In a study in the Journal of Geophysical Research a paper, Influence of the Southern Oscillation on tropospheric temperature, researchers Chris de Freitas, John McLean, and Bob Carter find that the El Niño-Southern Oscillation (ENSO) is a key indicator of global atmospheric temperatures seven months later. By their analysis they have shown that natural forces related to ocean heat cycles are the dominant influence on climate. See the WUWT post on it here and the original paper here.
This guest post by Bob Tisdale is a response of interest to both critics and supporters of the paper and illustrates how the multiyear processes of an El Nino event such as occurred in 1998 are missed. – Anthony
Regression Analyses Do Not Capture The Multiyear Aftereffects Of Significant El Nino Events
Guest post by Bob Tisdale
INTRODUCTION
This post illustrates why regression analyses do not capture the multiyear aftereffects of significant El Nino events. To emphasize this, I’ve provided a detailed explanation of the processes that take place before, during, and after those significant El Nino events, using graphics and videos from earlier posts.
EXAMPLE OF RESULTS FROM A REGRESSION ANALYSIS
Regression analyses are used by climatologists to determine and illustrate the impact on global temperature of one or more variables, such as ENSO, Solar Irradiance, and Volcanic Aerosols. Figure 1 shows the results of one such study. It is a multi-cell illustration of “Surface Temperature Variability Components” from Lean and Rind (2008) “How Natural and Anthropogenic Influences Alter Global and Regional Surface Temperatures: 1889 to 2006” [GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L18701, doi:10.1029/2008GL034864, 2008].
Link to Paper:
http://pubs.giss.nasa.gov/docs/2008/2008_Lean_Rind.pdf
http://i32.tinypic.com/2lmw477.png
Figure 1
My Figure 1 is Figure 2 from Lean and Rind (2008). Under the heading of “Datasets”, Lean and Rind write, “Monthly fluctuations in ENSO, volcanic aerosols, solar irradiance and anthropogenic influences are shown in Figure 2. The multivariate ENSO index, a weighted average of the main ENSO features contained in sea-level pressure, surface wind, surface sea and air temperature, and cloudiness [Wolter and Timlin, 1998], extends from 1950 to 2006. It is augmented with an index derived from Japan Meteorologial Agency sea surface temperatures from 1868 [Meyers et al., 1999]. Volcanic aerosols in the stratosphere are compiled by [Sato et al., 1993] since 1850, updated from giss.nasa.gov to 1999 and extended to the present with zero values. The adopted solar forcing, consistent with IPCC [2007], is less than half that reported in prior IPCC assessments. Monthly irradiances since 1882 are estimate d from competing effects of sunspots and faculae in observations made by space-based radiometers, extended into the past using solar flux transport simulations [Wang et al., 2005]. The anthropogenic forcing is the net effect of eight different components, including greenhouse gases, landuse and snow albedo changes, and (admittedly uncertain) tropospheric aerosols [Hansen et al., 2007] (inset, Figure 2d).”
Lean and Rind then go on to detail the analyses they performed. Under the heading of “Amplitudes and Patterns of Natural and Anthropogenic Influences,” they state, “Natural changes cannot account for the significant long-term warming in the historical global surface temperature anomalies. Linear trends in temperature attributed to ENSO, volcanic aerosols and solar irradiance over the past 118 years (depicted by the lines in Figure 2) are, respectively, 0.002, -0.001 and 0.007 K per decade. Only by associating the surface warming with anthropogenic forcing is it possible to reconstruct the observed temperature anomalies.”
Basically, using a short-term comparison of NINO3.4 SST anomalies and Global RSS MSU TLT anomalies, my Figure 2, regression analyses like those used by Lean and Rind argue that natural variables cannot explain the upward divergence of global temperature from NINO3.4 SST anomalies. And if natural variables cannot explain the additional rise in global temperature, then the anthropogenic global warming hypothesis dictates that anthropogenic forcings must cause the rest. BUT…
http://i32.tinypic.com/2rw9pbq.png
Figure 2
REGRESSION ANALYSES TREAT ENSO AS A “FORCING”, NOT AS A PROCESS WITH MULTIYEAR AFTEREFFECTS
Regression analyses regard El Nino events as a climate forcing of varying frequency and magnitude, the same way they consider other natural forcings such as volcanic aerosols and solar irradiance. They do not consider the multiyear processes that can occur after those El Nino events. Before presenting these, I’ll first provide a detailed description of the processes that take place before, during, and after significant El Nino events.
