"turbulence is on the rise" Is it?
Join Date: Jun 1999
Location: world
Posts: 3,424
Likes: 0
Received 0 Likes
on
0 Posts
I wonder whether the introduction of RVSM could be a factor in the perceived increase or decrease of CAT encounters?
BTW OP, speaking strictly as a passenger, I personally have experienced less turbulence on the NATs the past decade in contrast to previous decades. Then again, I may just have been lucky and have now put the kaibosh on future smooth rides
Join Date: Mar 2010
Location: Reading
Age: 41
Posts: 100
Likes: 0
Received 0 Likes
on
0 Posts
It's fascinating how many pilots find the time to qualify themselves as experts in climate science, to the extent they feel justified in rubbishing work by qualified scientists of years training, PhDs etc etc.
These same pilots are the first to criticise anyone without a pilots background for commenting on flight matters, quite rightly in most cases.
I wouldn't trust a climate scientist to fly a plane, maybe you should take your own advice and let them do your job, and you do yours.
Ironically of course, the same people who deny man made climate change will often use the evidence that the earth has warmed and cooled naturally in the past, as if that somehow prevents the possiblity of non natural causes now, which is a logical fallacy. Of course this evidence is provided by the same scientists who produced the evidence for man made climate change, the deniers just pick and chooose which science they believe.
These same pilots are the first to criticise anyone without a pilots background for commenting on flight matters, quite rightly in most cases.
I wouldn't trust a climate scientist to fly a plane, maybe you should take your own advice and let them do your job, and you do yours.
Ironically of course, the same people who deny man made climate change will often use the evidence that the earth has warmed and cooled naturally in the past, as if that somehow prevents the possiblity of non natural causes now, which is a logical fallacy. Of course this evidence is provided by the same scientists who produced the evidence for man made climate change, the deniers just pick and chooose which science they believe.
Ghengis the ''Engineer'' is using climate model output as data for a modelling exercise. Feed climate model results into another model and looky here: we have another grant. Trebles all around.
Sorry to rain on your lucrative professionally rewarding ''Engineer'' parade, but model outputs aren't data.
Sorry to rain on your lucrative professionally rewarding ''Engineer'' parade, but model outputs aren't data.
I'm not really Genghis the "modeller" - the last computer model I wrote was years ago to model the behaviour of the Jaguar after pickling in a steep dive in ISA++ conditions; validating it from the back seat of a T2 was fun. I work however with people who do modelling very well, my skills are elsewhere, mostly in helping them obtain real world data to validate those models.
But you are quite right that models are only models - but they're also something the entire world relies upon nowadays. Financial models, weather forecasting models, aircraft performance models, medical research drug response models.... Personally I'm mostly working with data, good old fashioned equations, and professional knowledge. And working with some hellishly clever scientists and aviation professionals across several countries.
If you actually bothered to read what I'd posted, you'd also see that I said that CAT data is very weak, and relatively fringe to what we're studying. It happens that a newspaper found it interesting to pick up and print, and a major carrier is interested enough to let us data mine 4 million hours of FDR data to try and make some sense of the question.
Care to tell us your own scientific qualifications, as you're doubting other peoples'?
You could also perhaps explain why you disapprove of the process of (1) establish basic track record, (2) create research proposal, (3) competitively use proposal to apply for research grant, (4) do research if you got funded, is wrong in some way? It is the way most of the western world manages and commissions scientific research, and unsurprisingly, different funders have their own various priorities they use in allocating funds - which for some funders includes anthropogenic climate change (I don't like the term "global warming" as it's too simplistic, ditto the obsession with CO2 to the disregard of all of the other factors.)
G
Last edited by Genghis the Engineer; 13th Sep 2016 at 16:21.
Join Date: Jun 2007
Location: Beyond the Blue Horizon
Age: 63
Posts: 1,257
Received 150 Likes
on
93 Posts
DaveReidUK
Out by two digits. AF004 Boeing 707 Nebraska carried onto Paris (should have put down)where we were greeted by fleet of ambulances. My last AF flight, and that of my Father to. Long time ago, but can honestly say I think we had worse on trips up from South America, but not so many people /carts moving around so not so dramatic. Also BCAL would have put down I am sure. AF captain apparently went onto fly Concorde so his decision making must have been judged to be correct.
Cheers
Mr Mac
Out by two digits. AF004 Boeing 707 Nebraska carried onto Paris (should have put down)where we were greeted by fleet of ambulances. My last AF flight, and that of my Father to. Long time ago, but can honestly say I think we had worse on trips up from South America, but not so many people /carts moving around so not so dramatic. Also BCAL would have put down I am sure. AF captain apparently went onto fly Concorde so his decision making must have been judged to be correct.
Cheers
Mr Mac
QUOTE:
Because major CAT encounters are particularly associated with the edges of the jetstream, then theoretically this is going to both create more opportunities for CAT encounters (as there will be more intersections of the NPJ) and more severe CAT (because of the greater sheer stresses caused by the greater core velocities).
I am/ was a meteorologist as opposed to a climate scientist. I do not know what an "intersection" is in the above context.
