Support the Arctic Sea Ice Forum and Blog

Author Topic: Atmospheric connections, structure, and long range weather forecasting  (Read 86236 times)

sark

  • Guest
Dr Judah Cohen has published an update to the AER blog.  Forecast ensemble sees a continued cooling in upper level polar cell with continued troposphere warmth into the first weeks of July.

https://www.aer.com/science-research/climate-weather/arctic-oscillation/

I was really hoping this pattern would break as soon as the snow melted of land

FishOutofWater

  • Nilas ice
  • Posts: 1088
    • View Profile
  • Liked: 696
  • Likes Given: 332
Ocean heat is impinging on the Arctic from both the Atlantic and Pacific sides. That's what's intensifying the warm Arctic cold continents pattern. Blocking highs tend to form over the oceans at preferred locations near 0 and 180 degrees. This leads to increased heat transfer from the Atlantic and Pacific ocean heat sources to the arctic atmosphere. This situation weakens the polar vortex and  causes WACCy weather. I wouldn't call it the failure of the polar cell, but the polar circulation is increasingly being disrupted by heat advected from the Atlantic and Pacific oceans.

Glen Koehler

  • Grease ice
  • Posts: 931
    • View Profile
  • Liked: 738
  • Likes Given: 1413
Fish - Is there precedent for Atlantic ocean heat intrusion meeting up with Pacific side?  Any chance of that happening this year?
“What is at stake.... Everything, I would say." ~ Julienne Stroeve

sark

  • Guest
I think you are correct but I don't think it's exactly accurate to say the polar cell is failing -- the *single* polar cell system is now changing into a state where we have two smaller continental polar cells centered over North America and Eurasia, with increasing dominance of the NAmerican cell (IMO).

So, yes, the single-polar-cell system is failing, but we still have polar cells, they are just centered in abnormal locations and are now advecting heat into the High Arctic instead of dissipating heat entering the High Arctic (at least, advection is now occurring more often than dissipation).

Pretty much how I see it.  Except there's sort of a third polar cell going on, often over Sea of Okhotsk.

I love this video of a winter PV split



uniquorn

  • First-year ice
  • Posts: 5117
    • View Profile
  • Liked: 2163
  • Likes Given: 388
Quote
I love this video of a winter PV split
So do I. How do you make one?

Glen Koehler

  • Grease ice
  • Posts: 931
    • View Profile
  • Liked: 738
  • Likes Given: 1413
RE post #2751 about albedo in the 2019 Melt Season thread

Radiative Heating of an Ice‐free Arctic Ocean
Kristina Pistone Ian Eisenman V. Ramanathan
First published: 20 June 2019
https://doi.org/10.1029/2019GL082914

"During recent decades, there has been dramatic Arctic sea ice retreat. This has reduced the top‐of‐atmosphere albedo, adding more solar energy to the climate system. There is substantial uncertainty regarding how much ice retreat and associated solar heating will occur in the future. This is relevant to future climate projections, including the timescale for reaching global warming stabilization targets. Here we use satellite observations to estimate the amount of solar energy that would be added in the worst‐case scenario of a complete disappearance of Arctic sea ice throughout the sunlit part of the year. Assuming constant cloudiness, we calculate a global radiative heating of 0.71 W/m2 relative to the 1979 baseline state. This is equivalent to the effect of one trillion tons of CO2 emissions. These results suggest that the additional heating due to complete Arctic sea ice loss would hasten global warming by an estimated 25 years."

Trillion tons CO2, i.e. about 25 years of current annual global emissions.  That's just a theoretical benchmark number of course, we are a long way from Arctic being ice free all summer.  But every portion thereof adds another slice of warming energy. 

