Can Most Of The Rise In The Satellite-Era Surface Temperatures Be Explained Without Anthropogenic Greenhouse Gases?

The last 25 years of temperature variation

Satellite-Era Surface Temperature Record - Image via Wikipedia

Guest post by Bob Tisdale

In this post, I divide the globe (60S-60N) into two subsets and remove the linear effects of ENSO and volcanic eruptions from GISS Land-Ocean Temperature Index data since 1982. This is done using common methods. I further adjust the data to account for secondary ENSO-related processes. The Sea Surface Temperature subsets used for these adjustments are identified. The processes are briefly discussed, supported by links to past posts, and the data are presented that support the existence of these secondary effects. An additional volcanic aerosol refinement that increases the global trend is made. The bottom line is, the GISS LOTI and Reynolds OI.v2 SST data indicates that natural variables could be responsible for approximately 85% of the rise in global surface temperature since 1982. I’ll be the first to point out that I qualified my last sentence with the word “could”. This post illustrates a story presented by the data, nothing more. But this basic evaluation indicates these secondary effects of ENSO require further research.

This post continues with the two-year series of posts that basically illustrate that the effects of El Niño-Southern Oscillation (ENSO) cannot be accounted for using a single index like a commonly used SST-based dataset such as NINO3.4, or CTI, or MEI. These indices represent only the sea surface temperature of the central and eastern equatorial Pacific (that’s modified in the case of the MEI). They do not represent the process of ENSO. They do not account for the warm water that is returned to the western Pacific and redistributed during the La Niña. This post provides further evidence of those effects.

This post is long but I elected not to divide it in two. It’s 6,000 words or 13 single-spaced pages in length. It includes 32 Figures, a gif animation, and a video. So there’s a lot to digest. I tried to anticipate questions and answer them.

REMOVING THE LINEAR EFFECTS OF ENSO AND VOLCANIC AEROSOLS HELP TO SHOW THE TIMING OF THE WARMING

Many papers and blog posts that attempt to prove the existence of anthropogenic global warming remove the obvious linear effects of El Niño-Southern Oscillation (ENSO) events and of stratospheric aerosols discharged by explosive volcanic eruptions. An example is Thompson et al (2009) “Identifying Signatures of Natural Climate Variability in Time Series of Global-Mean Surface Temperature: Methodology and Insights”… http://www.atmos.colostate.edu/ao/ThompsonPapers/ThompsonWallaceJonesKennedy_JClimate2009.pdf

…and its companion paper Fyfe et al (2010), “Comparing Variability and Trends in Observed and Modelled Global-Mean Surface Temperature.”

http://www.atmos.colostate.edu/ao/ThompsonPapers/FyfeGillettThompson_GRL2010.pdf

Let’s run through the process using GISS Land-Ocean Temperature (LOTI) data. That’s their global temperature anomaly dataset with the 1200km radius smoothing. A known problem with that dataset is that GISS Deletes Arctic And Southern Ocean Sea Surface Temperature (SST) Data. Since that creates a bias, we’ll delete the GISS LOTI data where they extend land surface data (with its higher variability) out over the oceans. That is, we’ll confine the data used in this post to 60S-60N.

Someone is bound to complain that I’ve deleted the Arctic data from the GISS LOTI data and that the Arctic is warming much faster than lower latitudes. Keep in mind that the Arctic is amplifying the effects of the rise in temperature at lower latitudes. This is the basis of the concept of polar amplification. If the vast majority of the change in temperature at the lower latitudes is natural, the same would hold true for the Arctic. Regardless, these latitudes were also chosen because the effects I want to illustrate with this post are relatively easy to display using them.

Back to the data: since GISS switches sources for their Sea Surface Temperature data from HADISST to Reynolds OI.v2 data in December 1981, we’ll look at the LOTI data starting in 1982. Smith and Reynolds (2004) Improved Extended Reconstruction of SST (1854-1997)] states the following about the OI.v2 SST data: “Although the NOAA OI analysis contains some noise due to its use of different data types and bias corrections for satellite data, it is dominated by satellite data and gives a good estimate of the truth.”

The truth is a nice place to start.

And we’ll smooth the monthly data with a 13-month running-average filter to lessen noise and season variations.

Figure 1 shows monthly GISS LOTI data (60S-60N), from March 1982 to November 2010, compared to NINO3.4 SST anomalies. The NINO3.4 data represent the Sea Surface Temperature of a region in the central equatorial Pacific bound by the coordinates of 5S-5N, 170W-120W. NINO3.4 SST anomalies are a commonly used proxy for the strength and frequency of El Niño and La Niña events, also known as ENSO. (And for those new to ENSO, refer to An Introduction To ENSO, AMO, and PDO – Part 1.) Note also that the NINO3.4 data has been scaled (multiplied by a factor of 0.16) so that the rises of the two datasets are about the same during the evolution of the 1997/98 El Niño. The NINO3.4 SST anomalies have also been shifted down 0.01 deg C and moved back in time by 3 months (lagged) to align the leading edges of the two datasets at that time. (The data in the graph starts in March 1982 because of the 3-month lag in the NINO3.4 data.) I chose the 1997/98 El Niño because that event wasn’t opposed by a volcanic eruption and it was large enough to overwhelm the background noise. As you can see, the wiggles of lesser El Niño events after 2000 don’t match as well.

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Figure 1

Many of the large year-to-year changes in global temperatures are removed when we subtract the scaled NINO3.4 data from the GISS Global (60S-60N) LOTI data. Refer to the “olive drab” curve in Figure 2. Since the NINO3.4 data has a negative trend since 1982, we increase the trend in the GISS LOTI data by subtracting it. Also note how the ENSO-adjusted GISS LOTI data has “flattened” after 1998. Without the volcano-related dip and rebound starting in 1991, the period from 1988 to 1998 would also be relatively flat. It appears as though the ENSO-adjusted GISS LOTI rose in two steps since 1982. Let’s remove the cooling effects of the El Chichon and Mount Pinatubo eruptions to see if that holds true. We’ll use a GISS dataset that represents Stratospheric Aerosols. (ASCII data) Like the ENSO Proxy, we’ll scale the data and lag it. The estimated range of the impact of Mount Pinatubo on Global Temperatures varies from 0.2 to 0.5 deg C, depending on the study, so we’ll use approximately 0.35 deg C to account for its effect. Visually, that scaling appears right.

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Figure 2

Figure 3 illustrates the GISS Land-Ocean Temperature Index (LOTI) anomaly data with the linear effects of ENSO events and the effects of large volcanic eruptions removed. Also illustrated is the linear trend. I’ve included the linear trend line to illustrate the effect the straight line has on the appearance of the data. The trend line gives the misleading impression that there has been a constant but noisy rise in global temperatures.

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Figure 3

During the discussion of Figure 2, I noted that the data appeared to flatten after 1998. The upward steps in the data can be illustrated if we present the period average temperature anomalies for the three periods of 1982 to 1987, 1988 to 1997, and 1998 to 2010.

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Figure 4

WHAT COINCIDES WITH THE UPWARD STEPS?

The timings of those upward steps coincide with the transitions from the large El Niño to La Niña events that took place in 1988 and 1998. This can be seen in Figure 5, which includes the adjusted GISS LOTI data. The other dataset is scaled NINO3.4 SST anomalies that have been inverted (multiplied by a negative number). Figure 5 is a gif animation, and in it, the NINO3.4 data shifts up and down. That was done to show how precisely the upward steps in the adjusted GISS data coincide with ENSO transitions. The adjusted GISS data trails the NINO3.4 data by a month or two. And the scales are correct for both upward steps.

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Figure 5

But how can ENSO be impacting global temperature data if we’ve subtracted the scaled NINO3.4 anomaly data from the Global (60S-60N) GISS LOTI anomalies?

LA NIÑA EVENTS ARE NOT THE OPPOSITE OF EL NIÑO EVENTS

The assumption made when we removed the linear effects of ENSO (discussion of Figure 1) was that La Niña events were the opposite of El Niño events. But they are not. (This is the same incorrect assumption made by papers like Thompson et al 2009). This post is very long and to adequately describe how La Niña events are not the opposite of El Niño events would make it much longer. So it will be best to provide links to earlier detailed discussions on this topic.

