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#1375265 - 09/05/2016 16:39 Qbo
snowbaby Offline
Weather Freak

Registered: 05/08/2009
Posts: 295
Loc: Albany, W.A
The QBO, the dominant feature of the tropical stratosphere and, while still the subject of much interest &research, in combination with the solar signal may anticipate the variability of our polar vortex on long time lags(and hence influence our weather patterns via stratospheric-tropospheric coupling) - of particular interest to a lot of us as this winter approaches.

Snapshot of the qbo is from data provided by Free University Berlin, winds above Singapore. Wind speeds are expressed in 0.1ms units. Negative sign represents easterly phase winds.
Monthly mean zonal wind components at Singapore (48698), 1N/104E. Easterlies blue


2015
hPa JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
10 138 167 106 123 96 115 91 136 179 127 -55 -222
12 83 149 125 124 110 129 116 162 195 133 59 -124
15 -92 58 82 87 110 125 159 165 207 121 114 26
20 -355 -320 -151 3 97 127 170 163 189 133 129 96
25 -317 -300 -301 -231 8 98 145 156 171 127 142 109
30 -278 -295 -314 -311 -140 75 129 135 162 132 138 89
35 -276 -284 -291 -291 -249 11 84 132 157 128 124 59
40 -238 -248 -251 -258 -285 -121 35 112 151 118 112 33
45 -191 -192 -198 -214 -251 -208 -23 93 130 105 103 28
50 -110 -108 -141 -182 -217 -230 -116 46 108 102 99 55
60 -9 -15 -32 -99 -152 -194 -131 -51 75 91 108 112
70 -7 5 -9 -29 -123 -127 -158 -134 -20 70 96 93
80 -21 -23 -22 -36 -100 -78 -144 -81 -38 16 49 36
90 -18 -43 -45 -52 -87 -64 -156 -54 -44 -66 17 17
100 -24 -16 -54 -68 -83 -94 -157 -95 -83 -89 -52 10

Usually there are three regimes extant at the same time - the incoming phase - currently the easterly, then the previous westerly regime and finally the previous easterly phase exiting at the lower stratosphere. 2015 gives the early stage of that pattern.

2016
hPa JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
10 -231 -205 -148 -11
12 -145 -109 7 62
15 -15 49 90 113
20 91 135 123 115
25 108 120 112 94
30 100 95 21 -14
35 31 16 -99 -152
40 -17 -66 -155 -226
45 -6 -13 -10 -148
50 51 48 57 -54
60 100 87 77 38
70 27 54 50 2
80 -30 14 7 -26
90 -51 -26 -14 -13
100 -18 -62 -11 12



As phases change, occasionally, I’ve noticed, a re-emergence of the opposite wind phase sometimes -usually as either a one off lingering artifact of the outgoing wind regime or as the precursor to the incoming. Possibly this happens most frequently in the lower stratosphere though I am not certain of that.

However this year- something of particular interest- there seems to be a cluster of easterlies generating independently at 40hPa(from Jan bolded) which doesn’t seem tied to either the incoming or outgoing phase.

For those interested in having a closer look the link below to a pdf graphic from FU Berlin which displays the cycle of wind phase changes from 1953. I’m unable to find any pattern like the one that is presently emerging.

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

I can only trust I’m not reading too much into it - especially since noaa's data(for 30hPa) is still marginally in the westerly phase for april. That aside,I don’t have the knowledge to comment on the significance or possible effect - but I’m wondering if it arises from wave forcing. The easterly outbreak does seem to have imposed just where westerly velocities happen to be weakest. Possibly rossby or rossby-gravity waves since dominant westerly phase is not favorable to kelvin wave propagation into the qbo according to ( Yang et al (2012)”The influence of the QBO on the propagation of equatorial waves into the stratosphere”. Journal of the Atmospheric Sciences, 69 (10). pp. 2959-2982. ISSN 1520-0469 doi: 10.1175/JAS-D-11-0342.1). I remain cautious however since if it does originate purely from wave activity it’s difficult to accept that it hasn’t occurred before in the period since the 1950’s as the indication seems to be from the graphic (link above)

It’s often repeated observation that the easterly phase change tends to stall just below the 10hPa-35hPa level (an effect of wave driving) though I don’t know that it applies here. It is also said to be a generally slower descent.

If the westerly regime persists well into this winter, the vortex may evolve in a similar direction to last year - towards intensification - for the initial period of winter at least. On the other hand if this easterly cluster does continue to spread from the 40hPa level and a complete easterly phase establishes sooner rather than later, as well as possibly being a somewhat unique event, it would have to translate on to the winter &spring outlook for the polar vortex. Until the phase change resolves though, the picture itself is still quite complex .

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#1384341 - 10/08/2016 09:17 Re: Qbo [Re: snowbaby]
snowbooby Online   content
Cloud Gazer

Registered: 11/05/2016
Posts: 19
An abstract here

http://onlinelibrary.wiley.com/doi/10.1002/2016GL070373/abstract

describing the above as an unprecedented development in the structure of qbo.

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#1384447 - 11/08/2016 22:19 Re: Qbo [Re: snowbaby]
Surly Bond Offline
Weatherzone Addict

Registered: 23/08/2003
Posts: 2037
Loc: Manilla, near Tamworth NSW
As I read the second thread in this "General Weather" forum, the topic of this thread, like many others that I used to contribute to, is absolutely prohibited.
The suggestion that there may be "an unprecedented development in the structure of qbo" puts it squarely in the forbidden category of "climate change".
_________________________
Data are cheap; information is expensive!

