Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Stratosphere Temperature Watch 2014/2015


Recommended Posts

Good points Steve.

Of course we can't know if the different agencies already consider and include these in any model upgrades such as the new GFS due soon.

We have seen changes wrt the Stratosphere modelling in recent times so I would imagine forecasters would have an eye on these other factors you mention if they are on the ball.

Edit to add

Further to above this is worth a read from the MO Climate section

http://www.metoffice.gov.uk/services/climate-services/case-studies/improving-our-near-term-climate-predictions

It seems all recent changes are being considered in their LT forecasts.That,s the impression gained on reading that.

They do suggest that lower Arctic ice levels affecting the track of the jet and that it encourages +ve ht anomalies at high latitudes thus increasing chances of Easterly winds in Winter.

Just to say though that any imo Longer term outlooks can only give a general guide on probabilities and as ever should be treated with caution.☺

 

Cheers Phil-

 

Interested to see I made similar observations to the Met office top man... :)

It shows they are on the same wavelength.

 

 

An iconic impact of climate change is the melting of polar sea-ice. However, low Arctic sea ice cover is now becoming increasingly linked with significant changes in the North Atlantic jet stream in winter and hence the severity of European winters. A number of studies are indicating that Arctic sea ice depletion, in isolation, may increase sea level pressure over the Arctic in winter and drive more easterly winds across Europe in both observations and computer models. It is possible that continued low Arctic sea ice during the coming years might therefore drive additional changes in northern European climate due to changes in winds as well as the more direct warming effects of longer term climate change.

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Reading, Berkshire
  • Weather Preferences: Hot & Thundery or Cold & Snowy
  • Location: Reading, Berkshire

The wave 1 activity is pretty unusual in the 35 years recorded in the Merra dataset. Only 6 years even hold a candle to 2014 with similar wave activity during October, even then not as strong as current projections on the Berlin site.

 

Sounds very interesting, what years are they may I ask? I'd be interested to look to see how the following winters panned out. 

Link to comment
Share on other sites

Posted
  • Location: @scotlandwx
  • Weather Preferences: Crystal Clear High Pressure & Blue Skies
  • Location: @scotlandwx

No doubt that Polar temp gradient and Sea Ice Extent are 'hot topics' at present with respect to influence on the Jet. The Arctic Amplification paper Cohen et al has a great discussion on this, it's linked a couple of pages back on this thread. Extracts below.

 

post-7292-0-46973900-1413738493_thumb.pnpost-7292-0-03727600-1413738492_thumb.pn

 

The MERRA dataset is linked here http://acdb-ext.gsfc.nasa.gov/Data_services/met/ann_data.html#ncep_clim_stats_nh

 

For the years with the strong Wave 1 action in October 79/91/94/03/09/12, bold featured Canadian Warmings, before they seemingly went out of fashion. 

 

Adam Scaife, quoted in the Met Office paper linked above, also published an interesting letter in April on the NAO and AO in recognition of the problems currently being encountered by the GCMs which is worth a look.

 

http://onlinelibrary.wiley.com/doi/10.1002/2014GL059637/pdf

 

From an analog perspective the challenge remains small sample size, thereby tricky to glean the key differences between say all years since either the 50s or 70s,  versus recent decade if you chose to build from around 2000 to date, still worth doing though. 

 

 

 

 

 

 

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

Just completed an ozone comparison check from last year to this. And there is definitely a difference. Remember that an increased BDC will transport ozone from the tropical stratosphere to the polar stratosphere (both north and south) and the increased ozone levels will lead to a warmer strat.

 

 

post-4523-0-55238300-1413749080_thumb.pn

 

So last year at this point there was far more ozone spread throughout the tropical regions. This year there is far less tropical ozone and the ozone 'hole' above Greenland is not there this year. All promising so far but this will need to be checked again in another few weeks.

 

  • Like 6
Link to comment
Share on other sites

Yes Lorenzo can you link to the dataset.

 

I bet a lot of the high Wave 1 years correlate to the Canadian warming years.

http://www.microsofttranslator.com/BV.aspx?ref=IE8Activity&a=http%3A%2F%2Fwww.geo.fu-berlin.de%2Fmet%2Fag%2Fstrat%2Fprodukte%2Fnorthpole%2Findex.html

 

The Berlin site does actually have an English version - http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

 

The Merra dataset can be viewed/downloaded here - http://acd-ext.gsfc.nasa.gov/Data_services/met/ann_data.html

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Barnoldswick, Lancs, 500ft
  • Location: Barnoldswick, Lancs, 500ft
Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

Just completed an ozone comparison check from last year to this. And there is definitely a difference. Remember that an increased BDC will transport ozone from the tropical stratosphere to the polar stratosphere (both north and south) and the increased ozone levels will lead to a warmer strat.

