Stratospheric/ Ozone Information and Discussion 2016/17, Daily PV talk and model discussion Options

[so_whats_happeni...]

Hey Everyone hope the holidays were grand. I have seen from other forums about opening up a Stratospheric discussion thread where anybody can post questions, have daily discussions on the development of the Polar Vortex (PV), and have an area that people can find decent information on where to find PV data and the basics.

So lets begin what exactly is described as the Stratosphere. The Stratosphere is a portion of the atmosphere directly beyond the Troposhperic, where we live, layer.

 post_4523_0_18608100_1445108495.jpg ( 28.98K ) Number of downloads: 0


The Stratosphere ranges from about 10 to 50km above the surface with pressure values in the range from 100 hPa at the lower levels to just under 1 hPa at the upper levels. They consider the middle portion of the stratosphere to be from ~10-30 hPa.

As we approach the Autumnal Equinox (September 20-22nd) each year in the northern hemisphere the PV begins its strengthening, as this region experiences less solar radiation that hits the ozone located in the Stratosphere allowing the PV to cool and strengthen. The PV will continue to strengthen as we head deeper into the season because of temperature differences between polar and mid latitude regions. The Stratospheric PV has a strong interdependence with the Tropospheric PV as one can effect the other. Strengthening of the Stratospheric PV will usually allow for a connection to allow the Tropospheric vortex to strengthen while the Tropospheric vortex can also influence the Stratospheric vortex strength, but this is not always true.

As we head down toward the surface the strength of the PV dictates what values we look at for the Arctic Oscillation (AO). A strong PV during the winter will set up a positive AO which will tend to retreat the polar jet stream and bottling up the cold in the Arctic regions. While a negative AO translates into a weaker Stratospheric PV and will tend to allow the cold air bottled up in the Arctic to be released into the mid latitude regions around the Northern Hemisphere (NH), now just because we have a negative AO does not necessarily mean every region will experience the same result this also applies to a positive AO.

 post_4523_0_98399500_1445108530.jpg ( 42.56K ) Number of downloads: 0


The stratospheric PV can be influenced by different factors such as QBO, state of ENSO, solar influence, ozone distribution and levels, and snow cover and extent.

OZONE:

The ozone layer is collocated in the middle portion of the Stratosphere and is warmed by the incoming UV radiation. The main circulation is the Brewer-Dobson Circulation (BDC) ozone is formed in the tropical stratosphere and transported to the polar stratosphere. This circulation changes from year to year and can be influenced from time to time by many different factors. The ozone content can dictate stratosphere polar temperatures with collecting of ozone allowing for warming to occur in the polar stratosphere.

Ozone Basics: https://en.wikipedia.org/wiki/Ozone_layer
Ozone Tracking: http://www.cpc.ncep.noaa.gov/products/stra...2to/index.shtml

ENSO state:

The ENSO and the state that we see in the tropical Pacific region play a huge role in tropical regions but also the mid latitudes. During these events the effects on the Stratosphere change, when we experience El Nino (warming of Eastern Portion of the Pacific) the atmospheric upward propagating waves become more centered over the Pacific then the Indian Ocean and vice versa occurs.

http://link.springer.com/article/10.1007%2Fs00382-015-2797-5

http://www.columbia.edu/~lmp/paps/butler+p...er-ERL-2014.pdf

Where these waves occur dictate the "attacks" on the PV as well as the weather that we experience from these changes.

Quasi-Biennial Oscillation (QBO):

The QBO is a wind pattern of alternating (easterly and westerly), descending winds that occur in the Tropical Stratosphere over a period of 26-32 months, with an average of around 28 months at about 30hPa is the main region to measure QBO but stretches over an area from 10-50hPa. The easterly (negative) phase is thought to contribute to a weakening of the stratospheric polar vortex, whilst a westerly (positive) phase is thought to increase the strength of the stratospheric vortex. These changes and how quickly or not these winds descend can have substantial implications in the NH winter PV.

