Stratosphere Temperature Watch

[chionomaniac]

The 10 day stratospheric profiles fit in nicely with the idea of PV induced troughing from Scandinavia to Svalbard to Northern Siberia as per tropospheric models. The warmer strat area extends from the Pacific to North America which subsequently matches the NH displacement of the polar vortex from top to bottom.

Things look more believable when the stratospheric output matches that of the troposphere.

10 day forecasts

At 30hPa level

and lower down at the 100hPa level

8-10 500hPa Mean -http://www.meteo.psu.edu/~gadomski/ECMWF_0z/hgtcomp.html

This always leaves me wondering is the stratospheric PV positioning influencing the tropospheric PV positioning or is it the other way around. Both have good solid reasoning why they could be the drivers.

[Kentish Kiwi]

The first tentative signs of warming at the 30mb level in the arctic.

Ozone levels in the Arctic are again quite high which could very well be due to the uptick

in stratospheric temperatures as seen above.

It still remains to be seen that if we get any substantial warming in the stratosphere this

autumn and winter whether it will propagate down into the troposphere given that we are

now in a +QBO phase.

Do you think you could provide me with a link to the above (first) graph please CC? For me anyway it seems to be the most simple and straight forward chart to follow.

Tentative yet promising early signs in regards to the above warming, even though it would seem larger-scale signals are generally against sustained warming compared to last year anyway.

Cheers, KK.

[cooling climate]

Here you go.

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

[Duane S.]

Unrelated, i know Weymouth is right on the south coast, but seriously?!

Yep, some wet stuff fell on one day during January whilst I was at work but had all but melted by the time I got home.

[Fozfoster]

Great to see this thread back C.I feel winter starts now!

[knocker]

Just thought I'd have a quick look at the 100mb data plots and contours for midnight. Note the contours are every 120m not 60.

[chionomaniac]

Doors open at the ECM today with the first readings and forecasts.

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/diag.php

Main thing to see is a slight warming at the 10 hPa level at mid latitudes.This appears to dissipate rather than breaking into the main vortex. Both the GFS and ECM support this.

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ec.php?alert=1&level=10&forecast=all&lng=eng

The vortex is getting stronger every day regardless

[Weather-history]

I think this might of interest

[chionomaniac]

Fantastic. One of the first recorded SSW's!

[cooling climate]

Very interesting Data.

I see there is reference to the observed weather during the month but as we are

all to aware there is a lag effect to be taken into account if the warming propagates

downwards to the troposphere. I therefor decided to look at the archive charts for

March 1951 and low and behold by the 7 and 8th there is a 1065 mb Greenland

high which lasts for nearly a fortnight.

Solar flares and CME's (corona mass ejections) need to be monitored over the

next few months along with any rosby wave breaking.

Edited November 1, 2010 by cooling climate

[knocker]

Seems to be plenty of total ozone.

[knocker]

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.

Edited November 3, 2010 by weather ship

[Duane S.]

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.

Looking at the 'event' dropdown list there appears to be nothing between 1989 and 1998, is this because there were no notable SSW events in that period?

[knocker]

Not necessarily. it goes into a bit more detail in the 'about' section.

[chionomaniac]

Tentative?

Whereas it is good to see any above average temperatures in the stratosphere at this time of year, forecasts are suggesting that this will be temporary at both the 10hPa and 30hPa levels. What would be good to see is a sustained above average temperature anomaly at these levels. Going into this winter I suspect that this is unlikely, however, those ozone levels are higher than I would have expected so who knows?

[johnholmes]

The 30mb is quite similar to November 2008 but not the same at this time in 2009, for what, if anything, that is worth.

[cooling climate]

Zonal wave 1 amplitude. This looks very encouraging.

Geopotential height anomaly (when elevated = warming) is also very encouraging.

[knocker]

See next post. Had a senior moment.

Edited November 4, 2010 by weather ship

[knocker]

Going into this winter I suspect that this is unlikely, however, those ozone levels are higher than I would have expected so who knows?

I'm afraid my brain cell isn't working too well at the moment but I'm failing to see the significance of the current levels of ozone. I agree they seem fairly high compared to say 2005/06 which was a warm winter so PSCs didn't come into play. I can also see that a cold stratosphere affects the vortex but I'm missing the connection between this and current ozone levels. What little I know about SSW events is to do with long Rossby waves in the troposphere travelling upwards into the stratosphere. So I'm missing something.

