Axel Timmermann and Kevin Trenberth Highlight the Importance of Natural Variability in Global Warming…

Guest Post by Bob Tisdale

…and their recent interviews provided fodder for a blog post that should be educational for many people.

There were numerous oddities in a recent interview with Axel Timmerman and Kevin Trenberth. Those are the primary topics of this post. Let’s see what we can learn.

Then, looking at the subsurface temperature data for the extratropical North Pacific, there’s a possible explanation for the unusual warming of the surface of the eastern extratropical North Pacific, a.k.a. the “blob”.

But first…

PREFACE: AN INTERVIEW WITH AXEL TIMMERMANN

A press release from the University of Hawaiʻi at Mānoa got a lot of attention last week. It was Ocean warming picks up speed, hits warmest temperatures ever recorded. The press release was not about a scientific study. It was an interview with oceanography professor Axel Timmermann, in which Timmermann noted what every sea surface temperature dataset has been saying for months: global sea surfaces warmed this year to “record high” temperatures and that an unusual warming event in the North Pacific was the basis for those record highs. That interview with Timmermann received lots of comments on the Claim: Warmest oceans ever recorded thread at WattsUpWithThat.

For those who frequent ClimateObservations and WattsUpWithThat, the elevated sea surface temperatures in 2014 are old news. We first discussed them back in the June sea surface temperature update published four months ago. Then we discussed the basic reasons for the high global sea surface temperatures in the August 2014 post On The Recent Record-High Global Sea Surface Temperatures – The Wheres and Whys.

Important Note: As discussed in the above-linked “Wheres and Whys” post, there was also an unusual warming in the extratropical North Pacific in 2013. That’s something that’s often overlooked. The unusual warming of the surface of North Pacific in 2014 occurred on top of a similar event in 2013. See Animation 1. Also see the August 2013 post About the Unusual Warming Event in Extratropical North Pacific Sea Surface Temperature Anomalies and the February 2014 post The Hotspot in the North Pacific.

Animation 1

Animation 1

So it was the back-to-back, compounding, warmings in the North Pacific in 2013 and 2014 that caused the record high North Pacific and global sea surface temperatures in 2014. The events of 2014 in the North Pacific did not stand alone.

INTERVIEWS WITH TIMMERMANN AND TRENBERTH

Close on the heels of the University of Hawaii press release came a ReportingClimateScience.com article, which included interviews with Timmermann and Kevin Trenberth. Authored by Leon Clifford, that article has the very appropriate title Warming Pacific Drives Global Temperatures. As you read the article, you’ll note that much of it is speculation. The use of the words and phrases “could”, “may”, “whether or not”, and “still uncertain” broadcasted the fact that Timmermann and Trenberth were speculating about the end of the hiatus. The subtitle explains the content of the ReportingClimateScience.com article (my boldface):

Major warming in the Pacific Ocean has driven up global temperatures, impacted El Niño, affected weather systems and could signal the end of the so called global warming pause, say two leading climate scientists.

GOING UNSAID BUT OBVIOUS

The second thing to note about the article is that, while it goes unsaid, it’s blatantly obvious that Timmermann and Trenberth are noting that the annual, decadal, and multidecadal processes taking place in the Pacific can enhance global warming (cause global warming) or suppress it (stop it).

Do the climate models used by the IPCC for their alarmist predictions consider those processes?

Of course not. In fact, the models were aligned with the naturally enhanced warming from the mid-1970s to the turn of the century, without taking into consideration the other half of the Pacific processes that can suppress that warming. (Same thing with the North Atlantic processes that drive the Atlantic Multidecadal Oscillation or AMO.) This, of course, is one of the reasons for the hiatus and for all of those climate scientists scrambling for explanations. Someday the climate science community is going to admit their long-term projections of global warming are at least two times too high, because they failed to consider the natural enhancement of the warming from the 1970s to about 2000. Will I see that admission in my lifetime? Not likely.

WERE THE CHANGES UNPRECEDENTED?

The author of the ReportingClimateScience article used the word “unprecedented” a couple of times. In fact, the first word of his article is unprecedented. I’ve read the article a few times and I can find no reference to the 2013 warming in the North Pacific that preceded this year’s warming. In other words, the ReportingClimateScience article was about the events of 2014, not about an unusual warming in the North Pacific that also took place in 2013.

Figure 1 shows the change in the annual sea surface temperatures for the North Pacific (0-65N, 100E-90W), where the surface temperatures of the preceding year are subtracted from the current year. Because we only have 10 months of data this year, the annual data are only for the months of January to October. The dataset is NOAA’s ERSST.v3b, which is used by NCDC and GISS in their global land-plus-ocean surface temperature products. Keep in mind, when looking at sea surface temperature data subsets, the data before 1950 is suspect, and before 1900 it’s really questionable. There’s just too little source data. With that in mind, there is obviously nothing unprecedented about the change in North Pacific temperatures so far this year. There were at least 3 annual changes since 1950 that were comparable to the change in 2014.

Figure 1

Figure 1

Note: The 2013 change is difficult to see on the graph. It was +0.16 deg C.

Two of the previous comparable spikes occurred during the year between back-to-back El Niños. That is, one of the large one-year changes in North Pacific sea surface temperatures occurred in 1957 between the 1956/57 and 1957/58 El Niños, while another happened in 1977 between the 1976/77 and 1977/78 El Niños. The third spike prior to 2014 occurred in 1972, which was the evolution year of the 1972/73 El Niño.

It’s only when we look at the 2-year change in North Pacific sea surface temperature that the most-recent change (2014 minus 2012) becomes unusual. This indicates that it was the back-to-back unusual warming events in 2013 and 2014 that were freakish.

Figure 2

Figure 2

But the recent warming was most evident in the extratropical North Pacific, so let’s look at the data for that region as well to see what story it tells.

Figure 3 is similar to Figure 1, but in Figure 3 we’re looking at the annual changes in the sea surface temperatures of the extratropical North Pacific (20N-65N, 100E-100W). (And again, we’re only looking at the months of January to October.) That region covers the latitudes stretching from about the big island of Hawaii north to the Bering Strait, and stretches east and west from the coasts of North America to Asia. If we look at the recent annual changes in January to October sea surface temperatures of the extratropical North Pacific, we notice the small downtick from 2013 to 2014. That indicates the warming in 2013 was greater than the warming in 2014.

