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Stratosphere temperature watch - 2016/17

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12 minutes ago, weirpig said:

looking at the table above  if im reading it correctly  it does show a strong easterly qbo at 30Hpan  after only 2 months of a easterly being recorded at 10hPan    is this a good sign?.  or am i reading the chart totally ockerd.

The 30mb level isn't negative in the chart yet- only the 10, 15 and 20, but June's value will be negative at 30mb.

Edited by snowwman

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1 minute ago, snowwman said:

The 30mb level isn't negative in the chart yet- only the 10, 15 and 20, but June's value will be negative at 30mb.

Ahh yeas sorry the 20mb  level  which sits at just -207  after only at two months of going negative at 10Hpan   surely that must be a good sign.  infact i cant see another year which has the same intesity propagating down at that timeframe.

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A new study.

The relationship between Eurasian snow cover extent (SCE) and Northern Hemisphere atmospheric circulation is studied in reanalysis during 1979-2014 and in CMIP5 preindustrial control runs. In observations, dipolar SCE anomalies in November, with negative anomalies over eastern Europe and positive anomalies over eastern Siberia, are followed by a negative phase of the Arctic Oscillation (AO) one and two months later. In models, this effect is largely underestimated, but four models simulate such relationship. In observations and these models, the SCE influence is primarily due to the eastern Siberian pole, which is itself driven by the Scandinavian pattern (SCA), with a large anticyclonic anomaly over the Urals. The SCA pattern is also responsible for a link between Eurasian SCE anomalies and sea ice concentration (SIC) anomalies in the Barents-Kara Sea.

Increasing SCE over Siberia leads to a local cooling of the lower troposphere, and is associated with warm conditions over the eastern Arctic. This is followed by a polar vortex weakening in December and January, which has an AO-like signature. In observations, the association between November SCE and the winter AO is amplified by SIC anomalies in the Barents-Kara Sea, where large diabatic heating of the lower troposphere occurs, but results suggest that the SCE is the main driver of the AO. Conversely, the sea ice anomalies have little influence in most models, which is consistent with the different SCA variability, the colder mean state, and the underestimation of troposphere-stratosphere coupling simulated in these models. http://journals.ametsoc.org/doi/pdf/10.1175/JCLI-D-16-0623.1

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On 29/06/2017 at 11:55, snowwman said:

The 30mb level isn't negative in the chart yet- only the 10, 15 and 20, but June's value will be negative at 30mb.

Yep  and as you stated  Junes 30mb was indeed negative.   all ticking along quite nicely.

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June's value was -3.81 and negative for first time in 25 months, I've plotted it below with the previous two "normal" cycles since Jan 2011

qbpo.png

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1983-84 saw a mild December followed by tasty January for snow in the north but frustrating elsewhere, due to predominantly polar maritime airmasses, after which February was distinctly uninteresting - well as far as I can gather from various reports. Good thing the QBO isn't the only factor that matters :D. The winter was not long past a solar maximum for example - but then again, we're not yet on the right side of the minimum for any significantly different forcing to be expected (based on current literature, anyway).

Overall there is still a lack of particularly strong signals regarding the overall 2017-18 winter prospects but it is only July after all :hi:. Best I can say is that the QBO shouldn't be an obstacle like it was during the last one! :good:

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The reason for the "hold- up" in the progression of the Easterly QBO is that the lower levels of the stratosphere were anomalously westerly in the lower strat during the Westerly phase which is on the way out at the moment; actually, by historical standards, there is no hold up- the Easterly QBO is progressing down the stratosphere no less quickly than average, now that it's encountered the anomalously Westerly lower- reaches of the strat; it's just a matter of time before those levels turn Easterly, too. A further point is that winters we consider "Easterly", e.g. 1962/'63, weren't Easterly at the 70mb level until way later than now, and when winter was over!

 

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9 hours ago, Singularity said:

1983-84 saw a mild December followed by tasty January for snow in the north but frustrating elsewhere, due to predominantly polar maritime airmasses, after which February was distinctly uninteresting - well as far as I can gather from various reports. Good thing the QBO isn't the only factor that matters :D. The winter was not long past a solar maximum for example - but then again, we're not yet on the right side of the minimum for any significantly different forcing to be expected (based on current literature, anyway).