 

 

attachicon.gifScreen Shot 2014-10-19 at 20.51.41.png

 

So last year at this point there was far more ozone spread throughout the tropical regions. This year there is far less tropical ozone and the ozone 'hole' above Greenland is not there this year. All promising so far but this will need to be checked again in another few weeks.

 

Have you got a reference for this? The warming effect of ozone is limited because there is no sunlight for photo-dissociation in winter, so it's radiative effect only - the large ozone variation over the Antarctic is only thought to be worth around 1 degK in winter.

While the BDC controls the background values, the relationship between temperature and ozone anomalies is more to do with that they are both dependent on troposphere EP flux and the QBO  - eg see Sulby 2011 http://journals.ametsoc.org/doi/full/10.1175/2011JAS3671.1

With regards to this time of year -

During early winter, anomalous temperature and ozone are accounted for almost entirely by anomalous EP flux from the troposphere

Link to comment
Share on other sites

Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

Have you got a reference for this? The warming effect of ozone is limited because there is no sunlight for photo-dissociation in winter, so it's radiative effect only - the large ozone variation over the Antarctic is only thought to be worth around 1 degK in winter.

While the BDC controls the background values, the relationship between temperature and ozone anomalies is more to do with that they are both dependent on troposphere EP flux and the QBO  - eg see Sulby 2011 http://journals.ametsoc.org/doi/full/10.1175/2011JAS3671.1

With regards to this time of year -

During early winter, anomalous temperature and ozone are accounted for almost entirely by anomalous EP flux from the troposphere

I am sure that the heat flux of tropospheric ozone is interlinked to the strength of the BDC - so that we are more likely to see an increase in this flux in stronger BDC years.  The reduction in ozone in tropical areas this year isn't down to a lack of production but a step up in the circulation. I guess this research shows that that is more important later in the season - however, if we already have an strong wave 1 activity this early then this can help drive the increased EP flux already- and I suspect that we may already have that at play already this autumn. 

 

I think that this is the base of the whole ozone transport system and to quote from your linked paper

 

The residual circulation is driven by planetary waves that transmit momentum upward from the troposphere. When absorbed, that momentum drives a poleward drift, which converges at high latitude to force mean downwelling. The accompanying adiabatic warming maintains Arctic temperature as warmer and the polar-night vortex as weaker than each would be under conditions of radiative equilibrium. Compensating that vertical motion at lower latitudes is mean upwelling, which is accompanied by adiabatic cooling. Simultaneously, the poleward drift transfers ozone-rich air from its chemical source at low latitude into the winter hemisphere, where total ozone increases during winter by as much as 100%.

These consequences of the residual circulation are closely related to planetary wave activity, which transmits momentum upward from the troposphere. Measured by the net upward Eliassen–Palm (EP) flux near the tropopause 2011jas3671.1-inf1.gif, the momentum delivered to the middle atmosphere during winter is determined chiefly by planetary wave structure in the troposphere. An intensification of tropospheric planetary waves leads to anomalous upward EP flux, which, upon being absorbed in the middle atmosphere, forces intensified residual mean motion. In concert with intensified isentropic mixing by planetary waves, those conditions favor a polar-night vortex that is anomalously warm and weak. Conversely, a weakening of tropospheric planetary waves favors a polar-night vortex that is anomalously cold and strong.

 

 

Diagrammatically shown here:

 

http://www.iup.uni-bremen.de/sciamachy/sparc/downloads/weberrsparc07.pdf

 

But, as ever, your link to that paper shows that no matter how much one reads on the subject there is always more to learn!

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Strathblane/Killearn nr Glasgow
  • Location: Strathblane/Killearn nr Glasgow

Still looking good at 30hpa level. IIRC, this time last year, 30hpa level was purple throughout the entire run from start to finish. Long may it continue. Ozone also still looking good. I wonder if they will still look like that after the clocks change and there is dramatically less sunlight all of a sudden?

post-15287-0-50139000-1413977176_thumb.g

post-15287-0-07796600-1413977213_thumb.g

  • Like 3
Link to comment
Share on other sites

Posted
  • Location: Longden, Shropshire
  • Location: Longden, Shropshire

Solarflux around 200, that's far too high. http://solarham.net/regions.htm

 

It's to be expected considering we only had the solar max earlier this year.  The sun conditions will not be ideal for cold lovers this Winter, but that's the way it is and at least we are coming off the back of a weak maximum.

Link to comment
Share on other sites

It's to be expected considering we only had the solar max earlier this year.  The sun conditions will not be ideal for cold lovers this Winter, but that's the way it is and at least we are coming off the back of a weak maximum.

