Can El Nino Events Explain All of the Global Warming Since 1976? – Part 1
A guest post by Bob Tisdale
UPDATE 1 (January 12, 2009):
In my extremely brief description of an El Nino event, I wrote, “…and a subsurface oceanic temperature boundary layer called the thermocline pushes the warm subsurface water to the surface.” My oversimplification may be misleading, and while it does not undermine the intent of this post, a better explanation is available in the following video from NASA Scientific Visualization Studio video titled “Visualizing El Nino”: http://svs.gsfc.nasa.gov/vis/a000000/a000200/a000287/a000287.mpg
If I rewrite that sentence in the future, it would read something to the effect, “During El Nino events, natural changes in atmospheric and oceanic conditions cause the warm water that was ‘contained’ by the Pacific Warm Pool to shift east along the equator. The warm subsurface water rises to the surface.”
h/t Gary for noting the poor wording.
NOTE: For those who are new to the subjects of El Nino events and sea surface temperatures, I’ve tried to make the following discussion as non-technical as possible without overlooking too many aspects critical to the discussion. It includes detailed descriptions of many of the processes that take place before, during, and after El Nino events. The period after an El Nino event is often neglected, but it holds the oceanic responses that are the most significant over multiyear periods.
INTRODUCTION
Two things have always stood out for me in a graph of Global Sea Surface Temperature (SST). The first was the Dip and Rebound in the ERSST.v2 version of the Extended Reconstructed SST data from the 1800s to the 1940s. The link above discussed it in detail.
In Figure 1, I’ve boxed SST anomaly data for the period from 1854 to 1976 to indicate that, other than the dip and rebound and the temporary rise in the early 1940s caused by a multiyear El Nino, there really wasn’t a rise of any note in SST between the late 1800s and the period from the mid-1940s to mid-1970s. The ERSST.v2 data used in this post illustrates little to no change in SST anomalies from the one period (late 1800s) to the other (mid-1940s to mid-1970s).
http://i42.tinypic.com/2ibc87o.jpg
Figure 1
Second: After 1976, Global SST anomalies appear to rise in three steps. It’s very visible if monthly SST anomaly data has been smoothed with a 37-month filter, Figure 2, or if annual data has been smoothed with a 3-year filter. Many people try to correlate those steps with variations in TSI, because they seem to coincide with solar cycles. They don’t, so those trying to make the correlation fail in their efforts.
http://i41.tinypic.com/29omma1.jpg
Figure 2
Zooming in on the period from January 1976 to present, Figure 3, and changing the filtering from 37-months to 12-months do not eliminate the appearance of steps. Why did Global SST rise in steps after 1976?
http://i41.tinypic.com/71mbd3.jpg
Figure 3
Based on the title of this post, the rising step changes were caused by El Nino events, three in particular. The NINO3.4 SST anomalies from January 1976 to November 2008 are shown in Figure 4. Most people familiar with the recent El Nino-Southern Oscillation (ENSO) record could guess correctly that the 1997/98 El Nino event was one of the El Ninos that caused a step change. If the magnitude of El Ninos was the only factor, the second logical choice would be the 1982/83 El Nino, since it ranks a close second in terms of peak NINO3.4 SST anomaly. Yet that El Nino event did not create a rising step change in global SST anomalies, because another natural event had a greater impact on global climate.
http://i44.tinypic.com/s46yhe.jpg
Figure 4
A volcanic eruption. The El Chichon eruption of 1982 interrupted the normal heat distribution processes of the 1982/83 El Nino. Many persons understand and cite this on blogs. Few realize, though, that the 1991 eruption of Mount Pinatubo also interrupted a significant series of El Nino events. The Mount Pinatubo eruption didn’t occur at the same time as a singular El Nino event with monstrously high SST anomalies, but the string of El Ninos it influenced was significant in its length. “Full-fledged” El Nino events occurred in 1991/92 and 1994/95, with a minor El Nino occurring during 1993. At minimum, two of the early-to-mid 1990s El Ninos had their heat distribution processes altered.