Figure 3

Figure 3

Figure 4 presents the 2-year change in the sea surface temperatures of the extratropical North Pacific. While there was a large 2-year change, there was nothing unusual about it.

Figure 4

Figure 4

Let’s carry it one step farther. Someone was bound to ask anyway. Let’s look at the changes in the sea surface temperatures for the region of the hotspot (a.k.a. the blob) in the eastern extratropical North Pacific, where it existed in 2014. See the map here. Based on it, we’re using the coordinates of 30N-55N, 160W-130W. For a region this small, we would be better off using a satellite-enhanced sea surface temperature dataset like Reynolds OI.v2, but it starts in 1981, which isn’t useful when looking at the long term. With that in mind, looking at the long-term NOAA data, once again, there have been comparable annual changes in the past. Note also the little uptick between 2013 and 2014. The rise in the sea surface temperatures of the blob was a little bit larger in 2014 than it was in 2013. Otherwise there’s nothing unusual about the warming that took place.

Figure 5

Figure 5

And looking at the 2-year change in the surface temperature of the blob region, Figure 6, we can see that the really unusual recent warming occurred over the two years of 2013 and 2014, not in 2014 alone.

Figure 6

Figure 6

BUT TIMMERMAN AND TRENBERTH ONLY TALK ABOUT THE 2014 CHANGES IN THE NORTH PACIFIC

One of the curiosities about the interviews in the ReportingClimateScience article: Axel Timmermann and Kevin Trenberth are treating the warming and associated events as if they were standalone happenings in 2014. That is, there’s not even a peep about the warming that took place in the North Pacific the year before. Who knows? Maybe they mentioned the warming of 2013 to the author of the article but the author elected not to mention it. Then again, maybe Timmermann and Trenberth overlooked it.

AN ODDITY

The following statement by Axel Timmermann is very odd. It’s about the period from the late 1990s through, assumedly, 2013. The article reads:

“These cooling equatorial trade winds were so strong that they sucked up water from the eastern equatorial Pacific and moved it west,” said Timmermann.

Why is it odd? That’s the normal state of affairs along the equatorial Pacific, regardless of whether the trade winds are strong or weak, but Timmermann is making it sound as though it’s a freak occurrence. Here, let me explain:

The north and south equatorial currents (flowing east to west), driven by the trade winds (blowing east to west), cause subsurface waters to be drawn to the surface along the equator in a process called upwelling (Timmermann’s “sucked up water”). Because the north and south equatorial currents flow from east to west, that upwelled water is logically moved to the west. (And it is warmed by the tropical sun so that it’s warmer in the west than it is in the east.) Weaker trade winds yield less upwelling, and stronger trade winds yield more upwelling. Nothing magical about it. ENSO basics. As a result, there is a greater temperature gradient between the eastern (cool) and western (warm) equatorial Pacific when the trade winds are stronger, and less of a temperature difference when the trade winds are weaker.

(But keep in mind, it’s the temperature difference between the east and west equatorial Pacific that helps to strengthen or weaken the equatorial trade winds. The equatorial trade winds and temperature difference between the eastern and western equatorial Pacific are coupled and they provide positive feedback to one another…Bjerknes feedback.)

YES, THE TRADE WINDS WERE STRONGER AFTER THE 1997/98 EL NIÑO

The article continues with another quote from Axel Timmermann, who is still discussing the period of the late 1990s through last year:

“So the trade winds intensified, the equatorial Pacific cooled, sea levels in the west rose and this all goes together with the global warming hiatus,” explained Timmermann.

With stronger trade winds, there would be an extra “piling up” of warm water in the western tropical Pacific.

Were the trade winds stronger than normal after the 1997/98 El Niño? Yup. See Figure 7. It shows the merger (weighted average) of the three trade wind indices for the equatorial Pacific from 1979 to 2014 that are available from the NOAA/CPC Monthly Atmospheric and SST Indices webpage, which are based on a reanalysis. West Pacific (5S-5N, 135E-180) index is here. Central Pacific (5S-5N, 175W-140W) is here. And Eastern Pacific (5S-5N, 135W-120W) reanalysis output is here. Again, because we only have 10-complete months this year, “annual” is for the months of January through October. The downward spike in 1997/98 was caused by the 1997/98 El Niño. I’ve highlighted two periods when there were a series of weak-to-moderate El Niño events (which were likely secondary events to the 1986/87/88 and 1997/98 El Niños). The trade winds were obviously stronger during the 2000s than in the 1990s. Now the question is: which is unusual? Maybe the period before the 1997/98 El Niño was unusual, and the period after it is a return to a more normal state. That is, it’s possible that using the period before 1997 as a reference for the period afterwards skews our perspective. For example, using the period before 1997 as a reference, we would have expected there to have been a greater weakening of the trade winds during the 2009/10 El Niño, but that El Niño was still a moderately strong El Niño according to sea surface temperature-based indices.

Figure 7

Figure 7

WERE EQUATORIAL PACIFIC SEA SURFACE TEMPERATURES COOLER THAN NORMAL RECENTLY?

In the last quote, Axel Timmermann stated that equatorial Pacific cooled over the past 15 or so years. He may be correct about the equatorial Pacific being cooler after the 1997/98 El Nino…it depends on what two periods we compare.

Referring to the Reynolds OI.v2 data, the surface of the equatorial Pacific was cooler from January 2009 to Dec 2013 than it was from November 1981 to December 1996. (We’re looking at the equatorial sea surface temperature anomalies before and after the 1997/98 El Niño.) The latter period was 0.08 deg C cooler. That’s 8 one-hundredths of a deg C. See Figure 8.

Figure 8

Figure 8

But those results are obviously skewed by the 1982/83 “super El Niño”. So if we start the first period in January 1984, Figure 9, we discover that the equatorial Pacific sea surface temperature anomalies for the two periods are identical.

Figure 9

Figure 9

THE LARGE VARIATIONS IN TRADE WIND STRENGTH ALONG THE EQUATORIAL PACIFIC ARE CAUSED BY WEATHER EVENTS

Those of you who followed along with the numerous discussions of the development of the El Niño conditions in 2014 know that the weaker trade winds along the equatorial Pacific during the development of an El Niño are actually caused by weather events…weather events that cause westerly wind bursts. (In the post ENSO Basics: Westerly Wind Bursts Initiate an El Niño, we discussed the numerous causes of westerly wind bursts along the equator in the Pacific. See the heading 4.15 Further Discussion on What Initiates an ENSO Event.)