 qbo_wind.jpg ( 894.32K ) Number of downloads: 0

http://www.geo.fu-berlin.de/en/met/ag/stra.../qbo/index.html

As mentioned before about the Ozone and the BDC, the QBO seems to play a role in distribution from the Tropical Stratosphere. The tropical upward momentum of ozone is stronger in the eQBO , whereas in the wQBO ozone transport is stronger into the lower mid latitudes, so less ozone will enter the upper tropical stratosphere to be transported to the polar stratosphere.

 post_4523_0_84025300_1445109455.png ( 69.87K ) Number of downloads: 0


When the QBO is in a west phase during solar maximum there are more warming events in the stratosphere, as there is also during an easterly phase QBO during solar minimum, so the strength of the BDC is also affected by this also known as the Holton Tan effect .

Sunspots and QBO
http://strat-www.met.fu-berlin.de/labitzke...-et-al-2006.pdf

Holtan-Tan:
http://onlinelibrary.wiley.com/doi/10.1002...021352/abstract

Solar Cycle also plays a role in conjunction with other factors as stated above here is the solar indices as we head into what looks to be a solar minimum.
http://www.swpc.noaa.gov/products/solar-cycle-progression


So far we have gone over the ideas of QBO, ENSO, sunspots and Ozone on the startosphere and how they can influence the progression of the Stratosphere. We now turn to Sudden Stratospheric Warmings (SSW).

SSW:

There is another name for these types of warmings called Major Midwinter Warming (MMW), does not necessarily mean this takes place in the middle of winter. SSWs can be caused by large-scale planetary tropospheric (Rossby) waves being deflected up into the stratosphere and towards the North Pole, often after a strong mountain torque event. This can lead to warmer then normal temperatures from the mid latitude to rise into the polar stratosphere and cause a drop in winds associated with the PV, and even allow a reversal of winds. To start these type of events we usually have to look into the Troposphere for activity that could spawn a change into the Stratosphere. We can look at tropical flare-ups in convection as a way to see a start of an atmospheric Rossby wave. The positioning and strength of the tropical activity is very important and can be seen from the Madden-Jullian Oscillation (MJO) and the surrounding ENSO state. As the rossby wave forms from such convection processes it can moved and deflected by various mountainous regions across the globe which can be monitored by changes in the Global Wind Oscillations (GWO).

MJO monitoring:
http://www.cpc.ncep.noaa.gov/products/prec...k/MJO/mjo.shtml

ENSO monitoring:
http://www.cpc.ncep.noaa.gov/products/prec.../MJO/enso.shtml

GWO/AAM:
http://www.atmos.albany.edu/student/nschiral/gwo.html

When we do happen to get a Rossby wave to form from this process of tropical convection there is the possibility of this Rossby wave, after being deflected, to break. If the Stratosphere is more responsive to wave breaks then as time goes on we can see the development of a SSW or MMW. When a Rossby Wave break occurs in one place we see a wave 1 disturbance occur, usually involving a displacement of the PV. If we see two wave breaks, a wave 2 disturbance, we can see a squeeze on the PV occur and allow for a split.

Rossby Wave Break (RWB) Diagram:
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Currently the SSW is defined by a reversal of mean zonal mean winds from westerly to easterly at 60ÂșN and 10hPa, but this is being reviewed as to whether this definition will hold. If we do manage to see an SSW form this can lead to high latitude blocking (HLB) to occur, now this is not always the case but SSW's provide a better chance of this occurring where colder air is able to be transported to lower latitudes. The lag associated with an SSW to seeing tropospheric conditions seems to be around 6 weeks but there have been times where this is not quite the case.

http://birner.atmos.colostate.edu/papers/B...2014_submit.pdf

One last thing is how snowcover could influence changes in the Stratosphere by ways of creating a SSW from such occurrence. Below we see what Dr. Cohen postulates for what could happen do to snowcover as many know this is not an exact science and the correlations are there but again I warn this does not always follow a linear path with so many other influences that can change this outcome.

 post_4523_0_05125800_1445110713.png ( 326.23K ) Number of downloads: 0


Various Websites:

GFS
ECM/ Berlin Site
Instant Weather Maps
NASA Merra Site
NASA seasonal Evolution
* Various sites at the bottom of site
Current and previous seasons Temp and Wind

Please Please try to keep this thread on track with not posting single storm impacts unless it pertains to the evolution of the PV. Also if there is any information that anyone would like to add as far as websites, pictures, or any information feel free to add as needed. If you would like to help expand on this 1st post just shoot me a PM and I will add as see fit.