REFERENCE ILLUSTRATIONS
Figure 5 is a comparative graph of East Indian-West Pacific SST anomalies, scaled NINO3.4 SST anomalies, and inverted Sato Index of Stratospheric Mean Optical Thickness data (used as a reference of volcanic eruption timing and intensity). The data in Figure 5 have been smoothed with a 12-month running-average filter. The step changes in the East Indian-West Pacific SST anomalies are quite obvious. The graphs included in the following discussions are edited versions of Figure 5. In the latter graphs, I have simply limited the years in view to the periods being discussed. The three periods (January 1976 to December 1981, January 1981 to December 1995, and January 1996 to November 2008) are also shown in Figure 5. The periods were divided in this way because, working backwards in time, the first period discussed (1996 to 2008) has been covered in an earlier post and is, therefore, easiest to explain, the second period (1981 to 1995) includes the two volcanic eruptions, and the third period (1976 to 1981) is what was left over. Note that the NINO3.4 and Sato Index data are provided to illustrate timing and timing only; they have not been scaled to suggest magnitude of cause and effect. I did not want to get into a debate about scaling.
http://i44.tinypic.com/10oe6uo.jpg
Figure 5
In Figure 6, I’ve blocked off the area of the East Indian and West Pacific Oceans illustrated by the black curve in Figure 5 and in illustrations that follow. The coordinates are 60S to 65N, 80E to 180. It represents a significant portion of the world oceans, in the range of 25 to 30% of global sea surface from 60S to 65N.
http://i39.tinypic.com/5n55as.jpg
Figure 6
Figure 7 is a comparative graph of the NINO3.4 SST anomalies, inverted Sato Index, and the SST anomalies for the oceans segments not included in the East Indian-West Pacific SST anomaly dataset above. These include the East Pacific, the Atlantic, and the West Indian Oceans contained by the coordinates 60S-65N, 180-80E. The East Pacific-Atlantic-West Indian Ocean data (red curve) is overlaid onto the East Indian-West Pacific data (the black curve in Figure 5) during the discussions that follow to show the interactions between datasets.
http://i44.tinypic.com/2ljgxon.jpg
Figure 7
A final preliminary note: The filtering is used to reduce the visual impact of the noise within the datasets. It also affects (smoothes) the abruptness of the change in the Sato Index data when the volcanoes erupted. It has a minor visual impact, but it is something to consider when viewing the graphs that include the volcanic eruptions (Part 2). The impacts of the smoothing are shown in Figure 8.
http://i39.tinypic.com/be5x6a.jpg
Figure 8
A VIDEO
I illustrated the cause of the step change AFTER the 1997/98 El Nino in a video posted on the thread titled The Lingering Effects of the 1997/98 El Nino. The YouTube link is here: http://www.youtube.com/watch?v=4uv4Xc4D0Dk
Take five minutes and watch the video. It will help to illustrate the phenomena taking place and the causes.
Note: In the graphs for the video, I used the Optimally Interpolated SST anomaly data (OI.v2). The monthly time-series data for it starts in November 1981, and since I wanted to cover the period starting in 1976 in this post, I had to switch datasets. The SST anomaly data used in the following discussion is from the Extended Reconstructed Sea Surface Temperature, Version 2 (ERSST.v2), available from the National Climatic Data Center (NCDC). It runs from January 1854 to present.
THE STEP CHANGE FROM 1996 TO PRESENT – A RECAP AND EXPANSION OF DISCUSSION
The SST anomalies for the West Indian-East Pacific Oceans from January 1996 to November 2008 are shown in Figure 9, along with scaled NINO3.4 SST anomalies and the final few years of the inverted Sato Index data. The Sato Index ends in 1999, but because there has not been an explosive volcanic eruption capable of lowering global temperatures significantly since 1991, its end in 1999 has no affect on the discussion.
