail attachicon.gifosnap_array_schematic_small.jpg

 

The project started monitoring in 2014 and is set to run to at least 2018. Results are already coming in and the first 4 papers will be published over the next 6 months.

 

Their website is worth a look, particularly the Project Information page with a good overview of how the subpolar gyre works and the what, why and how of the project. http://www.ukosnap.org/

 

This is good news!!!

Can you arrange for a similar array in the South Atlantic?

 

:D :D :D

 

MIA

Link to comment
Share on other sites

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

AMO long dataset is located here

 

http://www.esrl.noaa.gov/psd/data/correlation/amon.us.long.data

 

Further link here

 

http://www.esrl.noaa.gov/psd/data/timeseries/AMO/

Edited by lorenzo
Link to comment
Share on other sites

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

I do not know, but to suggest we have to wait another 15 years for any change in AMO is in my mind incorrect and is delaying the obvious.

 

 

The Met Office reply to lorenzo a couple of days back included a link to their paper "Big Changes underway in the Climate System?". Here is their view about whether the AMO is about to flip:

 

Climate  records  show that the  North  Atlantic  Ocean surface  temperature has  alternated between  relatively  warm  and  cool  periods  over  at  least  the  last 100  years with  each  phase  lasting  a  few  decades.  This phenomenon has been named the ‘Atlantic Multidecadal Oscillation’ (AMO).

The current warm phase is now 20 years long and historical precedent suggests a return to relatively cool conditions could occur within a few years.

The  AMO  index  shows  that  the  current  warm  North  Atlantic  phase  reached  maturity  in about 2005, after which there has been no additional warming. The very end of the series hints at the start of a downturn.  Latest observations also show that cool anomalies have developed over parts of the North Atlantic Ocean. This also suggests the start of a decline in the AMO index, although its substantial year-to-year variations make it less certain that this decline will be sustained.

 

See page 9 onwards: http://www.metoffice.gov.uk/media/pdf/8/c/Changes_In_The_Climate_System.pdf

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey

Big Joe Bastaewardi mentioned about 2-3+ years go that AMO would be/due to enter -ve phase?....coud this be it?  Be interesting why he was thinking this as although he does call cold I think he is a very sound meteorologist

 

BFTP

  • Like 3
Link to comment
Share on other sites

Posted
  • Location: caernarfon, Gwynedd
  • Weather Preferences: very cold or very hot
  • Location: caernarfon, Gwynedd

On the topic of the cold Atlantic it seems to be sending low pressure around the cold pool and if you look at the current hurricane forecast it seems to be going around the edge towards ne America is this typical of what is thought to happen in these scenarios??

Link to comment
Share on other sites

Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary

BFTW...

 

Not sure it is to the contrary, but here goes ... it is a very Interesting graph, but where has it come from?.

 

I was not aware of any recording of the AMO going back to 1850.  Is it a reconstruction? Or produced from proxy data?

 

Genuine question as I have seen various articles stating that any AMO measurements only started about 1930. I could be wrong tho.

 

As to the comments after the graph above...

 

1) Where do you get the figures for the 5 years before 1930 from, as you only show the cold pooling from  about 1948?

2) What has 1964 got to do with it? .

 

Oh I understand now - you are looking at the midpoint of the cycles to prove your point about a changing trend at the top or bottom of the cycle?

 

I believe we are at the top of the AMO cycle and we are about to start to fall. You obviously are using the midpoint in the cycle argument to say that the cycle will last until about 2030?.  The midpoint argument states that we will break through into the downward section of the curve by then, but  as I will show you things will probably be changing long before then. Looking at your graph the previous AMO was generally characterised by higher peaks until the maximum  and then decreasing peaks  for the next 30 years to the minimum (including thru the midpoint). (as expected). But notice in the last 5 - 10 years that the peaks are falling quite quickly and we are now definitely seeing a decline..

 

Is this the start of the next downward trend of the AMO?    I submit it could well be.         You are obviously of a different opinion.

 

 

 

 

Why do I think it very well good be the start of change of the AMO?

 

 

Below I produce a graph which is genuine data from HADCRUT4, which has had everything detrended  (ENSO, volcanos,etc,etc) from it apart from the GW signal and what is thought to be the AMO (or some form of proxy for it!). I showed the graph back in March on this forum.