Refer to:

More Detail On The Multiyear Aftereffects Of ENSO – Part 1 – El Nino Events Warm The Oceans

And:

More Detail On The Multiyear Aftereffects Of ENSO – Part 2 – La Nina Events Recharge The Heat Released By El Nino Events AND…During Major Traditional ENSO Events, Warm Water Is Redistributed Via Ocean Currents.

And:

More Detail On The Multiyear Aftereffects Of ENSO – Part 3 – East Indian & West Pacific Oceans Can Warm In Response To Both El Nino & La Nina Events

I provide a relatively brief description in the following section.

WHY ENSO INDICES LIKE NINO3.4 SST ANOMALIES DO NOT ACCOUNT FOR THE PROCESS OF ENSO

ENSO is a process, and ENSO indices such as NINO3.4 SST anomalies, the Cold Tongue Index (CTI), or the Multivariate ENSO Index (MEI) do not account for that process.

El Niño description: A reduction in the strength of the Pacific trade winds triggers an El Niño. A number of interrelated events then take place. Huge amounts of warm water from the surface and, more importantly, from below the surface of the western tropical Pacific (the Pacific Warm Pool) slosh east during an El Niño and are spread across the surface of the central and eastern equatorial Pacific. The increased area of warm water on the surface allows the tropical Pacific Ocean to discharge more heat than normal into the atmosphere through evaporation. That, combined with the change in location of the convection, cause drastic changes in global atmospheric circulation patterns. As a result, global temperatures vary. And most parts of the globe outside of the central and eastern tropical Pacific warm during an El Niño. The changes in atmospheric circulation work their way eastward–over the Americas, the Atlantic, Europe and Africa, the Indian Ocean and Asia. Eventually, the changes reach the western Pacific, but by that time, the El Niño is transitioning to a La Niña.

Refer again to the NINO3.4 SST anomaly data in Figure 1. A La Niña event, based on the temperature values on a graph, appears to be an El Niño of the opposite sign, and for some regional responses in temperature and precipitation that is true. But as noted before the use of NINO3.4 SST anomalies or other ENSO indices does not capture the fact that ENSO is a process. Those indices fail to account for the relocation and redistribution of huge amounts of warm water.

In the description of the El Niño, I noted that huge amounts of warm water from the surface and below the surface of the West Pacific Warm Pool had sloshed east during an El Niño. What happens to all of that warm water from below the surface of the Pacific Warm Pool that had been spread across the surface of the central and eastern tropical Pacific during the El Niño? Before the El Niño, it was below the surface and not included in the measured global surface temperature anomalies. During the El Niño, some of the warm water that had been below the surface is now on the surface of the central and eastern tropical Pacific and included in the measured global temperature. In response, surface temperatures there rose. The ENSO index captures that part of the process and only that part.

But during the La Niña, what happens to the warm water? It wasn’t all “used up” by the El Niño. And what happens to all of the subsurface warm water that had shifted east during the El Niño and had remained below the surface. It doesn’t simply disappear during the La Niña. Answering those questions explains why La Niña events are not the opposite of El Niño events, and why an ENSO index does not capture the aftereffects of an ENSO event.

The leftover warm water returns to the western Pacific. This is accomplished in a few ways. One is through a phenomenon called a slow-moving Rossby Wave. This can be seen in Video 1. It illustrates global Sea Level Residuals from January 1998 to June 2001 and captures the 1998/99/00/01 La Niña in its entirety. The video was taken from the JPL video “tpglobal.mpeg”. The slow moving Rossby wave is shown as the westward moving band of elevated sea level at about 10N. Watch the effect it has on western Pacific Sea Level Residuals when it reaches there.

The second way that the leftover warm water is carried to the Western Pacific is through a strengthening of the trade winds. During a La Niña event, trade winds strengthen above their “normal” levels and the ocean currents carry the warm water back to the west and then poleward.

Animation 1 is taken from the videos in the post La Niña Is Not The Opposite Of El Niño – The Videos. It presents the 1997/98 El Niño followed by the 1998 through 2001 La Niña. Each map represents the average Sea Surface Temperature anomalies for a 12-month period and is followed by the next 12-month period in sequence. Using 12-month averages eliminates the seasonal and weather noise. The effect is similar to smoothing data in a time-series graph with a 12-month running-average filter.

There are a number of things to note in Animation 1. First, the El Niño and La Niña events cause changes in the sea surface temperatures in the central and eastern tropical Pacific. The NINO3.4 SST anomalies used in this post are a measure of that variation in the central equatorial Pacific, and only that variation. Second, during the El Niño, note how the sea surface temperatures warm first in the Atlantic, then in the Indian Ocean, and then in the western Pacific. The warming is caused by changes in atmospheric circulation. And by the time these changes in atmospheric circulation make their way east to the western Pacific and it starts to warm there, the El Niño is transitioning to La Niña. Third, note how the sea surface temperature anomalies in the Western Pacific (and East Indian Ocean) continue to rise as the La Niña event strengthens. Fourth, note how the SST anomalies remain elevated in the East Indian and West Pacific Oceans during the entire term of the 1998/99/00/01 La Niña.

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Animation 1

The Sea Surface Temperatures of the East Indian and West Pacific Oceans remain elevated during the La Nina because the stronger trade winds reduce cloud cover. The reduction in cloud cover allows more Shortwave Radiation (visible light) to provide additional warming of the tropical Pacific waters east of the Pacific Warm Pool. The ocean currents carry this sunlight-warmed water to the west and then poleward.

DIVIDING THE GLOBE IN TWO HELPS IDENTIFY THE REASONS FOR THE UPWARD STEPS IN THE GISS LOTI DATA

To help illustrate the reasons for the upward shifts in the ENSO- and Volcano-adjusted GISS LOTI data (Figure 4), let’s divide the data into two subsets split at 20N. Refer to Figure 6.

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Figure 6

First we’ll look at the Northern Hemisphere GISS LOTI anomaly data, north of 20N. It has a relatively high linear trend since 1982, about 2.8 deg C/Century. Part is due to the additional variability of the North Atlantic. To compound that, these latitudes have a relatively high land surface area, and land surface temperatures vary much more than sea surface temperatures. The land surface area of the Northern Hemisphere latitudes of 20N-60N is about 45% of the total surface area, but the land surface in the tropical and Southern Hemisphere latitudes of 60S-20N is only 17%.

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Figure 7

The dataset shown in Figure 7 has not been adjusted for ENSO or volcanic eruptions. Let’s correct first for ENSO, then for the volcanic eruptions, using the same methods we did for the Global (60S-60N) data. Figures 8 and 9 illustrate the interim steps and the required scaling factors, and Figure 10 illustrates the result.

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Figure 8

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Figure 9

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Figure 10

The Northern Hemisphere data still has a relatively high trend, approximately 2.2 deg C/Century. But what causes the additional variability if we’ve removed the effects of ENSO and volcanic eruptions? The additional variations are often described as noise, but they have sources.

THE KUROSHIO-OYASHIO EXTENSION HOLDS THE ANSWER

There is a strong ENSO-related warming of the Kuroshio-Oyashio Extension that occurs during La Niña events. This was discussed and illustrated in my recent post The ENSO-Related Variations In Kuroshio-Oyashio Extension (KOE) SST Anomalies And Their Impact On Northern Hemisphere Temperatures. That secondary warming can be used to explain a major portion of the year-to-year variability in Northern Hemisphere land and sea surface temperature. And, along with ENSO, it helps to explain nearly all of the variations in the Northern Hemisphere (20N-60N) GISS LOTI data, including the rising trend. Figure 11 illustrates the location of the KOE dataset used in this post (30N-45N, 150E-150W).

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Figure 11

The GISS LOTI anomalies for much of the Northern Hemisphere warm (cool) when the Kuroshio-Oyashio Extension SST anomalies warm (cool). This can be seen in the correlation map of annual (January to December) Kuroshio-Oyashio Extension SST anomalies and annual Northern Hemisphere (0-90N) GISS LOTI data, Figure 12. Also note the correlation with the North Atlantic.

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Figure 12

As mentioned above, the secondary warming of the Kuroshio-Oyashio Extension was discussed in detail in my recent post The ENSO-Related Variations In Kuroshio-Oyashio Extension (KOE) SST Anomalies And Their Impact On Northern Hemisphere Temperatures. A quick description of the process: During a La Niña event, leftover warm water from the El Niño is returned to the Western Pacific and spun poleward by the North and South Pacific gyres. Much of that warm water finds its way to the Kuroshio-Oyashio Extension, where it apparently impacts atmospheric circulation.