Note: You may wish to click on the TinyPic link (While holding the “Control” key) to open Figure 9 in a separate window. That would eliminate the need to scroll back and forth. This discussion goes on for a full page of single-spaced text in MSWord form.
http://i43.tinypic.com/zxr6vc.jpg
Figure 9
The Pacific Warm Pool, also known as the Indo-Pacific Warm Pool, is an area in the western equatorial Pacific and eastern Indian Ocean where huge volumes of warm water collect due to a number of natural processes (normally attributed to ocean currents and trade winds). The Pacific Warm Pool is visible in SST data and in subsurface ocean temperature data; the warm pool reaches down to depths of 300 meters. Figure 10 illustrates its location. Over decadal periods of time, it expands and contracts in area and increases and decreases in volume. 
http://i42.tinypic.com/2hdqydy.jpg
Figure 10
During El Nino events, natural changes in atmospheric conditions cause the warm water that was “contained” by the Pacific Warm Pool to shift east along the equator, and a subsurface oceanic temperature boundary layer called the thermocline pushes the warm subsurface water to the surface. The high SST anomalies in the eastern equatorial Pacific are known as an El Nino. It is a natural process that occurs at irregular intervals and magnitudes. The eastern equatorial Pacific SST anomaly data is divided into areas for monitoring purposes. Refer to Figure 11. These areas are known as NINO1, 2, 3 and 4. Global temperature responses to El Nino events correlate best with the SST anomalies of an area that overlaps NINO3&4 areas. That area is called NINO3.4. That’s the data set used in the following discussions.
http://i44.tinypic.com/97qt08.jpg
Figure 11
Back to the discussion of Figure 9: The purple curve in Figure 9 shows the SST anomalies for the NINO3.4 area [5S-5N, 170W-120W] in the eastern Pacific. The data has been reduced in scale by a factor of 0.2 so that it doesn’t overwhelm the graph. During the 1997/98 El Nino event, NINO3.4 SST anomalies rose to their highest levels during the 20th century. Its impact is visible in the long-term and short-term Global SST anomaly data shown in Figures 2 and 3. It affected global and regional temperature and precipitation patterns in the short term afterwards.
That’s usually about the end of a discussion of the 1997/98 El Nino. The video showed, however, that other processes continue long after an El Nino event. Much of the heat that rises to the surface during the El Nino is then transported west by the equatorial ocean currents, recharging the Pacific Warm Pool for the next El Nino and heating the surface of the East Indian-West Pacific Oceans. It’s important to keep in mind that before the El Nino most of the warm water was below the surface, contained by the Pacific Warm Pool. Since it’s below the surface to depths of 300 meters, it is not a part of the calculation of global SST, or global temperature, for that matter. Then, after the El Nino, much of it is on the surface and included in the SST data. The resulting rise in the SST anomalies of the East Indian-West Pacific Oceans (the black curve in Figure 9) lags the change in NINO3.4 SST anomaly by a few months. As shown, East Indian-West Pacific Ocean SST anomalies reached their peak in 1998, but by that time, NINO3.4 SST anomalies had already dropped back to “normal” levels. Then the NINO3.4 SST anomalies dropped further, into the subsequent La Nina (Negative) levels, but the East Indian-West Pacific Ocean SST anomalies only dropped a portion of the amount they had risen, about one-half of it. And before the East Indian-West Pacific SST anomalies can slowly decrease fully to the levels they were at before the 1997/98 El Nino, NINO3.4 SST anomalies increase in 2000 and cause the East Indian-West Pacific SST anomalies to rise again. That’s the step change.
In summary, a large volume of warm water that was once below the surface of the Pacific Warm Pool was raised to the surface by the El Nino and distributed across the surface of the East Indian and West Pacific Oceans, causing SST anomalies to rise in that region. East Indian-West Pacific Ocean SST anomalies began to drop but had not had enough time to return to “normal” before the start of the next El Nino event, which swept them upwards again.
They are slowly returning to the levels they were at before the 1997/98 El Nino, but because they were “pushed” higher again and again by the El Nino events of 2002/03, 2004/05, and 2006/07, the return has taken more than a decade.
