Stratosphere Temperature Watch 2012/2013

[chionomaniac]

Recretos, I would say that the wave pattern is location specific because the deflection of tropospheric planetary waves is only going to occur in set locations.

[Recretos]

Yes, I understand that part. What I meant with location specific was, like for example: wave 1 is always in one specific location and wave 2 also at a specific location. As you just said, the deflection is location or terrain specific, but the number for the specific wave is given because of the order, or sequence. Or at least that's how I now understand. And that was my main dilemma: Is the number given in respect to the wave succession, or is it given to a location specific event, just for example: wave 1 only in Asia and wave 2 only in Pacific/N America.

Edited November 27, 2012 by Recretos

[chionomaniac]

Yes, I understand that part. What I meant with location specific was, like for example: wave 1 is always in one specific location and wave 2 also at a specific location. As you just said, the deflection is location or terrain specific, but the number for the specific wave is given because of the order, or sequence. Or at least that's how I now understand. And that was my main dilemma: Is the number given in respect to the wave succession, or is it given to a location specific event, just for example: wave 1 only in Asia and wave 2 only in Pacific/N America.

This paper below shows where blocks have occured prior to the wave events that have led to SSW's. As you can see Atlantic blocks seem to favour displacements and Pacific blocks favour splits.

Look at table 1

http://www.columbia.edu/~lmp/paps/martius+polvani+davies-GRL-2009.pdf

[Recretos]

This paper below shows where blocks have occured prior to the wave events that have led to SSW's. As you can see Atlantic blocks seem to favour displacements and Pacific blocks favour splits.

Look at table 1

http://www.columbia....es-GRL-2009.pdf

Very interesting paper. I will read the whole thing as soon as I can find enough time.

I see the table 1 yes. Basically it could be safely to say that wave 1 and 2 are with respect to Atlantic and Pacific (on a general view) and with respect to displacement and splitting, as you were pointing out with your analogy.

Thanks again for your time. I probably look really stupid with these questions. I will go through some papers and/or studies to see if I can make things even more clear for me.

Best regard.

Edited November 28, 2012 by Recretos

[Catacol]

Excuse me if this sounds daft - and I cant see a better thread to ask the question in - but can volcanic eruptions affect the stratosphere in any way? I notice today that the previously inactive volcano Tolbachic in Kamchatka has exploded today, sending ash on day 1 33,000 ft up. I guess it may go a fair bit higher if today is only day 1.

Any impact or am I showing myself to be a total novice?

Genuine question...

EDIT: hey - guess what... the volcano erupted in both 1962/63 and 1968/69. Surely that must be a sign... :-)

Edited November 28, 2012 by Catacol_Highlander

[jethro]

Excuse me if this sounds daft - and I cant see a better thread to ask the question in - but can volcanic eruptions affect the stratosphere in any way? I notice today that the previously inactive volcano Tolbachic in Kamchatka has exploded today, sending ash on day 1 33,000 ft up. I guess it may go a fair bit higher if today is only day 1.

Any impact or am I showing myself to be a total novice?

Genuine question...

If it goes high enough and ejects enough sulphur, then yes, it can have an effect. There was a paper posted a while back in the Volcanic thread here: http://forum.netweather.tv/topic/62309-general-volcanic-activity-thread/page__st__1420

[Gael_Force]

http://pubs.giss.nasa.gov/docs/2001/2001_Shindell_etal_1.pdf

When this paper was compiled, the scientists had no idea that we would be looking at such an inactive sun in just a few short years.My question, on reading the details of the modelling of the processes in the troposphere and stratosphere - are we seeing evidence of what the models indicated in the current unusual patterns of disconnect between the atmospheric levels?

[Duane S.]

Chiono. Just thinking out loud...

Is it possible that wave 1 activity will actually have been be a hinderance this time around? Just thinking it must be at least part-responsible for the predicted zonal movement of the vortex pieces split up by wave 2 ? i.e. that if we JUST had wave 2 splitting the vortex that it would have been much more likely for HLB to set up over Greenland, with the western segment of the vortex dritfting out of the way across Canada?

[chionomaniac]

Possibly, in the short term, s4.

