Study: ‘Traffic Jams’ in the jet stream blamed for abnormal weather patterns

UChicago study explains blocking phenomenon that has baffled forecasters

The sky sometimes has its limits, according to new research from two University of Chicago atmospheric scientists.

This is an illustration of the Northern Hemisphere’s polar jet stream. CREDIT NASA’s Goddard Space Flight Center

A study published May 24 in Science offers an explanation for a mysterious and sometimes deadly weather pattern in which the jet stream, the global air currents that circle the Earth, stalls out over a region. Much like highways, the jet stream has a capacity, researchers said, and when it’s exceeded, blockages form that are remarkably similar to traffic jams–and climate forecasters can use the same math to model them both.

The deadly 2003 European heat wave, California’s 2014 drought and the swing of Superstorm Sandy in 2012 that surprised forecasters–all of these were caused by a weather phenomenon known as “blocking,” in which the jet stream meanders, stopping weather systems from moving eastward. Scientists have known about it for decades, almost as long as they’ve known about the jet stream–first discovered by pioneering University of Chicago meteorologist Carl-Gustaf Rossby, in fact–but no one had a good explanation for why it happens.

“Blocking is notoriously difficult to forecast, in large part because there was no compelling theory about when it forms and why,” said study coauthor Noboru Nakamura, a professor in the Department of the Geophysical Sciences.

Nakamura and then-graduate student Clare S.Y. Huang were studying the jet stream, trying to determine a clear set of measurements for blocking in order to better analyze the phenomenon. One of their new metrics was a term that measured the jet stream’s meander. Looking over the math, Nakamura realized that the equation was nearly identical to one devised decades ago by transportation engineers trying to describe traffic jams.

“It turns out the jet stream has a capacity for ‘weather traffic,’ just as highway has traffic capacity, and when it is exceeded, blocking manifests as congestion,” said Huang.

Much like car traffic, movement slows when multiple highways converge and the speed of the jet stream is reduced due to topography such as mountains or coasts.

The result is a simple theory that not only reproduces blocking, but predicts it, said Nakamura, who called making the cross-disciplinary connection “one of the most unexpected, but enlightening moments in my research career–truly a gift from God.”

The explanation may not immediately improve short-term weather forecasting, the researchers said, but it will certainly help predict long-term patterns, including which areas may see more drought or floods.

Their initial results suggest that while climate change probably increases blocking by running the jet stream closer to its capacity, there will be regional differences: for example, the Pacific Ocean may actually see a decrease in blocking over the decades.

“It’s very difficult to forecast anything until you understand why it’s happening, so this mechanistic model should be extremely helpful,” Nakamura said.

And the model, unlike most modern climate science, is computationally simple: “This equation captures the essence with a much less complicated system,” Huang said.

###

Citation: “Atmospheric Blocking as a Traffic Jam in the Jet Stream,” Nakamura and Huang, Science, May 24, 2018.

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82 thoughts on “Study: ‘Traffic Jams’ in the jet stream blamed for abnormal weather patterns

  1. Off topic, but a little while ago a guest post discussed development of a block chain based science fact checker. Now Elon Musk is saying he wants to create a general news fact check site (which he proposes to call Pravda), over his annoyance with what he considers fake news about Tesla’s troubles. I wonder if Elon visits here once in a while?

    • Musk is too funny. His troubles are of his own manufacturing. Space X functions well and his idea to compete with satellite internet companies could go well, if he uses his head. He has screwed up with Tesla, mostly as he needed Hillary to win in order for Tesla to be successful. Then there is the Boring Company wasting some of his resources, along with the Hyperloop. It just never seemed to occur to him to first get a revenue stream going, then move on to the frontier/concept ideas.

  2. “just as highway has traffic capacity, and when it is exceeded, blocking manifests as congestion,” ”
    When people that are driving too fast….run into traffic that’s going slower….and more fast cars keep backing it up and up…..same thing

    • Whether people are driving “too fast” is irrelevant. It’s the relative speed that counts.
      Many times I’ve been on a busy interstate highway where the traffic actually comes to a halt with no apparent cause. I thought about it- if you come up on traffic going slower, you slightly over-correct your speed. The person behind you does the same, and the next, and the next, until 100 cars or so back they’re dead stopped.