In Figure 12, I’ve added the SST anomalies for the East Pacific, Atlantic, and West Indian Oceans to the comparative graph. (It’s another graph you may want to open in a separate window.) The East Pacific-Atlantic-West Indian Ocean SST anomalies mimic the rise and fall of the NINO3.4 SST anomalies during the 1997/98 El Nino—to a point. Note how, during the La Nina that followed it, the NINO3.4 SST anomalies have dropped well below the levels they had been at before the start of the 1997/98 El Nino (highlighted with the blue line and arrows), yet the East Pacific-Atlantic-West Indian Ocean SST anomalies don’t follow the NINO3.4 SST anomalies below the level they had been at before the 1997/98 El Nino to any great extent; that’s another (but smaller) cause of the step change in Global SST anomalies after the 1997/98 El Nino. Then the East Pacific-Atlantic-West Indian Ocean SST anomalies follow the rise in NINO3.4 SST anomalies from 2000 to late 2002, the peak of the next El Nino. And, from 2003 to present, the SST anomalies for both of the major portions of the global oceans (red and black curves) “normalized” to levels near to one another, modulating back and forth as each area, at different time lags, responds to variations in NINO3.4 SST anomalies. These include the additional El Nino events of 2004/05 and 2006/07, and finally a substantial La Nina in 2007/08. Because of that La Nina, the East Pacific-Atlantic-West Indian Ocean SST anomalies (red curve) have dropped down close to the levels they had been at prior to the 1997/98 El Nino, but it has taken more than 10 years.
http://i40.tinypic.com/21o6a0z.jpg
Figure 12
In Figure 13, the Global SST anomaly curve from January 1976 to November 2008 (same graph as Figure 3) has been annotated to indicate the causes of the step change. As illustrated and discussed in the preceding, the temperature rise resulted from the significant step response of the East Indian-West Pacific SST anomalies to the 1997/98 El Nino event–that was compounded by a similar response (but of lesser magnitude) to the 2002/03 El Nino—that was then “maintained” by the El Nino events of 2004/05 and 2006/07.
http://i44.tinypic.com/hunip3.jpg
Figure 13
CLOSING TO PART 1
That’s enough for one post. In the second part, I’ll cover the two earlier periods. For a preview, simply scroll back up to Figure 5 and note the step changes during those two periods and the effects of the two volcanic eruptions. (Remember that the Sato Index data is only there to illustrate the timing of the volcanic eruptions.) I’ll also add another phenomenon that confirms the step changes caused by the El Nino events are drivers of global temperature anomalies.
SOURCES
Smith and Reynolds Extended Reconstructed SST Sea Surface Temperature Data (ERSST.v2) and the Optimally Interpolated Sea Surface Temperature Data (OI.v2) are available through the NOAA National Operational Model Archive & Distribution System (NOMADS).
http://nomads.ncdc.noaa.gov/#climatencdc
The Sato Index Data is available from GISS at:
http://data.giss.nasa.gov/modelforce/strataer/
Specifically:
Leif Svalgaard (20:31:01) :
“You have all the data and should be able to calculate about 60 yearly values of temperature for each area and make a plot with two curves showing these temperatures as a function of time.”
You have lost me: ‘for each area’. For which areas precisely? What temperatures?
Bear in mind that the critical factor driving the El Nino in the Pacific is the strength of surface pressure in the east versus the west. The west varies little. Almost all the variation is in the east because that is where 200hPa temperatures are coolest the downdraft is strongest, the ozone content is greatest and the reactivity of the air to incoming and outgoing radiation is greatest. If you want advance notice go to that part where the driver manifests most strongly.
But of course others will have their own notions of the cause of El Nino events. I am concerned with global temperature in the tropics and the phenomenon of global warming, not the vexed question of what El Nino is and what drives it. That is a can of worms. We have already seen Maximovich getting into oscillator theory, then there are others who talk about the wind piling up the water in the west, and yet others talking of the emergence of warm waters from the deep and so on. For clarity, the issue is what causes the entire tropics to warm up and supply energy to higher latitudes. Let’s not get bogged down in El Nino theory.
You have a predictor for global tropical temperature. Now, ask yourself, why does it work? What drives surface pressure 30°-40°S , 100-120°west, off the coast of South America.
erlhapp various posts
Simplfy.Your “theory is overly complex and tends to show so may answers I do not know what the question is.We can visualize this so, on a graph with the vertical axis showing complexity and the horizontal axis showing the transformation from orderto disorder.A hockey stick soon appears.