The agreement between the variations in KOE SST anomalies and the adjusted Northern Hemisphere GISS LOTI anomalies is shown in Figure 13. I find that match quite remarkable. The additional spike (highlighted in blue) in the KOE data that starts in 1990 is out of place. It will make itself known later in this post. The other thing to note is the scaling factor required to align the two datasets in Figure 13. The scaling factor of 0.7 is very high. We’ll discuss this later in the post.

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Figure 13

Some might think the agreement between those datasets is a lucky coincidence. Of course, the agreement between the adjusted LOTI data and the unadjusted KOE data in Figure 13 is based solely on the lags and scaling factors I used. But the scaling and lags were established logically. Eyeballing the data, the scaling factors appear to be correct. And as we shall see, using the same methods, the results are very similar for the data that covers the Tropics and Southern Hemisphere.

LET’S LOOK AT THE TROPICS AND SOUTHERN HEMISPHERE

The Southern Hemisphere and Tropics dataset includes the GISS LOTI data from 60S-20N, Figure 14. This subset has a relatively low trend, approximately 1 deg C/Century. Some of this is related to the amount of continental land mass. For these latitudes, land represents only about 17% of the surface area. The Southern Ocean (90S-60S), which is outside of the latitudes portrayed in the post, also impacts the Southern Hemisphere data. And since the Southern Ocean SST anomaly trend over this period is negative, its interaction with the Southern Hemisphere oceans lowers the trend of the dataset.

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Figure 14

And again, using the same methods, we’ll adjust for ENSO, then volcanic eruptions, Figures 15 and 16, and present the results, Figure 17. Refer to Figures 15 and 16 for the scaling factors.

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Figure 15

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Figure 16

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Figure 17

As shown in Figure 17, removing the effects of the volcanoes has once again lowered the trend, and removing the ENSO data reduced the year-to-year variations.

Now we need a dataset for these latitudes to illustrate the secondary warming due to the leftover warm water from El Niño events and use it to account for the adjusted GISS LOTI data for the latitudes of 60S-20N.

THE SOUTH PACFIC CONVERGENCE ZONE (SPCZ) EXTENSION SST ANOMALY DATA AND CORRELATION MAP ARE REVEALING

The KOE was used in the discussion of the Northern Hemisphere data, so it seems logical that a similar area exists in the South Pacific. And for this discussion, we’ll designate that area as the South Pacific Convergence Zone (SPCZ) Extension. The SPCZ Extension data will be the SST anomalies of the area east of Australia (35S-20S, 160E-150W). As shown in Figure 18, it had a relatively high SST anomaly at the peak of the 1998/99 portion of the 1998 through 2001 La Niña.

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Figure 18

The SST anomalies for SPCZ Extension are shown in Figure 19.

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Figure 19

Like the KOE Extension data, the SST anomalies of the SPCZ Extension warm greatly during transitions from El Niño to La Niña events and appear to shift upward at those times. Refer to Figure 20.

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Figure 20

Creating the correlation map of annual (January to December) SPCZ Extension SST anomalies and annual Tropical and Southern Hemisphere (90S-20N) GISS LOTI data was eye-opening. It appears the SPCZ data is a good proxy for those areas in the western tropical Pacific and southwest Pacific that warm during La Niña events. It would also appear to show the effects those western Pacific areas have on the rest of the globe. As we can see in Figure 21, when the SPCZ Extension warms (cools) many areas throughout the tropics and Southern Hemisphere warm (cool). But as illustrated in Figure 20, the warming that occurs during La Niña events is not counteracted by the cooling during El Niño events. This causes the data to rise in steps during the La Niña events.

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Figure 21

Does the correlation map indicate that the upward shifts in the SPCZ Extension data also exist in the tropical and Southern Hemisphere GISS LOTI data? My understanding of correlation maps is that they emphasize the larger events in the data, and if we refer again to Figure 20, the larger events are those that occur during these upward shifts. We can also confirm this by comparing the respective time-series graphs.

Figure 22 illustrates the adjusted GISS LOTI data for the Tropics and Southern Hemisphere north of 60S. Also shown are scaled (0.25) SPCZ Extension SST anomalies. There are minor divergences from time to time, but in general the two curves agree surprisingly well.

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Figure 22

WHAT’S THE BOTTOM LINE?

What do the curves and linear trends of the adjusted GISS LOTI data look like if the KOE and SPCZ Extension data are removed? And what happens when you combine the two results to form a global dataset with all of the adjustments? Let’s take a look. The Northern Hemisphere GISS LOTI data (20N-60N) that’s been adjusted for ENSO and volcanic aerosols and the KOE SST anomalies is shown in Figure 23. Recall the divergence circled in blue in Figure 13; that’s the cause of the significant additional dip in 1990. Other than that, this was not a bad first attempt with scaling factors. But notice how small the trend is, 0.13 deg C/Century. If that dip was removed, the trend would be even lower.

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Figure 23

The Tropical and Southern Hemisphere GISS LOTI data (60S-20N) with the ENSO, Volcano, and SPCZ Extension adjustments is shown in Figure 24. The trend is basically flat. This dataset appears noisy, but look at the temperature scale. The range is only one-quarter of one used in Figure 23.

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Figure 24

We can combine the Northern Hemisphere data (20N-60N) with the Tropical and Southern Hemisphere data (60S-20N) using a weighted average. (The latitudes of 20N-60N represent approximately 29% of the surface area between 60S-60N.) Figure 25 shows the result. The linear trend is basically flat at 0.06 deg C/Century. The saw-tooth pattern is interesting, but…

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Figure 25

Due to the timing, the saw-tooth pattern appears to indicate that there was a lagged (repeated) volcano signal in the data. Refer to Figure 26. The reason I say repeated is that originally when the volcanic signal was removed, the Aerosol Optical Depth data was lagged 3 months and the leading edges of the data aligned well in Figures 9 and 16. The volcano signals in Figures 25 and 26, assuming those spikes are volcano signals, are lagged 9 months. The additional signal may also simply mean the Sato Mean Optical Thickness data doesn’t account perfectly for the decay of the volcano signal and that an additional adjustment is required.

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Figure 26

So let’s make the secondary volcano correction, refer to Figure 27. That will raise the linear trend of the adjusted GISS LOTI data.

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Figure 27

After all of the adjustments are made, there is a small trend, about 0.24 deg C/Century. Compared to the original, unadjusted data, Figure 28, the trend of the adjusted data is only about 15% of the original GISS LOTI data for 60S-60N.

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Figure 28

This makes perfect sense since there is little to no evidence of an anthropogenic global warming effect on global Ocean Heat Content (OHC) data. All one needs to do is divide the global oceans into tropical and extratropical subsets per ocean basin. Then it’s relatively easy to determine that ENSO, changes in Sea Level Pressure, and AMO/AMOC are responsible for that vast majority of the rise in OHC since 1955. Refer to:

A. ENSO Dominates NODC Ocean Heat Content (0-700 Meters) Data

B. North Pacific Ocean Heat Content Shift In The Late 1980s

C. North Atlantic Ocean Heat Content (0-700 Meters) Is Governed By Natural Variables

SHOULDN’T THE KUROSHIO-OYASHIO EXTENSION AND SPCZ EXTENSION DATA BE DETRENDED?

In this post and in The ENSO-Related Variations In Kuroshio-Oyashio Extension (KOE) SST Anomalies And Their Impact On Northern Hemisphere Temperatures, we illustrated that the Kuroshio-Oyashio Extension and South Pacific Convergence Zone Extension SST anomalies rise in steps during La Niña events. Since those upward steps are clearly responses to ENSO, there should be no need to detrend those datasets.

A NOTE ABOUT THE ATLANTIC MULTIDECADAL OSCILLATION

There is a natural variable I did not account for in this post, and it is the Atlantic Multidecadal Oscillation, or AMO. I did not remove its impacts on the Northern Hemisphere data. For those new to the AMO, refer to An Introduction To ENSO, AMO, and PDO — Part 2.