What I do know is that the argument assumes that, whereas jetstreams will increase increase in velocity, the surroundings [above, below, left, right] will not.
Otherwise the sheers will not, may not, increase.
Is there a fallacy here?
Because major CAT encounters are particularly associated with the edges of the jetstream, then theoretically this is going to both create more opportunities for CAT encounters (as there will be more intersections of the NPJ) and more severe CAT (because of the greater sheer stresses caused by the greater core velocities).
I am/ was a meteorologist as opposed to a climate scientist. I do not know what an "intersection" is in the above context.
What I do know is that the argument assumes that, whereas jetstreams will increase increase in velocity, the surroundings [above, below, left, right] will not.
Otherwise the sheers will not, may not, increase.
Is there a fallacy here?
The important factor is the difference in velocity vectors, rather than the scalar velocity.
There are indications that the velocity vectors are shifting, that's what Paul Williams recent papers have been about. They've not necessarily been aligning themselves with the NPJ. Without running through the maths (as I don't think I could on my own) intuitively some vectors will be closer to the NPJ, most will be more different.
G
There are indications that the velocity vectors are shifting, that's what Paul Williams recent papers have been about. They've not necessarily been aligning themselves with the NPJ. Without running through the maths (as I don't think I could on my own) intuitively some vectors will be closer to the NPJ, most will be more different.
G
So many people in this thread don't seem to have had the idea you can correct for more flights by *dividing CAT encounters by number of flights, or mileage, or pax-miles, or ton-miles*. It is to laugh.
Wind in general, and jet streams in particular, are ultimately driven by temperature contrast [and of course modified by earth rotation].
I have no idea if jet streams are becoming faster: the period of accurate measurement is too brief to be very informative [only Aireps or whatever, many and often, give enough data, and then only on busy routes].
If they are becoming faster, surely the circulations outside the cores will also be faster, as part of the global mechanism for distributing the unequal heating of the planet polewards.
This being so, I cannot see why sheers [contrasts] of wind vector might be increasing.
And I still don't know what these "intersections" are.
I have no idea if jet streams are becoming faster: the period of accurate measurement is too brief to be very informative [only Aireps or whatever, many and often, give enough data, and then only on busy routes].
If they are becoming faster, surely the circulations outside the cores will also be faster, as part of the global mechanism for distributing the unequal heating of the planet polewards.
This being so, I cannot see why sheers [contrasts] of wind vector might be increasing.
And I still don't know what these "intersections" are.
Join Date: Dec 2013
Location: Norfolk
Age: 67
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
langleybastion
Try replacing "intersections" with "interactions" and the meaning will become clearer. That it what I took it to mean.
On the subject of whether pilots are truly qualified to question or comment on the work of profession climatologists and weather experts, I believe they are. Pilots, mariners and farmers all interact daily with the weather in ways that affect their personal survival and livelyhood. They may not have the maths and figures to back it up, but personal experience and living to a ripe old age must count for something.
Try replacing "intersections" with "interactions" and the meaning will become clearer. That it what I took it to mean.
On the subject of whether pilots are truly qualified to question or comment on the work of profession climatologists and weather experts, I believe they are. Pilots, mariners and farmers all interact daily with the weather in ways that affect their personal survival and livelyhood. They may not have the maths and figures to back it up, but personal experience and living to a ripe old age must count for something.
Join Date: May 1999
Location: Vancouver, BC.
Posts: 748
Likes: 0
Received 0 Likes
on
0 Posts
Surely, it shouldn't be too difficult to answer the question, 'are north Atlantic Jetstream velocities on the increase? We should have at least of 50 years of upper air data, not to mention real time NAT position reports with wind/temps to research. But over a 46 years career in airline ops and flight planning, I look at the upper charts these day an do think that Jetstream velocities are in the increase, or at least the incidence of very strong Jetstream are.
Join Date: Jun 2006
Location: Brisbane
Posts: 265
Likes: 0
Received 0 Likes
on
0 Posts
On the subject of whether pilots are truly qualified to question or comment on the work of profession climatologists and weather experts
Climatologists, no. That requires numbers, and lots of them. Anecdotal evidence counts for nought in the climate change discussion.
ECON cruise, LR cruise...
Join Date: Apr 2002
Location: MIRSI hold - give or take...
Age: 52
Posts: 568
Likes: 0
Received 0 Likes
on
0 Posts
And another random graph for those that still doubt we are, ahem, having intercourse with the climate...
http://imgs.xkcd.com/comics/earth_te...e_timeline.png
http://imgs.xkcd.com/comics/earth_te...e_timeline.png
Join Date: Dec 2006
Location: Florida and wherever my laptop is
Posts: 1,350
Likes: 0
Received 0 Likes
on
0 Posts
A change in climate is said to be a change that is noted over a 30 year period. Changes from one year to the next or even one decade to the next are weather not climate.
That buggers weather prediction for ever, then!
The definition of "climate" is "average weather"
Very hard to know what that is without a lot of observations and a lot of maths. And that over a long period of time to say if it's changing or not.
G
Very hard to know what that is without a lot of observations and a lot of maths. And that over a long period of time to say if it's changing or not.
G