Repose your hypothesis as first a simple( or series) of general statements,then ask a set of appropriate binary(yes/no questions.
For example (opening)
“From 1985 till 2000 the gradual decrease of global cloud coverage and albedo were observed. The value of this decrease was ~ 6 % and solar energy flux reflected back to space decreased at ΔF ≈ (6) W/m2. Since 2000 the values of global cloud coverage and albedo became to increase slightly”
(Closing)
“Therefore we can see the change to Albedo that balances the radiative equations is in the area of 6 w/m2, the forcing response of GHG being 2.4 w/m2.”
This Equivalent to 2% increase in solar irradiance, a factor 20 more than typical maxima to minima variations. This brings some interesting questions.
1) Reversibility suggests natural variations.
2 GCM do not show such variations.
3) What is the climatic impact? Recent warming.
This then opens logical discussion,literature citation,contrarian opinions etc and accordingly we can nodify(evolve) from there.
erlhapp (21:36:23) :
You have lost me: ‘for each area’. For which areas precisely? What temperatures?
You said:
erlhapp (13:49:43) :
“Perhaps someone can enlighten me as to how temperatures in the upper troposphere (South East Pacific) can lead the surface (global tropics 20°N to 20°S by 6-18 months when annual data is considered”,
so temps for upper troposphere SE Pacific lead surface temps for global tropics.
Area 1: upper troposphere SE Pacific
Area 2: global tropical
erlhapp (21:36:23) :
Let’s not get bogged down in El Nino theory.
erlhapp (08:23:33) :
So what causes El Ninos? […]
Here is the explanation in brief…
I thought that was your whole spiel…
erlhapp (21:36:23) :
Let’s not get bogged down in El Nino theory.
The standard explanation for El Nino sounds clear enough:
In non-El Niño conditions the trade winds blow towards the west across the tropical Pacific. These winds pile up warm surface water in the west Pacific with tenps about 8 degrees C higher in the west, with cool temperatures off South America, due to an upwelling of cold water from deeper levels.
During El Niño the trade winds weaken in the central and western Pacific leading to a depression of the thermocline in the eastern Pacific, and an elevation of the thermocline in the west.
So El Nino is controlled from the west, not from the east.
Put in different words: Kelvin waves [associated with density fluctuations inside the ocean], can be seen in the sea-level measurements made by altimeters [several tens of cm high].
The Kelvin waves travel east and set up changes in the eastern Pacific that lead to El Niño by depressing the thermocline there.
A nice explanation is here: http://www.pbs.org/wgbh/nova/elnino/anatomy/origins.html
From that site:
“There are other, more elaborate theories about what causes El Niño, but one element seems common to all of them: when you look closely, you see a dog chasing its own tail. The truth is, no one knows what really causes El Niño. It might very well be the last El Niño that starts the next one. The official scientific name for El Niño, ENSO (El Niño-Southern Oscillation) reflects an understanding of this teeter-totter nature. An oscillation is a reverberation back and forth between two states, like between summer and winter. El Niño is one extreme of a years-long oscillation in the entire pacific basin and the atmosphere above it. As the cycle unfolds, an “anti-El Niño,” dubbed La Niña, appears as El Niño disappears. Like a mirror image of El Niño, it produces extreme weather and abnormal conditions in the western Pacific similar to those El Niño produces in the east. Back and forth, east and west, this cycle has run continuously for many thousands of years.’
The recent run of El Ninos that Bob Tisdale discussed are just the dog chasing its tail.
Leif Svalgaard (15:17:59) :
I said: How and why the short wave radiation varies so as to produce the upper troposphere temperature that we observe is a question that, so far as I can see, is currently very difficult to explain.
You said: The simplest explanation is that the upper troposphere temperature is not produced by UV [you misuse ‘short wave’ because that is mostly visible light]. The explanation is that the light reaches the surface, then heats the troposphere, upper, middle, and lower. No mystery.