      • isn’t that exactly what I just said??…..and if everyone would slow down and drive the same speed it wouldn’t back up

      • No because the phenomenon occurs regardless due to any disruption in flow of any oscillating system.
        A ripple effect is created where the front of the wave is free to move unhindered and quickly catches up to the back end of the wave where the blockage is. This can compound itself until traffic or any “fluid” comes to a complete stop-start situation even when the disruption is no longer present.

      • This truck driver ain’t slowing down except a little during the period starting June 4th and ending June 8th which is a DOT hit week.
        As for back ups? One distracted driver or just somebody being a butt head can cause a back up in heavy traffic conditions even when there are 3 lanes or more.
        Now concerning the article. The path of “Super Storm Sandy” was well predicted. Joe Bastardi pretty much nailed where it would come ashore five full days before it did.

      • Eustace Cranch
        “Whether people are driving “too fast” is irrelevant. It’s the relative speed that counts. ….”
        —-
        Well the wider picture is one of constricted capacity, for the constant flow volume. The jetsteam is becoming constricted, but why, as the number of air molecules is the same for blocked, or not blocked.
        And where it unblocks, the flow turns into … an acellerated jet of air molecules.
        Guess I’ll have to read the paper.

    • I think this is a different phenomenon. On a lightly traveled freeway, traffic moves smoothly at high speed with ample separation. As density increases, average following distance decreases until drivers feel they are too close for safety and slow down a little. This increases traffic density further, reducing separation, and drivers slow even more. This chokes traffic to a bumper-to-bumper crawl with almost zero following distance and maximum traffic density. This is analogous to “hydraulic jump” in open channel fluid flow.

      • I remember decades ago when highway speed radar units were installed along the 401in southern Ontario. Tickets were issued if you went, I think, 5 mph over the limit. Everyone slowed down, everyone traveled the same speed, there were far fewer accidents and the ripple effect described above just didn’t happen. My clear recollection is that it was much easier to get rom here to there and traffic jams were scarce.

      • Piers Cornby proposes an electromagnetic model for the behavior of the jetstream, in which “the weather is not driven by the weather” but by magnetic infuences of sun and moon. The model seems to allow him to make quite good predictions about the behavior of the jetstream. I think his approach is not so well liked, because it also predicts, that CO2 is not the cause of climate change.

      • Marcus,
        Its nonsense, look at where the highs and lows are (nullschool shows this quite well), it is pressure-driven, and the pressure difference is driven by heat differences, equator to pole.
        i.e. the jetstream is already physically explained by regional pressure change, why do you think our weather models work so well for days in advance? And why they predict jetstream movements many days in advance also, all the way to predicting polar vortex altitude dynamics, days in advance, also. We don’t lack detailed mechanisms for predicting these.

      • Research I read several years ago attributed “caterpillaring” and “brake light backups” mainly to too uniform a spacing between vehicles. People tend to follow just a bit too close for comfort, and most people choose pretty much the same spacing. If the traffic flow is over some critical number if anyone just taps the brakes the flow comes to nearly a complete halt at that point and it can remain for hours. The highway can carry about the same traffic at 3-4 mph bunched up as it can at 60 or so spread out evenly.
        That study found that inserting some cars that kept 2-3 times the usual following distance in a random pattern greatly reduced the backups.
        Unfortunately, if you do try to leave a bigger space jerks will always come zooming along, switching lanes back and forth to try to get through just a little bit quicker.

        • What affects traffic are people who do not want to drive at the speed of the rest of the traffic. My experience is that slow drivers are the most common disruptor, and my stepniece the deputy Sheriff noted it was against policy to ticket such people. If the consensus of the traffic on I 5 is to go 75, anyone driving 65 is obstructing traffic.

      • I’ve traveled through many stop and go traffic back-ups where the problem was something going on near, but off, the road. Every lane is actually clear; travel is not physically impeded in any way except by dumb driver reaction. Immediately after the gawking scene traffic speeds up to normal. These nothing situations, that is nothing relevant to actual traffic, cause an extremely congested and almost stopped flow for several miles back that can take an individual car 30 to 60 minutes to traverse.

    • Traffic congestion is dealt with by Poisson’s queuing theory where the probability of congestion is determined by the time interval between vehicles. Control of these time intervals would go a long way to reduce congestion. Controlling speed doesn’t work.
      As usual the authorities can’t get their heads around this simple fact.
      How you control jets streams is beyond me; but perhaps being able to predict could be very useful.

