Stratosphere Temperature Watch 2011/2012

[knocker]

If this is true then does that mean the constantly strong, over the past couple of decades or so, polar vortex is disrupting the jet stream and weather in the northern hemisphere.

And do they take this in to consideration in regards to AGW? Maybe it's the ozone layer and not CO2?

I don't know the answer to this but I'll make a couple of observations.

We know that the more intense and colder vortex in Antarctica facilitates the formation the huge ozone hole in that area. A very recent paper has speculated that the latter has altered the atmospheric circulation to such an extent that sea ice has actually increased which is opposite to what is occuring in the Arctic.

Now if the lower stratosphere in the Arctic continues to cool, thus increasing the ozone hole, will this similarly alter the circulation patterns and perhaps effect the UK and north west Europe? I'm certainly not qualified to give an opinion on that.

Regarding CO² I'm not sure it's relevant unless of course you ago along with the idea that pumping it into the atmosphere is causing the troposphere to warm and the lower stratosphere to cool when it becomes extremely relevant.

Edited January 20, 2012 by weather ship

[Gray-Wolf]

I think the physical geography of the N.H. is so markedly different than the S.H. that it'd be hard to see the type of 'circumpolar pattern evolve here? The various ( and spaced) mountains/plateau's impact the circulation and so we'd probably end up with a high energy,very sinuous Jet?

[chionomaniac]

Will update later today. In short, things are really encouraging.

[cyclonic happiness]

Will update later today. In short, things are really encouraging.

Good stuff Ch!

I'm actually in two minds at to whether I want a cold spell this winter or not lol!

You can bet your life we'll get one to remember!

[chionomaniac]

Today's update in full.

So far this winter we have seen an extremely cold stratosphere dominate proceedings. This has led to a protracted period of zonality caused by the vortex intensification that resulted from the cold.

Around Christmas time we had the first signs that things would change and sure enough just under a month later the changes are working there way through to the tropospheric output. These changes resulted from a series of remote wave breaking events at the top of the stratosphere introducing warmer air that has taken time as it has propagated nodally down the stratosphere.

We are now at a situation where currently we are seeing a warming into the core of the vortex far closer to the troposphere than encountered so far this winter - at the 30 hPa level.

The upper warnings so far have had the net effect of dragging the mean zonal negative winds equator wards which has somewhat inhibited the effect felt in northern latitudes tropospherically with the stratospheric polar vortex reducing but still present.

However this could change with the positioning of the next warming at 30 hPa:

And we are likely to see a far greater lower negative anomaly of mean zonal winds by the end of the month:

So we can compare the forecast for the mean zonal winds and look to see that the polar vortex has reduced dramatically in intensity as we are not too far away from a technical SSW.

So what does this mean for us on the ground?

Well to get a better idea we need to be looking at the charts for the lowest part of the stratosphere at around 100 hPa

Both the GFS and ECM are modelling a weaker less stable vortex that is constantly on the shift. In fact there has been some suggestions of splitting by day 10

If this occurs then any Siberian vortex could exert some pressure on the Siberian High pushing the Russian high further west towards the UK followed by a Greenland pressure rise after that. This also fits in nicely with the GWO rather than working against this.

The troposphere models are coming up with these scenarios. Finally, the slow drip feed of the stratospheric change into the troposphere is coming close to bearing fruit.

c

[phil nw.]

Thanks Ed-a good summary of things there.

Yes the fact that mean Zonal winds have dropped and are forecasted to drop to virtually zero at High latitudes by day 10 is a sure sign that the vortex is very much on the wane now.

Edited January 21, 2012 by phil n.warks.

[mcweather]

Thanks for the update Chiono. I have found your stuff extremely helpful this winter. Certainly the charts are now beginning to show some of these effects as we head over the next ten days. Todays ECM00Z at 240 pretty much shows up what you have said about the russian high being pushed westwards by a siberian vortex it even shows the very early signs of retrogression towards greenland as well.

Figres crossed.

[Orgu]

Hello everybody! I found this forum early this winter and have followed it with great interest. Very enlightening posts, even for a professional meteorologist! Now, I want to bring some contribution on my own, and it is about whether SSW is leading the troposphere or the other way around.

It seems to be to cut both ways. Last winter, I did some statistics for the temperature in Oslo before and after a SSW, and found the temperature to be lower than normal the first weeks, a notch towards normal 20-30 days after the SSW, and then a new dip 30-40 days after.