EL NINO OVERVIEW
For those new to the process of El Nino events, Bill Kessler and David B. Enfield, both of NOAA, provide excellent descriptions of ENSO in their ENSO Q&A web pages. Link to Bill Kessler’s:
http://faculty.washington.edu/kessler/occasionally-asked-questions.html
Link to David B. Enfield’s:
http://www.aoml.noaa.gov/general/enso_faq/
I’ll expand on their descriptions.
During non-El Nino years (La Nina and ENSO-neutral years), warm water accumulates in an area of the western tropical Pacific known as the Pacific Warm Pool (PWP); also known as the Indo-Pacific Warm Pool (IPWP). Refer to Figure 3.
http://i30.tinypic.com/b3tpah.gif
Figure 3 (Source CRCES. Link to follow.)
Some of the warm water in the Pacific Warm Pool is water that returns there after El Nino events (the Equatorial Countercurrent in the Pacific relaxes after an El Nino and the North and South Equatorial Currents move the warm water back from the eastern to the western equatorial Pacific). More on that later. Some of the warm water in the Pacific Warm Pool results from solar radiation that warms the tropical Pacific and from the trade winds that push those warm surface waters from east to west in the Pacific during La Nina events and during ENSO-neutral periods. And some of the buildup of warm water in the Pacific Warm Pool occurs during the El Nino event itself, when cloud amounts over the Pacific Warm Pool drop significantly, causing a major rise in downwelling shortwave radiation (visible light). During the 1997/98 El Nino, it has been estimated that downwelling shortwave radiation rose as much as 25 watts/sq meter over the PWP. Refer to Figure 4. (This change in downwelling shortwave radiation was discussed in my post Recharging The Pacific Warm Pool Part 2.)
http://i41.tinypic.com/2435kbb.jpg
Figure 4
Figure 4 is from the Pavlakis et al (2008) paper “ENSO Surface Shortwave Radiation Forcing over the Tropical Pacific”:
http://www.atmos-chem-phys-discuss.net/8/6697/2008/acpd-8-6697-2008-print.pdf
The accumulation of warm water in the Pacific Warm Pool over months and years from trade winds pushing surface waters west, the periodic transport of the warm water out of the PWP by El Nino events, the blast of downwelling shortwave radiation during El Nino events, and the replenishment of the warm water during the subsequent La Nina all cause the size and temperature of the Pacific Warm Pool to vary.
Figure 5 illustrates the variations in area and temperature of the Pacific Warm Pool. The illustration is from the CRCES webpage “Natural decadal-multidecadal variability of the Indo-Pacific Warm Pool and its impacts on global climate” by Mehta and Mehta:
http://www.crces.org/presentations/dmv_ipwp/
http://i28.tinypic.com/6e3skg.png
Figure 5
CRCES also provides a Quicktime movie (2.7MB) of the annual variations in Indo-Pacific Warm Pool area and SST anomalies here:
http://www.crces.org/presentations/dmv_ipwp/images/SST_WP.MOV
The variability of the Pacific Warm Pool can also be seen in the Western Equatorial Pacific Warm Water Volume, Figure 6, which is from my post Equatorial Pacific Warm Water Volume.
http://i34.tinypic.com/xfyro1.jpg
Figure 6
Note how, during the 1997/98 El Nino, the Western Equatorial Pacific Warm Water Volume (light blue curve) drops as NINO3.4 SST anomalies (black curve) rise. This is one indication that the warm water is being carried away from the Pacific Warm Pool during the El Nino event. Also note how quickly the Western Equatorial Pacific Warm Water Volume replenishes itself. It has “recharged” by the second phase of the 1998/99/00 La Nina.
