Stratosphere Temperature Watch 2012/2013

[bluearmy]

interesting to see that 30hpa temps over the pole having showed a brief drift above average have now dropped quickly to below average. would be good to see a displacement of the lowest temps in the mid strat away from the pole which may well be under way re ed's post above.

[snowking]

Some very slight rising of temps in the upper reaches of the strat visible today too. Nothing anywhere near significant yet but I'd prefer to see it going in this direction rather than down further:

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/01mb9065.gif

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/02mb9065.gif

Meanwhile the tropical stratosphere continues to remain well below average:

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/30mb2525.gif

But things starting to warm up towards the upper levels:

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/01mb2525.gif

To those more knowledgeable than me I pose a question...Could this potentially be a good thing though...what I'm wondering is with things in the Southern Hemisphere now cooling once again:

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/01mb6590.gif

Is this potentially a sign of ozone transportation back towards the equator...and therefore is there the chance of an increase in o-zone over the tropics potentially ready to be transported to the northern hemisphere?

[Relativistic]

Some very slight rising of temps in the upper reaches of the strat visible today too. Nothing anywhere near significant yet but I'd prefer to see it going in this direction rather than down further:

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/01mb9065.gif

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/02mb9065.gif

Meanwhile the tropical stratosphere continues to remain well below average:

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/30mb2525.gif

But things starting to warm up towards the upper levels:

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/01mb2525.gif

To those more knowledgeable than me I pose a question...Could this potentially be a good thing though...what I'm wondering is with things in the Southern Hemisphere now cooling once again:

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/01mb6590.gif

Is this potentially a sign of ozone transportation back towards the equator...and therefore is there the chance of an increase in o-zone over the tropics potentially ready to be transported to the northern hemisphere?

I'm no expert, but the SSW down south has me thinking the BDC was working in overdrive towards the south pole for a while (would explain anomalously low ozone levels at the north pole). But perhaps now things are changing, as these short warmings are popping up, perhaps a strengthening in the BDC towards the Arctic? Will have to keep watching the ozone forecasts.

EDIT:

Also, Perhaps the Asian MT event could help to introduce some wavebreaking into the stratosphere which may aid ozone transportation (I think, still learning).

Edited October 18, 2012 by 22nov10blast

[snowking]

That's pretty much where my thoughts were headed....I'm not sure it's necessarily an indication of the BDC strengthening, but it could well be a sign that should we eventually see some decent transportation from the tropics, there will be ample 'reserves', if you like, of o-zone to be transported.

I would guess, however, that such a movement of o-zone (ie SH > tropics, then after some time tropics > NH) could result in a short lived spell of higher vortex activity given an increase in the thermal gradient between the pole and the tropics

[Relativistic]

That's pretty much where my thoughts were headed....I'm not sure it's necessarily an indication of the BDC strengthening, but it could well be a sign that should we eventually see some decent transportation from the tropics, there will be ample 'reserves', if you like, of o-zone to be transported.

I would guess, however, that such a movement of o-zone (ie SH > tropics, then after some time tropics > NH) could result in a short lived spell of higher vortex activity given an increase in the thermal gradient between the pole and the tropics

Yes, never thought of it like that, a brief increase in strength does seem logical, then possibly a quick turnaround when the ozone makes it to the Arctic.

[chionomaniac]

Funny that you should mention this, snowking. I was just wondering today whether or not the SH events could have a repercussion on the next month stratospherically in the northern hemisphere. With the tropical stratosphere ozone well run dry will we need it to recharge again before the BDC can return the newly formed ozone towards the NH?

If that is the case then it may be upto a month before NH ozone increases and stratospheric warming starts to occur. Just in time for winter.

PS ozone forms in the tropical stratosphere and then travels to the poles through the BDC - it dissipates here.

Edited October 18, 2012 by chionomaniac

[snowking]

Perfect thank you very much chiono

Yes that's very much why I was wondering whether we were starting to see signs of more o-zone around the tropics with reserves looking very low at present, but I did not realise that new o-zone was produced rather than a transportation system backwards and forwards

Would o-zone creation over the tropics require any sort of temperature profile or other favourable factors?