 

Note it is a rate of change of temperature graph and fulfills your aims of being a 30 year period. So 1973 graph cutoff is actually up to 2013.

 

It  more clearly shows a more cyclic oscillation than your AMO chart (it is more sensitive as it shows rate of change rather than actual temps) and even extends back into the 19th century (but with an increasing amplitude over time - probably the GW signal showing its hand).. It clearly shows we are at the top of some form of cycle as shown by the rate of change of world temperatures.

 

 

http://i175.photobucket.com/albums/w152/Mart1n0615/hadcrut30-from%201850_zps4wgxon40.jpg

 

Now if the cycles are correct (they look remarkably similar to your graph), but remember the ones I show  are displaced by 30 years compared to yours, then, it probably is showing the same effect, but by a different route of calculation and display...

 

The thing I note is that the rate of change of temperature preceeds any effect on the world's actual temperature. A bit like a large ship stopping, I guess. After the peak in warming produced by the current ElNino, what is going to happen?

 

I do not know, but to suggest we have to wait another 15 years for any change in AMO is in my mind incorrect and is delaying the obvious.

 

I would expect it to seriously start to have an impact after the El Nino runs its course.

 

As we all agree, these are interesting times.  I am afraid that we will have to wait and see the outcome.

 

MIA

 

Edit I have  just read Lorenzo's report recommended by the Met Office.

 

Can I refer you to pages 10 an 11 (it is all very good by the way!), where it talks about the AMO apparently having changed to an apparently cooler phase in 2004!!!

 

Much the same as my graph above.

 

Yeah, I got my dates mixed up on in that post, replace 1930 with 1960, and replace 1964 with 1994 :doh:

 

Yarmy provided the link for the long series AMO.

 

Did you create that graph yourself, MIA? It shows a clear upward trend, so it's definitely not detrended. It's just showing the rate of change rather than the absolute change. Your graph shows a short term leveling off in the rate of global temperature increase, which means temps are still increasing at a very fast rate, they just haven't accelerated for a few years.

 

The MO said the AMO reached maturity in 2005 and hasn't gained any heat since. This is very different to entering a negative phase. Even if we may have started on the path toward a negative phase (as happened last time around 1940) it could still be another decade or two before we actually enter the -ve phase. 

 

We might well be headed toward a -ve AMO and the NA cold pool could be a part of that. But, the long term decline in the AMOC and the accelerating melt water release from Greenland cannot occur in complete isolation. All these things are likely to be interacting with eachother.

Perhaps the extra melt and slowed AMOC is going to bring a new -ve AMO phase quicker than usual? I don't think anything can or should be dismissed at this stage.

  • Like 4
Link to comment
Share on other sites

If we take the July SSTs for the region of 45-60N and 14-45W (shown in the red box), we get the following time series graph.

 

 

Clearly the coolest SSTs in that region on record.

Interestingly it appears that the other various NOAA datasets - ERSST v3b and v4, Reynolds OI, and Kaplan all have 1994 as colder. The Met Office HadISST has it the coldest since 1976.

Link to comment
Share on other sites

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

The 30th September SST anomaly chart has just been published by Unisys, so just for interest we can compare this with the same chart from 30th August.

 

30th Aug post-20040-0-49333800-1443711013_thumb.g 30th Sept post-20040-0-65363200-1443711036_thumb.g

 

Clearly the cold pool has shrunk somewhat in overall size, but as my earlier analysis of the last 4 years showed, the months of Sept and Oct have been the (most consistent) months for the cold anomaly of the pool to ease, before temperatures decline again in Nov, with the pool consistently recording its coldest anomaly in Dec or Jan.

 

As soon as the monthly figure is available I'll re-do my graph for the latitude & longitude coordinates of the pool.

  • Like 6
Link to comment
Share on other sites

Posted
  • Location: Solihull, West Midlands. - 131 m asl
  • Weather Preferences: Sun, Snow and Storms
  • Location: Solihull, West Midlands. - 131 m asl

Yeah, I got my dates mixed up on in that post, replace 1930 with 1960, and replace 1964 with 1994 :doh:

 

Yarmy provided the link for the long series AMO.

 

Did you create that graph yourself, MIA? It shows a clear upward trend, so it's definitely not detrended. It's just showing the rate of change rather than the absolute change. Your graph shows a short term leveling off in the rate of global temperature increase, which means temps are still increasing at a very fast rate, they just haven't accelerated for a few years.