As noted in that post, RealClimate defines the Atlantic Multidecadal Oscillation (“AMO”) as, “A multidecadal (50-80 year timescale) pattern of North Atlantic ocean-atmosphere variability whose existence has been argued for based on statistical analyses of observational and proxy climate data, and coupled Atmosphere-Ocean General Circulation Model (“AOGCM”) simulations. This pattern is believed to describe some of the observed early 20th century (1920s-1930s) high-latitude Northern Hemisphere warming and some, but not all, of the high-latitude warming observed in the late 20th century. The term was introduced in a summary by Kerr (2000) of a study by Delworth and Mann (2000).”

I could have accounted for the AMO before removing the impacts of ENSO and the volcanic eruptions. But I chose to leave it in so that I could include the impact of the KOE on the North Atlantic.

As shown in Figure 29, the trend of the North Atlantic SST anomalies between 20N-60N is 70% higher than the North Pacific SST anomalies trend. By accounting for that additional “some, but not all” trend from the AMO, the scaling factor required to align the KOE dataset with the North Hemisphere data would drop.

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Figure 29

THE KOE SCALING IS TOO HIGH

The scaling factor for the Kuroshio-Oyashio Extension data in Figure 13 was 0.7. To some, it would not seem likely that the secondary warming of the KOE could raise temperatures for the Northern Hemisphere (20N-60N) that high, especially when one considers the multiplier for the SPCZ Extension was 0.25 in Figure 22.

First: Let’s consider the known effects of an El Niño event. When surface temperatures around the globe warm in response to an El Niño, most of those areas warm due to changes in atmospheric circulation. That is, they do not rise because the heat released into the atmosphere is warming the land and sea surfaces. The following is an example I often use. During an El Niño, the tropical North Atlantic warms even though it is separated from the Pacific by the Americas. The tropical North Atlantic warms during the El Niño because the El Niño causes a weakening of the North Atlantic trade winds. With the decrease in Atlantic trade wind strength there is less evaporation, and if there is less evaporation, sea surface temperatures rise. There is also less upwelling of cool water from below the surface when the trade winds weaken. This also causes sea surface temperatures to rise.

Therefore, it is through teleconnections or atmospheric bridges, not the direct transfer of heat, that the KOE would impact the areas of the Northern Hemisphere.

Second: There is a second western boundary current extension in the Northern Hemisphere, and it is the Gulf Stream Extension in the North Atlantic. For this quick discussion, we’ll define the Gulf Stream Extension by the coordinates of 35N-45N, 75W-30W. The map in Figure 30 is a correlation map and it shows that when the Gulf Stream Extension warms (cools) there are many parts of the Northern Hemisphere that warm (cool). And note that the eastern tropical Pacific is negatively correlated, indicating that these areas warm during La Niña events.

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Figure 30

Scroll back up to Animation 1. It also shows the parallel warming of the Gulf Stream Extension with the KOE.

But do the SST anomalies of the Gulf Stream Extension cool during El Niño events? As shown in Figure 31, the SST anomaly variations of the Gulf Stream Extension and the Kuroshio-Oyashio Extension are very similar. Both datasets can warm significantly during La Niña events but they do not drop proportionally during El Niño events. In an earlier linked post, I described the process that causes the KOE to warm, but I have not found a paper that describes the warming of the Gulf Stream Extension at those times. Why does the Gulf Stream Extension respond differently to El Niño and La Niña events? Like the KOE, is the warm water created during an El Niño also carried north by the Gulf Stream during the following La Niña? Do the changes in atmospheric circulation caused by the La Niña add to the warming? During the La Niña, does an increase in the strength of the North Atlantic trade winds also reduce cloud cover over the tropical North Atlantic? Does the warm water created by the decrease in cloud cover and resulting increase in sunlight then get transported to the Gulf Stream Extension? There are too many unanswered questions for me to use the Gulf Stream Extension data in this post.

http://i52.tinypic.com/4g6i9w.jpg

Figure 31

But, the parallel warming of the KOE and the Gulf Stream Extension during the transitions from El Niño to La Niña events would help to reduce the KOE scaling factor required to explain the step changes in the adjusted GISS LOTI data.

WHAT ABOUT SOLAR?

If we scale sunspot numbers so that the variations from solar minimum to maximum represent about a 0.1 deg change in temperature, and if we lag the sunspot data 6 years, it compares well visually with the adjusted GISS LOTI data. Refer to Figure 32. Someone with additional data processing tools could duplicate the steps taken in this post and confirm how well the two curves align.

http://i51.tinypic.com/23jsjo1.jpg

Figure 32

WHAT FUELS THE EL NIÑO EVENTS?

The warm water created during the previous La Niña(s) via the increase in Downward Shortwave Radiation (visible light) fuels El Niño events. This was discussed in More Detail On The Multiyear Aftereffects Of ENSO – Part 2 – La Nina Events Recharge The Heat Released By El Nino Events AND… …During Major Traditional ENSO Events, Warm Water Is Redistributed Via Ocean Currents.

CAN THE THIS TYPE OF EVALUATION BE EXTENDED BACK IN TIME?

I would not expect that what was presented in this post could be extended back in time. The Pacific climate shifted in 1976/77. In the abstract of Trenberth et al (2002), they write, “The 1976/1977 climate shift and the effects of two major volcanic eruptions in the past 2 decades are reflected in different evolution of ENSO events. At the surface, for 1979–1998 the warming in the central equatorial Pacific develops from the west and progresses eastward, while for 1950–1978 the anomalous warming begins along the coast of South America and spreads westward. The eastern Pacific south of the equator warms 4–8 months later for 1979–1998 but cools from 1950 to 1978.”

The way ENSO events interacted with the Kuroshio-Oyashsio Extension and the SPCZ Extension also appear different before and after 1979 in the correlation and regression analyses presented in that paper. Link to Trenberth et al (2002):

http://www.cgd.ucar.edu/cas/papers/2000JD000298.pdf

SOURCES

Most of the data used in this post are available through the KNMI Climate Explorer Monthly observations webpage. GISS LOTI is identified there in the second field under “Temperature” as “1880-now anomalies: GISS”, with the “1200km” radius smoothing. The Reynolds OI.v2 is listed under SST as “1982-now: 1° Reynolds OI v2 SST”. The coordinates used are identified in the text and/or on the graphs.

And if you want to attempt to duplicate my results but have never used the KNMI Climate Explorer, refer to the post Very Basic Introduction To The KNMI Climate Explorer for a place to start.

The dataset used to simulate the impacts of the volcanic eruptions is available through GISS:

http://data.giss.nasa.gov/modelforce/strataer/tau_line.txt

The Sunspot data is available through the KNMI Climate Explorer Monthly climate indices webpage. Refer to the Sunspots (1749-now, SIDC) field under the heading of “Sun”.

CLOSING REMARKS

This was a very basic attempt to approximate the effects of natural variables on global temperatures, using scaling and lags that were eye-balled. Sometimes basic things work well, and in this case, they appear to have done that. The similarities between the adjusted GISS LOTI datasets and the respective KOE and SPCZ Extension data were remarkable. While those similarities and the correlation maps do not prove the KOE and SPCZ Extension SST anomalies cause those addition rises in surface temperature, they imply that natural factors are causing the upward steps in global temperatures illustrated in Figure 4.

After some preliminary discussions, I divided the global (60S-60N) GISS LOTI data into two sections. The linear impacts of ENSO and volcanic eruptions were then removed from those subsets. The processes that cause the Sea Surface Temperatures in two parts of the Pacific to warm greatly during La Niña events were discussed. The unadjusted SST anomalies of the KOE and the SPCZ Extension were then compared to their respective adjusted GISS LOTI anomalies. The related curves were surprisingly similar. After removing the impacts of the KOE and the SPCZ Extension from the related GISS LOTI data, the linear trends dropped significantly. When the two GISS LOTI datasets were again combined, we had removed approximately 85% of what some consider to be the “anthropogenic global warming signal.”

This post differs from studies such as Thompson et al (2009). Thompson et al assumed that the ENSO proxy accounts for all of the processes within the Pacific that take place during ENSO events. In reality, NINO3.4 SST anomalies (or the CTI SST anomalies they used) can only account for the linear responses to the changes in equatorial Pacific SST anomalies. NINO3.4 SST anomalies cannot be assumed to account for the ENSO processes that take place within the Pacific or the aftereffects of those processes. What I presented in this post was a simple way to view those aftereffects within the Pacific and the global responses to them.

