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Cold Phase Amo


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

Folks

We know we are in a negative PDO and this shows clearly with a reverse 'C' of Northwest US and west Canada as per below.

sst_anom.gif

Now we are appaerently heading towards a cold phase AMO. Does anyone know what that looks like? Do e get similar reverse C. As you can se above tentative signs of one to west of UK/Europe. Love to hear from someone that knows

BFTP

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

Does this mean no one knows or couldn't care less? Come on have you looked at the SST signal in the Atlantic.

BFTP

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Posted
  • Location: hertfordshire
  • Location: hertfordshire

Judging by the unisys sst anomaly charts it does suggest that the AMO is starting to trend negative.

The AMO index has been running negative since January with the index for April at -0.078 compared with +0.096 for April 2008. I don't think May's figure is out yet.

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Guest Shetland Coastie
reverse 'C' is what BFTP?

I assume he means the crescent shaped pool of colder water off the western seaboard of the US/Canada that looks like the letter "C" reversed and the similar shaped colder water pool off UK/Portugal/N.Africa?

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Guest North Sea Snow Convection
Can somebody tell me what AMO stands for? I hate abbreviations!

Karyo

Hi Karyo - it stands for Atlantic Multidecadal Oscillation. ie the mode of SST phase variability in the said ocean. It is supposed to have both cold and warm phases up to 70/80 yrs. This has knock on effects to rainfall/drought patterns in parts of the world like India for eg - and also hurricane development and frequency thereof, in the tropical atlantic. Plus it also effects global climatic temp trends of course.

This thread is hinting, I think, at the possiblity that the next cold phase AMO is about to start :rolleyes:

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Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)
Hi Karyo - it stands for Atlantic Multidecadal Oscillation. ie the mode of SST phase variability in the said ocean. It is supposed to have both cold and warm phases up to 70/80 yrs. This has knock on effects to rainfall/drought patterns in parts of the world like India for eg - and also hurricane development and frequency thereof, in the tropical atlantic. Plus it also effects global climatic temp trends of course.

This thread is hinting, I think, at the possiblity that the next cold phase AMO is about to start :rolleyes:

Thank you Tamara. You are a fountain of knowledge! :-)

Now I understand what it is, I am also really interested to see if we are getting into the cold AMO phase!

I guess the May AMO index should be out soon...

Karyo

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Guest North Sea Snow Convection
Thank you Tamara. You are a fountain of knowledge! :-)

Now I understand what it is, I am also really interested to see if we are getting into the cold AMO phase!

I guess the May AMO index should be out soon...

Karyo

Yes, it is another interesting factor and potential natural negative feedback coming into the equation. It does seem possible that over the next decade or so we could be looking at quite a raft of negative feedbacks kicking in all at once!

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Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey
I assume he means the crescent shaped pool of colder water off the western seaboard of the US/Canada that looks like the letter "C" reversed and the similar shaped colder water pool off UK/Portugal/N.Africa?

Spot on Bob, sorry John should have made it clearer. Yes Tamara spot on, this thread opened as I believe the AMO is due to turn negative and also wondered if anyone knew if it looked like the -ve PDO set up?

ta for replies

BFTP

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Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)
Yes, it is another interesting factor and potential natural negative feedback coming into the equation. It does seem possible that over the next decade or so we could be looking at quite a raft of negative feedbacks kicking in all at once!

That's music to my ears! :good:

By the way, can anybody provide me with a link for the monthly AMO index?

Thank you

Karyo

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Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)
The AMO was negative for most of the 80's and a large chunk of the 90's as well.

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

This gives a monthly update, as we can see that last 4 months where slightly negative.

I am not sure there is any correlation between AMO and CET though.

Just as you think there are some good news, here comes iceberg! :good:

Thanks for the data, it shows that we can't draw any simple conclusions!

I think however, that the CET is not the only point of interest. This thread should be interested in the effects of the AMO further afield as well, not just the UK.

kARYO

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks
Spot on Bob, sorry John should have made it clearer. Yes Tamara spot on, this thread opened as I believe the AMO is due to turn negative and also wondered if anyone knew if it looked like the -ve PDO set up?

ta for replies

BFTP

pardon

why me chum

I asked you a simple question to explain a comment you made!

tks for the other person explaining what you apparently meant.

as most know I detest abbreviations or lack of explanations-many on here feel the same it takes very little longer to write your full explanation the first time its posted or a link to what you mean!

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Posted
  • Location: Putney, SW London. A miserable 14m asl....but nevertheless the lucky recipient of c 20cm of snow in 12 hours 1-2 Feb 2009!
  • Location: Putney, SW London. A miserable 14m asl....but nevertheless the lucky recipient of c 20cm of snow in 12 hours 1-2 Feb 2009!

"Spot on Bob, sorry John should have made it clearer....."

John, I think Blast was attempting to apologize to you. Unfortunately by leaving out the comma after 'John', it read as if he were criticizing you instead!

The moral is, punctuation is not just a pointless obsession of pompous middle-aged farts. :clap:

And yes, abbreviations without initial explanations are a bit of a pain. It's over two weeks since this thread was started, and this is my first visit - purely because I saw 'AMO' in the title, and thought "Oh gawd, if I go there I'll need to do an hour or two's research before I even understand what they're on about"; and I already spend far too much of my life on the internet.