The direction shifts in the Pacific Equatorial Currents that are part of an El Nino show how the warm water volume of the Pacific Warm Pool is lowered during those events. The Equatorial Countercurrent increases in size and carries the warm water from the Pacific Warm Pool to the east. When the El Nino ends, the Equatorial Countercurrent ebbs, and the North and South Equatorial Currents carry the warm water back to the west, to the Pacific Warm Pool. These shifts can be seen in Video 1 “Equatorial Currents Before, During, and After The 1997/98 El Nino” from my post of the same name:
http://bobtisdale.blogspot.com/2009/02/equatorial-currents-before-during-and.html
Video 1
And there are subsurface changes that take place during an El Nino event. The warm water that was in the Pacific Warm Pool, most of it below the surface, shifts east during the El Nino, where it rises to the surface. These changes in the subsurface waters of the Pacific can be seen in my Video 2 “Cross-Sectional Views of Three Significant El Nino Events – Part 1”. Link to post:
http://bobtisdale.blogspot.com/2009/02/cross-sectional-views-of-three.html
Video 2
Though not discussed in Video 2, the rise of the thermocline at the end of the 1997/98 El Nino is visible. “Rewind” to minute 3:00 and start the video. After the commentary, the thermocline rises, further illustrating that warm water that was once below the surface of the Pacific Ocean has been brought to the surface by the El Nino.
Some BUT NOT ALL of the warm water that had sloshed east during the El Nino returns to the Pacific Warm Pool during the subsequent La Nina. And the warm water that doesn’t return to the Pacific Warm Pool is carried westward by the Equatorial Currents of the Pacific, Figure 7, to the surface of the Western Pacific and the Eastern Indian Oceans.
http://i30.tinypic.com/wvzu6r.png
Figure 7
There, the warm water raises the surface temperature of the Western Pacific and the Eastern Indian Oceans, Figure 8.
http://i29.tinypic.com/2a75q2t.png
Figure 8
The transport of this warm water and its aftereffects can be seen in Video 3 “Recharging The Pacific Warm Pool”. Link to post:
http://bobtisdale.blogspot.com/2008/11/recharging-pacific-warm-pool.html
Video 3
In other words, warm water that was below the surface of the Pacific Warm Pool (and not included in the calculation of global temperature anomaly) is redistributed around the surface of the nearby oceans by the El Nino, (and it is now included in the calculation of global temperature). Phrased yet another way, before that El Nino, the warm water was not included in surface temperature record but afterward the warm water was included in surface temperature record. This raises global temperature anomalies without any heat input. Keep in mind that the rearranging of waters during an El Nino does not in and of itself create heat; it only shifts warm water from below the surface of the Pacific Ocean to the surface where it impacts temperature measurements.
THIS CAN BE SEEN AS UPWARD STEP CHANGES IN THE SEA SURFACE TEMPERATURE OF ~25% OF THE GLOBAL OCEANS
And those upward step changes after the 1986/87/88 and 1997/98 El Nino events can be seen in the sea surface temperatures of the East Indian and West Pacific Ocean, the black curve in Figure 9. Also illustrated in Figure 9 are scaled NINO3.4 SST anomalies (purple curve) and Sato Index data (green curve), which I’ve added to illustrate the timing of explosive volcanic eruptions that impact sea surface temperature (and global temperature).
http://i31.tinypic.com/24l5rlw.png
Figure 9
The area represented by the East Indian and West Pacific Ocean SST anomalies (the black curve in Figure 9) is shown in Figure 10.
http://i39.tinypic.com/5n55as.jpg
Figure 10
Refer to my posts for further information:Can El Nino Events Explain All of the Global Warming Since 1976? – Part 1
Can El Nino Events Explain All of the Global Warming Since 1976? – Part 2
SEA SURFACES OUTSIDE OF THE EQUATORIAL PACIFIC ARE ALSO WARMED BY THE EL NINO THROUGH THE EXCHANGE OF HEAT FROM THE ATMOSPHERE TO THE OCEAN
During the El Nino events, heat from the surplus of warm surface waters along the equatorial Pacific is pumped into the atmosphere where it is carried around the globe. This raises land surface temperatures, (not illustrated). And the higher atmospheric temperature also raises the surface temperature of the oceans outside of the tropical Pacific. These increases in SST can be seen in Video 4 “Global SST Anomaly Animation 1996 to 2009”. Video 4 is from my post “Animations of Weekly SST Anomaly Maps from January 3, 1996 to July 1, 2009.” There is no narrative with Video 4. The description is included in the post.
http://www.youtube.com/watch?v=1ir1w3OrR4U
Video 4
The exchange of heat from atmosphere to ocean in the East Indian and West Pacific Oceans adds to the elevated surface temperatures that are caused by the warm water that had been carried there by ocean currents, discussed earlier. The El Nino also warms the East Pacific, South Atlantic, and West Indian Oceans through the atmosphere. Those portions of ocean basins are in turn cooled by the La Nina event that follows. But there is another portion of an ocean basin where the heat from the El Nino lingers; that is, the SSTs of that ocean basin are not impacted proportionately by the La Nina. And that ocean basin is the North Atlantic.
