From the “settled science” department. It seems even Dr. Kevin Trenberth is now admitting to the cyclic influences of the AMO and PDO on global climate. Neither “carbon” nor “carbon dioxide” is mentioned in this article that cites Trenberth as saying: “The 1997 to ’98 El Niño event was a trigger for the changes in the Pacific, and I think that’s very probably the beginning of the hiatus,”
This is significant, as it represents a coming to terms with “the pause” not only by Nature, but by Trenberth too.
Excerpts from the article by Jeff Tollefson:
The biggest mystery in climate science today may have begun, unbeknownst to anybody at the time, with a subtle weakening of the tropical trade winds blowing across the Pacific Ocean in late 1997. These winds normally push sun-baked water towards Indonesia. When they slackened, the warm water sloshed back towards South America, resulting in a spectacular example of a phenomenon known as El Niño. Average global temperatures hit a record high in 1998 — and then the warming stalled.
For several years, scientists wrote off the stall as noise in the climate system: the natural variations in the atmosphere, oceans and biosphere that drive warm or cool spells around the globe. But the pause has persisted, sparking a minor crisis of confidence in the field. Although there have been jumps and dips, average atmospheric temperatures have risen little since 1998, in seeming defiance of projections of climate models and the ever-increasing emissions of greenhouse gases. Climate sceptics have seized on the temperature trends as evidence that global warming has ground to a halt. Climate scientists, meanwhile, know that heat must still be building up somewhere in the climate system, but they have struggled to explain where it is going, if not into the atmosphere. Some have begun to wonder whether there is something amiss in their models.
Now, as the global-warming hiatus enters its sixteenth year, scientists are at last making headway in the case of the missing heat. Some have pointed to the Sun, volcanoes and even pollution from China as potential culprits, but recent studies suggest that the oceans are key to explaining the anomaly. The latest suspect is the El Niño of 1997–98, which pumped prodigious quantities of heat out of the oceans and into the atmosphere — perhaps enough to tip the equatorial Pacific into a prolonged cold state that has suppressed global temperatures ever since.
“The 1997 to ’98 El Niño event was a trigger for the changes in the Pacific, and I think that’s very probably the beginning of the hiatus,” says Kevin Trenberth, a climate scientist at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado. According to this theory, the tropical Pacific should snap out of its prolonged cold spell in the coming years.“Eventually,” Trenberth says, “it will switch back in the other direction.”
…
…none of the climate simulations carried out for the IPCC produced this particular hiatus at this particular time. That has led sceptics — and some scientists — to the controversial conclusion that the models might be overestimating the effect of greenhouse gases, and that future warming might not be as strong as is feared. Others say that this conclusion goes against the long-term temperature trends, as well as palaeoclimate data that are used to extend the temperature record far into the past. And many researchers caution against evaluating models on the basis of a relatively short-term blip in the climate. “If you are interested in global climate change, your main focus ought to be on timescales of 50 to 100 years,” says Susan Solomon, a climate scientist at the Massachusetts Institute of Technology in Cambridge.
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The simplest explanation for both the hiatus and the discrepancy in the models is natural variability. Much like the swings between warm and cold in day-to-day weather, chaotic climate fluctuations can knock global temperatures up or down from year to year and decade to decade. Records of past climate show some long-lasting global heatwaves and cold snaps, and climate models suggest that either of these can occur as the world warms under the influence of greenhouse gases.
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One important finding came in 2011, when a team of researchers at NCAR led by Gerald Meehl reported that inserting a PDO pattern into global climate models causes decade-scale breaks in global warming3. Ocean-temperature data from the recent hiatus reveal why: in a subsequent study, the NCAR researchers showed that more heat moved into the deep ocean after 1998, which helped to prevent the atmosphere from warming6. In a third paper, the group used computer models to document the flip side of the process: when the PDO switches to its positive phase, it heats up the surface ocean and atmosphere, helping to drive decades of rapid warming7.
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Scientists may get to test their theories soon enough. At present, strong tropical trade winds are pushing ever more warm water westward towards Indonesia, fuelling storms such as November’s Typhoon Haiyan, and nudging up sea levels in the western Pacific; they are now roughly 20 centimetres higher than those in the eastern Pacific. Sooner or later, the trend will inevitably reverse. “You can’t keep piling up warm water in the western Pacific,” Trenberth says. “At some point, the water will get so high that it just sloshes back.” And when that happens, if scientists are on the right track, the missing heat will reappear and temperatures will spike once again.
Read the full article here:
http://www.nature.com/news/climate-change-the-case-of-the-missing-heat-1.14525
NZ Willy says:
January 17, 2014 at 12:51 pm
Where to start?
The oceans are rotating at the same speed as the earth, so they are in equilibrium and will not move unless a force causes them to. Absent other forces, the ocean would sit there like a giant swimming pool. If you put an unattached bouy in the water, it would be in the same place tomorrow.
The Coriolis effect is a deflection of moving objects, when they are viewed in a rotating reference frame. The Coriolis effect is due to the rotation of the reference frame. The object does not change, if it is not moving in relationship to the reference frame. It is a force, that is used to describe the path of on object, from the point of view of the rotating reference frame. But the oceans are in the same rotating reference frame. The earth doesn’t rotate out from under them. If it did, it would leave them behind, and the movement would appear to be in the opposite direction to the rotation of the earth.
If what you are claiming is true, the same forces would be acting on the ocean, from surface to seafloor, 24/7. It would indeed create a lot of force.