Figure 10 includes a pair of Hovmoller diagrams from the NOAA GODAS website. This is an updated version of the one included in the July update. The Hovmoller diagrams show the wind stress along the equator during the development of the 1997/98 El Niño and the El Niño conditions this year. Looking at each Hovmoller, the y-axis (vertical axis) is time in months, January at the top. The x-axis (horizontal axis) is longitude. The equatorial Indian Ocean is to the left, the equatorial Pacific in the middle and the equatorial Atlantic to the right of each Hovmoller. We’re interested in the center portion for the equatorial Pacific. The different shades of blue indicate strong trade winds, and the yellows and reds are westerly wind bursts. Note how in 1997 there was a series of westerly wind bursts, while in 2014 there were only a few. That’s one of the primary reasons why conditions in 1997 developed into a super El Niño, while the El Niño conditions fizzled in 2014.

Figure 10

Figure 10

So some persons might believe that the strengthening of the trade winds after the 1997/98 may simply have been the result of fewer weather events that cause westerly wind bursts…though I’ve never seen a study presenting that.

Referring back to Figure 7, the Hovmoller diagrams in Figure 10 help to put that 1997 dip in trade wind strength into perspective.

ANOTHER ODDITY

Once again, it’s from Axel Timmermann. The article reads (my boldface):

“Over the last 15 years or so – the period of the global warming hiatus – the Pacific has been anomalously cold and there has been a very strong negative IPO,” explained Timmermann. “This has now stopped. The negative IPO has stopped. This is the same as saying the global warming hiatus has stopped.”

The “Pacific has been anomalously cold”? Data contradict that statement. Even the graph provided with the press release contradicts that statement. My Figure 11 is a graph of monthly sea surface temperature anomalies for the Pacific Ocean (60S-65N, 120E-80W), using the standard NOAA reference period of 1901-2000 for anomalies. The horizontal red line represents the average sea surface temperature anomalies for the period of January 1999 through December 2013. As shown, the average sea surface temperature anomaly for the entire Pacific Ocean was +0.37 deg C. There’s nothing “anomalously cold” about that.

Figure 11

Figure 11

And there had been nothing anomalously cold in the tropical Pacific during that time period. See Figure 12. Using periods before and after the 1997/98 El Niño, like those in Figures 8 and 9, we see the tropical Pacific was about the same temperature before and after that major event. Nothing “anomalously cold” about the tropical Pacific either.

Figure 12

Figure 12

NOTE: Notice the strong rise in tropical Pacific sea surface temperature anomalies in 2014. That rise is comparable to a moderately strong El Niño…what we would have expected from the size of the Kelvin wave that traveled along the equator earlier this year in the Pacific. All of that warm water had to have gone somewhere.

By using classic definitions of an El Niño are we’re overlooking a moderately strong event taking place in tropical Pacific this year, where the water was spread out over the tropical Pacific and not concentrated along the equator?

A QUICK INTRODUCTION TO THE INTERDECADAL PACIFIC OSCILLATION (IPO) AND PACIFIC DECADAL OSCILLATION (PDO) INDICES

The Interdecadal Pacific Oscillation (IPO) and Pacific Decadal Oscillation (PDO) indices are commonly referred to by climate scientists, including Timmermann and Trenberth in their recent interviews. Their discussions of them, though, in the interviews may confuse some persons who aren’t familiar with those indices. So here’s a quick overview.

The IPO and PDO indices are prepared similarly. They both rely on statistical analyses of the sea surface temperature anomalies of the Pacific Ocean. The PDO is limited to the extratropical North Pacific, while the IPO reaches into the mid latitudes of the South Pacific. See the map in Figure 13.  The IPO index is derived from the entire region shown in the map.   The statistical analyses are called Empirical Orthogonal Function (EOF) analysis and the related Principal Component (PC) analysis. See the NOAA Analysis Tools and Methods webpage here.

Basically, the Empirical Orthogonal Function (EOF) analysis determines the dominant spatial pattern (for example, warmer in the eastern North Pacific than in the central and western portion) from the respective portions of the Pacific Ocean. And the dominant spatial pattern of sea surface temperature anomalies in the Pacific is the one created by strong East Pacific El Niño events, which is also shown in Figure 13.

Figure 13

Figure 13

The Interdecadal Pacific Oscillation (IPO) and Pacific Decadal Oscillation (PDO) indices are numerical representations of how closely the spatial pattern of sea surface temperature anomalies at any time resembles the dominant pattern created by El Niños. A high positive IPO or PDO index value one month, for example, indicates the spatial pattern closely resembles the one created by strong El Niños. Conversely, negative values indicate an opposite pattern, one created by La Niñas.

It’s very important to understand that the IPO and PDO indices do not represent the sea surface temperatures of the Pacific or North Pacific; they only represent how closely the patterns of sea surface temperature anomalies resemble those created by El Niño and La Niña events.

If you were to compare the IPO or PDO indices to an ENSO index such as NINO3.4 sea surface temperature anomalies, you’d note that they do not track one another at all times. The reason: the wind patterns (and related sea level pressures) in the Pacific (IPO) and North Pacific (PDO) also influence the spatial patterns of sea surface temperature anomalies.

TIMMERMANN AND TRENBERTH’S REACTIONS TO THE SWITCH TO POSITIVE IPO AND PDO VALUES

In the interviews, Timmermann and Trenberth both seem ecstatic that the IPO and PDO indices switched from negative to positive values. Timmermann makes additional curious statements. The article reads under the heading of “End of the global warming pause” (my boldface):

Timmermann is very clear about what this means for global warming. “Over the last 15 years or so – the period of the global warming hiatus – the Pacific has been anomalously cold and there has been a very strong negative IPO,” explained Timmermann. “This has now stopped. The negative IPO has stopped. This is the same as saying the global warming hiatus has stopped.”

How odd! The IPO represents the spatial pattern of the sea surface temperature anomalies in the Pacific Ocean, not the sea surface temperature anomalies themselves. A switch to a positive IPO could also have been caused by an unusual cooling of the Kiroshio-Oyashio Extension east of Japan and of the South Pacific Convergence Zone east of Australia and New Zealand.