THE SST ANOMALIES OF THE NORTH ATLANTIC ALSO HAVE UPWARD STEP CHANGES AFTER SIGNIFICANT EL NINO EVENTS
The title of the linked post “There Are Also El Nino-Induced Step Changes In The North Atlantic” explains the content. And these SST anomaly step changes in the North Atlantic correlate well with the step changes in the East Indian and West Pacific Oceans, though they result from different aftereffects of the significant El Nino events. Refer to Figure 11. Keep in mind that the North Atlantic is also impacted by the Atlantic Multidecadal Oscillation.
http://i39.tinypic.com/15cocop.jpg
Figure 11
Assuming the North Atlantic represents approximately 15% of the global ocean surface area, then the East Indian and West Pacific plus the North Atlantic account for approximately 40% of the global ocean surface area. In the years that follow significant El Nino events, ocean currents and atmosphere-ocean processes “mix” the lingering elevated SST anomalies of the East Indian, West Pacific and North Atlantic Oceans with the remaining 60% of the global oceans. This causes the rise in global SST anomalies that presents itself as the divergence of Global SST anomalies from NINO3.4 SST anomalies, similar to that shown in Figure 2. That natural increase in SST anomalies is mistaken for warming due to anthropogenic causes.
THESE STEP CHANGES ALSO APPEAR IN GLOBAL LOWER TROPOSPHERE TEMPERATURE (TLT) ANOMALIES
The RSS MSU Time-Latitude Plots of Global TLT illustrate the transport of heat from the tropics toward the poles that result from significant El Nino events. This is illustrated and discussed in detail in my post “RSS MSU TLT Time-Latitude Plots…Show Climate Responses That Cannot Be Easily Illustrated With Time-Series Graphs Alone”. In that post, I combined Time-Series Graphs with the Time-Latitude Plots to show the effects of the significant El Nino events. But even without the time-series graphs, the 1997/98 El Nino is easy to find in Figure 12. It appears as an area of elevated tropical TLT anomalies that begins in 1998 and ends about a year later. Note that most of the heat that had been in the tropics is transported to the mid-to-high latitudes of the Northern Hemisphere, where it lingers through the 1998/99/00 La Nina. Regression analyses cannot capture that lingering aftereffect of an El Nino.
http://i42.tinypic.com/2hfukjm.jpg
Figure 12
The Time-Latitude Plots also show the impacts of the 1986/87/88 El Nino and limited TLT response to the 1982/83 El Nino. Refer to Figure 13. The 1982/83 El Nino was counteracted by the explosive eruption of El Chichon.
http://i41.tinypic.com/2vwzmdj.jpg
Figure 13
THE DIFFERENCE BETWEEN SIGNIFICANT EL NINO EVENTS AND THE OTHERS
This post primarily discussed the processes and aftereffects of the significant El Nino events of 1986/87/88 and 1997/98, using the 1997/98 El Nino as reference in many of the discussions and links. There were two other significant El Nino events since 1970, the 1972/73 and 1982/83 El Nino events. The 1982/83 El Nino was counteracted by the eruption of El Chichon, which turned it into a nonentity. As illustrated in Figure 14, there are striking similarities between the multiyear periods that followed the 1972/73, 1986/87/88, and the 1997/98 El Nino. This was discussed in detail in my post “Similarities of the Multiyear Periods Following Significant El Nino Events Since 1970.” Are these lesser El Nino events simply aftereffects of the significant El Ninos?
http://i27.tinypic.com/2gt6k5t.png
Figure 14
CLOSING
Regression analyses do not account for the multiyear aftereffects of significant El Nino events and do not account for the resulting El Nino-induced step changes in SST, TLT, and Land Surface Temperatures.
Regression analyses falsely attribute the divergence of global temperature anomalies from NINO3.4 SST anomalies to anthropogenic causes when, in fact, the divergence is caused by the lingering aftereffects of significant El Nino events.
