![places_gulfstream_sat3[1]](http://wattsupwiththat.files.wordpress.com/2014/03/places_gulfstream_sat31.jpg?quality=83)
NARRAGANSETT, R.I. – March 3, 2014 – Several recent studies have generated a great deal of publicity for their claims that the warming climate is slowing the pace of the Gulf Stream. They say that the Gulf Stream is decreasing in strength as a result of rising sea levels along the East Coast.
However, none of the studies include any direct measurements of the current over an extended period to prove their point.
But this is exactly what has been underway at the University of Rhode Island and Stony Brook University for the last 20 years: measurement of the strength of the Gulf Stream. And according to a paper published in Geophysical Research Letters, the researchers find no evidence that the Gulf Stream is slowing down. These new results reinforce earlier findings about the stability of Gulf Stream transport based on observations from as far back as the 1930s.
H. Thomas Rossby, a professor at the URI Graduate School of Oceanography, has spent much of his long career studying ocean circulation – especially the Gulf Stream – and how it makes its way across the Atlantic towards Europe and as far north as northern Norway. For the last 20 years he and his colleagues have measured the Gulf Stream using an acoustic Doppler current profiler (ADCP) attached to a ship, the freighter Oleander, which makes weekly trips across the Gulf Stream from New Jersey to Bermuda. The instrument, which measures the velocity of water moving beneath the ship down to more than 600 meters, has collected some 1,000 measurements of the Gulf Stream since it was installed in late 1992.
“The ADCP measures currents at very high accuracy, and so through the repeat measurements we take year after year, we have a very powerful tool by which to monitor the strength of the current,” said Rossby. “There are variations of the current over time that are natural — and yes, we need to understand these better — but we find absolutely no evidence that suggests that the Gulf Stream is slowing down.”
The rapidly flowing Gulf Stream plays a major role in the global heat balance through its transport of very warm water from the Caribbean toward Europe.
For this reason alone, Rossby says, there is good reason to be concerned about the long-term stability of the Gulf Stream, since if the Gulf Stream were slowing, a decrease in the flow of warm water to the northern North Atlantic could cause significant cooling in parts of Europe. But the data tell him that there is no evidence that this is happening, contrary to recent claims in the literature.
Although he officially retired in 2011, Rossby is continuing his Gulf Stream research and hopes to install a new instrument on the Oleander in the coming years that will be able to profile currents to even greater depths.
“Once we do that, all of the water going north will be well within our reach,” he said.
###
h/t to WUWT reader “Patrick”
================================================================
On the long-term stability of Gulf Stream transport based on 20 years of direct measurements
T. Rossby1,*, C. N. Flagg2, K. Donohue1, A. Sanchez-Franks2, J. Lillibridge3
Abstract
In contrast to recent claims of a Gulf Stream slowdown, two decades of directly measured velocity across the current show no evidence of a decrease. Using a well-constrained definition of Gulf Stream width, the linear least square fit yields a mean surface layer transport of 1.35 × 105 m2 s−1 with a 0.13% negative trend per year. Assuming geostrophy, this corresponds to a mean cross-stream sea level difference of 1.17 m, with sea level decreasing 0.03 m over the 20 year period. This is not significant at the 95% confidence level, and it is a factor of 2–4 less than that alleged from accelerated sea level rise along the U.S. Coast north of Cape Hatteras. Part of the disparity can be traced to the spatial complexity of altimetric sea level trends over the same period.
http://onlinelibrary.wiley.com/doi/10.1002/2013GL058636/abstract
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“50 measurements a year” doesn’t mean the measurement of current in one spot. From the context of the article and press release it is clear that each transit of the Gulf Stream while continuously measuring is considered “one measurement”.
Think “50 transit lines per year” rather than 50 point measurements.
I have a comment in moderation,
thanks
Steven Mosher says:
March 4, 2014 at 11:24 am
“The instrument, which measures the velocity of water moving beneath the ship down to more than 600 meters, has collected some 1,000 measurements of the Gulf Stream since it was installed in late 1992.”
imagine the results were the opposite of what was claimed. Imagine they found a slow down.
around 50 measurements a year?