BUT There is no relationship between surface temperature in the south east Pacific and 200hPa temperature. See http://i249.photobucket.com/albums/gg220/erlandlong/SSTVs200hPatempSEPacific.jpg
Please acknowledge that 200hPa temperature is not driven by surface temperature!
And there is an excellent relationship between 200hPa temperature and surface pressure as seen here: http://i249.photobucket.com/albums/gg220/erlandlong/200hPaandPressure30-40S240-260E.jpg
Notice also:
1. Massive shift in 200hPa temperature between 1976 and 1980. This was the Great Pacific Climate Shift and was it also the last turning point for the PDO?
2. Gradually declining 200hPa temperature after 1980 while surface temperatures rose.
3. Between 1976 and 2005 sea level pressure is mostly depressed.
4. There was a big recovery of SLP in 2007 but it fell away in 2008.
5. The relationship breaks down under volcanic activity.
And is this what you are asking for, the relationship between 200hPa temperature in the south east Pacific and global temperature in the tropics between 20N and 20S.
http://i249.photobucket.com/albums/gg220/erlandlong/240-26030-40STemperatureVsSST20N-20.jpg
Notice please:
1. 200hPa temperature peaks in the south east Pacific tend to precede global sea surface temperature peaks.
2. The relationship between 200hPa temperature and sea surface temperature holds during the time of volcanic activity when surface pressure stayed low between 1990 and 1994. Sea surface temperature is not associated with pressure per se but upper atmosphere temperature, humidity and cloud condensation phenomena.
3. The rise and fall in sea surface temperature is not explained by the gradual increase in CO2. It is however explained by the known relationship between upper atmosphere temperature and cirrus cloud cover.
So far as the thermal maximum is concerned at 200hPa in August in the south Pacific I suspect that a couple of factors are involved in the increase of LWR at that time:
1. Loss of cloud cover in the southern hemisphere in mid year allowing more radiation to reach the surface.
2 Less heat loss by convectional decompressive process in winter tending to boost the long wave emission from the atmosphere.
3. Angular travel of long wave from the tropics to subtropical latitudes.
And also, as you surmise an increase in the movement of ozone towards Antarctica which is the major downdraft area in the middle of the year, the Arctic being too warm.
Leif
“The recent run of El Ninos that Bob Tisdale discussed are just the dog chasing its tail.”
This is the sort of nonesense that the AGW crowd want to promote because it enables them to sell the idea that ENSO is temperature neutral, just the very thing that Bob Tisdale is at pains to refute. Where in the IPCC reports is there an estimation of the ENSO factor driving global temperature change?
None of the conventional theories account for the addition to the Earth heat budget involved in tropical warming events.
None of the conventional theories properly consider the atmospheric drivers of warming events. The atmospheric driver is plainly a loss of cloud cover. My observations explain that loss. My observations explain how the event is initiated by a rise in upper troposphere temperature due to ultraviolet radiation acting upon ozone that is heaviest in concentration in the mid latitude high pressure cells.
There is an interesting increase in sea surface temperature currently occurring in the latitude band 20-40 degrees in both hemispheres. This is feeding warm water into the cold tongue area of the east Pacific.
The promoters of current theories have models to predict the course of ENSO and all these models swung (in early January, see NOOA advisory) to predict La Nina conditions for the next three months just as the La Nina is breaking down in the eastern Pacific.
No cigar for these modelers I am afraid.
Just as an aside. The inversion of 200hPa temperature (by comparison with the surface regime) is strongest outside the tropics. This reflects increasing ozone content as one moves away from the equator but there is also a gradual diminution in OLR . How much does UV radiation influence 200hPa temperature. Well, 200hPa temperature has a seasonal rise and fall almost three times that at the surface and is very much more volatile on an interannual basis than is OLR. If OLR were the only thing driving 200hPa temperature the two would consistently rise and fall together. They don’t.
Do we know how ozone content varies in the upper troposphere by latitude? No. Do we know how UV varies at the tropopause over time? No. Is the strong reaction of ozone to OLR recognised in climate science? No. Is the failure of that heat to propogate downwards from the upper troposphere recognised in climate science? No. Do our men of science want to know the answers to these questions. Apparently not.