 

The MO said the AMO reached maturity in 2005 and hasn't gained any heat since. This is very different to entering a negative phase. Even if we may have started on the path toward a negative phase (as happened last time around 1940) it could still be another decade or two before we actually enter the -ve phase. 

 

We might well be headed toward a -ve AMO and the NA cold pool could be a part of that. But, the long term decline in the AMOC and the accelerating melt water release from Greenland cannot occur in complete isolation. All these things are likely to be interacting with eachother.

Perhaps the extra melt and slowed AMOC is going to bring a new -ve AMO phase quicker than usual? I don't think anything can or should be dismissed at this stage.

 

BFTV...

 

I am in reasonable agreement with the above, except for your claim that it will be 2030 before we enter the 'negative phase'. You clearly mean before it has dropped down below the median level. I take it to be when the AMO starts to decline. I see negative AMO as the period whilst the AMO is actually falling. You clearly see it whilst its below the median. Your definition obviously means that we will be in a negative pattern even when the AMO is actually increasing and turning positive again.

 

Also, re your enquiries where you  discuss/enquire  the graph I produced for you?.

 

Again you haven't read my comments correctly.            I AM a believer in AGW (but a bit watered down compared to some in here,but I call things as I see them..)              I obtained the graph on a basically warmist forum and was produced by a warmist to show global warmng.!!  He clearly didn't see any significance in AMO terms.(only looking at the  AGW signal!).

 

I think I can suggest to you, you have done the same!!!. Please read my notes properly if you want to criticise, otherwise it looks like a strawman argument.... (not suggesting you intended it as such).    My post clearly states  that is fully detrended from everything (,,,), APART for the Global Warming signal, and ALSO what is a perfect proxy for the AMO.

 

As your graph provided by Yarmy shows the graph I provided is a perfect fit for the AMO,,   BUT  with the extra warming signal superimposed on top...

 

It shows the varying rate of change of temperature and is therefore a very good identifier of any ongoing (short or long) term fluctuations within the general warming trend. As you suggest it shows that since approx 2004 there has been no increase in trend for warming (aka, the pause??). But to me it looks as if it is about to turn downwards exactly as it did in the 1940's. (I appreciate that the El Nino will probably push it up temporarily, but something similar occured in the 1940's maximum (ie a spike), before the general coolng then took place.

 

As you suggest, nothing is fixed, and it is going to be an interesting next 5 years. Please note also,  I do not discount that melt water is also impacting the sst's in the North Atlantic. My first post in this series said that. But we are not close to understanding the full reasons for this abnormality. Hence my call for more rapid type arrays in both the north and south Atlantic. At least Blessed W has answered my call for the North Atlantic!!

 

I still wonder whether the 'push' from the south has not changed recently (with the RAPID array showing largish reductions in the south of the North Atlantic) and particularly as the Antarctic ice patterns are also behaving strangely over the same time-scales as the cold pool in the Atlantic.

 

MIA

Edited by Midlands Ice Age
  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl

The 30th September SST anomaly chart has just been published by Unisys, so just for interest we can compare this with the same chart from 30th August.

 

30th Aug attachicon.gifsst_anom Aug 30 2015.gif 30th Sept attachicon.gifsst_anom Sept30 2015.gif

 

Clearly the cold pool has shrunk somewhat in overall size, but as my earlier analysis of the last 4 years showed, the months of Sept and Oct have been the (most consistent) months for the cold anomaly of the pool to ease, before temperatures decline again in Nov, with the pool consistently recording its coldest anomaly in Dec or Jan.

 

As soon as the monthly figure is available I'll re-do my graph for the latitude & longitude coordinates of the pool.

 

Not too surprising given as you say September typically sees a warming, and the synoptic pattern this month has been conducive to significant warming. Will be interesting to see where we are in a months time.

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary

The cold patch hasn't looked this weak in quite a while.

 

q32b1tz.gif

 

Temporary blip or fading away?

  • Like 3
Link to comment
Share on other sites

Posted
  • Location: Rotherhithe, 5.8M ASL
  • Location: Rotherhithe, 5.8M ASL

The remnants of hurricane Joaquín is also modelled to draw up warm air from Azores adding insult to injury so we're going through a bit of a wobble all will be good in the end?

post-19153-0-31652800-1443971616_thumb.j

Link to comment
Share on other sites

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

Is some of that intense warm anomaly of the NE coast of America now 'seeping' across?