Many thanks

[Relativistic]

I don't think it requires any kind of temperature profile, just UV radiation, perhaps someone could clarify?

Here's a link to an article containing info with regards to the creation of ozone in the tropical stratosphere:

http://en.m.wikipedia.org/wiki/Ozone-oxygen_cycle

[chionomaniac]

I don't think it requires any kind of temperature profile, just UV radiation, perhaps someone could clarify?

Here's a link to an article containing info with regards to the creation of ozone in the tropical stratosphere:

http://en.m.wikipedi...ne-oxygen_cycle

Yes, the UV radiation is both responsible for the formation and destruction of ozone.

There is a link on the BDC in the technical papers thread.

[Relativistic]

Yes, the UV radiation is both responsible for the formation and destruction of ozone.

There is a link on the BDC in the technical papers thread.

Ok thanks, will have a look later.

[bluearmy]

anything of interest there ed? seems quite a warming forecast by ncep at the very top of the strat at day 10. ecm not yet quite on the same page with it less marked and at a bit lower lattitude

note that wave no 1 activity forecast remains good in the medium term.

[chionomaniac]

anything of interest there ed? seems quite a warming forecast by ncep at the very top of the strat at day 10. ecm not yet quite on the same page with it less marked and at a bit lower lattitude

note that wave no 1 activity forecast remains good in the medium term.

Well spotted Nick. I have had this image on my computer since I spotted it at lunch time but have been too busy to post - it's good to see that someone else has their eye on the ball!

I suspect that this is indeed due to the increase in wave number 1 activity that is forecast to rebound from the top of the stratosphere.

Still waiting for the GWO update.

Promising.

[Barry12]

anything of interest there ed? seems quite a warming forecast by ncep at the very top of the strat at day 10. ecm not yet quite on the same page with it less marked and at a bit lower lattitude

note that wave no 1 activity forecast remains good in the medium term.

Looks nice

[bluearmy]

Ncep still to update but ECM is more inline with yesterday's 1hpa ncep forecast today. The middle strat remains cool but it may well be getting squeezed from two directions soon.

[chionomaniac]

Ncep still to update but ECM is more inline with yesterday's 1hpa ncep forecast today. The middle strat remains cool but it may well be getting squeezed from two directions soon.

Would agree here ba.

I said that we would need to wait until the last third of October to try and get some idea of how the start of winter could shape up and we are starting to get an idea now..

Unfortunately the stratosphere at all levels has cooled below average for this time of year. Cooling has been aided by a lack of NH ozone and I suspect a knock on from a rapid warming in the SH.

Strong wave activity in the SH spring has aided and abetted the southern arm of the BDC, reducing the amount of tropical ozone available cooling the tropical stratosphere. It is only in the last week or two that we have seen a reduction of SH stratospheric temperatures and a recovery of tropical stratosphere temperature - this suggests that ozone is slowly reforming and recovering here.

The balance view and my suspicions are at this point that the tropospheric autumnal blocking will slowly fade away as winter gets nearer unless we see some warming of the NH polar stratosphere. So looking at the forecasts one of the things we note is that the tropospheric blocking pattern does feed back somewhat on the lower stratosphere through wave breaks through the tropopause and this introduces warmer air at the lower stratosphere level. However, looking at the lowest level (100hPa) the temperature still never quite reaches average though it does come close.

http://wekuw.met.fu-...ast=all&lng=eng

I think that we will need to see greater warming and disruption in the coming month than this if we are to maintain the disrupted pattern.

Luckily, at the 30 hPa the mean zonal winds are still well below 20 m/s but yet again we are still in autumn when the polar vortex is gaining in strength and even with the contra flowing QBO a further increase is likely.

So next we look at the upper vortex and there are signs that a weak wavenumber 1 activity is causing some disruption on the upper temperatures with a 10ºC warmer section riding the surf zone - we need to see this have further affect lower down though.

So, the overall picture is that the stratosphere is cooling down this month and the temperature is currently below average. There are signs that this cooling will be interrupted by some minor warmings but as of yet these look too small to make a significant impact.