This winter I did some statistics, including the period before the SSW, and dividing it in La Nina and El Nino winters, inspired by an artice I read recently, which was about the frequency of SSW, which was found to be equally frequent in El Nino as La Nina (less frequent in neutral).

The results were surprising in more than one way. The temperature in La Nina winters were 50 days before SSW 2 degrees above normal (fits with the findings of a colder stratosphere in La Nina winters and as this winter have been), and in El Nino 2 degrees below normal. During the winter a SSW occured, and in La Nina the temperature sank- towards normal after the SSW, reaching normal in the end. In El Nino the temperature increased (!) during the winter, also after the SSW and also reached normal temperatures 30-40 days after SSW.

Several articles describe tropospheric blockings as a precursor to SSW, with warming propagating upwards. There seems to be much discussion in this forum focusing on the downward propagation. I don't know the details, but I guess this has to do with wave 1 and wave 2 activity, where one of them is more connected to upward and the other downward, and also to the EP-flux through 60 degrees, where southward flux is connected to downward, and northward to upward.

This winter therefore seems to have had more southward flux, associated with downward warming, but recently the charts has shown northward flux, associated with the blocking-tendency we have seen in several prognosis, which have been supported by the warming stratosphere. In El Nino winters the dynamics are totally different.

My view on how to handle the stratosphere is that it goes hand in hand with the troposphere, but it should be handled carefully how they interact, and I still dont master the details.

I would gladly present my excel-graphs but dont know how..

[chionomaniac]

Hi Orgu and a warm welcome to Netweather.

Thank you for your contribution. I agree entirely with the notion that the troposphere goes hand in hand with the stratosphere with both feeding back to each other.

The paper that you describe I think has been mentioned before, but how interesting that a cold stratosphere persists before a possible La Nina SSW. That is exactly what we have seen this winter with a period of vortex intensification(VI) followed by the warming episodes.

Good paper here on subject

http://www.mri-jma.go.jp/Dep/cl/kuroda/2007JD009550.pdf

I have to say every year I learn a little bit more on a fascinating subject which goes hand in hand with the tropospheric output.

c

[J10]

Hello everybody! I found this forum early this winter and have followed it with great interest. Very enlightening posts, even for a professional meteorologist! Now, I want to bring some contribution on my own, and it is about whether SSW is leading the troposphere or the other way around.

It seems to be to cut both ways. Last winter, I did some statistics for the temperature in Oslo before and after a SSW, and found the temperature to be lower than normal the first weeks, a notch towards normal 20-30 days after the SSW, and then a new dip 30-40 days after.

This winter I did some statistics, including the period before the SSW, and dividing it in La Nina and El Nino winters, inspired by an artice I read recently, which was about the frequency of SSW, which was found to be equally frequent in El Nino as La Nina (less frequent in neutral).

The results were surprising in more than one way. The temperature in La Nina winters were 50 days before SSW 2 degrees above normal (fits with the findings of a colder stratosphere in La Nina winters and as this winter have been), and in El Nino 2 degrees below normal. During the winter a SSW occured, and in La Nina the temperature sank- towards normal after the SSW, reaching normal in the end. In El Nino the temperature increased (!) during the winter, also after the SSW and also reached normal temperatures 30-40 days after SSW.

Several articles describe tropospheric blockings as a precursor to SSW, with warming propagating upwards. There seems to be much discussion in this forum focusing on the downward propagation. I don't know the details, but I guess this has to do with wave 1 and wave 2 activity, where one of them is more connected to upward and the other downward, and also to the EP-flux through 60 degrees, where southward flux is connected to downward, and northward to upward.

This winter therefore seems to have had more southward flux, associated with downward warming, but recently the charts has shown northward flux, associated with the blocking-tendency we have seen in several prognosis, which have been supported by the warming stratosphere. In El Nino winters the dynamics are totally different.

My view on how to handle the stratosphere is that it goes hand in hand with the troposphere, but it should be handled carefully how they interact, and I still dont master the details.

I would gladly present my excel-graphs but dont know how..

Excellent analysis there

It is possible to download an entire Excel file, so it is possible to download graphs that way.

[sebastiaan1973]

There is also a possibility to upload the files with e.g. mediafire or zippyshare and place the link overhere.

Thanks for sharing your research.

