Interitus
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1 hour ago, Yarmy said:
Meteociel archives the major models, e.g. GFS:
WWW.METEOCIEL.FRMeteociel propose des cartes du modèle americain de GFSUse the 'Activer Live Compare' for comparisons of runs within 24 hours. For longer comparisons, weatheronline expert charts allow selecting a lead time then varying the base time, as does tropicaltidbits
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11 hours ago, cheeky_monkey said:
Yellowknife in the Yukon has had a cold December thus far some -5c below normal..and got down to -45c yesterday..looks like staying cold right into the new year..on a whole the Yukon has had a cold year all round only March was above the norm by any real margin..its strange that no one mentions that the majority of the continent of NA has a cold year this year..yet because Alaska has had an anonymously warm year that is in the media a lot.
Two sides of the same coin regarding flow patterns. That said, cool anomalies have not been as large as warm anomalies. BTW, Yellowknife is in NWT, Yukon has been mild like Alaska.
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2 hours ago, Midlands Ice Age said:
Masie today
A small decrease in sea ice content today (-2K Km2).
Chukchi(+25K), Bering(+8K) and SOO(+9K) all gained, beginning to fill out the basin in the East
Barents(+20K) and Greenland(-20K) cancelled each other out.
Baffin (-16K) and Hudson(-30K) lost ice today after many recent gains.
Lets check things out tomorrow, to see if these results have started a new trend!!
Elsewhere Rutgers is now showing a reduction in snow coverage anomaly almost totally caused by a lack of snow in Europe,
A European snowfall will make a huge difference to this map.
MIA
The Alaskan anomaly is the most intriguing - it was unusual when pointed out in this thread over a month ago (Nov 15th) but to be still present now is staggering. Sure, Anchorage has had some snow in the intervening period, but then followed a December record maximum of 10.6°C (previous record 8.9°C).
Last 30 days temperature anomaly of 7.2°C
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4 hours ago, Midlands Ice Age said:
Interitus...
Any evidence (links) for your statements above?
As ever nothing is that simple... It really is not caused directly by a sudden build up of UV in spring time (or lack of Ozone in the winter)....
The papers I have seen state that the reason the Ozone hole is in the spring in the stratosphere above Antarctica is because at temperatures below -78C the reaction to RECREATE Ozone do not occur, and not because of a lack of UV. On the other hand, the reactions to reduce Ozone with CFC's occur at any temperatures.
The reason that depletion only occurs in the spring is because the stratosphere above Antarctica is the only place on earth that these temperatures are reached, and in the spring at that time of year. That is the reason reported in all the reports I have read!!!
If it was a response to UV, it would/could occur anywhere (including the north pole). I have not seen anywhere reports of Ozone depletion in the Arctic.
To think that UV is not present up there at the moment does not correlate with any balloon data I have seen (from Finland), it is pretty constant average level, (though extremely varying) as it is attracted to the poles by the magnetic pull of the poles. Why do auroras only occur in the polar regions? Also the CHANGES in UV striking the earth during the solar minimum are not directly produced by our sun. They are more related to the background radiation, coming in from all directions.
The current Mosaic project will hopefully give us more detail.
Re your second sentence - What is the response that causes the lob-sided distribution and what has caused it to appear the way it has, this year?
All the papers I have read state that the chemistry of Ozone over the poles is very complex, and not just a straight forward response to UV.
It appears it is made easier to understand over Antarctica since one side of the equation becomes shut down, but it is still extremely complex.
MIA
Ozone and CO2 concentrations -
QuoteThe peak concentration of ozone occurs at an altitude of roughly 32 kilometers (20 miles) above the surface of the Earth. At that altitude, ozone concentration can be as high as 15 parts per million (0.0015 percent).
https://ozonewatch.gsfc.nasa.gov/facts/SH.html
While tropospheric CO2 is now >400 ppm, it is slightly lower in the stratosphere and with increasing altitude and latitude because of the lag of the transport mechanisms -
QuoteGlobal distribution of CO2 in the upper troposphere and stratosphere - Diallo et al (2017)
https://www.atmos-chem-phys.net/17/3861/2017/acp-17-3861-2017.pdf
Antarctic ozone holes -
QuoteThe depth and area of the ozone hole are primarily governed by the amounts of chlorine and bromine in the Antarctic stratosphere. Very low temperatures are needed to form polar stratospheric clouds (PSCs). Chlorine gases react on the surface of these PSCs to release chlorine into a form that can easily destroy ozone. The chlorine and bromine chemical catalytic reactions that destroy ozone need sunlight. Hence, the ozone hole begins to grow as the sun is rising over Antarctica at the end of the winter.