Same authors did an earlier, more practical study:
Observational determination of albedo decrease caused by vanishing Arctic sea ice
Kristina Pistone, Ian Eisenman1, and V. Ramanathan
322–3326 | PNAS | March 4, 2014 | vol. 111 | no. 9
www.pnas.org/cgi/doi/10.1073/pnas.1318201111


"The decline of Arctic sea ice has been documented in over 30 y of
satellite passive microwave observations. The resulting darkening
of the Arctic and its amplification of global warming was hypothesized
almost 50 y ago but has yet to be verified with direct
observations. This study uses satellite radiation budget measurements
along with satellite microwave sea ice data to document
the Arctic-wide decrease in planetary albedo and its amplifying
effect on the warming. The analysis reveals a striking relationship
between planetary albedo and sea ice cover, quantities inferred
from two independent satellite instruments. We find that the Arctic
planetary albedo has decreased from 0.52 to 0.48 between 1979
and 2011, corresponding to an additional 6.4 ± 0.9 W/m2 of solar
energy input into the Arctic Ocean region since 1979. Averaged
over the globe, this albedo decrease corresponds to a forcing that
is 25% as large as that due to the change in CO2 during this period,
considerably larger than expectations from models and other less
direct recent estimates. Changes in cloudiness appear to play
a negligible role in observed Arctic darkening, thus reducing
the possibility of Arctic cloud albedo feedbacks mitigating future
Arctic warming."

Note that study period ended in 2011.  After 2019 easy to think that 25% could be up to 30%.

« Last Edit: June 28, 2019, 09:13:30 PM by Glen Koehler »
“What is at stake.... Everything, I would say." ~ Julienne Stroeve

sark

  • Guest
Scary storm fires up off thunderstorm activity in the GFS, hour 70-180

wdmn

  • Grease ice
  • Posts: 584
    • View Profile
  • Liked: 231
  • Likes Given: 182
What am I looking at here? Green is rain? Am I looking at the part over the lower Great Lakes St. Lawrence?

sark

  • Guest
That's the Eastern US and East Atlantic. Click to run gif.  Midlats cyclone headed north up the Eastern seaboard in hour 70+



b_lumenkraft

  • Guest
Sark, there is no GIF. :P

jdallen

  • Young ice
  • Posts: 3410
    • View Profile
  • Liked: 650
  • Likes Given: 244
Scary storm fires up off thunderstorm activity in the GFS, hour 70-180
I'm just hoping for a Thunderstorm in DC just in time for the parade.
This space for Rent.


vox_mundi

  • Multi-year ice
  • Posts: 10153
    • View Profile
  • Liked: 3510
  • Likes Given: 745
^ +1 ... LMAO
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― anonymous

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

jdallen

  • Young ice
  • Posts: 3410
    • View Profile
  • Liked: 650
  • Likes Given: 244
^ +1 ... LMAO

Ditto.  My Schadenfreude meter just pegged itself.  ;D  XD XD XD
This space for Rent.

vox_mundi

  • Multi-year ice
  • Posts: 10153
    • View Profile
  • Liked: 3510
  • Likes Given: 745
Indian Ocean Causes Drought and Heatwaves in South America
https://phys.org/news/2019-07-indian-ocean-drought-heatwaves-south.html

New research has found the record-breaking South American drought of 2013/14 with its succession of heatwaves and long lasting marine heatwave had its origins in a climate event half a world away—over the Indian Ocean.



It all started with strong atmospheric convection over the Indian Ocean that generated a powerful planetary wave that travelled across the South Pacific to the South Atlantic where it displaced the normal atmospheric circulation over South America.

"The atmospheric wave produced a large area of high pressure, known as a blocking high, that stalled off the east coast of Brazil," said lead author Dr. Regina Rodrigues.

"The impacts of the drought that followed were immense and prolonged, leading to a tripling of dengue fever cases, water shortages in São Paulo, and reduced coffee production that led to global shortages and worldwide price increases."

That impact wasn't just felt on land as the high-pressure system stalled over the ocean.

"The result of this blocking high was an unprecedented marine heatwave that amplified the unusual atmospheric conditions and likely had an impact on local fisheries in the region."



... The 2013/14 South American drought and marine heatwave is the latest climate case study to show how distant events in one region can have major climate impacts on the other side of the world.

"Researchers found that Australia's 2011 Ningaloo Nino in the Indian Ocean, which completely decimated coastal ecosystems and impacted fisheries, was caused by a La Niña event in the tropical Pacific," said Australian co-author Dr. Alex Sen Gupta.

"Here we have yet another example of how interconnected our world is.

Regina R. Rodrigues, et.al., Common cause for severe droughts in South America and marine heatwaves in the South Atlantic, Nature Geoscience (2019).