=================
You failed to include the following sentence in your quote:
” …. Doppler current profiler (ADCP) attached to a ship, the freighter Oleander, which makes weekly trips across the Gulf Stream from New Jersey to Bermuda. …”
Can you see how “around 50 measurements per year” is understandable?
You write “imagine the results were the opposite of what was claimed. Imagine they found a slow down.” You have quite an imagination.
Minor correction in my last comment.
“Gulf stream slows down [1957 and 2004]”
should say
“Gulf stream slows down [1957 TO 2004]”
SDB says:
March 4, 2014 at 12:17 pm
=============
You make a good point.
Charlie A;
Think “50 transit lines per year” rather than 50 point measurements.
>>>>>>>>>>>>>>>>>>>
It is also a measurement of one thing at one place on earth over 20 years. We’re not trying to calculate an average ocean current index for the whole earth where we don’t know if a rise in one spot is off set by a decrease in another spot. Just the Gulf Stream at THAT spot. Unless the data is highly variable, and it doesn’t sound like it is, I for one am OK with 50 per year.
To my comment above about gigatons of CO2…
I think I incorrectly interpreted the approximately 32 gigatons as cumulative over the entire course of human fossil fuel use, when in reality that number is for 2012 alone. See here:
http://www.newscientist.com/data/images/ns/cms/dn11638/dn11638-4_738.jpg
It’s really rather simple physics. With warming, the seawater becomes less viscous and the current speeds up. It is with cooling that the current slows down because it becomes more viscous. Sediment studies from South of Florida clearly show that warm and cold periods have fast and slow currents, respectively. It is simply wishful-thinking that warming would slow the current, it fits their political agenda. Idiots, all.
daddylonglegs says:
March 4, 2014 at 1:13 pm
Alternation between periods of stronger and weaker gulf stream flow probably constitutes the main element of the AMO
————————————
That is exactly what I thought. It is simply the best match with global and local temperatures and Arcitc sea ice.
I think we need more retired professors publishing because they have less fear of being blackballed by the global warming movement for telling the “truth”.
The Gulf Stream not slowing down also means that the Winds which drive it (the trade winds in the equatorial Atlantic forcing it into the Gulf of Mexico and into the mid-depth channel next to Florida, and the mid-latitude winds coming off of North America moving it back across the north Atlantic), have also not slowed down or changed.
http://www7320.nrlssc.navy.mil/GLBhycom1-12/navo/equatlspdcur_nowcast_anim30d.gif
http://www7320.nrlssc.navy.mil/GLBhycom1-12/navo/intramspdcur_nowcast_anim30d.gif
http://www7320.nrlssc.navy.mil/GLBhycom1-12/navo/glfstrspdcur_nowcast_anim30d.gif
http://www7320.nrlssc.navy.mil/GLBhycom1-12/navo/natspgspdcur_nowcast_anim30d.gif
Mid-depth ocean depth down to 400 metres is required for this type of current.
https://goo.gl/maps/m63H6
Darwins quote of ‘survival of the fittest’ was not about brute force it was referring to the breeding of one generation to another and so on. That is why the Nazis killed children and adults, breaking the line of biological inheritance. But in last glacial periods there were warmer periods firstly and the melting of the ice caps introduced fresh water into the gulf stream and it diverted the warmer currents from the Northern hemisphere countries and they froze. Some idiot scientists suggested a few years ago placing huge fans under the sea to keep the gulf stream circulating? Talk about windmills being bird choppers, what would they do to fish?
I have always thought that scientists have tried to convince people through subterfuge that the planet was warming and their real fear was another glacial age, that we are overdue for. This would have a drastic effect on human kind in the Northern Hemisphere where the globes population is mainly concentrated. And on energy supplies.