The ozone hole begins to grow in August and reaches its largest area in depth from the middle of September to early October. In the early years (before 1984) the hole was small because chlorine and bromine levels over Antarctica were low. Year-to-year variations in area and depth are caused by year-to-year variations in temperature. Colder conditions result in a larger area and lower ozone values in the center of the hole.
https://ozonewatch.gsfc.nasa.gov/meteorology/index.html
The chlorine / bromine levels as mentioned of course increased with the release of now outlawed CFCs.
Comparison of Arctic/Antarctic ozone holes -
QuoteFundamental differences between Arctic and Antarctic ozone depletion - Solomon et al (2014)
Antarctic ozone depletion is associated with enhanced chlorine from anthropogenic chlorofluorocarbons and heterogeneous chemistry under cold conditions. The deep Antarctic “hole” contrasts with the generally weaker depletions observed in the warmer Arctic. An unusually cold Arctic stratospheric season occurred in 2011, raising the question of how the Arctic ozone chemistry in that year compares with others. We show that the averaged depletions near 20 km across the cold part of each pole are deeper in Antarctica than in the Arctic for all years, although 2011 Arctic values do rival those seen in less-depleted years in Antarctica. We focus not only on averages but also on extremes, to address whether or not Arctic ozone depletion can be as extreme as that observed in the Antarctic. This information provides unique insights into the contrasts between Arctic and Antarctic ozone chemistry. We show that extreme Antarctic ozone minima fall to or below 0.1 parts per million by volume (ppmv) at 18 and 20 km (about 70 and 50 mbar) whereas the lowest Arctic ozone values are about 0.5 ppmv at these altitudes. At a higher altitude of 24 km (30-mbar level), no Arctic data below about 2 ppmv have been observed, including in 2011, in contrast to values more than an order of magnitude lower in Antarctica. The data show that the lowest ozone values are associated with temperatures below −80 °C to −85 °C depending upon altitude, and are closely associated with reduced gaseous nitric acid concentrations due to uptake and/or sedimentation in polar stratospheric cloud particles
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4035972/
The Arctic vortex is more disturbed by planetary wave activity so tends to be warmer thus the PSC formation is lower, less frequent and widespread (areally and altitudinally), or persistent into spring and the returning sunlight -
QuoteThe winter meteorological conditions in the Northern Hemisphere, just like in the Southern Hemisphere, lead to the formation of an isolated region bounded by strong winds, in which the temperature is also cold enough for polar stratospheric clouds to form. However, the geographic symmetry about the North Pole is less than about the South Pole. As a result, large-scale weather systems disturb the wind flow, making it less stable over the Arctic region than over the Antarctic continent. These disturbances prevent the temperature in the Arctic stratosphere from being as cold as in the Antarctic stratosphere, and fewer polar stratospheric clouds are therefore formed. Nevertheless, chemically active chlorine and bromine compounds are also formed over the Arctic, as they are over Antarctica, from reactions at the surface of the clouds. But the cold conditions rarely persist into March, when sufficient sunlight is available to initiate large ozone depletion.
https://uk-air.defra.gov.uk/research/ozone-uv/moreinfo?view=arctic-ozone-hole
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21 hours ago, Midlands Ice Age said:
1)Amounts of Ozone (concentration) compared to CO2 - I stated that it was in the Stratosphere and the Upper Atmosphere. I am totally aware that lower down it is only a minor player. (Note - where it is a GHG)...
However - it is in the stratosphere where it acts as a 'cooling agent'.
2)This year the Ozone is 'lob-sided' in the Arctic, and yet the totals are still above average over the last month compared say to last years totals.
That means that the concentrations are much higher in the half of the Arctic and much lower in other areas. That is exactly what I am suggesting is causing the changes observed.
3)Your comments about the lack of UV in the Arctic...
The mechanism I have assumed/suggested for the Arctic is exactly the same as that proposed by every Ozone scientist for the ozone hole production in the Antarctic. Why should there be UV in the Antarctic, but little in the Arctic?
Stratospheric ozone peaks at about 15 ppm, CO2 is >370 ppm.
With regards to the stratosphere vortex, the lob-sided ozone distribution is a response, not the cause.
There is UV in the Arctic like the Antarctic......in spring time! Later winter and spring is when the depletion occurs and ozone holes are formed.
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3 hours ago, Midlands Ice Age said:
Interitus...