------------------------------------

Summer Eurasian Nonuniform Warming Found Related to the Atlantic Multidecadal Oscillation
https://phys.org/news/2019-07-summer-eurasian-nonuniform-atlantic-multidecadal.html



"Previous studies indicate the Eurasian nonuniform warming since the mid-1990s may be related with the phase shift of the AMO, and we validate this point by using ensemble experiments with three AGCMs [atmospheric general circulation models]," the lead author says. "The overall consistency among the three AGCMs illustrates the robustness of the AMO's influence, although the models are not the most recent updated versions," she adds.

The authors diagnose the underlying mechanism of the AMO's influence on the Eurasian nonuniform warming from the perspective that the boundary forcing modulates the intrinsic atmospheric variability. The results highlight the role of the Silk Road Pattern.

"The AMO-related tropical diabatic heating anomaly excites the Silk Road wave-train over Eurasia with positive geopotential height and anticyclonic circulation anomalies over Europe-West Asia and Northeast Asia, but negative geopotential height and cyclonic circulation over Central Asia. Such opposite circulations lead to opposite changes in temperature advection, precipitation, cloud cover and solar radiation. When these effects overlap the signals of global warming, it causes amplified warming," the authors explain.

Xueqian Sun et al, Simulated Influence of the Atlantic Multidecadal Oscillation on Summer Eurasian Nonuniform Warming since the Mid-1990s, Advances in Atmospheric Sciences (2019)
« Last Edit: July 08, 2019, 11:12:13 PM by vox_mundi »
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― anonymous

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #65 on: September 21, 2019, 05:07:17 AM »
It's my fault.  I should have made this thread more useful.  Perhaps a new thread in Consequences?  I dunno

Role of the stratosphere (sudden warmings) on intraseasonal tropical-extratropical interactions
•Published on Nov 28, 2017


Introduction to stratospheric dynamics and stratosphere-troposphere coupling
•Published on Nov 28, 2017


Rough Weather Ahead with Dr. Jennifer Francis
•Published on Aug 22, 2019


My polar vortex PhD thesis: explained
•Published on Feb 21, 2019


How I chose my research field (PhD)
•Published on Jan 30, 2019



https://diegofdezsevilla.wordpress.com/






uniquorn

  • First-year ice
  • Posts: 5117
    • View Profile
  • Liked: 2163
  • Likes Given: 388
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #66 on: September 21, 2019, 10:48:13 AM »
cross posting for future reference.
When was the last time the jet stream regularly reached the North Pole from both sides of the planet simultaneously besides the 16 times it happened this year?  (Jan 2014?)

What's the difference from prior years?  Now it's symmetrical and intense and unlike any weather ever recorded.

Whiplash hot/cold with 7" of rain in a pop up thundercloud, wiping out whole counties.  There are squall lines with outburst that knock down enough crops to require adding it to the spreadsheet.  108.7f in Paris? 

It's a funny failure of human dignity to observe it, until it arrests their personal experience.  The hero of the story is a fool.  It's the technique of a joke. 

Why would anyone think a completely split, dual polar cell that breaks up into pieces that fling out of the Arctic is a system we can count on to die slowly?

Apparently packets of vorticity in the Arctic will fling out and become tremendous storms as we watch tropical height atmosphere establish & grow over the North Pole first.

Well, whatever happens, do you agree that you and I both have the opportunity to observe it?

https://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl

https://www.esrl.noaa.gov/psd/data/composites/day/


https://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nhem&pkg=z500_mslp

here's our bad guy: https://earth.nullschool.net/#2014/09/10/0000Z/wind/isobaric/250hPa/anim=off/orthographic=-90.45,90.52,547

The polar cell is failing.

You'll notice that actual air temperatures are often colder over land than over the Arctic.  Now we got a major dynamic polar shit storm going on.  Sometimes that makes me laugh, but not often. 

Potential temperature is a pressure level which speaks more to the dynamics of the atmosphere than they do to "global warming".  Because instead of a pinwheel centered mostly over the Arctic Ocean, it's a fidget spinner with dual Arctic systems.

are they gonna do the Fujiwhara and maintain position over the pole?  no way.

May Day, 2019

We saw a sample of this back in November and again in January.  That was a result of Sudden Stratospheric Warming #1 of winter 2018/2019.  Then we experienced a 2nd at the final warming of the winter polar vortex.  It died very badly in 2019 in a SSW, 2nd of the year.

Yearly average is 0.6 sudden stratospheric warmings.

