Stratosphere Temperature Watch

[summer blizzard]

Tentative?

Idon't know whether anyone has looked at this site but gives a history of warming events. http://www.appmath.c.../ssws/index.php An example for Jan. 1968.

I think that is good news for late November, however from what i am aware of, it is fairly typical to get a sudden cooling followed by a sudden warming early in the season, but that these are generally small events.

[johnholmes]

I think that is good news for late November, however from what i am aware of, it is fairly typical to get a sudden cooling followed by a sudden warming early in the season, but that these are generally small events.

Not so sure about that SB

There have been several occasions, Nov 2009 for instance, 6 November it started or maybe 5th, a sudden spike in the 30mb temperature and 15-20 days later colder weather took hold over the UK.

This in spite of almost every other indicator suggesting a mobile Atlantic would continue?

Please correct me anyone who has a better understanding of these temperature changes?

[chionomaniac]

Not so sure about that SB

There have been several occasions, Nov 2009 for instance, 6 November it started or maybe 5th, a sudden spike in the 30mb temperature and 15-20 days later colder weather took hold over the UK.

This in spite of almost every other indicator suggesting a mobile Atlantic would continue?

Please correct me anyone who has a better understanding of these temperature changes?

John, I believe last year was exceptional with regard to the November stratospheric temperatures as the following chart shows. I can't find another year like it.

http://acdb-ext.gsfc.nasa.gov/Data_services/met/metdata/annual/t60_90n_30_2010.pdf

Generally speaking as sb suggests there tend to be warming fluctuations as the stratosphere cools during November, but last year we saw a sustained temperature increase during November that led to the repeated weakening and splitting of the tropospheric polar vortex. This led to a winter decreased mean zonal wind that only went above average for the middle third of January.

http://acdb-ext.gsfc.nasa.gov/Data_services/met/metdata/annual/u60n_30_2010.pdf

This Autumn I very much doubt that we will see any thing similar and we could see a right battle between the stratosphere and GP's latest suggested AAM and La Nina derived December composite.

c

Edited November 4, 2010 by chionomaniac

[chionomaniac]

I can see potential in this 10 day ECM forecast at the 10 hPa level. Worth watching.

[chionomaniac]

I can see potential in this 10 day ECM forecast at the 10 hPa level. Worth watching.

Yes, there is definitely potential in this one . We are seeing a strong wave number 2 forecast to be breaking into the upper stratosphere in around 10 days time. We will need to see if this warms the stratosphere sufficiently enough to cause some disruption and weakening of the vortex. It may not of course (but I suspect it will).

Worth checking the GFS later.

[chionomaniac]

GFS on board.

Just the right time to get some early season warming!

[cooling climate]

GFS on board.

Just the right time to get some early season warming!

Very much agree CH, and I think north central Russia is where one part of the vortex

will take up residence this winter. The other part being around the Hudson bay area.

[picog]

GFS on board.

Just the right time to get some early season warming!

How exciting! We're off already (perhaps)!

[knocker]

Trying to get to grips with some of the troposphere-stratosphere interactions. Losing battle of course. With this in mind I have been looking at the Eliassen-Palm (E-P) Flux. As I understand it meridional fluxes of westerly momentum and sensible heat can be calculated from constant pressure charts at various levels in the atmosphere. As per the E-P theory, these parameters give fluxes of geopotential wave energy in the meridional-vertical plane. Streamlines can then be drawn in the plane. Giving the direction and intensity of flow of energy in this plane.

From this web site http://www.atmosp.ph...5/coupling.html the NAM plays an important role in this. In the ‘high’ phase wave fluxes tend to be directed equatorward within the troposphere and to converge in the subtropical troposphere, whereas in the ‘low’ phase wave fluxes tend to be directed upward from troposphere to stratosphere and to converge, implying an anomalous westward wave force, in the mid- and high latitude stratosphere. So my question is (got there in the end) are we looking for the latter for goings on in the stratosphere and can I take it that the image below indicates the former and should it be looked at in conjunction with the height -time cross section of the zonal wind?

Edited November 6, 2010 by weather ship

[johnholmes]

gordon bennett Fred-post something simple mate-that is far worse than most of even GP and Ch posts in terms of understanding?

After all I'm a simple retired weather forecaster not a pupil of Einstein!

[dallas]

gordon bennett Fred-post something simple mate-that is far worse than most of even GP and Ch posts in terms of understanding?