In short, I presented a story told by the GISS Land-Ocean Temperature Index and Reynolds OI.v2 SST data between the latitudes of 60S to 60N.

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All of that took a lot of work. I have considered performing such an analysis, but never did it. I worked it from the other direction. I worked the standard deviation of a 10,000 year period from the Vostok ice core. Since the data from Vostok is a data point every 20 years or so it is important to compare to 20 year averages.
Based on that the world is well within one standard deviation which would give the same result that the current warming is normal and CO2 emissions have not altered anything.
http://theinconvenientskeptic.com/2010/10/the-warmest-in-600000-years/

Alan S. Blue

Bob, I think you’ve established enough plausibility to move on to exploring purely empirical model discovery. “Empirical” meaning “I have no idea why, exactly, the apple falls, but I know enough to try to find a numerical model of what actually happens.”
You’ve weaseled parts of this information out by determining the scaling factors and various lags. But it seems as if you’ve got enough to actually sequester some data and actually calculate a predictive error.
Another (more frustrating) step would be to take all of the available parameters, permute them, and throw them into a multivariate regression. This can often highlight “Hey, you don’t want to ‘scale by 42’, you want to square it instead.” Or “use the derivative”. Or testing any sensible permutation.

Tim

I just broke the button on my mouse scrolling down through this article!
I read a little and then scrolled down to see how much was left — and i scrolled and scrolled and then, maybe metal/plastic fatigue my mouse died.
I reckon it will take probalbly 2 hours and a good brain to read and comprehend this article, so it’s unlikely to see many responses for a while. i just thought i’d bump things along with a silly comment.
This dang Climate change is even killing mice.
tim

john edmondson

Is it possible to make a prediction of what will happen in the next 5 to 10 years?

R. Gates

Bob said:
“Someone is bound to complain that I’ve deleted the Arctic data from the GISS LOTI data and that the Arctic is warming much faster than lower latitudes. Keep in mind that the Arctic is amplifying the effects of the rise in temperature at lower latitudes. This is the basis of the concept of polar amplification. If the vast majority of the change in temperature at the lower latitudes is natural, the same would hold true for the Arctic. Regardless, these latitudes were also chosen because the effects I want to illustrate with this post are relatively easy to display using them.”
____
Indeed, someone IS bound to complain, for your basic definition of polar amplfication of AGW is quite incorrect. It is not that the polar regions are amplifying the warming “going on” at lower latitudes, it is that any warming going on AT THE POLES is amplified through inherent positive feedback processes AT THE POLES, and specifically this is primarily the ice-albedo positive feedback process whereby more open water leads to more warming leads to more open water, etc.
I would direct readers to these links:
http://www.cgd.ucar.edu/oce/pubs/03pubs_files/Holland-ClimDyn.pdf
http://www.ossfoundation.us/projects/environment/global-warming/arctic-polar-amplification-effect
http://www.nature.com/nature/journal/v464/n7293/full/nature09051.html
With these extracts from them:
“Climate model simulations have shown that ice albedo
feedbacks associated with variations in snow and sea-ice
coverage are a key factor in positive feedback mechanisms
which amplify climate change at high northern
latitudes…”
“We conclude that diminishing sea ice has had a leading role in recent Arctic temperature amplification. The findings reinforce suggestions that strong positive ice–temperature feedbacks have emerged in the Arctic15, increasing the chances of further rapid warming and sea ice loss, and will probably affect polar ecosystems, ice-sheet mass balance and human activities in the Arctic…”
___
This is the heart of polar amplification and has very little to do with your stated defintion of amplifying the effects of warming going on at lower latitudes. The polar regions have their own set of dynamics that create the conditions for the inherent polar amplification of warming. To limit your analysis to part of the planet (60 degrees S to 60 degree N) and cast out the data from the latitudes where the majority of the earliest signs of AGW are occurring is, in my perception, more than a bit deceptive, and leaves your entire analysis quite hollow. As you yourself say:
“Regardless, these latitudes were also chosen because the effects I want to illustrate with this post are relatively easy to display using them.”
How convenient that the “effects you want to illustrate” are relatively easy using a select part of the planet…but do those effects have any relationship to what is actually happening to the whole planet? You might as well say, “let’s leave out the parts of the planet that GCM’s have long since modelled would see the first and most severe effects of AGW, and see if we can find any evidence of AGW.”
Bob, I certainly couldn’t hold a candle to you in terms of scientific knowledge or background, but I find your premises and logic baffling, as you knew, a priori exactly what point you wanted to make, and knew you could make it by throwing out the places on the planet where the first and most severe impacts of AGW have been projected to be seen, and are being seen, and then you mischaracterize the nature of polar amplification to try and further justify your point.
Other than that, your post was quite excellent….

R. Gates

john edmondson says:
January 10, 2011 at 11:38 am
Is it possible to make a prediction of what will happen in the next 5 to 10 years?
_____
10 years…yes. There will be year-to-year Arctic sea ice than there is today, and it is more likely than not that the decade of 2010-2019 will be warmer than any other decade on instrument record.

onion

After you remove ENSO and Volcanic forcing you ask:
“WHAT COINCIDES WITH THE UPWARD STEPS?”
The answer: SOLAR CYCLE!
Both the upward steps coincide with ascent into the next solar maximum. The flat periods coincide with descent into solar minimum.
What is left is a background warming trend. We have an explaination for that too – CO2.

R. de Haan

An incredible piece of work.
I wonder if we are going to see some clear steps down.
According to Joe Bastardi:
GREATEST OCTOBER-DECEMBER POSITIVE SOI ON RECORD.
The SOI value of around 20.4 for October-December looks to be the strongest positive ever for that three-month period, defeating the “La Freaka” of 1917 for the same period, though that was the strongest yearly value ever. This strong signal for cooling assures us that the Earth’s energy budget is such that continued cooling of the global temp to beyond the reaction to the previous ninos, such as 1997-98 and 2006-07 is highly likely and the coldest monthly and yearly global temp since the 1990s are indeed possible in 2011 and/or 2012. I may need to adjust down a bit my forecast for normal for next year.
Ciao for now.

R. Gates.
If Bob used a different dataset instead of GISS that didnt have the problem he worried about ( deletion of some SST) would that be better? Honest question

eadler

I admit that I haven’t followed the details of Tisdale’s above post. From what I have read of it, it seems to be take most of the observed sea surface temperature variations out of the global surface temperature variations between 60S and 60N, and then come to the conclusion that there has been no global warming of the surface. Since the sea surface represents most of the surface of the globe, my reaction is “duh!”.
In fact if one looks at the heat balance of the oceans down to 2000M, which cannot be driven to first order by surface related ocean cycles, we come to the conclusion that the earth is warming due to radiative imbalance. This is estimated at about 0.8W/M^2.
http://climateprogress.org/2009/10/10/skeptical-science-global-warming-not-cooling-is-still-happening-ocean-heat-content/

Brent Hargreaves

Well said, John Edmondson!
Einstein predicted precisely how much the sun’s gravity would deflect starlight, and at the 1919 eclipse was proved to be smack on. Both our friend Bob Tisdale, and also the Global Warming Brigade, need to make predictions so that their ideas can be falsified if wrong. Give it a go, Bob! If you’re right you’ll have made your mark; if wrong we’ll celebrate your integrity. The prophets of the AGW religion are always careful not to commit to specific predictions (even end-of-days religious nutters give us a date – and give us a laugh – every decade or so). So come on, Bob, give us max and min for 2013. We’ll carry you on our shoulders if you’re right!

holbrook

Understood GISS to be not that reliable especially in the hands of Hansen…..so why use it.
Hopefully the scientists on here will be able to evaluate and explain….however I did note that the author expects the next decade to be even warmer…..is there a solar physicist in the house to explain the facts of life???
Or should HM Government cancel the new snow ploughs!