“Simplfy…theory is overly complex and tends to show so may answers I do not know what the question is…Repose your hypothesis…”
I believe this follows from a sincere desire to be helpful. Clearly this is theory doubtless including many hypotheses.
Now I don’t know a lot about clarity of expression but two principles seem reliable:
Niklaus Wirth’s ‘Top Down’ design (which kernel programmers may not employ). Do not worry about the details at the start of an exposition, just the concepts. Drill down to the details on elaboration, and in this case via successive iterations.
Second, from Spurgeon, “Tell them what you’re about to tell them. Tell them. Tell them what you told them.” It’s not pedantic to lead the horse by varied routes, I’m learning this with my infant daughter.
It was a heat pump it was.
=================
erlhapp (23:35:33) :
erlhapp (13:49:43) :
“Perhaps someone can enlighten me as to how temperatures in the upper troposphere (South East Pacific) can lead the surface (global tropics 20°N to 20°S by 6-18 months when annual data is considered”,
What you say is that T(global tropics, t) ~ T(200nPa SE P, t-12). This is what you should establish with a graph. If you send me the annual values [that you must have in order to make the statement you did] then I’ll be glad to make the graph for you.
erlhapp (05:36:32) :
Is the strong reaction of ozone to OLR recognised in climate science? No.
Is the failure of that heat to propagate downwards from the upper troposphere recognized in climate science? No.
Climate science has long recognized O3 as a greenhouse gas and measured the downward heat flux:
TES observations of tropospheric ozone as a greenhouse gas
Worden, H. M. et al. American Geophysical Union, Fall Meeting 2007, abstract #A51D-0735
“We present satellite observations of the downward radiative flux from tropospheric ozone, for cloud free ocean conditions. This analysis uses infrared (IR) radiance spectra, integrated over the 9.6 micron ozone band between 985 to 1080 cm-1, and ozone profile retrievals from the Tropospheric Emission Spectrometer (TES) on EOS-Aura. We examine the sensitivity of the outgoing longwave radiation (OLR) in the 9.6 micron band to upper tropospheric ozone and water vapor by separating the data into hemispherical and sea-surface temperature (SST) ranges. For 2006 data, we estimate an annual average downward flux for upper tropospheric ozone of 0.48 ± 0.13 W/m2 with a standard deviation of 0.24 W/m2 for the latitude range between 45°S to 45°N. This estimate includes natural and anthropogenic ozone sources and is higher than the 2007 IPCC average for climate model estimates of anthropogenic tropospheric ozone radiative forcing of 0.35 W/m2. We also observe that water vapor dominates the clear-sky ocean variability of the outgoing IR radiation in the 9.6 micron ozone band for SSTs higher than 299 K, consistent with the “super greenhouse effect”. This underscores the importance of chemistry-climate coupling in forcing predictions for tropospheric ozone.”
Do our men of science want to know the answers to these questions. Apparently not.
we do know many of the answers.
Leif Svalgaard (08:54:38) :
erlhapp (05:36:32) :
Is the strong reaction of ozone to OLR recognised in climate science? No.
Yes:
http://www.adorc.gr.jp/ozone/ozone1.pdf page 10:
“Ozone has a powerful capacity to absorb infrared light with a wavelength of around 10 microns. Since these wavelengths do not overlap those of water vapor (H2O) and carbon dioxide (CO2), ozone in the atmosphere efficiently absorbs the infrared rays radiated from the Earth and thereby has powerful greenhouse effect. […]
First, let us examine the relationship between altitude and the greenhouse effect efficiency of ozone. Figure 3-1 shows the rate of change of ground-level temperature caused by increased ozone concentrations at different altitudes. As shown by the figure, the effect of warming is small at ground level. As we approach the upper troposphere, the effect becomes stronger, reaching the maximum around the tropopause, which divides the stratosphere and the troposphere, about ten kilometers above the Earth. In the lower layer of the stratosphere as well, ozone has a positive greenhouse effect. However, at an altitude above about 30 kilometers, an increase in ozone concentrations lowers the temperature at the ground level.