      • Experienced commuters are also likely to follow much closer, be less disturbed by the emergence of apparent danger, and more likely to drive fast. The number of cars passing a point per minute is higher. There are fewer jams as a result. Inexperienced drivers with a greater response to threats are to be found in weekend traffic heading to cottage country. The worst jams happen in those groups. The jams occur because people over-compensate when braking and do not move forward at the earliest opportunity.
        As an individual you can assist ending a jam by slowing gradually and never coming to a complete stop. Behind you, people react the same way and the pulse of ‘stopping’ gradually disappears. Stopping for any longer than necessary creates an additional pause behind you (by force) and makes the situation worse and worse.
        The comment above on Hwy 401 being smoother when there was strict speed regulation is very interesting. I am looking forward to evidence in that regard. Autonomous cars will probably be a great help because in theory they could all be programmed to start moving simultaneously, opening the gap to 2 seconds as space permitted. After all, stopped cars are more than 2 seconds apart if they are stationary.

        • Yes Crispin, but your intuition is only partially right. It is correct to say that closer driving increases the number of cars passing a point; but at the same time the probability of congestion is increased due I expect to the reduction in the spring element in the queue. The graph of this rises steeply as the time interval is reduced.
          It take about 0.68 secs to register a danger. about 0.6 secs to react which only leaves only 0.72 secs for the deceleration process if you are only 2.0 secs behind. Ok it works most the time but does carry risk. I tend to have 3.0 secs between me and the car ahead but I am of vintage years. Take your pick.
          Your last para. – : dead right.
          I wasted some time a few years ago taking out a Patent Application for a method of controlling this time interval. A dead duck now since the rise of AI gps etc. ; but at least mine would have worked with any car of whatever vintage, so would have been far cheaper to implement. It’s an interesting subject particularly when you get involved in the maths. In one of my mad moments I even contemplated designing a roundabout operating on the same principle as firing bullets through a Tiger Moth’s propellor. Don’t worry – It’s in the wakker packer bag!! But Hey! maybe AI could do this. You never know.
          Cheers!

      • Sorry Crispin, electric vehicles are evil, they bring dogs and cats together in un-natural ways, and run over pedestrians, then explode.

    • In ’68 at PSU, we discussed traffic ‘pulses” in my fluid dynamics class. Fluid in a pipe, think molecules instead of cars, exhibits the same “pulses (like water hammer). Same equations explain traffic flow and fluid flow when traffic volume is over 50% of maximum laminar flow conditions. Not surprised the jet stream blocking can be explained by the same equations, long since forgotten by me.

    • Maybe a “crash” course in Fluid Logics would help those guys n’ gals to figure out the “cause” of the Jet Stream’s “blocking” problem.
      The “meandering” of the Jet Stream(s) Atmospheric Circulation is very similar to the “meandering” of the Thermohaline Ocean Conveyor Circulation.

  3. Pathetic. Surely consevation of mass dictates that there are as many aircraft flying east as west! Engineer here.

    • Yes but it flows in latitude bands not intermingling so much, Look at Jupiter for flow visualizations.

      • not so much, Rocket
        I flew for over 20 years way up high and am a seasoned vet of the [jet] stream. Also a vet in another arena because of my duty during those pilot days.
        That rascal weaves north and south a lot, and always seemed to me it did so more in the spring and then the fall. Out west we would get what they called zonal flow, with was not as serpentine.
        Anthony should comment here, as he is a bonifide weatherman and not the ‘practicing” weatherman I had to be in order to fly to a destination.
        So the Jupiter and Saturn flows are not a lot like our atmosphere.
        Gums sends…