[chionomaniac]

Possibly, in the short term, s4.

But is wave number two about to make a reappearance?

[bluearmy]

i think S4L has a valid point and i made similar in the MDT. however, the wave 2, wave 1, wave 2 scenario will ultimately do more damage to the vortex than a simple split and reformation. we may lose out on an early dec very cold spell but the benefits down the line could be better for sustained cold.

[Glacier Point]

I suspect wave 1 activity in mid to late December will deal the killer blow.

Already seeing signs that the vortex transfer is raising heights over the Siberian side and drawing up the Kamchatkan ridge into the fold. Next evolution would be for the Aleutian low to develop and bingo, 20 days later you're looking at a vortex literally scattered to the four winds.

Meantime, as speculated, episodic wave 2 activity really cutting into this vortex.

[MattH]

Morning...Few ECMWF charts from yesterday's 12Z run to highlight which continue to seem of interest;

Continued trend for a major ridge to develop and bring a marked region of warming into more eastern areas of Canada in particular. What does seem to be evident if you run down the below charts is that despite the vortex re-developing after the split, the trend for the vortex to be 'pushed' into parts of northern Russia does seem to take place.

http://wekuw.met.fu-...l&lng=eng#fig11

Evident well on the 50hPa charts as well, perhaps this may promote ridging/higher pressure to the NW with time(?)

http://wekuw.met.fu-...l&lng=eng#fig11

Continued trend as well for the zonal winds to decrease and fall to far more promising levels given the above developments;

http://wekuw.met.fu-...l&var=u&lng=eng

Wave 2 activity continues to look as though it will peak in the next 3 or 4 days but then as this wanes, up steps Wave 1 within the 7 to 10 day time frame (as mentioned above by GP) and the magnitude of this particular wave by day 10 looks pretty impressive to me!;

http://wekuw.met.fu-...a2&lng=eng#fig5

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ha1&lng=eng

Overall I think we have and continue to be very lucky in terms of the lack of influence the strong vortex has had on the troposphere. Clearly many will remember this time last year and we were staring down the barrel of a zonal mess. So despite what has clearly been a noteworthy and significant vortex during the autumn, the above charts continue to be very interesting indeed. The clear progression within the short term, towards something more unsettled with quite a noteworthy region of 'energy' near southern Greenland allowing some Atlantic influence, I believe, will be temporary on the grand scheme of things for December. The last update of the EC 32 on Tue morning highlighted further blocking to the NW of the UK towards Christmas and clearly it did overall pick up this current pattern we are in and a colder end to November/start to December. So here's hoping, but without sounding like I'm repeating what others have mentioned, I do think that the second half of December and January are well primed for some noteworthy cold outbreaks and clearly if you want a decent cold synoptic setup then that (IMO) is the best time of the winter for it/them.

Regards to all, Matt.

Edited November 29, 2012 by MattHugo

[Ice BIast]

Will the EPV Flux have much of an effect? It appears to be forecast to be going away from the pole if I'm reading it correctly, or is this usually the case?

[FrenchScotPilot1]

Is this a warming at 1hPa starting on day 9 over Spain?

http://wekuw.met.fu-...st=f240&lng=eng

Edited November 29, 2012 by FrenchScotPilot1

[chionomaniac]

Is this a warming at 1hPa starting on day 9 over Spain?

http://wekuw.met.fu-...st=f240&lng=eng

Yes- I was just going to mention that even though that this warming is not as strong as previously forecast on the extended GFS, it is still strong enough to cause sufficient displacement towards Iceland. Again, the position translating down to the troposphere actually translates to that MW to SE flow seen at 100hPa:

It doesn't appear that this wave 1 activity will yet lead to a warming lower than the top of the strat - so I think that we may need 1 more tropospheric led blow to be GP's killer blow. There is a lot of uncertainty regarding exact vortex positioning post day 10. As I mentioned last night in the model thread there have been a few suggestions that the vortex may split or relocate to the Canadian sector - and I will be keeping a close eye on developments here to get an idea of the overall trend.

Will the EPV Flux have much of an effect? It appears to be forecast to be going away from the pole if I'm reading it correctly, or is this usually the case?