Levi

Bob, great post, and I really appreciate the work you put into this. It was very enlightening.nI do, however, have a couple of things to point out that stuck out to me when you said them.
“The Sea Surface Temperatures of the East Indian and West Pacific Oceans remain elevated during the La Nina because the stronger trade winds reduce cloud cover.”
This seems wrong. The stronger trade winds during La Nina do not extend past 130E on average, and are met over the western Pacific by stronger than normal westerlies coming from the east Indian Ocean, causing strong convergence and above-normal rainfall in the western Pacific and around the Maritime Continent. The weaker than normal trades in the eastern Indian Ocean help keep SSTs warm there. This is confirmed by viewing the correlation between surface zonal wind and Nino 3.4 SST data. One can see that during La Nina events (in which case you mentally reverse the anomalies shown in the image), there is net convergence over the western Pacific which results in increased cloud cover and precipitation.
A second statement that you made, similar to the first, also stuck out:
“The tropical North Atlantic warms during the El Niño because the El Niño causes a weakening of the North Atlantic trade winds.”
Again, this seems wrong. The increased upward motion in the eastern Pacific during El Ninos draws stronger than normal easterlies across the tropical north Atlantic. This can again be confirmed by a correlation between Nino 3.4 and surface zonal wind, which shows a tendency for stronger trade winds in the deep tropics during El Nino episodes. I can see how the anomalous westerlies and high surface pressure could contribute to warmer SSTs north of 20N in the Atlantic during El nino episodes, but to say it weakens the trade winds in the tropical belt is incorrect, most especially during the summer months when the Azores-Bermuda High is farther north.
All that said, this was a great post.

eadler

R Gates says,
“Bob, I certainly couldn’t hold a candle to you in terms of scientific knowledge or background, but I find your premises and logic baffling, as you knew, a priori exactly what point you wanted to make, and knew you could make it by throwing out the places on the planet where the first and most severe impacts of AGW have been projected to be seen, and are being seen, and then you mischaracterize the nature of polar amplification to try and further justify your point.”
[snip]
REPLY: Mr, Adler, I grow quite weary of your judgements/pronouncements as to the character of people that post here. You contribute nothing but complaints yet at the same time offer nothing of your own qualifications, nor any of your own writings or analysis. Put up or shut up. – Anthony Watts

JoeH

Bob – that’s a lot of excellent work and I’ll have to read it a couple of times more before I’m sure I’ve got a good grip on it. You’ve also made me wonder if I’m becoming too sensitive to word parsing because; the more I read of the article the more my mind keeps going back to the title you’ve given it and wondering “Why has Bob included the words ‘most of ‘ in the title?”
The title as it stands seems to imply that (at least some) *Anthropogenic* warming must be assumed by the reader – yet the article well shows that the sheer chaotic mass of natural forces, acting on the climate, supply an overabundance of probable cause.

Dave Andrews

R Gates,
Hang on, this polar amplification that involves melting ice doesn’t seem to be happening in Antarctica so perhaps your concentration on the Arctic is a tad one sided.

1DandyTroll

‘Can Most Of The Rise In The Satellite-Era Surface Temperatures Be Explained Without Anthropogenic Greenhouse Gases?’
Yes.
And if the climate fanatic doom monger hippies don’t understand that they’ve obviously not read their own material, what with the anthropogenic signal only constitute, according to themselves, some 20% of the .8 rise in temperature, and since 20% is less ‘an 50% or, in this case, the opposing some 80% then yes the supposed rise in temperature can be explained without the anthropogenic cause.

LDLAS

Mr. Gates
“The warmest year in the extended Greenland temperature record is 1941, while the 1930s and 1940s are the warmest decades.” (from: Extending Greenland temperature records into the late eighteenth century, B. M. Vinther,1 K. K. Andersen,1 P. D. Jones,2 K. R. Briffa,2 and J. Cappelen3; JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, D11105, doi:10.1029/2005JD006810, 2006)
Greenland:
http://www.dmi.dk/dmi/index/klima/klimaet_indtil_nu/temperaturen_i_groenland.htm
Iceland:
http://en.vedur.is/climatology/clim/nr/1213
Svalbard:
http://met.no/?module=Articles;action=Article.publicShow;ID=882
Karasjok (Norway)
http://met.no/?module=Articles;action=Article.publicShow;ID=881
Uppsala:
http://www.smhi.se/klimatdata/meteorologi/temperatur/1.2855
Finland:
http://en.ilmatieteenlaitos.fi/normal-period-1971-2000
Alaska:
http://climate.gi.alaska.edu/history/History.html
And I recommend section 162: “warming of te Arctic” from:
http://www.archive.org/stream/arcticice00zubo#page/470/mode/2up
And as far as the Antarctic is concerned:
There hasn’t been no significant warming since 1955 (the 7 station series from New Zealand show the same and for what it’s worth I don’t trust the BOM temperature-series)
B.T.W. Mr. Tisdale, good job

Leone

Thanks for this excellent work! I think this is quite close to what factors have mainly affected to temperatures. But maybe there additionally is solar factor behind ENSO…

R. Gates

Steven Mosher says:
January 10, 2011 at 12:23 pm
R. Gates.
If Bob used a different dataset instead of GISS that didnt have the problem he worried about ( deletion of some SST) would that be better? Honest question
______
So long as the dataset can be shown to more accurately represent the areas and time frames in question. But I think it would be first of all more honest to use the true definition (with all the implied causes) of polar amplification. To link polar temperature amplification in a simple linear connection to temperatures in lower latitudes is to miss and exlude a key dynamic of those regions. To simply exclude the polar regions, especially the N. Pole, where every honest student of the subject knows that the earliest and most severe signs of global warming have long been forecast to be seen, is not honest. Yes, the data set for the polar regions is far more sparse and subject to educated extrapolations that other regions, but excluding any estimate at all for temperature changes in these all important polar regions by excluding them is to to give an incomplete and, IMO, quite inaccurate, view of climate change.

stevenmosher

john edmondson says:
January 10, 2011 at 11:38 am
Is it possible to make a prediction of what will happen in the next 5 to 10 years?
######
sure it’s possible to make a prediction. That’s not what you want to ask.

R. Gates

Dave Andrews says:
January 10, 2011 at 1:05 pm
R Gates,
Hang on, this polar amplification that involves melting ice doesn’t seem to be happening in Antarctica so perhaps your concentration on the Arctic is a tad one sided.
_____
Dave, with all due respect, you are quite out of your element here. This simple, and rather feeble attempt to try and equate the dynamics of what is happening in the Arctic with the Antarctic tells me that either you haven’t studied the subject quite enough or you’re just trying to be difficult. Look at any GCM projection for the polar regions– why do you think they show the N. Pole warming faster than the S. Pole? Find out the answer to this, and then let’s talk…with all due respect, you need to do some more research…

R. Gates says: “Indeed, someone IS bound to complain, for your basic definition of polar amplfication of AGW is quite incorrect.”
The RealClimate post on Polar Amplification…
http://www.realclimate.org/index.php/archives/2006/01/polar-amplification/
…begins with the statement, “’Polar amplification’ usually refers to greater climate change near the pole compared to the rest of the hemisphere or globe in response to a change in global climate forcing, such as the concentration of greenhouse gases (GHGs) or solar output (see e.g. Moritz et al 2002).”
And my point was, I’ve shown that much of the warming “to the rest of the hemisphere or globe” is not attributable to greenhouse gases or “solar output”. And if the warming over the rest of the world is not attributable to greenhouse gases or “solar output”, then “the greater climate change near the pole compared to the rest of the hemisphere or globe” is not attributable to them.
The RealClimate post continues, “Polar amplification is thought to result primarily from positive feedbacks from the retreat of ice and snow.” And that agrees with all of the links you’ve provided, I believe. And again, since the majority of the warming as described in this post is a function of natural variability, then the positive feedbacks are natural as well.

Robuk

onion says:
January 10, 2011 at 12:01 pm
After you remove ENSO and Volcanic forcing you ask:
“WHAT COINCIDES WITH THE UPWARD STEPS?”
The answer: SOLAR CYCLE!
What is left is a background warming trend. We have an explaination for that too – CO2.
Try UHI,
http://scialert.net/fulltext/?doi=rjes.2011.1.21&org=10
http://www.metlink.org/pdf/articles/past_and_projected_trends_wilby.pdf
Since the 1960`s, the intensity of nocturnal UHI in the spring and summer has increased by approximately +0.12 degC/dec, this has been contributed to more rapid night time warming in the city that in the outlying rural areas.
Where are the weather stations situated.