The counter-current occurs because of the equatorial low that generates upward flow to the Hadley cells. The suns rays are at maximum watts/meter, so it generates up-flow in the trop.
Both sides of the equator are doing this, so the trade winds are weak to non-existant along this boundry. Except during El Nino, when they are reversed from the normal trade wind direction.
I appreciate your sentiment, Russ, but look at http://en.wikipedia.org/wiki/Boundary_current which further describes, with full math, the contribution of the Coriolis force. And I’ll not reply to posters like “1sky1” as the relevant saying in my trade is “when you argue with a fool, chances are he is doing the same”.
As my last posting in this thread, I quote from the above article:
“The solutions of (5) with boundary condition that \psi be constant on the coastlines, and for different values of \alpha, emphasize the role of the variation of the Coriolis parameter with latitude in inciting the strengthening of western boundary currents. Such currents are observed to be much faster, deeper, narrower and warmer than their eastern counterparts. … For a non-rotating state (zero Coriolis parameter) as well as an ocean state at which the Coriolis parameter is a constant, the ocean circulation does not demonstrate any preference toward intensification/acceleration near the western boundary. ”
The subject matter is the Coriolis-caused “Western Intensification”, which is to say, the pile-up at the Western end of the oceans. And now, I need say no more.
NZ Willy:
Q.E.D. Your contribution to the triumph of smug ignorance is colossal!
The energy comes from the Earth’s rotation, the sun keeps the water liquid, the question is, why do the trade winds fail ?
Interesting that, in the warmist groupthink, the opposite of “sceptic” is “scientist”!
Graham Cresswell says:
“Interesting that, in the warmist groupthink, the opposite of ‘sceptic’ is ‘scientist’!”
You make a good point. George Orwell would understand what they’re trying to do to the language.
In fact, the only honest kind of scientist is a skeptic. Scientist must be skeptics, first and foremost. Otherwise, they might as well be the acolytes of witch doctors.
NZ Willy says:
January 17, 2014 at 3:51 pm
These are just descriptions of how the Coriolis effect causes the waves to move at an angle to the trade winds. The effect is stronger at higher latitudes and non-existent at the equator. It also causes the ocean currents to be deflected to the right in the NH. The last issue is the “Western Intensification”, which is an intensification of ocean currents on the western boundary of oceans, caused by the increase in the Coriolis effect as the current moves north. As it moves north Coriolis gets stronger, more water is turned right, current increases. This is all interesting, but it does not change the fact that the West Pacific Warm Pool is created by trade winds. And when the winds are no longer strong enough, the Pool starts moving back to the east.
Note that you are either a “scientist” or a “skeptic”. Scientists are not allowed to be skeptical I guess.
Russ, rotation-impelled forces aren’t understood. They don’t know why Jupiter’s atmosphere does what it does, but its west-to-east equatorial current is like ours but much stronger — likely due to its faster rotation. Rotation means that at different altitudes and latitudes, elements of air and sea have different inertial quantities — this causes turbulence which are handles for the Coriolis force. This is how I reckon the currents arise and why the equatorial current goes west to east, and the “trade wind” currents go east-to-west — as the Coriolis force prescribes. Your scenario is good & fine if we had all the answers, but I don’t accept that the trade winds can pile up the ocean because the ocean would push back far too hard. So we’ll just have to agree to disagree.
Werner Brozek says:
If they opened all the locks in the canal, what would happen? Werner answers:
“The higher ocean would start draining into the lower one until equilibrium is reached…”
+++++++++++++++++++++++++++++++
Werner, you are correct about almost everything.☺ But in this case, nothing would happen. The locks make it possible to raise ships over much higher ground. So if the locks were all opened nothing would happen, because the ground between the two oceans is far higher than the oceans on either side.
+++++++++++++++++++++++++++++++
And to everyone: Global warming has stopped. If it resumes, then it will have been a “pause”!
But I give up. The inappropriate term has won.☹
Russ R:
You’re on the right track in recognizing that the western pile-up of equatorial waters is due to zonal wind-stress from the trades, without any appreciable influence from the Coriolis effect. The western boundary currents, on the other hand, flow poleward and Coriolis effects thus come into play. But the direction of Coriolis deflection is always away from the western boundary coast in both hemispheres! Without getting into the dynamical intricacies of their speed intensification (largely a momentum conservation effect), it should be obvious that Coriolis supplies no energy to drive the circulation per se and is irrelevant to any western pile up.
I thought trade winds were seasonal. They are around the Pacific and S.E.Asia. That is why the Chinese c.1400 AD, only used them to expand into the Southern Pacific. Same as the Dutch and Macassans that visited Northern Australia to harvest sea cucumbers. They introduced tobacco to friendly Aborigines, steel fish hooks, and STD’s and smallpox. Well before the Europeans landed here.
If Trenberth manages to detect a miniscule rise in the deeps, that means the soonest it could affect the heat column in the atmosphere is hundreds of years from now, Crisis cancelled.
NotTheAussiePhilM says:
“Anyway, looks like us Luke-warmers are winning the argument!”
Since ‘luke warmers’ tend to claim that human activity causes some global warming [not UHI, but overall warming], I would point out that there is still no scientific evidence to support that assertion.
That means the scientifc skeptics’ position of “AGW still hasn’t been proved” is actually winning the argument.
AGW might exist. But even if it does, its effect is necessarily so minuscule that for all practical purposes, any putative AGW must be completely disregarded for Policy purposes.
This phrase is so apropos: “That has led sceptics — and some scientists…:
Tells you everything you need to know about the warmmongers…
http://www.youtube.com/rcgladstone
great photos tammy….