Stratosphere Temperature Watch 2013/2014

[sebastiaan1973]

I guess everybody knows this graphic from Labitzke http://lasp.colorado.edu/sorce/news/2011ScienceMeeting/docs/presentations/2f_Labitzke_KEY_SORCE_2011.pdf

 

It is still a couple of months ahead, so we have to wait if ENSO and Solarinfluence will be beneficial. QBO is.

Edited August 3, 2014 by sebastiaan1973

[Nouska]

I'm sure this research was covered in early strat threads on this forum, no harm in revisiting it.

 

http://www.atmosp.physics.utoronto.ca/SPARC/News23/23_Haigh.html

 

Looks like they came to the conclusion that low solar would create weak, sinuous and equatorward movement of the jetstream before they had the reality to observe in the latter part of last decade.

[knocker]

A recent paper unfortunately paywalled.

 

The downward influence of stratospheric sudden warmings

 

The coupling between the stratosphere and the troposphere following two major stratospheric sudden warmings is studied in the Canadian Middle Atmosphere Model using a nudging technique by which the zonal mean evolution of the reference sudden warmings are artificially induced in an ~100 member ensemble spun off from a control simulation. Both reference warmings are taken from a freely-running integration of the model. One event is a displacement, the other a split, and both are followed by extended recoveries in the lower stratosphere. The methodology permits a statistically robust study of their influence on the troposphere below.

The nudged ensembles exhibit a tropospheric annular-mode response closely analogous to that seen in observations, confirming the downward influence of sudden warmings on the troposphere in a comprehensive model. This tropospheric response coincides more closely with the lower stratospheric annular mode anomalies than with the mid-stratospheric wind reversal. In addition to the expected synoptic scale eddy feedback, the planetary-scale eddies also reinforce the tropospheric wind changes, apparently responding directly to the stratospheric anomalies.

Furthermore, despite the zonal symmetry of the stratospheric perturbation, a highly zonally asymmetric near surface response is produced, corresponding to a strongly negative phase of the North Atlantic Oscillation with a much weaker response over the Pacific basin which matches composites of sudden warmings from the ERA-Interim reanalysis. The Coupled Model Intercomparison Project phase 5 models exhibit a similar response, though in most models its magnitude is under-represented.

 

http://journals.ametsoc.org/doi/abs/10.1175/JAS-D-14-0012.1 

[sebastiaan1973]

Abstract

Several recent studies have found variability in the Northern Hemisphere winter climate related to different parameters of solar activity. While these results consistently indicate some kind of solar modulation of tropospheric and stratospheric circulation and surface temperature, opinions on the exact mechanism and the solar driver differ. Proposed drivers include, e.g., total solar irradiance (TSI), solar UV radiation, galactic cosmic rays, and magnetospheric energetic particles. While some of these drivers are difficult to distinguish because of their closely similar variation over the solar cycle, other suggested drivers have clear differences in their solar cycle evolution. For example, geomagnetic activity and magnetospheric particle fluxes peak in the declining phase of the sunspot cycle, in difference to TSI and UV radiation which more closely follow sunspots. Using 13 solar cycles (1869–2009), we study winter surface temperatures and North Atlantic oscillation (NAO) during four different phases of the sunspot cycle: minimum, ascending, maximum, and declining phase. We find significant differences in the temperature patterns between the four cycle phases, which indicates a solar cycle modulation of winter surface temperatures. However, the clearest pattern of the temperature anomalies is not found during sunspot maximum or minimum, but during the declining phase, when the temperature pattern closely resembles the pattern found during positive NAO. Moreover, we find the same pattern during the low sunspot activity cycles of 100 years ago, suggesting that the pattern is largely independent of the overall level of solar activity.

http://www.issibern.ch/teams/interplanetarydisturb/wp-content/uploads/2014/04/Mursula_03_2014.pdf

http://onlinelibrary.wiley.com/doi/10.1002/2013JD021343/abstract

Question to all of you. Right now we are in the maximum phase and QBO east, so if I understand this tends to a negative NAO but not significant.

In the next winters (after 2014/5?) we are in the declining phase, so positive NAO can be expected.

 

Edited August 25, 2014 by sebastiaan1973

[Interitus]

As a side note, according to the Berlin ECMWF charts, the 10mb winds at 60°N flipped to westerly today marking the start of the gradual return of the vortex. What will it do this winter?

[Steve Groome]

As a side note, according to the Berlin ECMWF charts, the 10mb winds at 60°N flipped to westerly today marking the start of the gradual return of the vortex. What will it do this winter?

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/gif_files/gfs_z10_nh_f00.gif

 

not according to this

[Interitus]

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/gif_files/gfs_z10_nh_f00.gif

 

not according to this

 

Cannot tell much from that low resolution chart, don't expect to see a deep low at this stage.

The Berlin analysis charts have a westerly circulation from the 25th onwards - http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/

 

The NASA Merra dataset gives a day earlier on the 24th - http://acd-ext.gsfc.nasa.gov/Data_services/met/ann_data.html

MERRA U 60 N 10 hPaDate     (m/s)---------- ---------2014-08-20     -1.632014-08-21     -1.262014-08-22     -1.612014-08-23     -1.252014-08-24      0.012014-08-25      0.132014-08-26 -99999.00

There is little variation in date, since 1979 it's been between 23rd and 31st August with the average about 25th and it doesn't appear to be especially significant, just showing the gradual cooling of the stratosphere as the sun lowers, isolated from much interaction with the NH troposphere until later in the autumn.