The additional rise in global temperatures after the significant El Nino events is in reality caused by subsurface waters from the Pacific Warm Pool being transported to the surface and remaining there after the El Nino event has ended.
SOURCES
Sources of the data used in the graphs are provided in the linked posts.
Joe: You asked, “Has the heat balance for these events been calculated over their known history ?”
I have not run across any attempt to calculate it.
Carl Wolk: You asked, “Bob – Have you ever found thermohaline slope timeseries data?”
No. But I suppose one could use the TAO Z20 (depth of 20 deg C isotherm) data. It’s available through the KNMI Climate Explorer:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere
Eric: You wrote, “If El Nino is the answer to surface temperature increases, because of a sea surface temperature after effect, what explains the subsequent increase in ocean heat. It must be due to a radiation forcing factor of some kind. From the solar irradience plot, it is clear that it is not the sun.”
As Nick also mentions, cloud cover may be the driver of OHC. Unfortunately, cloud cover data is the subject of lots of debate. And then there’s the supposition about greenhouse gases but if they had any measureable effect, then one would expect that the trend in global SST for the later 20th century warming period would be higher than the early period. But they’re nearly identical. Refer to:
http://bobtisdale.blogspot.com/2009/03/has-global-warming-accelerated.html
You wrote, “The El Nino index may not be a direct measurement of sea surface area x temperature. But how large an error is there?”
I can’t answer your question. I don’t keep track of it. The error would increase the further back in time you went. Prior to 1914 and the opening of the Panama Canal, the SST measurements in the tropical Pacific were very sparse. The ship-based data is being studied again for the 1940s through 1960s due to the discontinuity in 1945. But keep in mind that, more recently, the tropical Pacific is widely studied. TOA Project buoys have been in place since the late 1970s. The OI.v2 SST data is satellite based and it’s been available since November 1981. Most of the bias correction they perform on satellite based SST data is at high latitudes.
You wrote, “As you mentioned, the alternative to a simple regression analysis is a GCM.
It may not be predictive but it is the best alternative tool available.”
Did I mention that? Very few GCMs model ENSO, and those that do model it don’t model it well.
J.Hansford: Thanks for the Rossby wave link. I’m not sure if it’s mentioned in your link but there is a study (“Decade-scale trans-Pacific propagation and warming effects of an El Niño anomaly” by Jacobs et al, 1994) that discusses the effects of a Rossby wave that existed for a dozen years. http://www.nature.com/nature/journal/v370/n6488/abs/370360a0.html
Stephen Wilde: You asked, “Would you go with the proposition that the Trade Winds relax because the warmer waters (from an internal change within the oceans) speed up the hydrological cycle which changes the size and position of the major air circulation systems (slackening the Trade Winds) which in turn allows the warm water to slosh east ?”
The question I have is, what “internal change within the oceans?”
This is an extract from the initial post:
“SEA SURFACES OUTSIDE OF THE EQUATORIAL PACIFIC ARE ALSO WARMED BY THE EL NINO THROUGH THE EXCHANGE OF HEAT FROM THE ATMOSPHERE TO THE OCEAN
During the El Nino events, heat from the surplus of warm surface waters along the equatorial Pacific is pumped into the atmosphere where it is carried around the globe. This raises land surface temperatures, (not illustrated). And the higher atmospheric temperature also raises the surface temperature of the oceans outside of the tropical Pacific. These increases in SST can be seen in Video 4 “Global SST Anomaly Animation 1996 to 2009”. Video 4 is from my post “Animations of Weekly SST Anomaly Maps from January 3, 1996 to July 1, 2009.” There is no narrative with Video 4. The description is included in the post.
Video 4
The exchange of heat from atmosphere to ocean in the East Indian and West Pacific Oceans adds to the elevated surface temperatures that are caused by the warm water that had been carried there by ocean currents, discussed earlier.”
I’m puzzled by the assumption that there is any significant transfer of energy from air to water in the face of increased evaporation, radiation, convection and conduction from surface to space as a result of the increased temperature differential between surface and space.
It doesn’t seem necessary to include the concept in any event. The simple progression of warm water around the globe is enough to validate the thesis without the embellishment of an air to water flow of energy.