      • Gums,
        I find interesting the sort of remarks by Stephen Wilde that the jetstream becomes more north south looped, and jet-like, when the very top of the atmosphere falls lower, during a solar quiet (now) thus to cooling phases, as the altitude of the upper troposphere also falls (compacts) a few thousand feet lower, in that process of a reduction in ‘thermalisation’ of the molecules present, i.e. lower average kinetic energy of impact, from less high-energy solar particles hitting the air molecules and increasing their energy, pushing them apart more–as thermal is just kinetics, so a cooler more compacted atmosphere is the result. Thus cooling and higher more persistent highs.
        This jet stream traffic-jam notion fits perfectly with that, as compaction of the atmosphere is like necking down a 6 lane freeway, to 5 lanes. It creates a constriction, due less altitude for the same molecules to move in below the stratospere, so to higher pressure zones.
        So compaction due lower average kinetuc energy of the air, thus blocking air-jams creates the standing blocked highs, with the jet rushing around its outside, as the high itself is a further constriction to molecular flow, so the jet just wraps around the relatively more prominent mid-latitude lows, and is flung further north before recurving south again (hey, I’m from the southern hemisphere).
        In your fighter experience, it occurs more in Spring, and this is because summer convection increases the alt of troposphere and moisture in summer and fall (less jet constriction), but in winter the lower thermalisation of the air from less rays, and lower humidity, causes the troposphere to compact lower some, each winter season and spring. So spring remains somewhat constricted compared to fall, Spring still has a lower colder troposphere altitude—so like squeezing the end of a hose, you get a stronger jet, but from the same number of molecules flowing in five lanes in winter, and six lanes in summer, at the troposphere de-compacts.
        Which means in a low solar activity phase you only get 5.5 lanes in summer, and 4.5 lanes in winter, so even more standing highs, stronger jets, more mid latitude stirminess, more north to south loop tendency, and more cold approching closer to equatorial zones.
        This could also explain why we had less tropifal cyclones during high solar activity in the summers, i.e. the 5.5 lane solar quiet summers, which stir things more around tropical lows during the weaker summer jet’s recurve south again.
        This explains quite nicely why the reduction in thermalisation during a solar minimum, would produce a greater constriction, and more jetstream wander and storminess in solar quiets.
        And it’s also not dependent on Stephen Wilde’s notion of ozone priduction pumping the tropisphere’s max height verses latitude.
        Instead the mechanism is a DIRECT function of lower thermalisation of air, when ‘rays’ are net fewer, or else the ‘rays’ becone net weaker, due to seasons, plus lower magnetic sunspot acceleration of impacting thermalising particles, so a more compact denser (higher pressure) atmosphere.
        This seems to neatly explain both the cooling, and meridonal flow, and the standing blocking high pressure increases via common garden-variety thermalisation and gas kinetics, with no specific need for greater cloudiness, or a lower albedo.

    • “Pathetic. Surely consevation of mass dictates that there are as many aircraft flying east as west!”
      Yes and No. I’m pretty sure that what happens in practice in the mid latitudes is that West to East air traffic tries to fly in the jet stream while East to West tries to stay out of the jet stream. Not a symmetric situation since jet stream travel will be faster than not-jet stream travel so there is likely more East West traffic in the air at any given time than West to East?
      Just a guess.

    • Yep. Much as in the same way that conservation of mass dictates there is as much of the earth rotating to the east as there is rotating to the west – errm? I guess thats what comes from living on a spherical planet.

      • Are you suggesting that we must act quickly to solve the sphericity (spericality?) problem???

      • You almost got it, it’s the antipodal hemisphere rotating west with respect to a horizontal observer at the equator who’s head is facing north which balances the energy. Which proves that conservation of energy is relative to an observer of a relativistic cosmos.

  4. Introducing the concept of Poisson distributions, as used in predicting the behaviour of cars (discrete entities), into a chaotic, non-linear differentiable system I find odd. Blocking could simply be that a stationary point has been found in the system.Trying to explain it in terms of anything other than solutions of coupled-linked non-linear diferential equations seems very un-Occam’s Razor.

    • “the jet stream is reduced due to topography such as mountains or coasts”
      I was too circumspect about topagraphy’s ability to channel jet streams.as the lowest jest streams are higher than the tallest mountains, and those would have to be some pretty steep coastal cliffs to rise 30k feet..

      • But you still substantially reduce the entire volume of stratosphere that the fluid has to travel through when over mountains.

      • actchally, good flows of well over 60 knots and higher, are frequently found below 20,000 feet, especially in the winter..
        Ask any sailplane pilot that rides the “mountain wave”. The stream bounces up, and some sailplane folks have reached 35,000 to 40,000 feet.
        We routinely clocked 120 kt and higher at 20,000 feet or so coming south along the Atlantic Coast near Virginia. No mountain wave due to the low mountains, but ATC would ask us what we read using our cosmic nav system.
        Gums sends…

      • The pilot better be dressed for it, that’s for sure. I wouldn’t know why it would be necessary to have a system permanently installed in the aircraft. Just a bottle, regulator and mask. Military freefall guys carry their own O2 when they jump from high altitude. Since the system on a C-130 isn’t set up for supplying O2 for all those people when the door or ramp is open the jumpers have their own console with 220 bottles they bring on the aircraft and use that until they hook into their smaller capacity bottle they jump with.