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#1384453 - 12/08/2016 08:11 Re: Qbo [Re: snowbaby]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 2478
Loc: Buderim
Unprecedented things could still happen without climate change.

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#1384454 - 12/08/2016 08:25 Re: Qbo [Re: snowbaby]
Hopefull Offline
Weather Freak

Registered: 24/12/2008
Posts: 966
Loc: Burpengary QLD
My head is spinning just reading this. What does it mean, though, for the weather where we live? Just more of the same maybe!

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#1384637 - 15/08/2016 22:26 Re: Qbo [Re: snowbaby]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 6780
Loc: Adelaide Hills.
There are some pretty straightforward books, online links, and academic resources, which can be looked up, searched for and generally found interesting for those who want to understand how the weather and broader-scale dynamics function in their neck of the woods. It's not that hard to find them, they are in layman's terms, and you don't have to have a scientific background for them to make sense. I would rather read these sources I've mentioned than post questions into the internet aether with no guarantee of feedback or getting a beneficial response I will appreciate and be thankful for smile .


Edited by -Cosmic- (naz) (15/08/2016 22:26)

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#1384749 - 17/08/2016 20:10 Re: Qbo [Re: Seira]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 6780
Loc: Adelaide Hills.
Originally Posted By: -Cosmic- (naz)
There are some pretty straightforward books, online links, and academic resources, which can be looked up, searched for and generally found interesting for those who want to understand how the weather and broader-scale dynamics function in their neck of the woods. It's not that hard to find them, they are in layman's terms, and you don't have to have a scientific background for them to make sense. I would rather read these sources I've mentioned than post questions into the internet aether with no guarantee of feedback or getting a beneficial response I will appreciate and be thankful for smile .

Like this:

http://images.slideplayer.com/15/4767562/slides/slide_6.jpg

Originally Posted By: Mike Hauber
Unprecedented things could still happen

That's about it -- no need to mention anything controversial smile .


Edited by -Cosmic- (naz) (17/08/2016 20:15)

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#1388187 - 25/09/2016 09:39 Re: Qbo [Re: snowbaby]
snowbooby Online   content
Cloud Gazer

Registered: 11/05/2016
Posts: 19
The QBO has currently reverted to a "normal" structure - a westerly regime descending from the upper region and the easterly below about 50 hpa.(source Free University of Berlin, Singapore data to August 2016)

Interested to see the 2015-16 "hiccup" described as the QBO reboot. Part of the research brief from the abstract I pointed to above, is looking at possible connections to 15-16 el-nino.

I would have to speculate there may have been some pretty bizzare wave activity to have produced it. Possibility of near term tropospheric impact?

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#1390175 - 13/10/2016 10:33 Re: Qbo [Re: snowbaby]
snowbooby Online   content
Cloud Gazer

Registered: 11/05/2016
Posts: 19

For anyone interested.

There have been simulations run using varying sulphate aerosol loadings in the stratosphere to map the affects on the Qbo under the auspices of NASA - the Goddard Earth Observing System and the Climate-Chemistry Model Project. Anything like “modification of the qbo&geoengineering” into google should find a number of documents.

Worth a mention is a youtube video on this subject by a Michelle W (use similar search terms) which speculates whether experimentation along these lines may have already occurred with the anomalous behaviour of the Qbo in 2015-16 a direct result.

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#1421891 - 21/04/2017 09:00 Re: Qbo [Re: snowbaby]
snowbooby Online   content
Cloud Gazer

Registered: 11/05/2016
Posts: 19
I thought the abstract below was worth quoting in full as it links the anomalous QBO of 15-16 with the nino. Source is the ESRL/PSD Seminar Series "Impacts of anomalous mid-latitude wave activity during a strong El Niño"(Sam Lillo. School of Meteorolgy,University of Oklahoma. Oct 2016).

"The winter of 2015-16 featured a strong El Niño with enhanced tropical convection in the central Pacific, forcing the classic anomalous Hadley cell and poleward Rossby wave dispersion. This classic response in the tropics interacted with a background flow in the mid-latitudes that diverged from the canonical strong El Niño climatology.

The North Pacific was characterized by significant synoptic-scale Rossby wave activity emerging from Asia, including multiple wave packets tracking around the globe during February and March. The interaction of one of these packets with the ENSO-driven subtropical anticyclone resulted in a large wavebreak over the East Pacific, leading to the deepening of a trough over Mexico of unprecedented amplitude on 10 March 2016.

The anomalous mid-latitude wave activity potentially also had impacts in the stratosphere. The state of the tropical and subtropical stratosphere was controlled largely by the strongest westerly QBO on record. The waveguide for mid-latitude tropospheric wave activity typically weakens above the tropopause, however, the anomalous westerly QBO provided an extended continuum into the lower to mid stratosphere for the mid-latitude wave activity to propagate upward and equatorward.

Beginning during the 2015-16 winter, the QBO evolution took an anomalous turn from the reliable pattern that has been observed for decades. The convergent wave activity resulted in westerly momentum fluxing out of the mid stratosphere, and easterlies developing prematurely. As a result, the westerly waveguide in the tropics was cut-off, and the descending easterly phase of the QBO was, for all intents and purposes, skipped over during this cycle."

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