I am very aware of the wave 1 activity, but this 'activity' has been going on since the end of October (and probably before unnoticed), as I have been reporting on this thread, (long before the wave 1 activity occurred). Please check back on this thread for my reports.
Are you aware that most reactions involving Ozone are exothermic?
That Ozone is the major 'chemical' in the stratosphere.
That it is extremely reactive.
That it is even more reactive when disassociated by UV?
That is more abundant in the stratosphere than CO2 and everything else, and more likely elsewhere in the upper atmosphere.
That it is better at absorbing any radiation (across the whole range of the spectrum, from IR to UV), than CO2.
This the latest graphic from C.R.of the temperature anomalies....
I could have chosen anyone from the last 6 weeks. They are all virtually identical, with the 'warmth' bottled up in exactly the same areas.(although it is now virtually all ice covered). and yet almost all the land surrounding the ocean is below normal temperatures.
That the area is the same one as that being covered by Ozone.
Ice has been forming in the Western Arctic much more quickly this year than for many years past (15 at least).
Yet you suggest that there is no connection between all the events?
To ignore its effect in the Arctic stratosphere was understandable 20 years ago, as it was on a very rapid decline due to the CFC's.
This year we had record amounts of Ozone in the atmosphere as at the end of November (since Ozone records were started 1979). From the charts we have record amounts in the atmosphere all due to the SSW in the southern Antarctic hemisphere.
To just ignore all the above facts is non-scientific.
Something has been changing up in the Arctic for nearly 2 months.
I do not know what is causing the above data, but it should not be ignored as BAU.
I will continue to watch and report.
MIA
MIA...
Yes ozone is very reactive, though there is very little UV dissociation it is the polar night. However, you really might want to reconsider its concentration compared to CO2!
As for the surface temperature/ozone distribution, there appears to be no coherent correlation whatsoever.
And to repeat the graph posted before, there is not an anomalously high amount of NH polar ozone
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On 13/12/2019 at 19:05, Midlands Ice Age said:
Interitus….
Your reference above is an old one, and talks about the Ozone effect of wave breaking.
......
IThis year the action has been to promote a lob-sided Ozone excess in N Canada and the Bering Sea area (Pacific Gateway), so far, which has been waxing and waning for the last 6 weeks. See your graph above, which also shows the peak at the beginning of this month. Also see the following link which shows where it has been located ..
and the very latest map -
Is still showing the same distribution and anomaly.
It has, a displaced large concentration of Ozone over the west, and also shows a very low concentration in the East. It is this differential which I believe could well produce a thermal differential in the stratosphere, causing instability and hence a pushing of the Stratospheric polar vortex. It is this 'pushing' displacement action at the top, which is why I expect to see the PV eventually develop over the East this year (my forecast!).
If it does not happen then I may have the mechanism wrong.
Compare this to last year (run the mp below for the period up to the end of December and you will see a later outburst of Ozone and then a general 'spread' of the Ozone giving little chance for differential of the temperatures), and hence no 'pushing'' effect.
This may well yet still happen this year. We will see.
The age of the paper was intentional to show that ozone has long been used as a tracer following the forcing of the planetary waves as stated. It is the planetary waves forcing the vortex, the ozone follows these. The 'lob-sided ozone excess' is because the air within the vortex is to a large extent isolated from the more ozone rich air which mixes into the stratospheric Aleutian anticyclone. As explained, the peak in the graph at the beginning of the month is because we have just had a substantial period of wave 1 displacing the vortex and transporting ozone polewards. The difference last year of course was that at the end of December - start of January there was a SSW and the vortex broke down. This is what allowed the spread of ozone across the pole.
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1 hour ago, Midlands Ice Age said:
Interitus….Thanks for your response.
I have developed my views after watching a huge lob-sided build up of Ozone this year in the Arctic, in combination with the chemistry of Ozone.(I trained as a chemist, hence my original interest).
I have also extensively read the following report (and others)….
https://www.geos.ed.ac.uk/~dstevens/publications/isaksen_ozone_climate_ec03.pdf
For details of why Ozone is not a 'follower' please read the above report, where one only needs to pay particular attention to Chapter 1 and particular to the table/graph on page 28, which details relative forcing, which clearly shows that it will act as a cooling agent, when in the stratosphere.
I have read the whole document several times. On an initial reading it seems as though your beliefs are correct, as the report is very much concerned with (at the time) very much lowering of Ozone levels in the atmosphere.
But more detailed reading identifies that the effect of Ozone in the Arctic stratosphere is admitted to be poorly understood and requires further research. I have thus looked for more research on this particular topic, but found very little.