      • Oh, they also do HAHO or High Altitude High Opening jumps. Go out at 30,000 ft, pop the chute and fly their chutes into their projected DZ. So even a jumper under a parachute can carry enough 02 for a significant period of time above 15,000′

      • The sailplane pilots I know from the AIr Force Academy were cadets, and they had oxygen. Went up to 25K or so riding the wave from Pike’s Peak.
        The partial pressure of O2 is a problem, so above that ( 20K or so) you need “positive’ pressure O2.
        They were dressed very warm.
        Gums sends…

      • The jetstream’s altitude can be just as wavey in the verticle, as the horizontal,. It’s much slower at lower levels, but can drop down as low as18k feet (rarely). But it’s base often begins around 25k feet, and its thickness can vary between 10k and 25k feet. The top and bottom altitudes move at only 25 to 50% the velocity of the core flow, but it’s still more or less a part of the one pressure-induced flow channel.

  5. “and the swing of Superstorm Sandy in 2012 that surprised forecasters”
    Huh?

    “Track forecast for Hurricane Sandy, from its birth as a tropical cyclone through landfall in Atlantic City. Southern New Jersey was positioned in the center of track guidance by Thursday at 5 a.m., roughly 108 hours prior to landfall…although there were some minor fluctuations in the forecast .”
    https://www.washingtonpost.com/blogs/capital-weather-gang/post/the-national-hurricane-centers-striking-forecast-for-superstorm-sandy/2012/11/01/e2633b5e-2427-11e2-ac85-e669876c6a24_blog.html

    The Euro model (European Center for Medium‐Range Weather Forecasting (ECMWF)) had the Sandy track pegged pretty close for New Jersey even a couple of days before NOAAs Global Forecast System (GFS) model finally resolved about 4 days out from landfall. To wit:

    Accuracy of early GFS and ECMWF Sandy (2012) track forecasts: Evidence for a dependence on cumulus parameterization published in GRL, 2014.
    “The extremely damaging Hurricane Sandy (2012) is noteworthy for the significant track bifurcation among several forecast models approximately 6–7 days before landfall.”
    …..
    “This paper demonstrates that these differences were caused not by resolution or initial condition differences but rather due almost exclusively to choice of cumulus parameterization. ”
    source: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GL059839

    The inability to correctly”parameterize the puffy clouds (cumulus) led to the US models being out to lunch for most of the early forecast runs on Sandy. Sounds strangely familiar.
    Is someone trying to revise history?

  6. Maybe models will finally get a little better. I am not against models. Not even against bad models. I am against overhyping bad models.

    • The European weather model out performs the US weather model forecasts on a pretty consistent basis. And the European is pretty good I think. The Japanese also have a decent weather model. Not all models are bad, just the ones put together with an agenda other than accuracy in forecasting or projecting. Ones like the majority Climate models.

  7. Given that all the models say that Global warming (all praise be upon it’s name) is supposed to decrease the temperature difference between the tropics and the arctic.
    Given that it is this temperature difference that drives the jet stream.
    Therefore, how exactly does Global warming (all praise etc.) “run the jet stream closer to its capacity”.

    • Atmospheric constipation. Tell the planet it needs to eat more prunes. 😎

    • MarkW
      Because with a decrease in temperature difference between the tropics and the arctic. Means that the temperature difference between land mass and oceans starts playing a more important in how the jet stream behaves.