Edited September 2, 2014 by Interitus

[Interitus]

 

Edited August 27, 2014 by Interitus

[summer blizzard]

When will the earliest wave breaking occur?

[picog]

When will the earliest wave breaking occur?

Around October I think.

[Recretos]

I guess its time to slooowly get this show on the road.

 

All my graphics will be in a bit higher resolution this season, and perhaps a few new visualizations.

Edited September 2, 2014 by Recretos

[lassie23]

Never seen this thread before and don't know much about stratosphere temps but I have a question which might have already been asked! Sorry in advance! Did last year's extremely cold stratosphere prevent northern blocking from forming last winter? Or was this just one of the ingredients that gave us a snow less winter?

[tcc]

In a nutshell, yes! Although the reasons as to why it was so cold are still open for debate, teleconnections such as  a +QBO, SSTs, active sunspot activity, BDC, (movement of ozone), ENSO etc all played a part I believe.

 

This year does look a lot more promising for cold weather for this corner of our world. One of the reasons is that we'll be in a strong -QBO, (see opening post for explanation, basically helps with Northerly Blocking), at most a moderate El Nino (although there are doubts as to how much of an influence this has on our weather) and waning sunspot activity. Obviously at this early stage we can't be sure as to what's going to happen, but I'm a lot more hopeful of seeing some of the white stuff this year down here!

Edited September 4, 2014 by tcc

[lassie23]

In a nutshell, yes! Although the reasons as to why it was so cold are still open for debate, teleconnections such as  a +QBO, SSTs, active sunspot activity, BDC, (movement of ozone), ENSO etc all played a part I believe.

 

This year does look a lot more promising for cold weather for this corner of our world. One of the reasons is that we'll be in a strong -QBO, (see opening post for explanation, basically helps with Northerly Blocking), at most a moderate El Nino (although there are doubts as to how much of an influence this has on our weather) and waning sunspot activity. Obviously at this early stage we can't be sure as to what's going to happen, but I'm a lot more hopeful of seeing some of the white stuff this year down here!

Thanks for the info!

[syed2878]

Never seen this thread before and don't know much about stratosphere temps but I have a question which might have already been asked! Sorry in advance! Did last year's extremely cold stratosphere prevent northern blocking from forming last winter? Or was this just one of the ingredients that gave us a snow less winter?  I beleave it was 1 of the factors behind last winter. I maybe wrong in wich case i'm sure some1 will come along and correct me.

[picog]

Temperature at the 30HPa level normal for the time of year. Let's hope it plays ball this year and gets a few warmings!

[Ross Andrew Hemphill]

when will the next thread start for this season?? I'm thinking its too early just now.

[tcc]

when will the next thread start for this season?? I'm thinking its too early just now.

 

Probably next month, normally when ECMWF starts churning out those graphs again!

[Ross Andrew Hemphill]

Probably next month, normally when ECMWF starts churning out those graphs again!

Good stuff!

[bluearmy]

Probably next month, normally when ECMWF starts churning out those graphs again!

 

you can start to look today if you want to

 

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/

 

not that it will tell you much

 

the grahps begin 1st november

[tcc]

you can start to look today if you want to

 

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/

 

not that it will tell you much

 

the grahps begin 1st november

 

Cheers BA

[Frozen Britain]

Could someone tell me if mountain torques etc can cause warming of the stratosphere in the autumn time like it does during winter?

We get strong MJO waves during the year which GP has told us is essential for good weather in June for example. Is that applicable to the stratosphere?

Are there any strong waves forecast which could help to warm the stratosphere over the coming weeks?

I think that the warm stratosphere we got in 2009 and December 2010 were caused by the Brewer Dobson circulation being enhanced. Thank you.

[chionomaniac]

Could someone tell me if mountain torques etc can cause warming of the stratosphere in the autumn time like it does during winter?

We get strong MJO waves during the year which GP has told us is essential for good weather in June for example. Is that applicable to the stratosphere?

Are there any strong waves forecast which could help to warm the stratosphere over the coming weeks?

I think that the warm stratosphere we got in 2009 and December 2010 were caused by the Brewer Dobson circulation being enhanced. Thank you.

Re MT,Yes is the answer - but normally later on in the autumn when the stratospheric vortex is stronger and therefore a strong breaking tropospheric wave can have more of an impact.

[Frozen Britain]

Re MT,Yes is the answer - but normally later on in the autumn when the stratospheric vortex is stronger and therefore a strong breaking tropospheric wave can have more of an impact.

The warm autumn stratosphere in 2009 and 2010 were both caused by enhanced Brewer Dobson Circulation or planetary waves?

And thanks for responding. When will you post some early thoughts on this winter?

[chionomaniac]

The warm autumn stratosphere in 2009 and 2010 were both caused by enhanced Brewer Dobson Circulation or planetary waves?

And thanks for responding. When will you post some early thoughts on this winter?

I would have to look back to check. Early thoughts probably around the end of October.