This is Eemian weather.  2019 is too much already.

So far this year has been alarmingly off the charts abnormal in every aspect.  that's why I'm not explaining this much, because I'm pretty convinced it doesn't make a difference

But FWIW it's been lining up as a quadrupole.  It's ok to say quadrupole.  It's in Mitchell 2013.


Essentially it wants to be an equable climate but it stayed too cold at the pole to allow it.  Like the Southern Hemisphere.  Well, we hit the point where that's no longer working.

now we're seeing a mix of interglacial / equable climate regimes blending together.

It is changing faster than it is warming.  It's the dynamics that are in trouble.  Almost every year will be palpably worse.  That is abrupt climate change featuring a runaway of the climate structure.

Jet streams will start dissolving as big packets of tropical height atmosphere flood to the pole.

Fast atmospheric response to a sudden thinning of Arctic sea ice
https://link.springer.com/article/10.1007/s00382-015-2629-7
« Last Edit: September 21, 2019, 11:02:29 AM by uniquorn »

Shared Humanity

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #67 on: September 21, 2019, 03:07:48 PM »
A relevant thread had already been created!  :)

Shared Humanity

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #68 on: September 21, 2019, 03:08:49 PM »
cross posting for future reference.


Thank you very much for this.

Shared Humanity

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #69 on: September 21, 2019, 03:11:03 PM »
It's my fault.  I should have made this thread more useful.  Perhaps a new thread in Consequences?  I dunno


No. This is the perfect place. Keep up the good work. Be sure to comment on current atmospherics on the upcoming freeze season thread but link to here for the more in depth discussion.

Great work!

El Cid

  • Young ice
  • Posts: 2507
    • View Profile
  • Liked: 923
  • Likes Given: 225
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #70 on: September 21, 2019, 04:55:22 PM »
I agree. It would be nice to have a thread with a discussion of this topic.
Question: Does anyone know about a paper about a possible winter atmospheric setup and its consequences in the future, where there are two poles of cold (Siberia and Greenland-Canada) with a warm(er) Arctic in between?

Pmt111500

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #71 on: September 21, 2019, 05:36:25 PM »
Cross-posting the image with expanded Hadley Cell and mixed Ferrel/Polar Cell here. The thought was, summers might see a temporary exclusion of Polar Cell during summers with a Blue Arctic, but what we would see during winters, would be unclear. Really the thing should be remade with maps somewhat like Sark has done by observational data selecting weather situations to expect.

nanning

  • Nilas ice
  • Posts: 2487
  • 0Kg CO₂, 37 KWh/wk,125L H₂O/wk, No offspring
    • View Profile
  • Liked: 273
  • Likes Given: 23170
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #72 on: September 21, 2019, 05:43:24 PM »
<snip>
How I chose my research field (PhD)
•Published on Jan 30, 2019


Great to listen to your youtube video ("How I chose my research field (PhD)") sark :) . Very nice that you have found an important goal, and be able to pursue that amibition and curiosity.
I wish you the freedom to do good research.

Something's puzzling me: at 2m52 what do you mean by "circuits"?
"It is preoccupation with possessions, more than anything else, that prevents us from living freely and nobly" - Bertrand Russell
"It is preoccupation with what other people from your groups think of you, that prevents you from living freely and nobly" - Nanning
Why do you keep accumulating stuff?

wdmn

  • Grease ice
  • Posts: 584
    • View Profile
  • Liked: 231
  • Likes Given: 182
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #73 on: September 21, 2019, 06:32:18 PM »
Following up on Nanning's comments, the other video (about your thesis) does not have the correct link.

Also, guys, sark IS a scientist.

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #74 on: September 21, 2019, 07:35:30 PM »
That was not my intention.  I am not that PhD guy.  It is the field of research that needs to be highlighted.

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #75 on: September 22, 2019, 02:35:35 AM »
No I'm not a Dr. but probably need one

posting these here for posterity

I'm at a 3 out of 5 on alarm right now.  But my mood swings with the AO index.

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #76 on: September 22, 2019, 03:02:46 AM »
Quote
Something's puzzling me: at 2m52 what do you mean by "circuits"?

I think he is saying electrical circuits, among the things he studied, along the way with optics and then finally fluids caught his attention

Yes, this guy is amazing.  Also, the work he did is a truer description of how the atmosphere is coupled.  It only makes sense, but to actually put it into a chart is hard.