Overall there is still a lack of particularly strong signals regarding the overall 2017-18 winter prospects but it is only July after all :hi:. Best I can say is that the QBO shouldn't be an obstacle like it was during the last one! :good:

I've reached the conclusion that severe winters have more to do with absolute solar activity and the length of time that activity has been anomalously low than they do with relative levels- for example the location in the cycle. Depending on what station you're examining, cosmic ray levels are already at 2009 levels.

 

http://www.nmdb.eu/nest/  .

 

Cool side of neutral enso conditions, an Easterly QBO and such levels of solar activity are, from what I can gather, extremely well positioned for an exceptional winter.

 

Edited by snowwman
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On 7/27/2017 at 19:50, snowwman said:

I've reached the conclusion that severe winters have more to do with absolute solar activity and the length of time that activity has been anomalously low than they do with relative levels- for example the location in the cycle. Depending on what station you're examining, cosmic ray levels are already at 2009 levels.

 

http://www.nmdb.eu/nest/  .

 

Cool side of neutral enso conditions, an Easterly QBO and such levels of solar activity are, from what I can gather, extremely well positioned for an exceptional winter.

 

That's a very interesting proposition - it sounds to me like it relates to the amount of energy absorbed over time by ozone for example which will be anomalously low when solar activity has also been such relative to the position in the cycle?

Given the effect on winter prospects, I like this theory very much :D.

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Whether it be negative or positive qbo no  one really knows what actual forcing it has on the other teleconnects. I have my own theory that  when the qbo is in either phase  in a very strong mode it does not bode well for the prospects of cold for the UK in winter. it is basically a lottery that no one knows the answers to. The same can be said for strat warmings as we have seen the last couple of years, yes we may be able to predict when a warming is more likey than not given the qbo state etc but we are definitely no nearer forecasting what likey impacts the warming would have and where.

Last year the met came a cropper announcing that they cold now reliably predict UK winters a year in advance due mainly to GLOsea 5 etc only to fail at the first hurdle

 

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On 27-7-2017 at 20:50, snowwman said:

I've reached the conclusion that severe winters have more to do with absolute solar activity and the length of time that activity has been anomalously low than they do with relative levels- for example the location in the cycle. Depending on what station you're examining, cosmic ray levels are already at 2009 levels.

 

http://www.nmdb.eu/nest/  .

 

Cool side of neutral enso conditions, an Easterly QBO and such levels of solar activity are, from what I can gather, extremely well positioned for an exceptional winter.

 

Cool side? I suspect you mean warm side of neutral ENSO? http://easternmassweather.blogspot.nl/2017/07/preliminary-profiling-of-winter-2017.html

I tend to agree with comet about strong QBO phases.  

Edited by sebastiaan1973

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17 minutes ago, sebastiaan1973 said:

Cool side? I suspect you mean warm side of neutral ENSO? http://easternmassweather.blogspot.nl/2017/07/preliminary-profiling-of-winter-2017.html

I tend to agree with comet about strong QBO phases.  

At the moment, yes, but then the forecasts seem to be moving slowly in the cool direction. CFSv2 even recently forecast a very weak La nina for NDJ, and still, the forecast is for cool side of neutral by then:

 

http://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2seasonal.shtml

 

. Also, there has been a sudden cooling in this region and region 4 (from what I can make out) in the past week. My guess is that the strong Easterly QBO is what's primarily feeding this.

Edited by snowwman
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11 hours ago, sebastiaan1973 said:

Cool side? I suspect you mean warm side of neutral ENSO? http://easternmassweather.blogspot.nl/2017/07/preliminary-profiling-of-winter-2017.html

I tend to agree with comet about strong QBO phases.  

Just to add to what the poster below said SST's in 3.4 are now at 0.0 after a period of strong trade winds over the central pacific and we have a cold blob underneath the surface.

El Nino is dead.  

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Thanks guys.