After all I'm a simple retired weather forecaster not a pupil of Einstein!

Ha ha love that dry humour John, personally I was lost in the first sentance, but do find it a really interesting subject and would like to see another event like last Feb's one,

Ron

[knocker]

gordon bennett Fred-post something simple mate-that is far worse than most of even GP and Ch posts in terms of understanding?

After all I'm a simple retired weather forecaster not a pupil of Einstein!

Come off it John you know I realise that all retired MO forecasters are a class apart. Anyway I thought it would take your mind off imminent storms and short discussions on model output.

Edited November 6, 2010 by weather ship

[Fozfoster]

E-P flux charts look like a firework display to me:drinks:

[cooling climate]

Trying to get to grips with some of the troposphere-stratosphere interactions. Losing battle of course. With this in mind I have been looking at the Eliassen-Palm (E-P) Flux. As I understand it meridional fluxes of westerly momentum and sensible heat can be calculated from constant pressure charts at various levels in the atmosphere. As per the E-P theory, these parameters give fluxes of geopotential wave energy in the meridional-vertical plane. Streamlines can then be drawn in the plane. Giving the direction and intensity of flow of energy in this plane.

From this web site http://www.atmosp.ph...5/coupling.html the NAM plays an important role in this. In the ‘high’ phase wave fluxes tend to be directed equatorward within the troposphere and to converge in the subtropical troposphere, whereas in the ‘low’ phase wave fluxes tend to be directed upward from troposphere to stratosphere and to converge, implying an anomalous westward wave force, in the mid- and high latitude stratosphere. So my question is (got there in the end) are we looking for the latter for goings on in the stratosphere and can I take it that the image below indicates the former and should it be looked at in conjunction with the height -time cross section of the zonal wind?

Yes we are hoping for the latter. E-P Flux has a much higher tendency to be deflected back towards the equator during +QBO phases (phase we are now in) compared to the - QBO phase (phase we were in last winter). The Earth's coriolis at work.Therefor warming events in the stratosphere are less likely.

Having said that Ozone plays are very big role in stratospheric warmings as does solar activity especially during low solar

activity phases.This is my understanding of how it works from what I have read, hopefully others (GP and CH especially) will also add some imput.

Edited November 6, 2010 by cooling climate

[Kentish Kiwi]

Signs that the tentative early warming may have already peaked, with it taking a dive towards average, and, as many expected, will not be sustained such as we saw last November. That said, the warming itself can't hurt at all and it may still 'regather' itself and hold the Stratospheric temperature above average. At a simplified level this could be an illustration of a +QBO year compared to a -QBO one, like last year.

[knocker]

Yes we are hoping for the latter. E-P Flux has a much higher tendency to be deflected back towards the equator during +QBO phases (phase we are now in) compared to the - QBO phase (phase we were in last winter). The Earth's coriolis at work.Therefor warming events in the stratosphere are less likely.

Having said that Ozone plays are very big role in stratospheric warmings as does solar activity especially during low solar

activity phases.This is my understanding of how it works from what I have read, hopefully others (GP and CH especially) will also add some imput.

Thanks for that CC. I must admit that even attempting to get a basic grip on the subject isn’t helped by the fact that there is so much ongoing research into what we know is a very complex area anyway. I’ve just read a paper (not pretending for one moment that I fully understand it) by Kodera and Kuroda, Tropospheric and Stratospheric Aspects of the Arctic Oscillation, in which tropospheric and stratospheric circulation change is investigated during large month-to-month variations of the AO selected from 17-year data. The AO is positive at the moment. Impossible to summarise but the E-P flux figures significantly. I would upload it but for © restrictions. As you say any imput from those who have a grip on this would be very welcome.

I don’t know whether you have read this paper, or even if it’s of interest but here it is anyway.

http://web.mit.edu/j...s/Cohen_GRL.pdf

Edited November 6, 2010 by weather ship

[Isolated Frost]

I just came in here to say:

It's all gobbeldygook to me.

[chionomaniac]

Thanks for that CC. I must admit that even attempting to get a basic grip on the subject isn’t helped by the fact that there is so much ongoing research into what we know is a very complex area anyway. I’ve just read a paper (not pretending for one moment that I fully understand it) by Kodera and Kuroda, Tropospheric and Stratospheric Aspects of the Arctic Oscillation, in which tropospheric and stratospheric circulation change is investigated during large month-to-month variations of the AO selected from 17-year data. The AO is positive at the moment. Impossible to summarise but the E-P flux figures significantly. I would upload it but for © restrictions. As you say any imput from those who have a grip on this would be very welcome.