Don’t let the hockey team get their hands on that data. You never know what adjustments might occur.
daddylonglegs says on March 4, 2014 at 1:13 pm:
“This does not make sense. Higher gulf stream flow means more heat transported to the Arctic and less Arctic sea ice. By contrast slowdown in the gulf stream will lead to Arctic ice recovery. Alternation between periods of stronger and weaker gulf stream flow probably constitutes the main element of the AMO.”
Except for invoking an imaginary AMO you have it right. Arctic warming today proceeds twice as fast as climate models predict. It is not greenhouse warming because it is caused by warm Gulf Stream water carried into the Arctic Ocean by currents. And because it is not greenhouse warming it is the only warming going on today while the rest of the world is enjoying a hiatus-pause of warming for the thirteenth year in a row. That pause is caused by the failure of the greenhouse theory of warming which predicts that putting carbon dioxide in the air as we do should warm the atmosphere. Arctic warming itself started at the turn of the twentieth century, after two thousand years of slow, linear cooling. The start of the warming was sudden and there was no concomitant increase of atmospheric carbon dioxide which rules out the greenhouse effect as a cause. It paused for thirty years in mid-century, then resumed, and is apparently still active. This on-again, off-again, on-again behavior is caused by changes in north Atlantic current flow patterns. But what has happened in nature before can happen again so I don’t rule out the possibility of another cold spell like what happened in the middle of the last century. To learn more download my paper from Climate Etc.
I would not expect the pace of the current to vary much.
I would be most interested in the total volume of the waterflow at speed over time.
Wishful thinking?
UnfrozenCavemanMD says:
March 4, 2014 at 12:09 pm
“It is interesting to note that H. Thomas Rossby at URI is the son of the legendary Carl Gustav Rossby, after whom Rossby waves are named.”
——————
Thanks for that bit of info – the first thing I thought of when I saw the author’s name is if there was a connection to the legendary Rossby.
Here is another paper by Rossby et al. from 2010:
http://www.po.gso.uri.edu/rafos/research/ole/Files/Rossby_etal_JMR_2010.pdf
In it they compare data from the first oceanographic research expedition ever (HMS Challenger in 1873) with modern conditions. The Challenger data on water flow in the Gulf Stream (derived from temperature profiles) is identical to modern values (though there is a 15% uncertainty due to the somewhat more primitive measurement methods of the 1870’s).
There’s only one reason for the existence of the Gulf stream: transporting excess heat from the tropics to the cold of the pole(s). In fact, the Gulf stream is the predominant transporter in the Northern Hemisphere.
Claiming that it “could” slow down is like saying that heat could stop flowing from to cold places.
SasjaL says:
March 4, 2014 at 11:27 am
These people are on a continuous “trip” and hallucinate about the new Utopia where everything is controlled, even the number of inhabitants and Gaia is their new master. … As a result our science has been corrupted and no sane argument comes through. No wonder it is difficult to have a level exchange of opinion because a psychotic and neurotic public doesn’t listen [b]and lost any ground for reason.[/b]
>>>>
Don’t want to ‘alarm’ you SasjaL, but they did not ‘lose’ any grounds for reason. 90% of them never had it, to begin with, and were never going to develop it. And that includes a significant fraction of university graduates. Sad, but true.
The reality of the situation is that most of us are expecting ordinary people to make sense of and to understand thinking, and how to do it systematically. They don’t have that talent or capacity in them, and they aren’t going to improve.
It’s a conundrum, because the majority, who can’t understand the subject, get to elect savvy manipulators who play them with ruthless efficiency and thus get to make the policy ‘decisions’.
I’m sure you see the functional problem with that process, or rather, the dysfunctional potential of it, that we see expressed, today, a result of it.
Because they don’t actually try apply themselves to understand AGW in the way we do. But they still profess that it is something which they are really, really, [b]reeeally[/b] ‘concerned’ about. Well, shock horror, they clearly aren’t serious enough to care to know much about it, despite its end of the world potential.
It’s all a bit much you see
So becomes our problem; firstly, because we do know something about it, and secondly, because in their naive innocence, they’re easily manipulated by CAGW Al’s daft and dishonest propaganda, and cheap-shot dishonest terms like, ‘denier’.