Nor am I aware of any serious attempt to seperate out and quantify any waming effect of air on water outside the tropics to differentiate it out from the warming effect of water on the air above around the entire globe. Usually the cooler water just cools the air for no significant increase in water temperature and such energy as is extracted from the air is just lost immediately by an increase in the rate of evaporation.
How does energy in the air get past the thermal barrier of the evaporation process in order to warm the water ?
Nick Stokes: You wrote, “Postulating that ocean is the heat source for the air means that OHC should decrease as the air warms.”
It does from year to year, as discussed earlier. But over decadal periods, if El Nino events are releasing the build-up of tropical Pacific heat, shouldn’t the frequency and magnitude of El Nino events exceed La Nina events while OHC is rising and vice versa? From 1955 to 1975, OHC declined, and the frequency and magnitude of La Nina events were higher then El Ninos. And from 1975 to 2003, OHC rose, and the frequency and magnitude of El Nino events were greater than La Ninas. In the following graph, I didn’t want to be accused of selecting an OHC dataset that agreed with that, so I averaged the four that are available.
http://i32.tinypic.com/nuwly.png
Bob Tisdale (03:57:08)
“The question I have is, what “internal change within the oceans?”
We observe approximately 30 year phase shifts in the Pacific ocean when the rate of energy release to the air alters.
We observe similar phase shifts in other oceans.
How likely is it that such a large constantly moving liquid with it’s own internal circulations will always maintain a stable rate of energy release to the air above it ?
No one has so far suggested changes outside the oceans that correlate at all to 30 year intervals.
The logic demands that one at least considers the possibility that those changes are internal to the oceans or at least caused by some factor which does not involve the air.
The interesting feature of that proposal is that once the rate of energy release from the oceans is taken to be the primary climate driver for the air then a great number of other observed phenomena fall into place and the problems of ‘chicken and egg’ largely disappear.
Bob Tisdale (04:51:47)
It does not need to follow that a spell of predominant El Nino is a reflection of higher ocean heat content and a spell of predominant La Nina a reflection of lower ocean heat content. We are back to the ‘chicken and egg’ problem yet again.
The background energy flow through the entire Earth system is sun to sea to air to space. Put the ocean in it’s rightful driving seat and the observations and logic both follow.
The oceans sometimes slow down the transmission of energy through the entire system (La Nina) when energy is denied to the air which cools but ocean heat content will increase UNLESS the solar input is too weak to take advantage of the reduced rate of energy release from the oceans (as at present).
The oceans sometimes speed up the transmission of energy through the entire system (El Nino) when energy is released faster to the air which warms but ocean heat content will decrease UNLESS the solar input is large enough to more than offset the increased rate of energy loss to the air (as from 1975 to 2000).
Often solar output and ocean rates of energy release are out of phase. We are now in the position where a period of both being positive has been quickly followed by a period where both are negative. A good time to observe the difference. When both are in phase the fastest temperature trends will be observed whether upwards or downwards.
From 1950 to 1975 they were out of phase so a strong sun and negative oceans just gave a shallow temperature trend (downwards as it happened).
Time to watch and learn but so far my suggestion is being validated. We shall see.
Sorry:
[youtube]DHrapzHPCSA&feature=related[/youtube]
Where does Nick get all this heat from that the ocean is supposed to have swallowed. Is it from the SST data obtained from throwing a bucket over the side, which AFAIK is still in abeyance because the bucket to engine inlet correction was discovered to be flawed – by Jones indeed (after McI). Or is he referring back to the land index which has 0.4 of the trend coming straight from seemingly bogus TOBS adjustments.
As far as I can tell (via Pielke snr), the only reliable SST measurement is from the ARGOS buoys and they have shown flat trends (or even cooling) for 6 years. No doubt there was some heating before that via the natural cyclic effect that De Freitas discussed and we are therefore starting the down cycle. If we don’t go down then that’s the point to say maybe there is missing heat. At this point the only missing heat is that which we are supposed to have experienced by GHG warming and which is supposed to be hiding like a bogeyman in the currently non-warming sea.