The 2-year unusual regional warming in the North Pacific caused the increase in global sea surface temperatures, and, this year, caused the IPO to switch from negative to positive.

Trenberth is more cautious than Timmermann. The article reads:

Trenberth believes that the end of the pause “very much relates to whether or not the PDO has indeed switched” adding that the kind of change that has been seen this year is “exactly, the sort of thing we would be looking for” to indicate that the pause had ended. He pointed out that the data shows that the PDO has moved from a negative (cooling) state to a positive (warming) state but it is still uncertain as to whether this is just a blip or whether it represents a more long-term flip. The PDO index in October was high and positive.

The PDO index data from JISAO is here. The PDO index value in October 2014 was about +1.5, so it was, in fact, positive.

And the author of the article expresses his misunderstandings of the PDO by adding the parenthetical (warming) and (cooling) to his sentence. It’s El Niños that cause long-term global warming and La Niñas that suppress it, not the mode of the PDO. The PDO and IPO (the spatial patterns) are simply aftereffects. But as we’ve also learned this year, two years of consecutive, compounding, warming events in the extratropical North Pacific (the blob) can also cause global sea surface temperatures to reach record highs—AND—cause the IPO and PDO to switch to positive values.

One would guess that Trenberth was more cautious because he understands (1) the blob might not return next year and (2) a La Niña could form next year. If those things were to happen, the PDO and IPO would likely switch back to negative values.

A FEW MAPS TO HELP YOU VISUALIZE WHY THE PDO AND IPO SWITCHED TO POSITIVE THIS YEAR

Animation 2 includes sea surface temperature anomaly maps for the IPO region of the Pacific. One is the average sea surface temperature anomalies for January to October 2013, and the other is for January to October 2014. In 2013, the blob was more centrally located in the extratropical North Pacific. By 2014, the blob had moved to the east and intensified. And along with a slight cooling in the western and central extratropical North Pacific, they provided a more classic PDO spatial pattern in the North Pacific. Thus the switch from negative to positive PDO.

Animation 2

Animation 2

One more introductory discussion for those wondering about something presented in the Timmermann and Trenberth interviews…

COASTALLY TRAPPED KELVIN WAVES

The ReportingClimateScience article also includes:

This period of strong equatorial trade winds came to an end at the beginning of 2014 resulting in a warming in the northern Pacific and especially along Alaskan coastal waters.

Next, a series of waves of warm water – known as Kelvin waves – moved across the Pacific from the west near Indonesia to the east and these were interpreted as signs that an El Nino Pacific Ocean warming event may be about to take place. Trenberth explained to reportingclimatescience.com that, as a result of this movement of water, sea levels rose in the central and eastern Pacific and fell back in the western Pacific. However, this warm water did not trigger the expected full blown El Nino.

Using animations of maps from the NOAA GODAS website, we’ve illustrated the equatorial Kelvin waves in the 2014/15 El Niño series. Animation 3 is the animation from the November update with the pentadal (5-day) maps sea level anomalies on the left and the average temperature anomalies to the depths of 300 meters on the right.

Animation 3

The article continues (my boldface):

Instead, the warm water moved across the Pacific until it hit the western coast of the Americas and moved north and south – warming coastal waters along the west coast of North America as far north as Oregon and causing a warming of the north eastern Pacific Ocean waters from April through to September.

Now, we know the blob existed long before the equatorial Kelvin wave reached the west coast of the Americas. In fact, we discussed the blob this year in the February 2014 post The Hotspot in the North Pacific. But…

The highlighted portion of the above quote refers to phenomena called coastally trapped Kelvin waves. And as described, after the downwelling (warm) equatorial Kelvin wave slams into the west coast of the Americas, the warm water travels north and south in coastally trapped Kelvin waves. Unfortunately, they’re difficult if not impossible to see in Animation 3.

They are, however, visible in an animation of sea level residuals that used to be available from JPL called “tpglobal.mpeg”. JPL has since removed it from their website, but I uploaded it to YouTube. See the full animation here on YouTube. It runs from 1992 to 2002. Animation 4 is a gif animation of the 1997 portion of that video. Two downwelling equatorial Kelvin waves, streaking west to east, are visible. The first Kelvin wave didn’t kick-start the El Niño, but the second one definitely did. And the coastally trapped Kelvin waves can be seen in the animation as well traveling poleward along the west coasts of the Americas, after the second equatorial Kelvin wave slams into Ecuador.

Animation 4

On the flip side of the coin, there are ENSO-related coastally trapped Rossby waves along the east coast of Asia. Animation 5 is a continuation of Animation 4. At the end of the 1997/98 El Niño, a downwelling Rossby wave forms at about 5N-10N off the coast of Central America. The leftover warm water from the 1997/98 El Niño is then carried back to the west, where it slams into the Philippines. While not as clear as the coastally trapped Kelvin waves along the coasts of the Americas, there are a number of papers about ENSO-related coastally trapped Rossby waves along the coast of Asia. And if memory serves, there was a paper written in the 1990s about the coastally trapped Rossby wave from the 1982/83 El Niño that remained along the Asian coast for a decade, where it altered weather patterns during that time. In other words, leftover warm water from strong El Niños can impact climate for a long time.

Animation 5

A POSSIBLE CAUSE OF THE 2-YEAR SPIKE IN THE SEA SURFACE TEMPERATURES OF THE EASTERN EXTRATROPICAL NORTH PACIFIC

We divided the sea surface temperature data of the North Pacific into quadrants in the “Wheres and Whys” post. Nothing stood out to say that the warming in the eastern extratropical North Pacific was simply caused by a pocket of warm water relocating from one region to another.

But the same cannot be said of the subsurface temperature anomalies of the eastern and western extratropical North Pacific for the depths of 0-700 meters. See Figure 14, which compares the NODC vertically averaged temperature anomalies for the eastern and western extratropical North Pacific, split at the dateline. The subsurface temperatures (0-700 meters) of the western extratropical North Pacific dropped abruptly in the second half of 2012 and at the same time the subsurface temperatures of the eastern portion of those extratropical latitudes warmed abruptly.