 

The Madden-Julian Oscillation (MJO), also known as the 30-60 day oscillation, is the strongest of the intraseasonal
climate oscillations and consists of an eastward propagating pattern of alternately intense and weak tropical
convection and precipitation. It has significant derivative effects on extratropical circulation and intraseasonal climate,
including effects on the North Atlantic Oscillation during northern winter. It has recently been found that
the stratospheric quasi-biennial oscillation influences the amplitude of the MJO during northern winter such that
amplitudes are larger during the easterly phase (QBOE) at 50 hPa than during the westerly phase (QBOW) [Yoo
and Son, GRL, 2016]. The initiating mechanism is a decrease in static stability near the tropopause under QBOE
conditions resulting from relative upwelling associated with the QBO induced meridional circulation. Positive
feedbacks from below further enhance the response during the northern winter season. Here, evidence is presented
that the QBO modulation of the boreal winter MJO is itself modulated by the 11-year solar activity cycle. Using
real-time multivariate (RMM) MJO amplitude and phase data covering the 1980-2015 period (36 years), it is found
that the increase in MJO mean amplitude during December, January, and February (DJF) under QBOE conditions
is especially large under solar minimum (SMIN) conditions while the decrease in MJO amplitude under QBOW
conditions is largest under solar maximum (SMAX) conditions. Consistently, the DJF mean static stability calculated
from ERA-Interim reanalysis data in the lowermost stratosphere over the warm pool region is especially
low under QBOE/SMIN conditions and is largest under QBOW/SMAX conditions. Specifically, while the mean
MJO amplitude in DJF is 33% larger in QBOE than in QBOW, it is 56% larger in QBOE/SMIN than in
QBOW/SMAX. Conversely, the mean MJO amplitude in DJF is only 14% larger in QBOE/SMAX than it is in
QBOW/SMIN. This dependence on the solar cycle is consistent with a solar-induced increase in relative tropical
upwelling under SMIN conditions and a decrease (relative downwelling) under SMAX conditions. However, these
results are based on a limited time record. For example, only 5 winters qualify for the QBOE/SMIN category while
7 winters qualify for the QBOW/SMAX category. During the coming solar minimum, at least one additional winter
in the QBOE/SMIN category should occur (possibly as early as 2017/2018) during which especially large MJO
amplitudes are expected and an initial test of the proposed relationship will be possible.

 

journals.ametsoc.org/doi/pdf/10.1175/JCLI-D-14-00625.1

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19 minutes ago, sebastiaan1973 said:

Thanks guys.

 

The Madden-Julian Oscillation (MJO), also known as the 30-60 day oscillation, is the strongest of the intraseasonal
climate oscillations and consists of an eastward propagating pattern of alternately intense and weak tropical
convection and precipitation. It has significant derivative effects on extratropical circulation and intraseasonal climate,
including effects on the North Atlantic Oscillation during northern winter. It has recently been found that
the stratospheric quasi-biennial oscillation influences the amplitude of the MJO during northern winter such that
amplitudes are larger during the easterly phase (QBOE) at 50 hPa than during the westerly phase (QBOW) [Yoo
and Son, GRL, 2016]. The initiating mechanism is a decrease in static stability near the tropopause under QBOE
conditions resulting from relative upwelling associated with the QBO induced meridional circulation. Positive
feedbacks from below further enhance the response during the northern winter season. Here, evidence is presented
that the QBO modulation of the boreal winter MJO is itself modulated by the 11-year solar activity cycle. Using
real-time multivariate (RMM) MJO amplitude and phase data covering the 1980-2015 period (36 years), it is found
that the increase in MJO mean amplitude during December, January, and February (DJF) under QBOE conditions
is especially large under solar minimum (SMIN) conditions while the decrease in MJO amplitude under QBOW
conditions is largest under solar maximum (SMAX) conditions. Consistently, the DJF mean static stability calculated
from ERA-Interim reanalysis data in the lowermost stratosphere over the warm pool region is especially
low under QBOE/SMIN conditions and is largest under QBOW/SMAX conditions. Specifically, while the mean
MJO amplitude in DJF is 33% larger in QBOE than in QBOW, it is 56% larger in QBOE/SMIN than in
QBOW/SMAX. Conversely, the mean MJO amplitude in DJF is only 14% larger in QBOE/SMAX than it is in
QBOW/SMIN. This dependence on the solar cycle is consistent with a solar-induced increase in relative tropical
upwelling under SMIN conditions and a decrease (relative downwelling) under SMAX conditions. However, these
results are based on a limited time record. For example, only 5 winters qualify for the QBOE/SMIN category while
7 winters qualify for the QBOW/SMAX category. During the coming solar minimum, at least one additional winter
in the QBOE/SMIN category should occur (possibly as early as 2017/2018) during which especially large MJO
amplitudes are expected and an initial test of the proposed relationship will be possible.