Meanwhile BigCityLib, try reading the second paragraph of De Frietas’s comment. And try to realize that determining a nonlinear cycle and determining a linear trend are two different things. If you are still on the upward part of the cycle, then yes there is a linear trend there but it’s utterly pointless to measure it until the postulated cycle is over because the linear trend will then disappear. Clear?
http://oceanworld.tamu.edu/resources/oceanography-book/Images/pmo-amo.gif
http://www.cru.uea.ac.uk/cru/info/warming/
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml
If one goes back 100 years in our global climate history, The common factors present during the warmer than normal global temperature periods like, 1860-1880, 1926-1944, 1995-2008 is, the presence of a warm AMO, a warm PDO/ENSO, the presence of El Ninos. The opposite happens [we have La Nina’s and cool AMO and PDO/ENSO] when we have cold periods like 1855-1865, 1900-1926, 1964-1976. The one factor that seems to have changed is that since about 1976 , the frequency of La Ninas and El Ninos seemed to have changed for more frequent El Ninos and less frequent La Ninas , which results in gradually higher temperature build up and the warmer than previous global warming periods like 1995-2008 since the warming exceeds the cooling. I think the answer lies in research, why the frequency change in LA NINAS and El NINOS?
1943-1975
# OF EL NINO’S 6
# OF LA NINA’S 9
1976-2008
# OF EL NINOS 10
# OF LA NINA’S 5
A new paper by Bo Nordell and Bruno Gervet of:
Department of Civil and Environmental Engineering
Luleå University of Technology
SE-97187 Luleå, Sweden
indicates that global temperature change can be attributed to human heat output and not CO2 emissions. I would like comments on this theory as I do not think it will hold true.
Here is the abstract:
Abstract: The increase in the global air temperature is an inadequate measure
of global warming, which should rather be considered in terms of energy. The
ongoing global warming means that heat has been accumulating since 1880 in
the air, ground and water. Before explaining this warming by external heat
sources, the net heat emissions on Earth must be considered. Such emissions
from, e.g., the global use of fossil fuels and nuclear power, must contribute to
global warming. The aim of this study is to compare globally accumulated and
emitted heat. The heat accumulated in the air corresponds to 6.6% of global
warming, while the remaining heat is stored in the ground (31.5%), melting of
ice (33.4%) and sea water (28.5%). It was found that the net heat emissions
from 1880–2000 correspond to 74% of the accumulated heat, i.e., global
warming, during the same period. The missing heat (26%) must have other
causes, e.g., the greenhouse effect, the natural variations in the climate and/or
the underestimation of net heat emissions. Most measures that have already
been taken to combat global warming are also beneficial for the current
explanation, though nuclear power is not a solution to (but part of) the problem.
Keywords: global warming; heat accumulation; heat emission; thermal
pollution.
Reference to this paper should be made as follows: Nordell, B. and Gervet, B.
(2009) ‘Global energy accumulation and net heat emission’, Int. J. Global
Warming, Vol. 1, Nos. 1/2/3, pp.378–391.
David (20:19:14) : ***“It is also instructive that you say that higher surface temperature reduced the albedo over the ocean due to clouds. This is an argument for positive cloud feedback, which increases climate sensitivity. This agrees with the recent literature on this subject.”Until you consider that higher SSTs are a result of El Nino phenomenon, and that El Nino can occur without extra heat additions. Therefore, the higher SST leads to less albedo from clouds, which causes more energy to enter the oceans, which causes a higher probability for ENSO, which causes higher SST, which causes….
Let’s see what the next few years bring. ***
It seems to me losing cloud cover would be a double-edged sword. It would allow more sunlight in during the day, but the lack of clouds would also allow more LW radiation to escape, no??
In any strict physical sense, ENSO is not a driver of the climate system, but simply a response mode. The ultimate energy-producing driver of the climate system is thermalization of solar radiation. Thermalization takes place largely near the surface, with minor contributions from cloud tops and stratospheric ozone. Insolation (i.e., solar radiation reaching the surface) is invariably regulated by clouds. Unlike the situation on land, it penetrates the oceans many tens of meters, and the heated water is mixed downward by turbulent processes. ENSO is but one mode for redistributing that heat.
Taken as whole on an annual basis, the oceans shed more heat through evaporation than through LW radiation. LW backradiation from the atmosphere is totally absorbed well within the top millimeter of water, where the energy goes mostly into the latent heat of evaporation. GHGs cannot heat the deeper oceans. On the contrary, the oceans heat the atmosphere from below. It is only in that limited sense that the enigmatic heat-purging phenomenon that we call ENSO can be said to drive surface temperatures. Even in the tropics, however, the coherence of surface temperature with the ENSO index is limited to certain characteristic frequency bands. The most powerful climatic oscillations are much lower in frequency than those of ENSO. Climate changes have different physical foundations.