Figure 14

Figure 14

I suspect a pocket of warm water migrated below the surface in 2012 from the western to the eastern extratropical North Pacific…a subsurface weather event. The warm water then rose to the surface in 2013 and 2014, creating and becoming coupled with the “ridiculously resilient ridge” of high pressure in the same location, and in turn those two phenomena exacerbated the California drought.

I suspect in a year or two—after the alarmists are done extolling the imaginary calamities being caused by the elevated sea surface temperatures—that a group of climate scientists will include that shift of subsurface waters in their explanation of the blob. But will they remember to show the subsurface waters of the extratropical Pacific have cooled to the depths of 0-700 meters and 0-2000 meters during the ARGO era? See Figure 15.

Figure 15

Figure 15

CLOSING

There are always things to learn from press releases and interviews…interviews that some people might find alarming or might use as alarmist propaganda. We covered many in this post.

The biggest oddity about the interviews with Timmermann and Trenberth is their beliefs that global warming ceases during IPO and PDO “cool” periods and global warming occurs during their “warm” modes. While the IPO and PDO are aftereffects of the actual driving mechanism, which is ENSO, that’s not what’s odd about their beliefs. The oddity is that skeptics have been presenting that same argument for more than a decade.

Oh, we can’t forget…

There was something that Timmermann and Trenberth forgot to mention in their interviews. It was, the recent upticks in the extratropical North Pacific sea surface temperatures, and in North Pacific sea surface temperatures, and in global sea surface temperatures did little to erase the monumental differences between observed warming rates and those simulated by the models used by the IPCC. See Figure 16.

Figure 16

Figure 16

The surfaces of the global oceans are still warming at a rate that’s about half as fast as hindcast by climate models. Think about that for a moment. The modelers knew the actual warming rate for most of that time period, and the models still doubled the observed warming rate. That’s a failure in anyone’s book, or should be.

SOURCE

Sea surface temperature data and maps and the outputs of the CMIP5 climate models are available through the KNMI Climate Explorer. The sources of other data are linked in the post.

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79 thoughts on “Axel Timmermann and Kevin Trenberth Highlight the Importance of Natural Variability in Global Warming…

  1. It is a travesty that you do not realise that Kevin Trenberth’s vision of heat hidding in the deep ocean is brilliant! No wonder he is a Nobel Laureate – well a pretend one!

  2. ‘Timmermann and Trenberth were speculating about the end of the hiatus. ‘
    I would have said fantasizing, as they know full well that the more it carries on the bigger problem they have of their gravy train coming off the rails.
    Meanwhile I am still waiting them telling us how modern accuracy levels where possible in 1850 and how the pin prick quantity of measures they have can tell us about 70% of the planet to any accuracy level worth a dam.

    • It’s astounding that these people can’t see how ridiculous it is that they are desperate for a natural event to rescue their failed CO2 models.

  3. But it is good that they acknowledge the “pause”. Now if the pause continues, they will have to think again.

  4. Let’s see if they are still claiming ‘the pause has ended’ around this time next year.

      • Of course you can. Someone else buys the ticket and gives it to you. That’s my plan for getting rich.

    • Here is our man Trenberth just over a year ago.

      [Dr. Kevin Trenberth] – NPR – 23 August 2013
      “They probably can’t go on much for much longer than maybe 20 years, and what happens at the end of these hiatus periods, is suddenly there’s a big jump [in temperature] up to a whole new level and you never go back to that previous level again,” he says…….
      “When the natural variability or when the weather is going in the same direction as global warming, suddenly we’re breaking records, we’re going outside of the bounds of previous experience, and that is when the real damage occurs,” Trenberth says….
      http://www.npr.org/2013/08/23/214198814/the-consensus-view-kevin-trenberths-take-on-climate-change

      • Yup, Trenberth finally admitted that strong El Nino events can cause the upward shifts in global surface temperatures, big jumps, which is something that skeptics have been saying for close to 6 years.

      • Maybe he was forced to that admission as a necessary corollary to his assertion that heat was hiding in the ocean depths. If heat can do that, then it should certainly be able to come out of hiding in the ocean to warm up the air. In fact, it would have to do that for his lame excuse to have a chance of working.

  5. From this it seems we have had an unusual event. Two consecutive years with a big rise in temperatures in the Pacific. Individually the two years are not remarkable but together they are.
    Now, how often do we get a year with a big rise in temperatures in the Pacific in a century? And are they unrelated events or does one make another more likely (positive feedback)?
    I’ve demonstrated in the past that Bob’s posts are above my level but it seems to me that these are the questions that need to be answered to see how exceptional this event really is.
    Something is always happening, after all.

    • “And are they unrelated events or does one make another more likely (positive feedback)?”
      Warmer sea surface temps make convection and thunderstorms more likely, so all it does is it accelerates the atmospheric steam engine, lifting heat up, making the planet light up in the infrared spectrum and shed the energy to space.
      Negative feedback. (A governor)

  6. “Figure 16
    The surfaces of the global oceans are still warming at a rate that’s about half as fast as hindcast by climate models. Think about that for a moment. The modelers knew the actual warming rate for most of that time period, and the models still doubled the observed warming rate. That’s a failure in anyone’s book, or should be.”
    I expect the warmists to eventually adjust a parameter, making the model hindcasting rise only half as fast, and claim victory; under that new scenario they will claim world catastrophy in 2200 instead of in 2100.
    They will try to delay this adjustment for as long as possible, but probably already prepare protective papers to justify it when it is needed.

    • Dirk, the standard CAGW approach would be to say that the missing heat is coiling like a Puff Adder waiting to launch itself and bit our fat, sweaty ankles. They won’t admit to being wrong with the model, they will say the model is correct and reality will catch up later. In fact the gap Bob points out only means that when the warming strikes it will be twice as rapid as earlier anticipated. It will be even worse than they have predicted!
      When you are never wrong because you ‘have the physics right’, it means never having to say you are sorry. You just up the ante on alarm.
      Oh, and don’t forget to cash your cheque.

      • No matter the excuses; they will have to make sure the models don’t deviate much further, lest they lose credibility and funding even with the admittedly mentally ill politicians.

  7. Thanks for that interesting post. And you quite rightfully mentioned what T & T presumably did not in their interview:
    “Keep in mind, when looking at sea surface temperature data subsets, the data before 1950 is suspect, and before 1900 it’s really questionable. There’s just too little source data.”