 

Definitely a much weaker cold anomaly now. Waters around Britain definitely average at worst now. Was in Woolacombe the other week and the sea felt pleasant for UK standards. Not colder than normal for that time of year definitely. 

 

A few weeks ago I remarked at how quickly the anomaly can seem to change. Personally, I wouldn't be unhappy to see the cold anomaly go. Been quite disappointing our core warmer months have all been noticeably cooler than average. A real lack of opportunities to sit outside late this year without needing layers.

Link to comment
Share on other sites

Posted
  • Location: Carryduff, County Down 420ft ASL
  • Location: Carryduff, County Down 420ft ASL

I wouldn't mind understanding better how this is calculated. It seem strange that the anomaly has weakened so quickly over the end of a month, start of a new month.

Link to comment
Share on other sites

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

I wouldn't mind understanding better how this is calculated. It seem strange that the anomaly has weakened so quickly over the end of a month, start of a new month.

 

The NOAA SST figures are derived from multiple sources. It goes without saying that there's always room for improvement in obtaining measurements, but nonetheless it's reasonably robust. This from the NOAA/NCEP website:

 

A daily, high-resolution, real-time, global, sea surface temperature (RTG_SST) analysis has been developed at the National Centers for Environmental Prediction/Marine Modeling and Analysis Branch (NCEP / MMAB). The analysis was implemented in the NCEP production suite 30 January 2001, and provides the daily ocean surface temperatures for the Meso-Eta model.

The daily sea surface temperature product is produced on a half-degree (latitude, longitude) grid, with a two-dimensional variational interpolation analysis of the most recent 24-hours buoy and ship data, satellite-retrieved SST data, and SST's derived from satellite-observed sea-ice coverage.

 

More info: http://polar.ncep.noaa.gov/sst/rtg_low_res/

 

And of course it's also worth bearing in mind that local SST is impacted by the amount of sunshine or cloud cover, and the mixing caused by wind stress turbulence and wave action (hence Daniel's point above about hurricane Joaquin is valid). So a sustained period of high pressure or cold wind off Newfoundland or Greenland (for instance) will have an impact on a particular area of the Atlantic.

 

As I've said previously, this time of year usually sees an easing of the cold anomaly. So is the current easing part of a longer-term dissipation of the cold pool, or just the usual annual pattern which will see a decline again in November? The last 3 years have seen the cold pool reach an ever colder anomaly each Dec/Jan, so we will probably need to wait until this coming January for the answer.

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Coniston, Cumbria 90m ASL
  • Weather Preferences: wintry
  • Location: Coniston, Cumbria 90m ASL

Isn't the increase in SST aligned with a fairly benign period of weather, hence not much agitation allowing SST to rise, but it will take a fair bit of Sun to warm that amount of water to any great depth.

Wouldn't surprise me if the cold pool came back once the Atlantic gets a bit more mixing over the next week or two...

I stand to be corrected of course!

Link to comment
Share on other sites

Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

Well this thread has managed to leave me confused about the AMO state... I seem to recall that Met Office were saying last month that it had most likely changed to negative?

 

Aha - found an article with the answer within (http://www.theactuary.com/news/2015/09/2015-likely-to-be-warmest-year-on-record-says-met-office/)

 

"AMO – a fluctuation in the sea surface temperatures in the North Atlantic – would likely be entering a “negative†or cooling phase, which could temporarily cool the climate. - See more at: http://www.theactuary.com/news/2015/09/2015-likely-to-be-warmest-year-on-record-says-met-office/#sthash.EacrltnU.dpuf "

 

On here, it seems to be more a matter of opinion with respect to how its analysed.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-29 07:13:16 Valid: 29/03/2024 0600 - 30/03/2024 0600 THUNDERSTORM WATCH - FRI 29 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather

    Difficult travel conditions as the Easter break begins

    Low Nelson is throwing wind and rain at the UK before it impacts mainland Spain at Easter. Wild condtions in the English Channel, and more rain and lightning here on Thursday. Read the full update here

    Netweather forecasts
    Netweather forecasts
    Latest weather updates from Netweather

    UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-28 09:16:06 Valid: 28/03/2024 0800 - 29/03/2024 0600 SEVERE THUNDERSTORM WATCH - THURS 28 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather
×
×
  • Create New...