FrankK

This post requires a lot of time to digest.! But in the concluding remark Bob you say: “When the two GISS LOTI datasets were again combined, we had removed approximately 85% of what some consider to be the “anthropogenic global warming signal.” So Bob, without going thru the whole of your article are you saying that at least 15% is due to AGW? or……………….

onion says: “The answer: SOLAR CYCLE!”
Most studies about the impact of solar variations on global temperatures include multiyear to multidecadal time lags. That is, depending on the study, if memory serves me well, the lag times between solar variation and response in global temperature is said to range between 5-7 years on the low end to a couple of decades on the high end due to the thermal inertia of the oceans. Don’t you recall the debate over this a couple of years ago?
So your added comment, “Both the upward steps coincide with ascent into the next solar maximum. The flat periods coincide with descent into solar minimum,” fails to account for lag times. It also fails to account for the agreement between the inverted NINO3.4 data and the GISS LOTI data that’s been adjusted for ENSO and volcanoes. Refer again to Figure 5. Here’s a link:
http://i54.tinypic.com/2i8b02b.jpg

john edmondson says: “Is it possible to make a prediction of what will happen in the next 5 to 10 years?”
This was not intended as a prediction tool. What I’ve presented is an attempt to explain why temperatures have risen. It also was intended to show that NINO3.4 SST anomalies do not capture the process of ENSO.

Paul Vaughan

Elaboration on this:
See Figure 3 & Table 3 (true gems) here:
Trenberth, K.E.; Stepaniak, D.P.; & Smith, L. (2005). Interannual variability of patterns of atmospheric mass distribution. Journal of Climate 18, 2812-2825.
http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/massEteleconnJC.pdf
Note the wave patterns and also note that they have been isolated using a varimax rotation, which dramatically simplifies interpretation by “sorting” naturally contrasting modes. Seemingly complex (if viewed linearly) aspects of nature are tied together in a simple nonlinear whole.
Interesting work Bob.

Steven Mosher says: “If Bob used a different dataset instead of GISS that didnt have the problem he worried about ( deletion of some SST) would that be better? Honest question”
There were a couple of reasons I elected GISS LOTI. One was the Reynolds OI.v2 data. The satellite data provides better coverage, and there is less infilling.
Also, I had planned a post on RSS TLT next.

FrankK says: “So Bob, without going thru the whole of your article are you saying that at least 15% is due to AGW? or……………….”
I have no idea what the “or” could turn out to be. I’ve shown that natural variables could account for 85% of the warming since 1982. Does it? Dunno. It might be more; it might be less. But this interpretation of the data illustrates that AGW might not be as strong a signal as many propose.

Jeff T

Bob, it seems that you have 1) found hot spots with about the right time signature (KOE and SPCZ) to do what you want, 2) multiplied their temperatures by arbitrary factors, and 3) subtracted them from the GISS temperature data. That process really doesn’t prove very much. At the same time as KOE and SPCZ are warm, the equatorial Pacific is cold. If you multiply the equatorial temperature by a suitable factor and subtract it from the brown curve in Figure 28, you’ll get something very much like the blue curve in Figure 4.

John

Bob, Anthony, I come to WUWT because they have published articles and analyses which the MSM wouldn’t touch, and which often have been scientifically accurate. WUWT, along with Climate Audit, showed the lack of clothes on the Emperor.
But if you believe that greenhouse gases (not just CO2, but also methane, tropospheric ozone, black carbon) aren’t responsible for some of the warming, I’m not with you.
The debate is about whether the increase in warming is small, medium or (unlikely in my mind) large, and then whether we should be further bankrupting already bankrupt societies to only slightly affect that rate of warming, whatever it is.
If we want to win the debate for the minds of people who aren’t hard set in their views, we don’t get there by denying what is, frankly, obvious on first principles: GHGs warm the atmosphere.
We get there by showing (1) the IPCC and their ilk have been BSing us, and now climategate shows that; (2) the models don’t know how to deal with important feedbacks such as clouds, and IPCC authors also acknowledge this, so that their vaunted models are untrustworthy (and overpredict current warming by quite a bit); and (3) the little the US could do, at very high cost today, will have almost no affect on future temperature changes, so why spend the money?

R. Gates

Bob Tisdale says:
January 10, 2011 at 1:40 pm
R. Gates says: “Indeed, someone IS bound to complain, for your basic definition of polar amplfication of AGW is quite incorrect.”
The RealClimate post on Polar Amplification…
http://www.realclimate.org/index.php/archives/2006/01/polar-amplification/
…begins with the statement, “’Polar amplification’ usually refers to greater climate change near the pole compared to the rest of the hemisphere or globe in response to a change in global climate forcing, such as the concentration of greenhouse gases (GHGs) or solar output (see e.g. Moritz et al 2002).”
And my point was, I’ve shown that much of the warming “to the rest of the hemisphere or globe” is not attributable to greenhouse gases or “solar output”. And if the warming over the rest of the world is not attributable to greenhouse gases or “solar output”, then “the greater climate change near the pole compared to the rest of the hemisphere or globe” is not attributable to them.
The RealClimate post continues, “Polar amplification is thought to result primarily from positive feedbacks from the retreat of ice and snow.” And that agrees with all of the links you’ve provided, I believe. And again, since the majority of the warming as described in this post is a function of natural variability, then the positive feedbacks are natural as well.
_____
Bob, with all respect, in your original post you stated:
“Keep in mind that the Arctic is amplifying the effects of the rise in temperature at lower latitudes.”
This would imply some kind of causal linkage to the temperatures at lower latitudes with those at the pole in the process of polar amplification. This is definitely NOT what is implied by the causal definition of polar amplification.
To leave out the polar regions, and specifically the northern hemisphere, which, both by observation and by measurement has seen a larger percentage warming than the mid-latitudes is to slice the greatest area of dynamic change related to global warming right out of the equation. No one is happy with the sparse data, but other confirmatory proof, such as the melting of permafrost and the reduction in sea ice, show that the extrapolation of arctic temperatures to show increases must be close t the mark.
The Arctic is the front-line of AGW, and to attempt to remove the front-line (and the wealth of data and real world effects found there) is to attempt to redefine the battle in terms that are both illogical and in my opinion…not founded on science.

Jim Steele

Polar amplification due to CO2 is based on warming melting ice that lowers albedo and thus raises temperatures. However there are several contradictory pieces of evidence. First most of the observed temperature increases is reported during the winter when there is little solar input to be amplified.
Second several papers by Rigor and others show that the loss of ice is due to changing wind patterns have caused greater ice export. This raises temperatures in 2 ways. As sea surface refreezes latent heat is released. The more the wind exports ice the more refreezing the more latent heat. Also less ice cover allows the vastly warmer sea water to warm the much colder arctic air.
One could argue that the ocean is warming due to loss of sea ice that allows the ocean to absorb more heat during the summer which carries over into the winter. I would argue that the higher temperatures more likely represent greater venting of heat from the ocean, thus represent a cooling. If the Arctic ocean is indeed warming we would expect the sea level to rise. If cooling we would expect sea levels to fall. Almost every sea level gauge in the Arctic show dramatic drops in sea level such as http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=025-001 on Svalsbard. Oddly when sea level is calculated those declining trends Arctic ocean sea levels are typically ignored because some argue it is due to glacial rebound. Yet satellite data observes a 2mm /year drop in sea level supporting the contention that observed “warm temperatures” are due to the Arctic cooling and venting through the more open water.
Finally most warming in Alaska has been shown to have increased when the PDO switched pushing warm air over most of Alaska. Lots of warming without the help of CO2.

Levi: Sorry for the wording of my statement, “The Sea Surface Temperatures of the East Indian and West Pacific Oceans remain elevated during the La Nina because the stronger trade winds reduce cloud cover.” I was speaking of trade winds in the Pacific, east of the PWP. It would best also if I had not included the East Indian Ocean in that explanation. It’s simply a (bad) habit I’ve grown into since I first posted (about two years ago) about the SST anomalies for 60S-65N, 80E-180 (the East Indian and West Pacific Oceans) rising in steps during those ENSO transitions.