  8. Seems to met hat these two gentlemen are now ‘deniers’. Unless they contend elsewhere that the PDO & IPO changes are driven by increasing CO2, didn’t they just admit that ‘global Warming’ is a natural event?

  9. Because natural variation is considerably stronger than any man-made variation, although long-term we expect temperatures to be warmer than they might be, in the short-term, because of the unusual warming at the end of the 20th century it is now more likely that the “end of the pause” will see a return to cooling.
    So, if you want to place bets – I recommend betting on a cooler next decade (before upjusting)

    • ……the ecstatic looks obviously their excitement as scientists of reworking heir data to fit a new gravy train

  10. As I said in your last post, the material point is that this warming is not CO2/back radiated induced warming, but rather it is part of a natural/ocean cycle event which event is not driven by CO2/backradiation.
    So the warmists may claim that ocean surface temps are at record highs, or 2014 is the warmest year ever (on record) or whatever hype they wish to run with, but this does not establish AGW. It merely demonstrates that natural variability and natural events rule (or at any rate are the dominant driver of temps and climate). .

    • +1 It is all about whether CO2 increases or decreases cloud coverage over the ocean. Increased cloud coverage = cooling. Decreased coverage = warming.
      No other factor is important.

  11. “It was the back-to-back, compounding, warmings in the North Pacific in 2013 and 2014 that caused the record high North Pacific and global sea surface temperatures in 2014.”
    Interesting but how an alarmist claim this regional warming as significant is baffling. The hypothesis is that atmospheric warming stops for 15 to 20 years because 15 to 20 years later a regional warming of the ocean is recorded. Apparently the warming went into a trust fund or escrow account only to be released 20 years later into this one region of ocean surface.
    This warming is a funny thing that even though temperature is measured in tenths or hundredths of a degree, sea warming has only become apparent in the last 2 years.
    Climate scientists like Timmerman go from glossing over what they don’t know or limitations in current data and methodology, to just being a little deceitful, to a behavioural disorder of endemic self-serving deceit.
    It is a slippery slope that noble lie thing…

  12. This post is timely , coming after 2 posts on the long term effect of volcanic eruptions . The first one, by Willis Eschenbach is of particular interest and involves a re-examination of the supposed effect of the Laki eruption in Iceland in 1783. He suggests that its effect was not as great as popularly believed, but the references / links to earlier posts lead one back to a very interesting essay by the author on the natural mechanisms which return the climate to a stable state after disruption ( or eruption) :
    http://wattsupwiththat.com/2009/06/14/the-thermostat-hypothesis/
    Are these the same mechanisms , involving oceanic oscillations, that are responsible for natural variation and possibly mitigating anthropogenic effects .
    The essay by WE appears to have been prompted by a study (NOAA funded) from authors at NASA Goddard and Columbia on whether the 2009/10 winter has similarities to that following Laki. They conclude not, and I copy their summary in full because I do not wish to be accused of cherry picking sentences :
    ” We have tested the hypothesis that negative‐NAO‐El
    Niño conditions, as in 2009–2010, can explain winter 1783–
    1784 conditions, without attributing them to Laki. Our paleoindex
    had the 2nd highest value of the past 600 years in
    1783–1784, with the most severe in 2009–2010. Conditions
    were thus more likely due to the rare occurrence of these
    events, neither of which can be clearly linked to Laki. Our
    results suggest that Franklin and others may have been
    mistaken in attributing winter conditions in 1783–1784
    mainly to Laki or another eruption, rather than unforced
    variability. Similarly, conditions during the 2009–2010
    winter likely resulted from natural NAO‐ENSO variability,
    not tied to greenhouse gas forcing. The 2009–2010 El Niño
    was unremarkable, and links between ENSO and greenhouse
    forcing are widely debated. Models suggest that rising
    greenhouse gases should force a positive, not negative,
    NAO [Intergovernmental Panel on Climate Change, 2007],
    despite Arctic sea ice loss creating a tendency to a negative
    NAO [Seierstad and Bader, 2009]. A solar minimum may
    have shifted the system towards a negative NAO [Lockwood
    et al., 2010], but it is unclear whether this could account for
    such a negative episode. Evidence thus suggests that these
    winters were linked to the rare but natural occurrence of
    negative NAO and El Niño events.

    GEOPHYSICAL RESEARCH LETTERS, VOL. 38, L05706, doi:10.1029/2011GL046696, 2011
    The role of natural mechanisms in stability or gradual warming and cooling seems to be a feature in posts recently and certainly merits further , unbiased , research .
    It may be that Trenbeth is right to highlight the role of the oceans , but has perhaps jumped to a premature conclusion.

  13. Thanks Bob Tisdale, it must really chap some grant seeker hide that you post this kind of in-depth detail of global climate. If you listen real close you can hear them howling at night from their beds. I love that sound.

  14. Where can one find the work by Timmermann and Trenberth that resembles Bob Tisdale’s compilation presented here?
    Have they not gone through the same process, study and considerations?
    It’s a little disturbing to think they have not compiled at least as much as Bob.
    If not what are they doing?
    I want to know why we have to get this kind of depth from Bob instead of the team?
    Who pays Bob?
    Who pays the Team?
    Can we get a profile of this juxtaposition?

    • Thanks Terry, a great read! Though I must admit watching David Appell floundering in the comments section is a guilty pleasure.

      • Appell stepped on pretty much every one of that forum’s pet semantic landmines. Perhaps your pleasure is guilty because do actually do know the difference between rhetorical b/s and an actual good faith debate.

    • Terry,
      His standard fare: basically if you want to know if temperature has gone up (or down, or stayed level), just look at the graph. Left unsaid: if you want to know a relationship between two variables, a scatter plot is a better choice than a time series plot.
      He had this new (to me) thing to say:

      Then something really odd happened: “warming trend of 0.11°C per century caused by urban warming” was removed. This leads to our second lesson.

      Which lesson is: even if one addresses something climate contrarians have been “saying for years”, they will still find a way to complain about it.

      • “Perhaps your pleasure is guilty because do actually do know (sic) the difference between rhetorical b/s and an actual good faith debate.”
        Perhaps I can’t tell the difference. But my guilty pleasure comes from poor David Appell whose arguments I find wanting and illogical, trying to argue against heavyweight Briggs who has a clarity of thought greater than ten ordinary men! From my reading, Appell understood nothing Briggs was explaining.
        You don’t agree and that’s fine with me!