EDIT: Sorry, LadyP, I see you beat me to it! I had it half-written and still sitting on the screen, but had to pop out for an hour before I completed it.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

my apologies-teach me to read carefully and spot the grammar/punctuation errors-but there you go!

tks Lady P and Osm

I thought you were a teacher BFTP-shame on your punctuation!

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

The last four posts have really made me chuckle. It reminds me of 'Eats shoots and leaves'.

Back to the point in question regarding the AMO.

Firstly, if the AMO were to follow a cyclical pattern then previous patterns would suggest that the AMO would not be likely to go negative until 2020, so if this is not a blip, then we are seeing the AMO turning negative ten years early? If this occurs ten years earlier than expected could this be as a result of a negative feedback come into play?

Is there any evidence to suggest that cooler North Atlantic may affect positioning of high pressure cells during both summer and winter and if so could this have an influence on the jetstream positioning when taken in conjunction with the negative PDO and state of stratosphere etc?

Also to achieve a negative AMO I would assume that the strength and possibly position of the gulf stream have shifted. Will this have any effect on the ice levels of the Arctic?

c

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Posted
  • Location: Putney, SW London. A miserable 14m asl....but nevertheless the lucky recipient of c 20cm of snow in 12 hours 1-2 Feb 2009!
  • Location: Putney, SW London. A miserable 14m asl....but nevertheless the lucky recipient of c 20cm of snow in 12 hours 1-2 Feb 2009!
.....I thought you were a teacher BFTP-shame on your punctuation!

Ahem....the words 'pot', kettle' and 'black' spring to mind, John....a marked lack of it in this lot - by you!? :winky:

"pardon

why me chum

..............many on here feel the same it takes very little longer to write your full explanation the first time its posted or a link to what you mean!"

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Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl
Guest North Sea Snow Convection
The last four posts have really made me chuckle. It reminds me of 'Eats shoots and leaves'.

Back to the point in question regarding the AMO.

Firstly, if the AMO were to follow a cyclical pattern then previous patterns would suggest that the AMO would not be likely to go negative until 2020, so if this is not a blip, then we are seeing the AMO turning negative ten years early? If this occurs ten years earlier than expected could this be as a result of a negative feedback come into play?

Is there any evidence to suggest that cooler North Atlantic may affect positioning of high pressure cells during both summer and winter and if so could this have an influence on the jetstream positioning when taken in conjunction with the negative PDO and state of stratosphere etc?

Also to achieve a negative AMO I would assume that the strength and possibly position of the gulf stream have shifted. Will this have any effect on the ice levels of the Arctic?

c

Hi

I agree that in theory the next phase of cold AMO is not due for another 10 yrs or so, but perhaps there is a relationship with the PDO phases that causes the AMO to deviate from any 'block' pattern phase. Addionally phases of nina dominance may also effect the SST profile in this way with the colder pacific waters progressively influencing the atlantic.

Hence my own post yesterday that a raft of negative feedbacks may be due to kick start a chain reaction that perpertrates one feedback into the next. So I would say 'yes' - it is the process of a negative feedback making another negative feedback develop more quickly than it otherwise might have done.

I think it should be pointed out that the cold AMO phases that Iceberg showed yesterday were just perfectly normally transient deviations from the dominant warm AMO phase - much in the same principle as we can see weak ninos in an otherwise dominant nina phase. Or vice versa. It is the long term dominant SST patterns that we need to look out for - a little deviation from this is to be expected.

I would have thought that all of these phases and changes must affect the jet stream trajectory and latitude - also affecting the QBO phases, stratospheric temp profiles, with the AMO being a key factor in determining MJO tropical thunderstorm development etc which in turn will affect global weather patterns etc.

Regarding the arctic - again any shift back southwards of the jet stream as a longer term trend should have a positive effect on the arctic with fewer warmer plumes of air being pushed as far north as often as we have seen through the last couple of decades or so, - in conjunction with the raft of natural positive feedbacks that have been in play.

Also of course with air pattern changes and different SST profiles, the melt pattern and albedo feedback patterns would change - with the potential knock on positive effects in terms of better ice retention and ice cover.

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
Hi

I would have thought that all of these phases and changes must affect the jet stream trajectory and latitude - also affecting the QBO phases, stratospheric temp profiles, with the AMO being a key factor in determining MJO tropical thunderstorm development etc which in turn will affect global weather patterns etc.

r.

Thanks for the reply, T, that's pretty much as I see it too. The bit that I have highlighted I am assuming (hopefully correctly) that tropical thunderstorm development is surpressed over the Eastern Atlantic due to the colder SST's in this area. Is that why the MJO is stuttering around phases 6 and 7 currently?

http://www.bom.gov.au/bmrc/clfor/cfstaff/m...Last40days.html

c

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Guest North Sea Snow Convection
Is that why the MJO is stuttering around phases 6 and 7 currently?

http://www.bom.gov.au/bmrc/clfor/cfstaff/m...Last40days.html

c

Quite possibly yes. But I don't know if any other factors are involved? I'm not sure of all the potential short term impacts regarding this feature.

I guess I am looking at it as another of the potential long term feedbacks - although its shorter term effects are interesting too as you suggest :lol:

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

Thanks for the imputting folks, looks like something to start getting our teeth into.

JH

Glad it has been clarified that I was apologising to you...yes and apologies also for my poor grammar. Also just to confirm I am NOT a teacher :lol:

have to check out again now, too little time

BFTP

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