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #77 on: September 22, 2019, 03:24:35 AM »
The hunch I have fostered is that the dynamics were not properly assessed... because of evidence like these

Based on how absolutely mad the weather has been.

I don't recall ever hearing about two polar cells "oh it looks like we have two polar cells."  Never.

Oh, by the way.  The pattern is changing to  an inverted quadrupole.  I didn't invent quadrupole (It's in Mitchell, 2013).  I'm pretty sure I did invent Octopole to describe the atmosphere

I work 55 hours a week machining parts, haha.

Enhanced Stratosphere/Troposphere Coupling During Extreme Warm Stratospheric Events with Strong Polar-Night Jet Oscillation

Atmosphere 2018, 9(12), 467; https://doi.org/10.3390/atmos9120467

Enhanced Stratosphere/Troposphere Coupling During Extreme Warm Stratospheric Events with Strong Polar-Night Jet Oscillation
by Dieter H.W. Peters, Andrea Schneidereit, Alexey Y. Karpechko
1
Leibniz-Institute for Atmospheric Physics, University of Rostock, Ostseebad Kühlungsborn, D-18225 Mecklenburg, Germany
2
Finnish Meteorological Institute, Arctic Research, PL 503, 00101 Helsinki, Finland

Extreme warm stratospheric events during polar winters from ERA-Interim reanalysis and CMIP5-ESM-LR runs were separated by duration and strength of the polar-night jet oscillation (PJO) using a high statistical confidence level of three standard deviations (strong-PJO events). With a composite analysis, we demonstrate that strong-PJO events show a significantly stronger downward propagating signal in both, northern annular mode (NAM) and zonal mean zonal wind anomaly in the stratosphere in comparison with non-PJO events. The lower stratospheric EP-flux-divergence difference in ERA-Interim was stronger in comparison to long-term CMIP5-ESM-LR runs (by a factor of four). This suggests that stratosphere–troposphere coupling is stronger in ERA-Interim than in CMIP5-ESM-LR. During the 60 days following the central date (CD), the Arctic oscillation signal was more intense during strong-PJO events than during non-PJO events in ERA-Interim data in comparison to CMIP5-ESM-LR runs. During the 15-day phase after CD, strong PJO events had a significant increase in stratospheric ozone, upper tropospheric zonally asymmetric impact, and a regional surface impact in ERA-Interim. Finally, we conclude that the applied high statistical threshold gives a clearer separation of extreme warm stratospheric events into strong-PJO events and non-PJO events including their different downward propagating NAM signal and tropospheric impacts.

https://www.mdpi.com/2073-4433/9/12/467/htm

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #78 on: September 22, 2019, 04:02:06 AM »
Quick prediction easy to make:  atmospheric blocking reaching the North Pole..   Sept 30, Oct 8, Oct 17, Oct 25th.

A ridge in the jet stream will form and dive right onto the Arctic to reach the North Pole on those dates.  Looking down from the north, traveling clockwise.  Often the loading pattern of high pressure anomalies as they travel together toward the Arctic will be across the international date line, or Prime Meridian.  Heat wave from Azores or Europe traveling straight up into the Arctic and reaching the pole, meanwhile, the same thing is coming across Alaska.  Little meridional handshake at the North Pole, that's all

:)
« Last Edit: September 22, 2019, 06:25:22 AM by sark »

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #79 on: September 22, 2019, 06:24:31 AM »
Anthony Masiello the absolute God

https://twitter.com/antmasiello/status/1175450831849775104

All defined stratospheric pressure levels are seeing new temperature minimums set over the Tropics, but 30mb for 25°S-25°N stands out. Any other SH strat-disturbed year (e.g. 2002) didn't see a response like this over the Tropics (strat data sets aren't great)!

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #80 on: September 22, 2019, 06:27:15 AM »
I agree. It would be nice to have a thread with a discussion of this topic.
Question: Does anyone know about a paper about a possible winter atmospheric setup and its consequences in the future, where there are two poles of cold (Siberia and Greenland-Canada) with a warm(er) Arctic in between?

El Cid.  Help.