I don’t know whether you have read this paper, or even if it’s of interest but here it is anyway.

http://web.mit.edu/j...s/Cohen_GRL.pdf

I have to admit that my understanding of the E-P flux interaction wrt the stratospheric circulation is very limited (though not for the lack of trying to read up about this). I have yet to find the ABC guide to this flux that I can use as a building block for further reading.

It is good to see someone else interested in the strat, ws, and I hope that you enjoy monitoring the stratosphere this winter.

Edited November 6, 2010 by chionomaniac

[DAVID SNOW]

I just came in here to say:

It's all gobbeldygook to me.

Dont be daft man.

Its all to do with the alternating flux capaciter linked to the rosby waves goodbye, that coupled with a back spilling stratoss ferric(13 year old cycle)with spots.

[Isolated Frost]

Dont be daft man.

Its all to do with the alternating flux capaciter linked to the rosby waves goodbye, that coupled with a back spilling stratoss ferric(13 year old cycle)with spots.

I see fireworks.

[knocker]

I have to admit that my understanding of the E-P flux interaction wrt the stratospheric circulation is very limited (though not for the lack of trying to read up about this). I have yet to find the ABC guide to this flux that I can use as a building block for further reading.

It is good to see someone else interested in the strat, ws, and I hope that you enjoy monitoring the stratosphere this winter.

I'm sure I'll find it interesting Ch and hopefully learn a wee bit. Funny enough I registered with the Berlin site many years ago (late sixties or early 70s I think) as they were as far as I know the only researchers who were producing 10mb charts on a daily basis and of course the SSW events were of great interest. It wasn't long after that that (may actualy have been at the same time) that we at Camborne started using high altitude radiosondes at midnight that regularly reached 38,000 to 40,000 metres, The only time I've seen two freezing levels on an ascent 38,000 metres apart!! Anyway enough of my morning twitter. Of no particular significance but the 100mb data and heights for midnight.

[beng]

Signs that the tentative early warming may have already peaked, with it taking a dive towards average, and, as many expected, will not be sustained such as we saw last November. That said, the warming itself can't hurt at all and it may still 'regather' itself and hold the Stratospheric temperature above average. At a simplified level this could be an illustration of a +QBO year compared to a -QBO one, like last year.

We lost a lot of snow cover across S Canada over the last week, I can't help wondering whether that's finished it off. QBO came in at around +10 for Oct - hopefully it won't get much stronger.

[Glacier Point]

We lost a lot of snow cover across S Canada over the last week, I can't help wondering whether that's finished it off. QBO came in at around +10 for Oct - hopefully it won't get much stronger.

Some +15 m/s values showing up over the equator......

http://ds.data.jma.g...lat_u30_nh.html

Edited November 7, 2010 by Glacier Point

[chionomaniac]

I'm sure I'll find it interesting Ch and hopefully learn a wee bit. Funny enough I registered with the Berlin site many years ago (late sixties or early 70s I think) as they were as far as I know the only researchers who were producing 10mb charts on a daily basis and of course the SSW events were of great interest. It wasn't long after that that (may actualy have been at the same time) that we at Camborne started using high altitude radiosondes at midnight that regularly reached 38,000 to 40,000 metres, The only time I've seen two freezing levels on an ascent 38,000 metres apart!! Anyway enough of my morning twitter. Of no particular significance but the 100mb data and heights for midnight.

Berlin site seems to be down this morning. I'm interested in the 10hPa forecast temps if anyone can get on.

It seems to me, ws, that you seem to know your way around the strat sites. I have links to all the papers by Mssrs Baldwin, Pulvani and Kodera if you are interested.

Oh and GP, Do you know of anywhere where there is a simple explanation of the E-P flux and its interactions and tropospheric sequelae? Thanks.

Edited November 7, 2010 by chionomaniac

[knocker]

Berlin site seems to be down this morning. I'm interested in the 10hPa forecast temps if anyone can get on.

It seems to me, ws, that you seem to know your way around the strat sites. I have links to all the papers by Mssrs Baldwin, Pulvani and Kodera if you are interested.

Oh and GP, Do you know of anywhere where there is a simple explanation of the E-P flux and its interactions and tropospheric sequelae? Thanks.

Berlin still seems to be down.

Interested in the links ch but there is no rush.