      • BULLSHIT
        : taxed
        “Because with a decrease in temperature difference between the tropics and the arctic. Means that the temperature difference between land mass and oceans starts playing a more important in how the jet stream behaves.”
        You made that comment up and if you didnt it further explains why all of climate science is a farce.
        If the difference in one set of 2 variables (initially and always) overroad the effect of the difference in another set of 2 variables AND the 1st set is then changed to wipe out the effect of the 1st differences; the 2nd set of variables cannot play a more important role than what they did before the 1st set was changed. If both sets of variables are in the same measurement units then the 2nd set of variables has no effect in the changed circumstances if it didnt have an effect before the changes were made. This is because the 2nd set of variables either 1) had an effect when the difference in temperature of the 1st set of variables was near 0 or 2) it always had an effect no matter what the difference was in the 1st set of variables. YOU CANNOT HAVE IT BOTH WAYS. EITHER THE TEMPERATURE DIFFERENCE BETWEEN LAND MASS AND OCEANS ALWAYS HAS AN EFFECT DESPITE THE DIFFERENCE IN TEMPERATURE BETWEEN THE TROPICS AND THE ARCTIC OR it has no effect. If it has no effect then your conclusion is wrong and if it always has an effect , then global warming theory is wrong. Take your pick. Either way; global warming theory is wrong. What climate science needs is a firm basis in logic,statistics , mathematics, and thermodynamics. Somehow all these disciplines got forgotten or downplayed when the atmospheric science faculties were set up in the 1980s. Computer models became almost 100% focus of their attention. Skeptics started calling them Faculties of global warming when the climate scientists got rid of the term global warming and changed it to climate change around 2010. I will end with one last quote by Dr, Pat Frank who said “he never met a climate scientist (and he has met many) that knew the difference between precision and accuracy”.

      • Alan Tomalty
        You seem to assume that only one of these variables will change.
        What if the process that causes warming in the Arctic also leads to cooling in the northern most landmasses.
        Where you have warmth entering into the Arctic mostly over the oceans but cold leaving the Arctic mostly over the landmasses. So the cold from the Arctic gets exported to the landmasses and so changes the balance of warmth and cold across the NH. So the difference between warmth and cold is not just north and south it, but also starts to become between east and west as well.
        That will have an effect on how the jet stream behaves.

    • Thinking like a climateer for a minute, I think they would say AGW pushes the hemispheric Hadley cells poleward. This squeezes the jets that run between the Hadley Cell and the mid-Latitudinal cell. Sort of like when the the highway department decides to close one lane in each direction of an 8 lane freeway at rush hour. The results are predictable traffic jams.
      If you buy that one, I also have a bridge in Brooklyn to sell you. At a Good price.

  8. The phenomenon of jet stream blocking leading to undulation reminds me of fluid flow dynamics going from laminar to turbulent flow and then to avulsion when the flow rate becomes so high that inertial forces overwhelm all other governing forces. In other words, the geometric dimension constraining the fluid must become greater to handle the flow, and it does this by increasing the overall length of the jet stream.

  9. Blocking highs are a global cooling signal and in the SH it kicked off in July last year, just as the PDO went negative.

  10. Plasma modifications induced by an X-mode HF heater wave in the high latitude F region of the ionosphere
    “We presented experimental results of strong plasma modifications induced by X-mode powerful HF radio waves injected towards the magnetic zenith into the high latitude F region of the ionosphere. The experiments were conducted in 2009–2011 using the EISCAT Heating facility,”
    https://www.sciencedirect.com/science/article/pii/S1364682612002490
    “1 Introduction
    Between 1980±1997 a large number of ionospheric
    modi®cation experiments have been performed using
    the HF heating facility located at Ramfjùrdmoen near
    Tromsù, Norway (Rietveld et al., 1993; Stubbe, 1996).”
    https://hal.archives-ouvertes.fr/file/index/docid/316449/filename/angeo-16-1212-1998.pdf
    What Is This Mysterious Spiral Anomaly in the Norwegian Sky?

  11. Actually, without even reading the paper I got the gist. Have been interested from undergrad days in math modelling of physical phenomena. Like recasting differential equation predator prey equations into Markov chain probabalistic equivalents (a real undergrad paper). For climate examples, see for example previous gust posts ‘The trouble with Models’ and ‘Why Climate Models run Hot’.
    So as an undergrad did (in Fortran) an ambitious model of Harvard Square traffic jams. A horrific five intersectiin multple lights problem. Turns out there were two key predictors. 1. Number of vehicles (natch, as here).2. Time of day, since turns out average reaction time to vehicle in front varies and is crucial. Morning reactiin times were slower, and so morning traffic jams were worse.
    “All models are wrong, but some are useful.”

    • For traffic models, you need to dial in the bozo factor. This is the effect where it only takes one bozo in the fast lane (often driving a Prius) to back up traffic for miles. I seem to recall Mythbusters testing and confirming something similar …

  12. I wonder how close this comes to the flow mechanisms of aerosol physics in constrained spaces or the flow models used for gas and aerosol dispersion.