This year is the first year when we may well see any impact of very much increased stratospheric Ozone, and since it requires its precursor warming agent (the increased UV radiation in the stratosphere, and which has mainly occurred in the last 2 years), it is unlikely that it could have occurred in recent climate history.
Impacts of the vastly increased amount of Ozone (several times in places, up there) in the stratosphere AND the solar forcing (U.V. hitting the earth up 30-50%) has not been seen, possibly, for many centuries.
This year has seen a huge apparent anomalous warming in the central and eastern Arctic since the middle of October.
Yet the ice has grown more quickly during this time since the late 90's. This despite the apparent warmth as recorded by climate 2M models.
Is it co-incidence that this occurred at exactly the same time that waves of Ozone entered the Arctic stratosphere?
Clearly something has changed this year up there. The SST's of the open water on the Atlantic side (and now the Pacific) are nothing like we have seen in recorded history and this has undoubtedly led to the ice rapid expansion in this area.
What is being seen in the stratosphere resembles an SSW, in that a warming of the stratosphere is occurring, but according to the experts it is not a normal SSW. So, since we know that Ozone is more in concentration in the stratosphere than anything else (except possibly the inert gasses) what else could be causing the warming?
As indicated in the paper, it is the reduction in ozone not its presence which causes a net cooling effect - reducing interaction with UV in the stratosphere and reducing blocking of IR radiation from the earth surface. The majority of the UV interaction is at lower latitudes, of course there is none now in the polar night, and it is from the lower latitudes that much ozone makes its way to the pole. Currently overall NH polar ozone is within normal bounds, a recent peak was seen with increased poleward transport associated with the vortex displacement -
source: https://ozonewatch.gsfc.nasa.gov/NH.html
Ozone transport has long been used as a tracer for stratospheric flow, indeed it was important in visualising the vortex with planetary wave breaking, the "surf zone" etc eg see this 1985 paper -
QuoteTransport of Ozone in the Middle Stratosphere: Evidence for Planetary Wave Breaking
Abstract
Data from the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) for the period 25 October 1978–28 May 1979 are used in a descriptive study of ozone variations in the middle stratosphere. It is shown that the ozone distribution is strongly influenced by irreversible deformation associated with large amplitude planetary-scale waves. This process, which has been described by McIntyre and Palmer as planetary wave breaking, takes place throughout the 3–30 mb layer, and poleward transport of ozone within this layer occurs in narrow tongues drawn out of the tropics and subtropics in association with major and minor warming events. Thew events complement the zonal mean diabatic circulation in producing significant changes in the total column amount of ozone.
https://journals.ametsoc.org/doi/pdf/10.1175/1520-0469(1985)042<0230%3ATOOITM>2.0.CO%3B2
Recent warming in the stratosphere is just a normal early winter event - best taken to the strat thread for further discussion!
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11 hours ago, Midlands Ice Age said:
As predicted by the continuing Ozone event up in the Stratosphere, which just keeps piling pressure to the top of the vortex, from the ozone rich US and pushing it further eastward...
MIA
The ozone is a tracer, it is not forcing it is following the forcing.
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2 hours ago, Dennis said:heat flux growing - good progress to weakening polarvortex
5 days later on this run, the 10mb 60N wind has recovered to a healthy 53.7 ms.
Wave forcing initially reduces zonal wind by changing the vortex shape, but also enhances the wind locally. Interestingly, at T357 (26/12 21:00) the 1mb wind reaches 177.9 ms just off the Scottish coast, or in units most might be more familiar with, a incredible 398 mph (640 kmh) -
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1 hour ago, Mike Poole said:
That is a really interesting analysis that you have done, there's been speculation about the relative performance of the FV3 and the GEFS on this thread for a few weeks, and even if there is no resolution about where we're going with the strat vortex, I think this proves some disconnect between what these models think, we will be cautious from now on!
(actually no we won't, the moment either the FV3 or GEFS mean shows support for a SSW, we will be it's cheerleaders...)
It looks like the FV3 has the edge on purely simulating the strengthening Autumn vortex but then when the planetary waves really kick in from the middle of November. both tend to go a bit wayward. Don't know whether this is a wave propagation thing in the strat or due to the unpredictability of the waves from patterns in the trop.
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23 hours ago, Yarmy said:
From the 15th-20th November (subtract 384 hours from each date on the x-axis). It's interesting that the FV3 has a stronger positive bias than the GEFS has a negative bias at that range. Perhaps @Interitus could do the same chart for T240 lead times?