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #81 on: September 22, 2019, 08:21:37 AM »
I produced this image of North / South winds at the level of the jet stream.  This is not anomaly graph, just the plain 5 day meridional wind, 1978 and recent.

the meridional wind component is positive if from the south, and negative if from the north.

not ground breaking stuff, it just helps me understand noticing more dissolving winds of the jet stream on weather maps.  It's also not obvious what's different, so I have something to help sleep tonight.

https://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl
https://www.esrl.noaa.gov/psd/data/composites/day/
« Last Edit: September 22, 2019, 08:32:36 AM by sark »

Pmt111500

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #82 on: September 22, 2019, 08:39:25 AM »
Well, it's spring/autumn switch time from summer to winter, and in stratosphere these show up much clearer than in troposphere. The Antarctic 'bent vortex' and the Masiello note of very cold mid-latitude strat show that something out of the ordinary is going on. I'd wait the two weeks i mentioned in SH vortex thread and see if this settles to something more familiar.

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #83 on: September 22, 2019, 09:39:43 AM »
Oh, well what will we talk about for two weeks?

Is there such a thing as a high pressure "storm"?

Pmt111500

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #84 on: September 22, 2019, 09:49:46 AM »
Oh, well what will we talk about for two weeks?

Is there such a thing as a high pressure "storm"?

That's just me, and I am NOT familiar with stratosphere patterns, this four-fold symmetry might be very unusual and result in unexpected cold bursts very far south and vice versa, high warmth in the north. (and opposite in S(outhern)H(emisphere) of course.

Visited nullschool for the first time since spring just to see how this shows up there. I'm out of touch. Ended up toying with the settings and found a new liking for the Atlantis-projection. Setting it so the equator is dead center in the middle and the edge shows the locations of jets quite nicely. Huge bit of SH midlatitude jet rotating over Australia f.e., I don't know what that means.

Also, I don't get why the jet over the Tropical Convergence Zone isn't on the Equator right now, Maybe this is normal, but I'd have expected it to be very much on the Equator and not mostly still on Northern Hemisphere?
« Last Edit: September 22, 2019, 09:59:25 AM by Pmt111500 »

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #85 on: September 22, 2019, 10:21:21 AM »
The ITCZ clouds move north and south throughout the year but normally north of the equator.

http://bmcnoldy.rsmas.miami.edu/tropics/itcz/index.html

http://iprc.soest.hawaii.edu/users/xie/ITCZ.html

Pmt111500

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #86 on: September 22, 2019, 10:46:50 AM »
The ITCZ clouds move north and south throughout the year but normally north of the equator.

http://bmcnoldy.rsmas.miami.edu/tropics/itcz/index.html

http://iprc.soest.hawaii.edu/users/xie/ITCZ.html

Thanks, Sark. Xie at Hawaii explains at lenght and it gets complicated, but probably right...

That off-center souther vortex though... Are there people present who have followed sci-discussions on stratosphere for decades/years? Please explain how that is the way it is?

(Added after seeing Gerontocrats message on Antarctic SSWs)
This is the third known time of this happening. So not common and I was too reticient on my comment before.
« Last Edit: September 22, 2019, 02:54:01 PM by Pmt111500 »

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #87 on: September 22, 2019, 11:09:22 PM »
The way I understand it:

Rossby waves climbing up & over the winter PV is the stratospheric sudden warming process.  The waves have to perturbate the atmosphere in a proper configuration for the SSW to occur.  Wave strength is not as important as timing.

I would expect:

The configuration required for a SSW event is aligning in the entire structure of climate & oceans, leading to increased destabilization of the polar vortices at both poles.


sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #89 on: September 23, 2019, 04:52:08 AM »
Am I crazy?

bbr2314

  • Nilas ice
  • Posts: 1817
    • View Profile
  • Liked: 158
  • Likes Given: 53
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #90 on: September 23, 2019, 04:56:49 AM »
Am I crazy?
No. This has quickly become one of the best threads on the forum.  :)

We should see +500MB height anomalies in the Arctic steadily worsen as we head through autumn as the PV repeatedly splits. As snowcover revs across the continents under the guts of the Arctic (-500MB anomalies, which seem end up being quite tenacious when they get going across the continents), this will get much worse through October.

El Cid

  • Young ice
  • Posts: 2507
    • View Profile
  • Liked: 923
  • Likes Given: 225
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #91 on: September 23, 2019, 07:57:40 AM »
Once again sark, please, explain your meaning a little bit better

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #92 on: September 23, 2019, 08:12:23 AM »
Once again sark, please, explain your meaning a little bit better

High pressure is dominating at the pole featuring intense meridional transport.  The system is locking into a wave 4.  And, it looks like a swastika.