[chionomaniac]

Hi WS,

If we put SSW's aside for the time being and look at the ozone levels. The amount of ozone in the polar stratosphere is related generally to the warmth of the stratosphere as ozone formation is an exothermic reaction. It also indicates the strength of the Brewer Dobson Circulation transported to the poles which can indicate reduced thermal gradients between the polar stratosphere and tropical stratosphere.

We don't need a SSW for a warmer stratosphere to exert an influence on the troposphere as was seen by the start to last winter.

Edited November 4, 2010 by chionomaniac

[knocker]

Thanks for that CM. I’m okay with the points you made ( Agreed SSW is a different matter) but I think the area that I’ve been thinking about concerns the question of why some stratospheric winters are cold and others warm? In simplistic terms I take this to basically depend on two points. The strength and stability of the vortex and the Brewer-Dobson circulation.

This brings me to the polar night jet. This I take it is important because it blocks any mixing of air between inside and outside the vortex during the winter. But the jet is not so effective in the Arctic in keeping out intrusions of warmer, ozone-rich midlatitude air as it is in the Antarctic where the vortex becomes isolated. So, I’m assuming, and please correct me if I’m wrong, keeping an eye on ozone levels and temp and gradient levels at points in the Arctic stratosphere is a way of seeing how effective the polar night jet is being from year to year and accounts for the annual variation.. If it’s being totally effective then this would lead to an isolated vortex and ozone depletion, particularly if PSCs were involved.

I’m sure there other aspects to be taken into consideration as not having given it that much thought before I didn’t realise how complicated Stratosphere/Troposphere interactions could be.

[johnholmes]

I didn’t realise how complicated Stratosphere/Troposphere interactions could be.

join the club Fred

[chionomaniac]

Thanks for that CM. I’m okay with the points you made ( Agreed SSW is a different matter) but I think the area that I’ve been thinking about concerns the question of why some stratospheric winters are cold and others warm? In simplistic terms I take this to basically depend on two points. The strength and stability of the vortex and the Brewer-Dobson circulation.

This brings me to the polar night jet. This I take it is important because it blocks any mixing of air between inside and outside the vortex during the winter. But the jet is not so effective in the Arctic in keeping out intrusions of warmer, ozone-rich midlatitude air as it is in the Antarctic where the vortex becomes isolated. So, I’m assuming, and please correct me if I’m wrong, keeping an eye on ozone levels and temp and gradient levels at points in the Arctic stratosphere is a way of seeing how effective the polar night jet is being from year to year and accounts for the annual variation.. If it’s being totally effective then this would lead to an isolated vortex and ozone depletion, particularly if PSCs were involved.

I’m sure there other aspects to be taken into consideration as not having given it that much thought before I didn’t realise how complicated Stratosphere/Troposphere interactions could be.

I think that this is pretty much right. I consider the stratospheric winter polar vortex and polar night jet to be the same thing caused by the lack of sunlight reaching the polar regions during winter. The stratospheric junction between the vortex and latitudes further south has been termed the stratospheric surf zone where deflected Rossby wave may ride without actually being able to penetrate. Of course some do, and this can lead to warming as the vortex slows and warmer infiltrates. This can occur either from a deflected Rossby wave riding the surf zone to the top of the stratosphere before entering the centre and propagating back down. Another way is by upward propagating waves from the troposphere disrupting the lower reaches of the central stratospheric vortex (and I believe that this was seen last winter.)

The mechanisms involved in the stratospheric vortex are complex and a lot of research is undergoing in this area to help understand the tropospheric/stratospheric interactions.

c

[Weather-history]

This short article by Dr H McIntosh written in late 1952

"In the daily publication, Wetterkarte of the Meteorological Service of the US zone of Germany for March 14 1952, Professor Scherhag described remarkable meteorological and ionospheric effects which he associated with the occurrence of an intense solar eruption in the early hours of February 24. the temperature at 27km over Berlin rose from -64C which is normal for the season at 9am GMT, to -47C at 3pm GMT and to -17C by next morning. The increase in temperature extended downwards, the temperature at 20km rising from -60C on February 26 to -39C on February 29. The wind at 18 to 30km, normally almost always westerly in winter changed direction to east and increased in speed by the afternoon of 29th to the remarkable value of over 60kt. The wind change is considered to have been produced by the development of an intense high pressure area in the stratosphere over northern Europe."

A month later came this famous late season snow event.

[shuggee]

Very interesting Mr Data - putting it into the future weather context there. I think many people on here worked out a couple of years a relationship between potential UK cold around a month after a stratospheric warming event and good to see historical confirmation again of such an apparent link. Early December cold spell??