  15. “That’s one of the primary reasons why conditions in 1997 developed into a super El Niño, while the El Niño conditions fizzled in 2014. ”
    Bob ,You are right .
    While the trade winds have not risen to the 1997/1998 levels , the SST temperatures in the Nino region seem to have risen during the first two to three weeks of November 2014 to weak /moderate Nino levels (0.6 to 1.1) ONI INDEX and this may last through November, December and January.If it meets the 3 month running mean criteria it may just make it as a weak El Nino but for a very short period ..[ like the 1958/59 case

  16. It’s almost as if they haven’t the first clue of how the Pacific current, winds and weather change and their linkages.
    Thanks Bob !! Great work as usual

  17. A spanish common saying: “The good, if brief, doubly good”. This article is desperately in need of, at least, some summary at the beginning or end of it. As it currently is, I may perhaps read it some time in the next months, once I finish reading my current 500 pages bedside book…

    • In this instance, I found the way Bob built it up rather easy to follow, as he just tracks the interview of the two warmists.

    • The trouble with “doubly good” brevity, is that it ALWAYS leads to questions, or “you forgot about this.”
      If I state something briefly, I’m accused of “assertion of authority” or some such idiocy, and I seldom gorget about anything; but may leave it out, for brevity. In science it is the doubter who has the burden of proving invalidity.
      So brevity should work; but it doesn’t, it just leads to questions.

      • That’s why I said there should be a summary, and not that you should omit anything. State the facts, then give the reasoning that leads to them. Pretty much like it is done in scientific papers, which begin with an abstract.

      • It seems to be that the abstracts for all scientific papers are automatically candidates for the Bullwer-Lytton prize, because they are invariably written in gobbledegook BS prose that is quite unintelligible, and they virtually never disclose the results. You have to buy the pay walled paper to find out what it is about; sort of Nancy Pelosi style.
        Nowadays, I ONLY state my personal opinions; and recommend that nobody make use of them for any reason; specially in any kind of life support system.
        So I don’t need to give a proof or citation to anything since it is just my opinion and intended form amusement only.
        Anyone is free to reject my opinion; or even try to prove it is valid, or invalid for themselves. Most people these days are better at maths than I am anyway, so why try to prove anything.
        So no appealing to authority for me; just my own opinions; which I could be the only person on the planet to believe.

  18. Bob doesn’t seem to understand that climate change happens gradually. Figures 2, 6 and 11 all show unprecedented values, even if others are comparable. And don’t confuse us with graphs of “changes.” The point is that temperatures keep going up, over the long term.

    • No, temperatures don’t. The trend was up from 1977 to 1996, but has been down since then, in the most reliable data set. They also fell from about 1947 to 1976, but before that went up for about the same time and at about the same rate as in 1977-96.
      The intermediate-term trend (~325 years), since about 1690 in the depths of the LIA has been up, but the long-term trend (~3250 years) since the Minoan Warm Period has been down. This secular trend is liable to continue no matter how much CO2 humans might add to the air over the next century or so. The ever so slightly increased GHG content might possibly have a measurable effect on the cycles within this secular trend, but more likely will be so negligible as not to be noticeable.
      The minor warming cycle of the late 20th century was no different from the many which preceded it. The Holocene is no different from prior interglacials, except generally colder than most.

    • Well it’s a matter of definition. If it changes fast it is “weather” and if it changes slow, it is “climate”.
      But it always changes. Gee it only takes about 12 hours give or take, to go from broad daylight to dark of night. That’s not climate; that’s weather.
      And Temperatures do NOT keep going up over the long term. Thermodynamics says that can’t happen.
      The universe is going to freeze to death.
      Yes it was pretty damn hot for the first 10^-43 seconds. It’s been getting colder ever since.

    • Barry says: “Bob doesn’t seem to understand that climate change happens gradually.”
      Realistically, Barry, I understand the assumptions you make that drive your beliefs. I have, however, for almost 6 years shown that most of your assumed human-induced global warming is, in fact, process related…via sunlight-fueled, naturally occurring processes.
      You have a good day, now.

    • Barry, you wrote: “The point is that temperatures keep going up”.
      Why is that the “point”? If temperature is going up at a rate of 1 degree per century (which it is), why should that cause us to spend Trillions of dollars to try and reverse the effect? Perhaps it’s natural. Perhaps it’s beneficial. Perhaps the Green Police State that would be required for the draconian changes environmentalists advocate would kill billions of people.
      Your post seems to somehow assume that ANY increase should cause us to rush about like chickens without heads. There is no point to your point.

  19. “Trenberth believes that the end of the pause “very much relates to whether or not the PDO has indeed switched” adding that the kind of change that has been seen this year is “exactly, the sort of thing we would be looking for” to indicate that the pause had ended. He pointed out that the data shows that the PDO has moved from a negative (cooling) state to a positive (warming) state but it is still uncertain as to whether this is just a blip or whether it represents a more long-term flip. The PDO index in October was high and positive”
    Good statement. We’ve had some big positive values in the PDO this year(around +1.50 recently). I can find only one time before during the previous -PDO that this happened. During 1957/58 in the middle of a strong -PDO, we saw numerous months with +1.50 or higher………..this was a temporary spike higher for a couple of years that gradually morphed back into the strongly negative PDO regime thru the 1960’s and much of the 1970’s.
    http://jisao.washington.edu/pdo/PDO.latest

  20. Hey Bob what are the odds of us getting a la nina next year? Did this year’s weak el nino release enough heat? What would be early indicators of a la nina?
    Thanks

    • TRM says, “What would be early indicators of a la nina?”
      Early indicator of a La Nina is an upwelling (cool) Kelvin wave….upwelling because it draws the thermocline up toward the surface. It’s the opposite of the downwelling (warm) Kelvin wave we saw earlier this year.

  21. Another incredible post by Bob, thank you so much. Trenberth seems to understand that natural cycles in the ocean are responsible for both warming and cooling. I would really like to understand why he thinks there’s an anthropogenic part of the story? As Bob has shown, the data doesn’t leave much room for other contributions!

  22. We are still being impacted here in the PNW and western Canada by the coastal kelvin wave. I’ve been watching it and every time I think it’s starting to fade it gets juiced up again. I’m wondering how much is left in the tank?