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #93 on: September 23, 2019, 08:21:51 AM »
jet stream meridional wind composite anomaly for 5/15-8/15 2019

you can see it by going to climate reanalyzer https://climatereanalyzer.org/wx/fcst/#gfs.nh-sat1.ws250-snowc-topo press > then +++++

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #94 on: September 23, 2019, 08:51:17 AM »
Ilkley Moor Swastika stone.  UFOs.  Time Travel.  Potential vorticity.

Nuff said

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #95 on: September 23, 2019, 09:50:32 AM »
“The 2015-17 unprecedented disruption of the stratospheric quasi-biennial oscillation”

Dr. Paul Newman, NASA Goddard Space Flight Center

Here we describe an unprecedented disruption of the stratospheric quasi-biennial oscillation (QBO) QBO during 2015-2017 period. The QBO is a tropical lower stratospheric, downward propagating zonal wind variation, with a period of ~28 months. First discovered in 1960, observations of the QBO extend back to 1953. The QBO propagates downward from the middle stratosphere to the tropopause with a period of about 28 months, with a range of 24-32 months. The QBO is a major source of stratospheric variability, and in addition to influencing the zonal wind behavior, the QBO affects stratospheric temperatures and trace gases, particularly ozone and water vapor. Here we describe the unprecedented disruption of the QBO during the Northern Hemisphere winter of 2015-17 using Singapore wind radiosonde observations and meteorological reanalyses. Normally, the QBO would show a steady downward propagation of the westerly phase. In 2015-17, there was an anomalous upward displacement of this westerly phase from ~30 hPa to 15 hPa. These westerlies impinge on, or “cut-off” the normal downward propagation of the easterly phase. In addition, easterly winds develop at 40 hPa.  Comparisons to tropical wind statistics for the 1953-present record demonstrate that this anomalous 2015-17 QBO is unprecedented. More specifically, this talk will focus on the impact of the QBO disruption on trace gas distributions. The disruption led to a reduction of ozone in the June-September period of the Northern and Southern hemisphere extratropics, along with perturbations to water and hydrochloric acid (HCl). In the NH, these total ozone values were either at or near record low levels.

https://science.gsfc.nasa.gov/sed/bio...



Singapore Sonde Station: https://acd-ext.gsfc.nasa.gov/Data_services/met/qbo/qbo.html#intro

Notice the drop in ozone in September of 2019.  Related to the SSW in the southern hemisphere, I'm sure.  The QBO process periodicity is 24 months, 30 months, or 36 months and I believe we are reaching 24?

uniquorn

  • First-year ice
  • Posts: 5117
    • View Profile
  • Liked: 2163
  • Likes Given: 388
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #96 on: September 23, 2019, 11:28:25 AM »
Am I crazy?
Probably not. Either way, it's interesting stuff. Please carry on.

El Cid

  • Young ice
  • Posts: 2507
    • View Profile
  • Liked: 923
  • Likes Given: 225
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #97 on: September 23, 2019, 12:55:56 PM »
I like longer timeframes so I took a look at geopotential height anomalies for this summer (jun-aug) vs 1980-2010 and the last few years. There were some very marked positive anomalies over the arctic.
I would be happy if someone could come up with a forecast and reasoning(!) as to what it means for arctic and midlatitude weather the following months

sark

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #98 on: September 24, 2019, 07:10:18 AM »
subtracting El Nino years would yield roughly the same.  I believe this summer had the largest increase in atmospheric height over the Arctic of any summer since observations began.

Pmt111500

  • Guest
Re: Atmospheric connections, structure, and long range weather forecasting
« Reply #99 on: September 24, 2019, 08:46:16 AM »
subtracting El Nino years would yield roughly the same.  I believe this summer had the largest increase in atmospheric height over the Arctic of any summer since observations began.

Arctic atmosphere is generally thickening because of repeated SSWs and warm incursions from south? The older model of tropopause heights lowering towards arctic isn't too good anymore? Is cloud height over Arctic increasing? Please do the same for dec-march. The warming should be more pronounced during winters, thus even higher anomalies might be present.