  13. From the article: “Their initial results suggest that while climate change probably increases blocking by running the jet stream closer to its capacity,”
    Probably. See, you get paid even if it’s a guess. You just need to make sure you connect it to CAGW. Even a “probably” will work to get your study approved and get your money.
    “How do we work CAGW into our study?” must be a common refrain today.

  14. “climate change probably increases blocking by running the jet stream closer to its capacity,”
    Doesn’t the jet stream largely separate hot from cold?
    Doesn’t global warming increase Arctic temperatures at a faster rate then tropical temps?
    As the planet warms, won’t the difference in energy between the hot and cold become less?
    How is this getting closer to the jet streams carrying capacity given constant yearly solar forcing?

    • see my bullshit comment to “taxed” above. Of course CO2 is innocent. They are trying to convict an innocent and (life giving) chemical on a farcical theory.

  15. Serious sailplane pilots intending to fly the mountain wave have at least one oxygen system, sometimes 2 or three and maybe a bailout bottle.
    I’ve been to 24,700 feet out of Minden Nevada, limited by one simple constant flow system and considerations of time of useful consciousness and personal limits set.
    Sailplanes have reached in excess of 51,000 feet (Argentina recently) and the previous record of over 50,000 feet also in Argentina set by the late Steve Fossett and Einar Enevoldson.
    They are hoping to get to 90,000 feet eventually (pressure cabin used) but I have my doubts that sufficient vertical velocity exists in the atmosphere at those altitudes. You need about 900 feet/minute just to maintain level flight and a couple of U-2 pilots I’ve spoken with say it is very, very smooth at 70,000 feet.
    I had a couple of variometers on the earlier Steve Fossett and Einar Enevoldson record flight and the data output of one, recorded on a PDA, showed that they had got into the stratosphere. The data recording device supplied by a well known US government air/space agency had failed.

    • Can a U2 pilot get sail plane records for the time spent gliding at altitude? 8<)
      Hey! An X-15 pilot got astronaut qual's for "gliding" above 100,000 feet.

  16. Lots of math. No physics. Result: friday funny.
    Like the flow of traffic? Traffic above a critical density is like an incompressible fluid and then constrained by the available space, i.e. the size of the roads. Air is a compressible fluid throughout. There is nothing but other air to constrain it at any density. Traffic jams in air would imply shockwaves at subsonic speeds. An extraordinary claim, requiring extraordinary observational evidence. Which I can’t see in this work.

  17. H.H.Lamb forecast more blocking in times of cold based on the reduction of energy available to the jetstream

    • The jet stream forms due to the Coriolis force as the air from the convection at the equator in the Hadley Cells moves poleward leading to the subtropical jet stream between the Hadley Cells and the Ferrel Cells. The same effect occurs between the Ferrel Cells and the polar cell. With sufficient heat in the system the energy forms distinct polar and subtropical jet streams running latitudinally.
      If the solar energy (heat) into the system is reduced then the convection reduces and the energy in the jets reduces. This is when Rossby waves form and the jet streams meander and become meridional or even break up into jet streaks and blocking can occur. There can also be effects from mountain ranges such as the Tibetan plateau which can cause the meridional jet streams passing poleward over them into vertical breaking waves in the tropopause that can lead to ‘Sudden Stratospheric Warming’ events over the Arctic.
      The atmosphere is a heat engine. Turn down the heat and it starts to run rough.

  18. There has been and Omega blocking high in the Great Australian Bight for a couple of weeks and now a cut off low has wormed its way into the picture.
    This pattern is a global cooling signal.

  19. Now the polar vortex and blocking situations isn’t exactly new concepts. H H Lamb made extensive studies of this subject in the seventies using historical data, and his results showed that periods with high frequencies of blocking situations were also characterized by
    1. Exceptionally large between-year variability and
    2. Strong glacier growth
    But those results wouldn’t pull in any research funds these days.

  20. Another traffic analogy. If windmills are drawing energy from weather fronts, then wouldn’t a weather front slow down? On it’s own, the slow down wouldn’t be enough to stall a huge system like Sandy, but what if a pile up happened?
    A Smart car wouldn’t be able to stop an 18 wheeler in a pile-up accident, but if a Mazda 2 get caught up, then an accord runs into the two of them, enough wrecks would stop an 18 wheeler at the end of the line.

  21. If one actually looks at the “deadly 2003 European heat wave”, one finds who was behind the “studies” and “reports”…

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