[blitzen]

Intresting comments from Matt Hugo on twitter which appear to be backing up GP's and Chiono's analysis?

https://twitter.com/#!/MattHugo81/status/161089572292403201/photo/1

Not sure if I should post this on here? If not, my apologies and Mods please remove.

[Cloud 10]

Just browsing through some stratosphere charts and came up with this from the gfs at 1mb.

Given the timescale to get that forecasted warming to the lower levels of the

stratosphere,could this be the first signs of the final warming which happens

every year.?

[cooling climate]

Intresting comments from Matt Hugo on twitter which appear to be backing up GP's and Chiono's analysis?

https://twitter.com/...2403201/photo/1

Not sure if I should post this on here? If not, my apologies and Mods please remove.

Zonal winds were forcast to be lower than this yesterday in the later timeframe, will be interesting to

see what the ECM says tomorrow.

[J10]

Thought I'd post this in here, the background signals seem to suggest heights rising in the Northern Latitudes including into Greenland, why are we not seemingly getting this in the model runs atm e.g. tonight's ECM 12HZ , or I am getting this completely wrong.

[chionomaniac]

One has to remember Jackone is that the tropospheric vortex does have it's own thermal and baroclinic driver which seems to be holding it's own against the stratospheric signal. It is still early days for the full effects of stratospheric warming to be modelled.

[chionomaniac]

Out of interest I am going to show the last 10 days forecasts at 100 hPa to see how relaible they were. I will put them on in descending order with FI at the beginning and won't check them until posted to see the difference.

And the theme- the main trouigh has maintained position and intensity over northern Greenland. The secondary trough didn't split, weakened and was due east of where it was initially forecast. Overall the theme has been maintained. So not bad.

And todays 10 day forecast

Not bad as well - heights building in from Azores towards Scandi with a little undercut built in as well - sound familiar.

Edited January 23, 2012 by chionomaniac

[geoffw]

does that equal cold and snow?

[chionomaniac]

Great GFS stratospheric charts this evening.

We are very close to achieving a technical SSW.

But look at the stretch on the vortex here at T+240 and 100 hPa

And look at the ozone levels!

What a contrast to a year ago!

I am already thinking that this will give us a good starting base for next winter!

[BLAST FROM THE PAST]

Great GFS stratospheric charts this evening.

We are very close to achieving a technical SSW.

But look at the stretch on the vortex here at T+240 and 100 hPa

And look at the ozone levels!

What a contrast to a year ago!

I am already thinking that this will give us a good starting base for next winter!

LOL.....nice

BFTP

Edited January 23, 2012 by BLAST FROM THE PAST

[phil nw.]

Great GFS stratospheric charts this evening.

We are very close to achieving a technical SSW.

But look at the stretch on the vortex here at T+240 and 100 hPa

And look at the ozone levels!

What a contrast to a year ago!

I am already thinking that this will give us a good starting base for next winter!

Does this mean we could have a less cold Stratospheric profile at the beginning of next Winter C.?

I mean those Ozone levels- do they hold for a prolonged period so that heat gained over Summer is retained as the Polar night recommences ?

[Isolated Frost]

I can only assume high ozone layer amounts lead to a higher chance of blocking heights over the area in question?

[BLAST FROM THE PAST]

Does this mean we could have a less cold Stratospheric profile at the beginning of next Winter C.?

I mean those Ozone levels- do they hold for a prolonged period so that heat gained over Summer is retained as the Polar night recommences ?

I believe more ozone leads to warmer stratos or prevents stratos from cooling....don't know if it signals a -ve QBO too

BFTP

[summer blizzard]

Does this mean we could have a less cold Stratospheric profile at the beginning of next Winter C.?

I mean those Ozone levels- do they hold for a prolonged period so that heat gained over Summer is retained as the Polar night recommences ?

In theory, higher O-zone levels encourage stratospheric warming.

In practice there are other factors which may work against stratospheric warming as a +QBO could develop anytime from November onward.

[Gray-Wolf]

The Methane seepage over the pole may also play a part here as Methane destroys Ozone in the Strat. When we look at monthly plots of CH4 from sat, data we can see that the Arctic winter leads to a lot of CH4 where as over melt season much of the ozone is able to react, due to UV, and so is not apparent. If the Siberian Shelf is losing increasing amount of CH4 then some of that will end up in the strat leading to ozone issues (did we not nearly have a hole in the ozone last spring?)