It is too early to forecast a strong vortex for the start of winter as of yet though because there are still just under 6 weeks to go.

On another note for the two week forecasts there are hints that the displaced vortex forecast over Scandinavia will change to a more split type vortex with one segent each over opposing continents. This type of pattern is far better to see at this stage than a displaced vortex slowly return to the pole - it has the potential to keep height rises over Greenland and could lead to second more potent autumnal cold shot.

[johnholmes]

thanks for that update chio; have you got a chart for a similar time over previous autumns?

[chionomaniac]

thanks for that update chio; have you got a chart for a similar time over previous autumns?

Only from November in 2010 where the split went up to the 50 hPa level.

Also there are many warmings at the 1 hPa level that don't really affect lower down the strat, so we have to be very wary when looking at any temeperature changes here.

[Snowstorm1]

Winter over then Chio? I got a negative idea from that post for start of winter at least or have I read it incorrectly

[AWD]

Oh god. That isn't going to go down well.

[bluearmy]

purely from a gut feel perspective but i currently see that wherever nature seems to put something in the way, something else is cropping up to potentially salvage the position. i would, of course like to see the 30hpa temps rather higher than they are now but i dont think this is a strong reason to be despondent. know more in a fortnight when, incidentally, the ecm temperature forecasts will have begun to be shown.

[chionomaniac]

purely from a gut feel perspective but i currently see that wherever nature seems to put something in the way, something else is cropping up to potentially salvage the position. i would, of course like to see the 30hpa temps rather higher than they are now but i dont think this is a strong reason to be despondent. know more in a fortnight when, incidentally, the ecm temperature forecasts will have begun to be shown.

They are already shown on the forecast charts though, ba.

[bluearmy]

They are already shown on the forecast charts though, ba.

Easier to see on tabular format and also shows deviation from average ed. Take your point though. Btw, your 'realistic assessment' seems to have burst some bubbles.

Edited October 20, 2012 by bluearmy

[Snowstorm1]

Easier to see on tabular format and also shows deviation from average ed. Take your point though. Btw, your 'realistic assessment' seems to have burst some bubbles.

Its popped my bubble ..

[snowking]

Easier to see on tabular format and also shows deviation from average ed. Take your point though. Btw, your 'realistic assessment' seems to have burst some bubbles.

I think it had to though....people are perhaps getting too carried away with the impending cool down without looking at the broader picture. There's two key points here really

1) as chio has already stated, there needs to be an increase in ozone over the tropics, ready to (hopefully) transport north for there to be a chance of sustained northern blocking or, perhaps more prominently, a weakening of the vortex during the main winter period. Such an increase will increase the polar - tropical thermal gradient, and therefore flatten the pattern somewhat at mid latitudes. That has to happen in order to increase the chances of warmings further down the line, and I would much rather see that happen through November than December....or January... I guess you can look at it from the point of view that cyclogenesis during November (assuming its brought about by a warming over the tropical stratosphere as opposed to a significant cool down over the polar regions) will be a good thing.

And if anybody wants a little more encouragement then

2) the pattern setting up (potentially) next week is one that is prone to repetition over a number of months. Lets take an example from oh I don't know, say November 1962:

http://modeles.meteociel.fr/modeles/reana/1962/archivesnh-1962-11-18-12-0.png

Bear any similarities to ridge placement?

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=150&mode=0&carte=1

I wonder if there's any examples of such a pattern repeating during said winter:

http://modeles.meteociel.fr/modeles/reana/1962/archivesnh-1962-12-26-12-0.png

http://modeles.meteociel.fr/modeles/reana/1963/archivesnh-1963-1-29-12-0.png

Now lets be frank, pattern matching is hardly the pinnacle of science and given the chaotic nature weather this is by no means a guarantee that we are going to see such repetition this year - the biggest potential chaos element here being should we see the stratosphere cool significantly. But as much as it amuses me to have seen the first 'winter is over' post in OCTOBER, lets have a little perspective and insight perhaps before we write off a 4 month period

SK

[chionomaniac]

post deleted

Edited October 20, 2012 by chionomaniac