Plus wonton deviates like Dr Suzuki make a nice living off this tremendous vegetable like gullibility of the oh so concerned “but please, you take care of it”, dimness of the general public.
Yes, its a downer that most people are like that. So we try to educate them, and that has some limited success. But if we get annoyed with them being so dim and unwilling to learn about what they vote about, this still does not help.
We have to keep it simple.
We can’t argue them into the ground, with data and stats, because they can’t function at that level.
The only level they may understand is simplified but empirically correct graphics and videos.
Because that is largely the outer envelope of their ability perceive.
And that is what the CAGW ratbags and govt have been using to sway them and misrepresent the entire issue.
And we continue trying to speak to them like they can understand the topic. But they majority did not lose any ground to reason, they never had it to lose in the first place.
So what should we [b]do[/b] about it, given these same people are actually voting in and out the governments of the entire developed world?
Arno Arrak says:
March 4, 2014 at 5:56 pm
daddylonglegs says on March 4, 2014 at 1:13 pm:
“This does not make sense. Higher gulf stream flow means more heat transported to the Arctic and less Arctic sea ice. By contrast slowdown in the gulf stream will lead to Arctic ice recovery. Alternation between periods of stronger and weaker gulf stream flow probably constitutes the main element of the AMO.”
Except for invoking an imaginary AMO you have it right. Arctic warming today proceeds twice as fast as climate models predict. It is not greenhouse warming because it is caused by warm Gulf Stream water carried into the Arctic Ocean by currents… [quote curtailed]
There is data from Levitus showing very close correlation between water temperatures in the Barents sea at 100-150m depth, and the AMO, posted here in 2009:
http://wattsupwiththat.com/2009/10/08/new-paper-barents-sea-temperature-correlated-to-the-amo-as-much-as-4%c2%b0c/
This correlation is the main reason for my belief that the AMO, whatever that represents, correlates with changes in strength of gulf stream flow to the Arctic since only ocean currents can change temperatures at 100-150m by up to 4degrees C, not weather only.
It’s news to me that “sea levels are rising”. I have a personal concern about this, because when we get a higher than usual tide, I have to pump out our basement. We live on a salt marsh, which is on Boston harbor. Our normal tide range is about 9.5 feet. I have a very well calibrated tide gauge: 9.5 feet, 10.5 feet, 11.5 feet, and our backyard stays dry. At 12 feet, our backyard
gets wet. At 12.5, the water reaches the basement door. At 13, I start the pumps and get out the mop. No, the seas are not rising, as far as I can tell. If they did, I would have to pump out our basement at EVERY high tide, not just the occasional 12+ footer, accompanied by some low atmospheric pressure and NE winds, pushing the water in towards us, and over 13 feet. So I see nothing different, nothing threatening, and no significant sea level rise. If I do, and this global warming thing works out, I have a plan; cement in the basement door, fish off the porch, tie up our boat in the back yard rather than the harbor, and enjoy my new, increased-in-value, “waterfront” property. I bet my taxes go up……,
I concur. A fine application of the Nyquist sampling theorem. If the effect you are looking for has a periodicity expected in the months to decades time frame, 1 measurement per week is more than sufficient and may even be a little bit of oversampling since 1 measurement a week is sufficient to capture a period of two weeks in the signal reconstruction.
“around 50 measurements a year?”
As opposed to interpolating temperatures around the globe from a few choice thermometers?
“Steven Mosher says:
March 4, 2014 at 11:24 am
imagine the results were the opposite of what was claimed. Imagine they found a slow down.”
I imagine, if all of the actual measurements being taken actually confirmed all of the models, projections and predictions ( rather than the opposite) we would be in a lot of trouble in the future.
However, based on almost all the data coming in we don’t have to imagine. Quit living in the imaginary “Model” world and come back to reality.
Is there some sort of proxy that could be used for Gulf Stream flow/speed. If so, I would like to be a PalioGulfStream expert.