Have fun with discussion!

This post has been edited by so_whats_happening: Jan 14 2017, 04:16 AM

[jdrenken]

Great intro!

Here is cranky's website which has so many stratosphere links it is just easier to post it.

[so_whats_happeni...]

Great intro!

Here is cranky's website which has so many stratosphere links it is just easier to post it.

Thanks for the addition and yea I did have some help from a couple others from another forum who I have talked to about this. Hopefully we can get some decent flow in this thread and get some great discussions.

[ClicheVortex2014]

Good stuff SWH. Glad we now have a separate thread for this.

Since this thread will likely be dead in the warm season, with exception to late in the warm season when people start getting excited, will this be the thread for all the future winters Stratosphere discussions as well?

And shoot, that link JD posted is a gold mine. Gonna have to dive into it sometime.

[so_whats_happeni...]

Good stuff SWH. Glad we now have a separate thread for this.

Since this thread will likely be dead in the warm season, with exception to late in the warm season when people start getting excited, will this be the thread for all the future winters Stratosphere discussions as well?

And shoot, that link JD posted is a gold mine. Gonna have to dive into it sometime.

Well what I have seen from other forum is they continually use the first page and gathered information for each season starting in about August timeframe we can surely do that or we can have one it's honestly up to everyone who feels they see fit.

[stuffradio]

Great links! Is there a link that shows general patterns for the NAO, PNA, EPO, WPO, and AO in the +/-? I have a WxBell subscription, and I sometimes see Joe show some charts of what the general pattern looks like during each phase. I don't think I've found it on WxBell.

[jdrenken]

Great links! Is there a link that shows general patterns for the NAO, PNA, EPO, WPO, and AO in the +/-? I have a WxBell subscription, and I sometimes see Joe show some charts of what the general pattern looks like during each phase. I don't think I've found it on WxBell.

Those are best to be addressed in the winter thread. This will be stratosphere based subjects, not tellies.

[jdrenken]

And shoot, that link JD posted is a gold mine. Gonna have to dive into it sometime.

Cranky's organization of weather links rivals like no other.

[so_whats_happeni...]

I'll post images later when I'm able to use my computer, but got a chance to look at the 12zecm and it looks as though we are starting to see some shifts in the pattern aloft. With a troposphere lead attack starting in the NEPAC with strong ridging showing up consistently as well as now some Atlantic help coming in with a Scandinavian ridging pattern. This looks to give the lower Stratosphere some trouble while aloft at 10mb we see some type of warming going on over Siberia.

It looks so far we will see a wave-1 disturbance led by the NEPAC development that may allow the PV to shift to our side of the globe.

[so_whats_happeni...]

To elaborate more from most post above the 12z GFS and 12z ECM seem fairly inline with each other in bringing what seems like a wave 1 disturbance from warming that takes place over Siberia by the end of the first week of January.

hr108:
 gfs_Tz10_nhem_108.png ( 176.3K ) Number of downloads: 0


Activity stays fairly decent for a few days while creating the classic comma look of a wave 1 disturbance. Around the middle of the run the activity in the Pacific begins to wane allowing the PV to kinda bounce back if you will, slowly, but at that time activity in the Atlantic begins to pick up.

hr180:
 gfs_Tz10_nhem_180.png ( 183.31K ) Number of downloads: 0


hr264:
 gfs_Tz10_nhem_264.png ( 179.1K ) Number of downloads: 0


I chose not to go much further as this tends to push the envelope a bit and get into what you can consider fantasy range. Comparing this to the 12z ECM it seems fairly inline up until hr 240, since I can only find till then, with the GFS. The ECM may tend to hold onto the Pacific energy a bit longer then the GFS but again being that far out is something to watch and see if the same attack on the PV continues, weakens, or strengthens.