 

journals.ametsoc.org/doi/pdf/10.1175/JCLI-D-14-00625.1

Much interesting information here. I haven't done the number crunching myself, and I wonder whether there's any increase incidence in phases 7 and 8 during cool end of neutral and a strong upper (or lower-) strat EasterlyQBO.

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On 31/07/2017 at 10:20, comet said:

Whether it be negative or positive qbo no  one really knows what actual forcing it has on the other teleconnects. I have my own theory that  when the qbo is in either phase  in a very strong mode it does not bode well for the prospects of cold for the UK in winter. it is basically a lottery that no one knows the answers to. The same can be said for strat warmings as we have seen the last couple of years, yes we may be able to predict when a warming is more likey than not given the qbo state etc but we are definitely no nearer forecasting what likey impacts the warming would have and where.

Last year the met came a cropper announcing that they cold now reliably predict UK winters a year in advance due mainly to GLOsea 5 etc only to fail at the first hurdle

 

There's no clear link unless you factor in solar activity. I recall a study by Labitzke et al which concluded that the vortex is weak in Easterly QBO winters at solar minimum and in Westerly QBO winters at solar maximum.

Where I probably agree is the link between split stratospheric vortexes and cold winters- I can find no link in the research I've done which confirms the oft- quoted causative effect; indeed, a split strat. vortex might even be harmful, though certainly a disturbed vortex may be crucial.

This link:

http://journals.ametsoc.org/doi/full/10.1175/JAS3883.1

 

might provide some useful links, though I haven't had time to read it.

Edited by snowwman

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Berlin have updated the QBO numbers for July:

http://www.geo.fu-berlin.de/met/ag/strat/produkte/qbo/singapore2017.dat

Monthly mean zonal wind components ( 0.1 m/s)
at Singapore (48698), 1N/104E

2017
hPa  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC
 10    2   10 -162 -270 -286 -304 -331
 12   76   75  -40 -229 -280 -294 -329
 15  112  123   73 -142 -268 -300 -309
 20  142  159  131   52 -207 -287 -310
 25  161  169  145  117  -85 -254 -294
 30  171  177  153  136   58 -145 -256
 35  169  185  155  141  116   38  -81
 40  165  170  158  146  136  110   57
 45  155  166  141  134  149  126   99
 50  132  145  107  118  148  134  111
 60   77   94   28   66  114  136  123
 70   15   36   10   50   73  126  127
 80  -22   21   11   30   39   94   88
 90  -55  -21   -1  -13    3   25   72
100 -150  -80  -38  -49  -53  -26  -10

 

http://www.geo.fu-berlin.de/met/ag/strat/produkte/qbo/qbo_wind_pdf.pdf

 

 

Edited by Yarmy
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On 08/03/2017 at 08:56, Yarmy said:

Berlin have updated the QBO numbers for July:

http://www.geo.fu-berlin.de/met/ag/strat/produkte/qbo/singapore2017.dat

Monthly mean zonal wind components ( 0.1 m/s)
at Singapore (48698), 1N/104E

2017
hPa  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC
 10    2   10 -162 -270 -286 -304 -331
 12   76   75  -40 -229 -280 -294 -329
 15  112  123   73 -142 -268 -300 -309
 20  142  159  131   52 -207 -287 -310
 25  161  169  145  117  -85 -254 -294
 30  171  177  153  136   58 -145 -256
 35  169  185  155  141  116   38  -81
 40  165  170  158  146  136  110   57
 45  155  166  141  134  149  126   99
 50  132  145  107  118  148  134  111
 60   77   94   28   66  114  136  123
 70   15   36   10   50   73  126  127
 80  -22   21   11   30   39   94   88
 90  -55  -21   -1  -13    3   25   72
100 -150  -80  -38  -49  -53  -26  -10

 

http://www.geo.fu-berlin.de/met/ag/strat/produkte/qbo/qbo_wind_pdf.pdf

 

 

Second most negative first two months at the 30mb level on record, if my calculation using the FUB data is correct.

Edited by snowwman

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Some further explanation of the vortex would be helpful. In terms of the stratosphere I think the dates relate to when we see downward cooling trend in temp levels.

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From Amy Butler:

"In summer it reverses direction. By "return", I mean it will return to westerlies. That's important because strat-trop coupling can occur".

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