 

 

I see a lot of people have not really understood the role of solar activity. There may well have peaked at 200, there will be no impact on the earth as these peaks are too short in time and in addition to all that, the CME thrown into space were rare even now . You will see that once this big stain is gone, the flow will drop again in the 120 flux is close to 200 mainly caused by the large spot. Elsewhere it's still flat and we can see the disappearance of spots on the northern hemisphere. All this to say that even the flow to 200, there will be no impact on the land because it does not last long enough

For there is an impact on the earth, it would have the solar flux is greater than 150 for at least one month minimum which was never the case in this cycle 24 except during the fall of 2011 and early this year but nothing since . And also that the CME are many and thrown to earth (and not on the other side)

Edited by neige57
  • Like 6
Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans

. I wonder if they will still look like that after the clocks change and there is dramatically less sunlight all of a sudden?

 

everyone seems to have missed the joke FB !

 

note the second consec ecm run to be increasing the zonal winds high up around 60/70N later on. nothing excessive at this point and no increase at all would be a surprise, given the time of year.  

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Leeds (Roundhay) 135m
  • Location: Leeds (Roundhay) 135m

Thought this was a very nice illustration of the climatic factors influencing the polar stratospheric vortex. Shows nicely why a weaker stratospheric vortex is favoured this year (weak El Nino, easterly QBO, strong Eurasian snow anomalies). Solar output is probably less favourable. Negative sea ice conditions promote -NAO

post-6181-0-35163300-1414098927_thumb.pn

Diagram by Richard Hall, UoS > http://www.climate-cryosphere.org/media-gallery/971-european-linkages-jet-stream-2014

Currently sifting through dozens of climate presentations on snow cover/ sea ice/ recent increase in SWW/ recent colder winter by academics like Cohen, Overland, Francis etc... If i find any useful links (or can find online references to figures in the PP) i'll post them :)

Edited by Mark Bayley
  • Like 8
Link to comment
Share on other sites

Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

The 6z GFS shows a rather stretched polar vortex with an Asian warming.

 

How do the current stratospheric temperatures compare with the average for the time of year?

 

Karyo

  • Like 3
Link to comment
Share on other sites

Posted
  • Location: Strathblane/Killearn nr Glasgow
  • Location: Strathblane/Killearn nr Glasgow

The 6z GFS shows a rather stretched polar vortex with an Asian warming.

 

How do the current stratospheric temperatures compare with the average for the time of year?

 

Karyo

Indeed Karyo. That wasn't there yesterday. Rapid cooling was underway. That is quite a big warming. We lose the white colour at 1hpa and almost lose it further down the stratosphere too. I really hope this is still showing tomorrow. Fingers crossed.

post-15287-0-40188900-1414408594_thumb.g

post-15287-0-42098000-1414408625_thumb.g

Edited by Frozen Britain
  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

Indeed Karyo. That wasn't there yesterday. Rapid cooling was underway. That is quite a big warming. We lose the white colour at 1hpa and almost lose it further down the stratosphere too. I really hope this is still showing tomorrow. Fingers crossed.

There is variation from run to run but the 6z is the most promising so far. 

 

Now that we have a guaranteed strongly negative OPI, we need to focus on the stratosphere for the early part of winter. November 2008 has a relatively warm stratosphere which helped with the December cold spells.

  • Like 3
Link to comment
Share on other sites

Posted
  • Location: Longden, Shropshire
  • Location: Longden, Shropshire

There is variation from run to run but the 6z is the most promising so far. 

 

Now that we have a guaranteed strongly negative OPI, we need to focus on the stratosphere for the early part of winter. November 2008 has a relatively warm stratosphere which helped with the December cold spells.

 

Correct me if I'm wrong, but didn't November 2009 have a record warm stratosphere for the time of year?  We really had so much in our favour for a cold Winter during Autumn 2009.

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Correct me if I'm wrong, but didn't November 2009 have a record warm stratosphere for the time of year?  We really had so much in our favour for a cold Winter during Autumn 2009.

 

http://acdb-ext.gsfc.nasa.gov/Data_services/met/metdata/annual/merra/t90n_50_2009_merra.pdf

 

Yes.

  • Like 1
Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
  • UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-29 07:13:16 Valid: 29/03/2024 0600 - 30/03/2024 0600 THUNDERSTORM WATCH - FRI 29 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather

    Difficult travel conditions as the Easter break begins

    Low Nelson is throwing wind and rain at the UK before it impacts mainland Spain at Easter. Wild condtions in the English Channel, and more rain and lightning here on Thursday. Read the full update here

    Netweather forecasts
    Netweather forecasts
    Latest weather updates from Netweather

    UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-28 09:16:06 Valid: 28/03/2024 0800 - 29/03/2024 0600 SEVERE THUNDERSTORM WATCH - THURS 28 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather
×
×
  • Create New...