The 00z GFS suite shows somewhat similar approach but finishes the Pacific influence off quicker and does a tossing game of the PV. Quite the interesting pattern it poses

This post has been edited by so_whats_happening: Dec 30 2016, 04:00 AM

[ClicheVortex2014]

Euro has been hinting that heat fluxes may start to become more favorable for PV weakening/elongation around day 10. So here's a couple interesting GFS runs at day 15.

[Mid Tn. Man]

Not as extreme as the GFS,but some good wave 2 coming up

 Stratosphere_diagnostics___Atmospheric_Dynamics___Department_of_Earth_Sciences.png ( 497.22K ) Number of downloads: 0

[jdrenken]

The east will be livid with these strat solutions!

[so_whats_happeni...]

Euro has been hinting that heat fluxes may start to become more favorable for PV weakening/elongation around day 10. So here's a couple interesting GFS runs at day 15.

Yea was going to post earlier but wasnt around my comp to do so.

Not as extreme as the GFS,but some good wave 2 coming up

 Stratosphere_diagnostics___Atmospheric_Dynamics___Department_of_Earth_Sciences.png ( 497.22K ) Number of downloads: 0

It looks as though they dont attack the PV at the same time the Pacific side gets going and allows for a nice shove of the PV to then relax a bit and have the Atlantic side start up but not quite as strong as I would at least like to see. This Atlantic attack elongates the PV but doesnt break it aloft more so near the troposphere where the attacks are being led. Should be interesting to see it progress.

The east will be livid with these strat solutions!

Yea not the best orientation for cold to come in the central and eastern. It will kinda keep the same pattern as we have seen. Could still make out here and there in the east as the cold slowly comes in

This post has been edited by so_whats_happening: Dec 31 2016, 02:10 AM

[MaineJay]

Don't have a ton of time these days, but I wanted to support the thread with something.

A good link for the basics

https://ozonewatch.gsfc.nasa.gov/facts/vortex_NH.html

A paper discussing the polar night jet and AO connection

http://onlinelibrary.wiley.com/doi/10.1029/2003JD004123/full

I'll try to add as time and events allow.

[Undertakerson]

The east will be livid with these strat solutions!

Only those who believe an invasion of the PV is always a good thing.

[ClicheVortex2014]

Nice Stratospheric warming event. Elongation, but no split or reversal. PV lobe is on the right side of the globe, but may be too far west to be ideal for the east.

[ClicheVortex2014]

I wonder if he's gonna point out the "Stratospheric SE ridge" now that it's popping back up?

Only those who believe an invasion of the PV is always a good thing.

I think it is though. We saw what happens when cold pools up in the PacNW/west Canada. As long as the pattern is progressive, it's gonna come east eventually. But if it's in Siberia, cold air doesn't exist on our continent

This post has been edited by ClicheVortex2014: Jan 1 2017, 07:18 PM

[ClicheVortex2014]

GFS and Euro both have the Strat PV moving into the western half of North America. Certainly not a reason to believe we're gonna see a long-term flip in the long-term pattern.




This post has been edited by ClicheVortex2014: Jan 3 2017, 02:03 AM

[so_whats_happeni...]

Been busy with local weather and have only checked in on the Strat every so often over the past week but so far everything seems to be going as foreseen so far. Pacific wave activity does a nice nudge on the PV and dies off to allow a nice Atlantic attack around mid month. One thing Im kind of curious about is at the end of the 12z GFS run today the Atlantic wave disturbance makes its way all the way over to Siberia region and looks to possibly set off another warming in that region?

 gfs_Tz10_nhem_31.png ( 177.77K ) Number of downloads: 0


Something of interest to take a look at as we get into January Euro shows still a decent Atlantic wave disturbance but only reaches to hour 240

 ecmwf10f240.gif ( 107.88K ) Number of downloads: 0


Here is 12z GFS same time:
 gfs_Tz10_nhem_21.png ( 179.02K ) Number of downloads: 0


They use slightly different height lines but you get the idea Euro does each line 16 while the GFS on TT does 20 decameters.

Again nothing to far out of the norm but just a few things to keep an eye on.