    • gyan1, What is the Kelvin Wave? I live on coastal BC. Early winter here . Got down to about -3 Deg C last week. Now we have the warmer low pressure system moving in to bring rain and temps up to 11 C.

      • Not sure how Kelvin wave fits into the colder than usual temperatures even though they show warm water off the coast

      • Mick
        November 19, 2014 at 11:36 am
        “Meant to say, how does Kelvin wave cause colder than average temps.”
        I don’t know if it had an influence on the Arctic high that brought us the cold clear weather. The Blob clearly was responsible for persistent ridging and I’m curious to see if the coastal Blob has the same effect.
        Snow in the forecast for the mountains so I’m hoping ski season will begin. I’m also hoping that the cooler SST’s in the central N Pacific will combine with the warm water off the coast and give us some big dumps!

  23. Does anybody else think KT looks a lot like Ted Turner. I used to work with a very smart and competent mechanical engineer, who was the spitting image of KT. Both of them are quite handsome at their age.
    Well all of us Kiwi are handsome; it’s in our genes. Kevin apparently got more handsome, and less smart genes.
    I do have a problem trying to cover for him when talking to relatives back in the old country. They think he might be a covert Aussie; that would explain it !

  24. Bob, thanks again for a nice post.
    Probably very few environmental writers have the inclination or ability to understand what you have written. Which is a travesty.

  25. The oceans are belching out the heat that was accumulated (both by endogenous El Nino type processes and by the high level of direct and/or indirect solar forcing) from the mid-70’s to 2000. Gonna get cold.
    Do the self-reinforcing heat-accumulation and heat-loss processes of ocean oscillations cancel out in the long run, so that their effects on climate (avg. temperature) are only temporary? In some degree at least. But they certainly create a heat absorption and heat-belching process, where instead of heat being evenly pressed into the oceans when forcings are high and evenly released back out when forcings fall, the heat travels in and out in waves.
    Too bad we don’t have the temperature history to know if there are typical patterns to the oceans’ belching and swallowing of heat in relation to changes in forcings.

  26. Eyeballing fig 1 a different take seems possible. Periods of cooling climate are associated with larger amplitude oscillations in N Pacific SSTs, such as 1890-1920 and 1950-1975. Warming periods have reduced amplitude oscillation such as 1920-1950 and 1975-2000.
    Speculative if course. But it would throw a different light on the current high spike in N Pacific SST.

  27. Hi Bob, What a job you’ve done; I’m going to apologize up front as I have just skimmed your post but promise to read it in detail later. I just wanted to get your take on some of the data presented by NOAA, etc, specifically the 850 level. Most of your posts grab the big picture whereas my attention focuses on the mesoscale or even micro scale. Now, to the 850. As I forecast the tropics for cruising yachts each day I first look at satellite loops, then go to jet level, 500 level then to 700 or 850 then finally surface data to get my picture. Now NOAA seems to imply the 850 level is a ‘trade wind’ level. This is absolutely rubbish. In the tropics there is almost always an inversion and the surface winds can be 180 degrees from those at 850 or roughly 5000 feet for those not using metric. Yachts remark quite frequently that the low cloud buildups always seem to move in a different direction from surface winds. And this is quite right. When I’m looking at MCS’s or smaller Cb clusters I use the level at 850 or 700 to forecast the direction of movement. So using data from 850 to imply trade wind direction and speed is ridiculous. Just wanted some feedback from you as conclusions drawn from this sort of data would make no sense.
    Great job as usual.
    Cheers from down under.

  28. I must reset my B.S. detector. In prior years, the word robust was the certain indicator of Warmist misinformation. Now, it appears that unprecedented is the tell-tale word. ‘Tis a Trenbesty!

  29. ““So the trade winds intensified, the equatorial Pacific cooled, sea levels in the west rose and this all goes together with the global warming hiatus,” explained Timmermann.”
    “This all goes together with,” when accompanied by appropriate hand flutters, is klimatspeak for “ENSO cooling is real but ENSO heating is imaginary.”

  30. Hmmm, a short baseline I know, but if you dump the pre 1940 figures in Figure 4 there are 4 pretty much identical peaks every 24 years.
    I wonder if it’s a process or just an artifact?

  31. Dave in Canmore,

    But my guilty pleasure comes from poor David Appell whose arguments I find wanting and illogical, trying to argue against heavyweight Briggs who has a clarity of thought greater than ten ordinary men!

    Which statements are illogical?
    Briggs is a heavyweight PhD statistician whose tagline is “If you want to know what y did vs. x, just look at the graph.” Which strikes me as incongruous at best, every time I read it. Apparently the best reason to get a doctorate in statistics is so as to be able to authoritatively tell folks to not use statistics. Bizarre.

  32. Yes, the “coastally trapped” waves are excess momentum that can’t be accommodated in any other way. They are the cause of the “T bone”. Something like a half T bone with the fillet removed happened this year when northward flowing monsoonal energy unusually far west allowed some warm water north (but not south) along the California coast. This bit of warm water is the basis for my intuition of a near normal rainfall year for California, but it is not about the ocean, it is not about the reaction waves, it is about the wind.
    That warm water heading north would never have happened last year because the NH trades were way too strong. NH trades were weak this year but the SH trades remain pretty strong.
    This points out a fundamental disagreement we have because while you believe PDO is leftovers from ENSO, I believe PDO is a macro scale residual of planetary winds which control both PDO and ENSO. Nothing new. Any 1960’s meteorology textbook will tell you that winds control the ocean currents. Mysterious eastward winds accelerated the reaction wave in 1997.
    The oceans slosh back and forth in myriad ways, but the sloshes are modulated by the winds. To understand climate we do not need to understand the water. we need to understand the wind.

  33. As discussed in the above-linked “Wheres and Whys” post, there was also an unusual warming in the extratropical North Pacific in 2013. That’s something that’s often overlooked. The unusual warming of the surface of North Pacific in 2014 occurred on top of a similar event in 2013.
    Isn’t that typical of a warm-phase Northern Pacific Oscillation, a thingie that goes warm when the PDO shifts to cool? Our current conditions? Considering this, I would have regarded the “blob” as a more-or-less typical phenomenon.

  34. Fyi: Animation 2 link needs to be corrected. It is not showing up properly.
    Good info Bob Tisdale. Apprecaited

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