Steven Wilde: Regarding your 06:46:17 and 07:03:54 comments, I’m a visual person. Show me with data and graphs.
JamesG: You wrote, “As far as I can tell (via Pielke snr), the only reliable SST measurement is from the ARGOS buoys and they have shown flat trends (or even cooling) for 6 years.”
Are you sure you don’t mean OHC instead of SST. ARGOS buoys measure temperature at varying depths over a multiday cycle, I believe 10 days. So they’d be measuring SST once every 10 days. Satellites are measuring it daily.
Dr. Robert Freerks (08:46:42):
Without passing any judgement on the paper whose abstract you present, I dare say that heat generated by human activity is a significant factor not in global temperatures, per se, but in the temperatures recorded in population centers. Unfortunately that’s where most of the long-term temperature records come from. Call it an anthropogenic effect upon climate data.
Bob,
This sort of analysis is all about numbers. I accept the observation that surface temperature effects on a portion of the ocean not covered by the El Nino index may have been made warmer by El Nino. In a complex situation like climate, no simple linear regression will be totally accurate.
Any quantitative analysis regarding climate will have errors. Anyone who reads about this subject knows that. You have found a source of error.
Your analysis begs the question, how much is the error and how much of the variation of climate does it explain? How far off does it make the Lean and Rind paper.
There is also the question of how do the frequency and intensity of El Nino events depend on radiative forcing. Without mechanistic studies one can’t say anything about cause and effect. I haven’t read the Rind and Lean paper, but I know that regression analysis is not a good way to analyse cause and effect. GCM’s are a better way to do that, although their predictive properties for actual situations are not good for a number of reasons – chaotic phenomena, and lack of accuracy in specification of empirical parameters involving clouds, aerosals etc.. There are GCM’s that predict phenomena like El Nino but the data on frequency and intensity versus forcing seems all over the place.
Stephen Wilde (01:16:41) :
“ . . . an expansion of the equatorial air masses . . . results in larger equatorial areas of warm air and a displacement of the Trade Winds so that they become weaker in the regions where they were initially situated.”
This makes sense.
Bob Tisdale: Thank-you for taking the time to respond to my questions. You answered my last question with your response to my second last question (which I saw as the same).
Bob Tisdale (09:28:05)
If you are not already aware of any such data and graphs then they do not exist and I have imagined those that I have seen.
Suffice it to say that my comments are wholly consistent with the data and graphs in the article from you at the top of this thread.
matt v: You wrote, “I think the answer lies in research, why the frequency change in LA NINAS and El NINOS?”
You need to look at the complete dataset, the analog signal, not just the frequency of El Nino and La Nana events, which is a digital rendition with qualifiers. Those El Nino and La Nina events that you’re counting are also changing in amplitude and the NINO3.4 SST anomalies between those events that you’re counting also change. An analogy: Imagine your favorite song and that awful bleat of the Emergency Broadcast System. Now imagine that someone has programmed the bleat to sound each time your favorite song rises above a certain note, one that doesn’t occur too often. If you were only listening to the random bleats, you’d have a different impression of your favorite song.
eric: Regarding your 10:14:07 comment, if and when GCMs are able to recreate the many facets of ENSO and, from that, determine its impacts on radiative forcing, on water vapor, on OHC, on SST, on TLT, etc., and how ENSO provides feedback to itself, they will have value. Until that time, they do not.
Regards
Leif Svalgaard (23:28:30) :
Nasif Nahle (23:12:16) :
We (a mathematician and I) have considered HSG = 0% into the formula used for extrapolations. 0 is not a valid entry for the second term (Ln (%HSG), so it is considered equal to 0. Consequently, the result would be 1361.5 W/m^2, over the corresponding maximum or minimum fluctuation.
And if %HSG was 0.1 or 0.0001, those are clearly valid… Then TSI would be a lot higher than 1361.5… It is the very form with a logarithm that is not right.
We have an input of + or – {0.3 W/m^2}, so the algorithm is correct. It is coherent with a logarithmic trend in the real nature, so it is right.
See Leif, I have not gotten mathematical madness; not yet. Nature is my best informant and mathematics is my best tool for conceptualizing what I observe in nature.