Manfred

Very interesting report. I would recommend to include a summary of the results at the beginning of the article as well (such as 85% of GISS warming can be explained without GHG, .. or adjustment biases) .
As a side note:
Polar feedbacks appear to be poorly understood as about anything else in climate “science”.
Just recently a “scientist” at the German hyper alarmist PIK “found out” that the (temporary) loss of sea ice in the arctic leads to increased ocean heat loss to the atmosphere resulting in more snow elsewhere. This would clearly be a negative feedback mechanism.

john edmondson

Bob Tisdale says:
January 10, 2011 at 1:57 pm
john edmondson says: “Is it possible to make a prediction of what will happen in the next 5 to 10 years?”
This was not intended as a prediction tool. What I’ve presented is an attempt to explain why temperatures have risen. It also was intended to show that NINO3.4 SST anomalies do not capture the process of ENSO.
Thanks Bob.
I like the idea of explaining variations in temperature due to natural forces. The difficulty being the large number of interconnected variables.
Your post is top class in this respect.
My thoughts are that the largest influence on climate is the sun. The magnetic field of the sun drives the formation of clouds, via GCRs.
However, opinions are worth nothing. What counts is evidence.

Hi Bob, continuing in the debate from your blog:
“I hate to answer a question with a question, but Has there been a climate shift?”
I think so. North Pacific peaked in 2005, North Atlantic peaked in 2006 (even there was recent peak). Actually, the whole NH SST peaked.
http://i54.tinypic.com/2mwrngw.jpg
http://i52.tinypic.com/2vs1bpv.jpg
http://i51.tinypic.com/20u78l4.jpg

Roger Andrews

No one seems to be grasping the full significance of Bob Tisdale’s results, so let me as briefly as I can try to put them into perspective.
According to conventional AGW wisdom the surface warming over the last thirty or forty years can be explained only by assuming a large GHG contribution. It can’t be explained by ocean oscillations such as La Niñas and El Niños because these are cyclic events that have only short-term impacts on global temperatures. They don’t generate any long-term warming trends.
What Bob is saying is that these oscillations do in fact cause long-term warming trends. He presents a mechanism showing how from time to time they cause warm water to rise to the ocean surface – and stay there. It doesn’t go away, it just reappears in different places as we switch from El Niños to La Niñas. As a result we get step-function increases in global temperatures. If this supposition is correct then the recent warming can be almost entirely explained by changes in ocean circulation patterns. We don’t need to assume any contribution at all from GHGs (unless of course, GHGs are what trigger the ocean circulation changes, which doesn’t seem likely).
Is the supposition correct? I don’t know. However, Bob presents some good evidence in favor of it. And if it is correct then AGW is no longer an issue.

adrian smits

It would appear that your reply to mr Gates makes a lot of sense Bob but if the warming signal over the last 30 or 40 years is as week as it looks doesn’t that portend an extraordinary cooling over the next 20 or 30 years with the pdo amo going into a unified cooling phase?

Paul Deacon

R. Gates says:
January 10, 2011 at 11:51 am
QUOTE
Indeed, someone IS bound to complain, for your basic definition of polar amplfication of AGW is quite incorrect. It is not that the polar regions are amplifying the warming “going on” at lower latitudes, it is that any warming going on AT THE POLES is amplified through inherent positive feedback processes AT THE POLES, and specifically this is primarily the ice-albedo positive feedback process whereby more open water leads to more warming leads to more open water, etc.
***
“Climate model simulations have shown that ice albedo
feedbacks associated with variations in snow and sea-ice
coverage are a key factor in positive feedback mechanisms
which amplify climate change at high northern
latitudes…”
“We conclude that diminishing sea ice has had a leading role in recent Arctic temperature amplification. The findings reinforce suggestions that strong positive ice–temperature feedbacks have emerged in the Arctic15, increasing the chances of further rapid warming and sea ice loss, and will probably affect polar ecosystems, ice-sheet mass balance and human activities in the Arctic…”
***
This is the heart of polar amplification and has very little to do with your stated defintion of amplifying the effects of warming going on at lower latitudes. The polar regions have their own set of dynamics that create the conditions for the inherent polar amplification of warming.
***
UNQUOTE
R Gates – as you refer to “the polar regions”, why are all your other comments confined exclusively to the Arctic? It is not clear to me why the Arctic region has become the poster child for the Warmists, other than that nobody lives there, it has few weather stations, and polar bears look cute in photos. If in practice a warmer (less cold) Arctic coincides with cooling in the world’s main population centres (NE USA, NW Europe, N India, N China), as appears to have happened in the early part of the current NH winter, it is not clear to me why a warming Arctic should be cause for AGW alarm (although it could perhaps in a crude/tabloid sense be used as cause for Global Cooling alarm).
And at a general level, I don’t see anything inherently wrong with Bob Tisdale isolating parts of datasets in order to ask questions. It’s the sort of thing climate scientists do all the time, isn’t it?
All the best.

R. Gates

Response to:
John says:
January 10, 2011 at 2:24 pm
____
Excellent post.

TomRude

R. Gates writes: “The Arctic is the front-line of AGW…”
One wonders where those 1065hPa anticyclones are coming from…

R Gates says, “…I find your premises and logic baffling, as you knew, a priori exactly what point you wanted to make, and knew you could make it by throwing out the places on the planet where the first and most severe impacts of AGW have been projected to be seen, and are being seen, and then you mischaracterize the nature of polar amplification to try and further justify your point.”
First, your complaint assumes that AGW is responsible for most of the warming. Big assumption.
Second, I’ve written posts or included graphs in blog comments for almost two years about these upward steps in SST for the East Indian-West Pacific Oceans, RSS TLT north of 20N, GISS LOTI (20N-65N), CRUTEM (20N-65N), etc. Of course I knew beforehand what the general outcome would be. I didn’t realize, though, how well the agreement would be between the adjusted GISS LOTI data and the scaled KOE and SPCZ Extension data.

Manfred says: “Just recently a “scientist” at the German hyper alarmist PIK “found out” that the (temporary) loss of sea ice in the arctic leads to increased ocean heat loss to the atmosphere resulting in more snow elsewhere. This would clearly be a negative feedback mechanism.”
Do you have a link to the study?

phlogiston

R. Gates says:
January 10, 2011 at 1:28 pm
Dave Andrews says:
January 10, 2011 at 1:05 pm
R Gates,
Hang on, this polar amplification that involves melting ice doesn’t seem to be happening in Antarctica so perhaps your concentration on the Arctic is a tad one sided.
_____
Dave, with all due respect, you are quite out of your element here.

Find out the answer to this, and then let’s talk…with all due respect, you need to do some more research…

In other words, “go away you pig ignorant pleb and do some serious research on marginal visibility as a culturally contextual fashion forward social statement and you will have your ‘aha’ moment and see that the Emperor is, and always has been, splendidly clothed.”

Robuk
DR

RGates said:

The Arctic is the front-line of AGW, and to attempt to remove the front-line (and the wealth of data and real world effects found there) is to attempt to redefine the battle in terms that are both illogical and in my opinion…not founded on science.

Dr. James Hansen said:
http://www.columbia.edu/~jeh1/2005/Imbalance_20050415.pdf
“This energy imbalance is the ‘smoking gun’ that we have been looking for”, referring ocean heat content.
and
Amplification of Surface Temperature Trends and Variability in the Tropical Atmosphere

Tropospheric warming is a robust feature of climate model simulations driven by historical increases in greenhouse gases (1–3). Maximum warming is predicted to occur in the middle and upper tropical troposphere.

Now it is known both of those tenets do not match reality, or are at least greatly exaggerated.
Since when is the Arctic the “front line” of AGW? Those who’ve followed the AGW storyline for the last two decades know that has not been the case until recently, namely 2007 and when all other AGW predictions have failed.
Could we please get a clear definition of just what AGW is and what the real fingerprints are?At some point there must be a way to falsify it. Are we now to believe the Arctic is is the location of the missing heat? Now we are told warming causes cooling; it’s become somewhat of a joke IMO.
There is no direct evidence to suggest the Arctic warming is due to GHG, CO2 or otherwise. There are several natural components (PDO, NAO, AO, AMO etc.) that comprise Arctic warming/cooling processes, and we don’t understand very much of them.

John said:
Bob, Anthony, I come to WUWT because they have published articles and analyses which the MSM wouldn’t touch, and which often have been scientifically accurate. WUWT, along with Climate Audit, showed the lack of clothes on the Emperor.
But if you believe that greenhouse gases (not just CO2, but also methane, tropospheric ozone, black carbon) aren’t responsible for some of the warming, I’m not with you.

If I may be so bold, Bob intent is not to show that CO2 and other GHG’s could not possibly be responsible for the warming. He’s showing is that the warming can be explained with out them, something the established (old school) climate scientists do not wish to acknowledge.