Day 10 verification graph - analysis from Nov 9th 00z - Dec 7th 00z, and forecasts on to Dec 17th 00z
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On 02/12/2019 at 19:25, feb1991blizzard said:
Yes - i think i may have to say hats off to @Recretos - He thinks the FV3 is decent at modelling the strat, now the EPS are more GFS op like and looks like the GEFS are on their own it looks like he is right
Here is a graph of the GFS and GEFS mean T384 forecast zonal wind compared to the actual analysis values, from November 15th onwards -
The GFS has forecast higher zonal wind speed, average +9.1 ms.
The ensemble mean has forecast lower zonal wind speed, average --4.2 ms. (Obviously a smoother plot as mean of 20 members). Interestingly these biases have been fairly consistent (i.e. above vs below) such that the average of the GFS and ensembles is closer than the two individually.
Must be remembered that this zonal wind is a pretty limited 1-dimensional quantity, compared to an areal analysis such as geopotential anomaly correlation - so forecast equal wind speeds which may appear accurate could be achieved from very different geopotential charts.
Case in point -
On 04/12/2019 at 09:34, mb018538 said:Or any GFS run to be honest...
Forecast:
Reality:
It's been over-cooking strat warmings and zonal wind-speed reductions all winter thus far. Best to not give them much serious thought until they get within a week if they are going to be so wrong.Here are the geopotential charts corresponding to the above temperature profiles -
The T384 forecast chart may have had the more noticeable warming posted above, zonal wind 28.6 ms, yet the second vortex of the 4th December analysis is more displaced and hence the vortex appears weaker from a zonal wind perspective at 18.1 ms. Not too much should be made of zonal wind or temperature charts in isolation.
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1 hour ago, Summer Sun said:
Would be worthwhile popping this in the strat thread
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28 minutes ago, ALL ABOARD said:
Shows easterly winds right from the trop into the strat as dipicted by the blue colours
It doesn't show easterly winds - as described at the top of the main webpage - https://acd-ext.gsfc.nasa.gov/Data_services/Current/seasonal_strat/seasonal_strat.html
"The plots are all 2-panel. The RHS plot shows the 60-day time-mean profile of the quantity, while the LHS shows the deviations from this 60-day mean."
So the blue colours in the forecast show winds below the previous two month average.
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1 hour ago, mushymanrob said:
thank you.
so in essence, its still just possible to get a strat induced white christmas , but it more likely afterwards, assuming these predictions go accordingly and with only a 66% chance anyway...In essence, don't put money on it!
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4 minutes ago, Beanz said:
I’d go with ‘milder blip’ too quite frankly.
You didn’t explain why it might be misleading, you just posted a few charts.
Those charts (and subsequent Skew-T) are self explanatory, surely?
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21 minutes ago, Snowman. said:
ECM still has a fairly strong wave event and warming at D10, I know the GEFS are still supporting some serious damage so why is a tech SSW looking unlikely?
Briefly, the ensembles have overdone the weakening throughout this period so far, just six days ago the 00z ensemble mean wind for today 06z was 15.2 ms compared with today's analysis of 21.6 ms.
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Interesting difference still in zonal winds between GFS and GEOS from today's 00z runs -
However, at day 10 they look by eye to be pretty much on the same page -
GFS
GEOS
The GEOS vortex is marginally more displaced with the GFS propped up with a touch of wave 2. The result is the polar night jet is shifted southwards slightly on the GEOS -
GFS
GEOS
And though the GFS is only marginally stronger - maximum windspeed of 88.6 ms vs 85.8 ms, the difference in windspeeds occurs almost smack bang on 60°N -
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26 minutes ago, Don said:
Yes, feet firmly on the floor for a while yet.
GFS 12z 10mb
30mb
Full steam ahead!
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19 minutes ago, Kirkcaldy Weather said:
No SSW in any of those Decembers. Admittedly they occurred in early Jan 1970 and 1977 (end of February for 1983/4) but this and another tweet are emphasising cold Decembers i.e. prior to SSW.
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1 hour ago, Yarmy said:
What is the x-axis scale on that chart? I initially assumed hours, but that can't be right. Is each tick 6 hours?
Yes, 6-hourly forecast times, just an unformatted rough and ready plot!
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GFS/GEFS zonal wind difference continues on 06z, though the ensembles have some support from the 00z GEOS
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Stratosphere and Polar Vortex Watch
in Spring Weather Discussion
Posted
The 10-day GEFS mean from December 7th 00z for December 17th 00z was 19 m/s, the eventual GFS analysis value was 52.9 m/s, just saying.