The ep flux in normal circumstances id directed away from the pole. In events when the EP flux is directed towards the pole we see both propagation and mid level disruption of the vortex that can lead to a SSW.

[FrenchScotPilot1]

Very roughly, Eliassen-Paml vectors represent the amount of heat and momentum fluxes from the troposphere to penetrate the polar stratosphere.

If I remember correctly vertical vectors are synonymous of heat and any deviation from the vertical indicate momentum.

Therefore, long vertical vectors indicate a good propagation and vertical flow of heat (good wave propagation).

Please correct me if this is wrong.

[picog]

It will be good to see this going in the opposite direction. I hope the posters' interpretation of the charts that affect stratospheric temps are right!

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/html_e/pole30_n.html

[garbagebags]

Anyone have any idea as to why the strat is so cold?

From what I gather the GFS has pockets tanking down to near -90 over the next few weeks. This is nearly off the chart. Why is it so cold, as in what causes this?

[lorenzo]

Here is a well written paper, by that I mean slightly easier to digest than some of the ultra-technical works, not looked at everything here yet, heat flux is the next area figure out !!

Within this the role of Wave 1 and Wave 2 upon the Polar Vortex is examined for correlation to SSWs, very topical. Other features covered include a re-analysis of work by Charlton & Polvani (2007) on definition, among other work the paper also looks at the influence of Blocking and other pre conditioning prior to SSWs.

Here is an image re-produced in the paper, great visual representation of our - currently cannot make up my mind where I want to live in GFS FI - friend.

[cooling climate]

Will the EPV Flux have much of an effect? It appears to be forecast to be going away from the pole if I'm reading it correctly, or is this usually the case?

Well according to these E-P flux charts the flux is pointing northward.

[MattH]

Morning all...

Just a quick one, but the EC 32 day continues to maintain a risk of +ve pressure anoms to the N and NW of the UK throughout the Dec with lower than average pressure to the S and SE. Clearly this is a persistent signal and the model runs through to the 30th of Dec now. The signal does weaken as the month progresses, but there remains little evidence at all to support lower than average pressure either to the NW, N or NE of the UK through the Dec.

Also just wanted to post this image as the correlation between the EC32 day between the same time frame matches this GFS ENS image very well;

http://raleighwx.americanwx.com/models/gfsensemble/00zENS11-15day500mbHeightAnomalyNH.gif

Clearly that is an pretty impressive anomaly distribution and again matches the EC32 almost perfectly towards mid-month. The possibilities through December look quite extensive and, to me, the risk now of a zonal, wet, windy and mild month looks highly unlikely. Lets hope that further wave 1/2 activity continues to bombard the vortex and aids it's demise, of sorts, during the second half of the month to then potentially setup a mouthwatering January perhaps.

Cheers, Matt.

[chionomaniac]

Thanks for the update Matt.

Still a lot of uncertainty regarding vortex positioning around day 10 - 15.

We have a warming programmed for the top of the stratosphere from day 10 - I don't think that this will propagate too much to lower levels as it looks to fail to thoroughly break the surf zone (displaces only).

My suspicions are currently that we will see a more significant warming around day 20 at the 10 hPa level. There are hints in the longer range forecasts suggesting that a warming is waiting in the wings at that timeframe ( late December).

Stewart - would that be consistent with your thoughts and have you spotted the trend at 10 hPa FI?

[Glacier Point]

This looks more in line with the long term trend to shift the core pv towards NW Russia. Still looking like we'll get the 'firing pistol' Pacific low around 20 December (which equates to vortex reacting around 9th Jan).

Vortex forecasts doing a good impression of cat on a hot tin roof. Transfer from one location to the other and elongating. Clearly this pv is not a happy bunny.

[Glacier Point]

Vortex all over the shop.

t204 part breaks off over Siberia

t240 elongated and displaced towards Greenland

t300 starting to form a dumbell and suggestion of heading back towards Siberia

t360 main core over Sibria and another split

When you start to see this modelled, you appreciate just what turmoil the vortex is in and what dynamical processes must be going on there. This invariably is a precursor to major cold outbreaks across the northern hemisphere. Expect continued model volatility from here on in.

Edited November 30, 2012 by Glacier Point