The reason why the effect at ground level is nearly zero is that the ozone’s absorption and radiation of infrared rays (from the Earth) is balanced, since the air temperature is almost the same as that of the Earth’s surface and there is no net absorption. At higher altitudes, where the temperature is lower, the net of infrared absorption by ozone is larger, making the greenhouse effect more efficient. Similarly, near the tropopause where the temperature of the atmosphere is at its lowest, the greenhouse effect of ozone is at its highest. In contrast, at higher altitudes in the stratosphere where the temperature is also higher, the net absorption of infrared rays by ozone is reduced, making the greenhouse effect negative above the middle layer of the stratosphere.
In short, ozone in the troposphere and the lower layer of the stratosphere has a positive greenhouse effect. Ozone has its strongest greenhouse effect in the upper troposphere.”
As I said, many of the answers are known [and have been for a long time].
erlhapp (05:36:32) :
My observations explain how the event is initiated by a rise in upper troposphere temperature due to ultraviolet radiation acting upon ozone
As you can see on page 12 of
http://www.pmodwrc.ch/uvconf2007/presentations/speeches/session4/4_1%20Haigh%20PMODUV.pdf
there is no excess heating due to UV or other shortwave radiation upon O3 at 200 hPa [or in the troposphere as such].
Page 15 shows that even more explicitly [perhaps you could comment on this Figure]
Her conclusion is that “The troposphere responds to changes in the stratosphere by a dynamical adjustment involving a feedback between the zonal wind and eddy propagation”
This recent meeting has lots of good stuff:
http://www.pmodwrc.ch/uvconf2007/presentations/speeches/
click on the various sessions to see more.
Leif Svalgaard (11:12:57) :
Her conclusion is that “The troposphere responds to changes in the stratosphere by a dynamical adjustment involving a feedback between the zonal wind and eddy propagation”
Bottom line page 28
Solar UV does affect (tropospheric) climate
Also from page 28
Calculations of stratospheric temperature are very sensitive to the specification of solar UV spectrum.
Exactly.eg
Wavelength dependence of isotope fractionation in N2O photolysis (2008)
In previous reports on isotopic fractionation in the ultraviolet photolysis of nitrous oxide (N2O) only enrichments of heavy isotopes in the remaining N2O fraction have been found. However, most direct photolysis experiments have been performed at wavelengths far from the absorption maximum at 182 nm. Here we present high-precision measurements of the 15N and 18O fractionation constants (e) in photolysis at 185 nm. Small, but statistically robust depletions of heavy isotopes for the terminal atoms in the linear N2O molecule are found.
Leif Svalgaard (08:54:38)
“We present satellite observations of the downward radiative flux from tropospheric ozone, for cloud free ocean conditions. This analysis uses infrared (IR) radiance spectra, integrated over the 9.6 micron ozone band between 985 to 1080 cm-1, and ozone profile retrievals from the Tropospheric Emission Spectrometer (TES)…
Whilst this is provided as an example .We can also see that it is a “steady state” and does not include dynamical responses such as convection and interchange.
eg
Role of Deep Cloud Convection in the Ozone Budget of the Troposphere
Jos Lelieveld 1 and Paul J. Crutzen 2
Convective updrafts in thunderstorms prolong the lifetime of ozone (O3) and its anthropogenic precursor NOx [nitric oxide (NO) + nitrogen dioxide (NO2)] by carrying these gases rapidly upward from the boundary layer into a regime where the O3 production efficiency is higher, chemical destruction is slower, and surface deposition is absent. On the other hand, the upper troposphere is relatively rich in O3 and NOx from natural sources such as downward transport from the stratosphere and lightning; convective overturning conveys the O3 and NOx toward the Earth’s surface where these components are more efficiently removed from the atmosphere. Simulations with a three-dimensional global model suggest that the net result of these counteractive processes is a 20 percent overall reduction in total tropospheric O3. However, the net atmospheric oxidation efficiency is enhanced by 10 to 20 percent.
http://www.sciencemag.org/cgi/content/abstract/264/5166/1759
When convective is coupled with radiative emissions CO2 doubling seems less of a problem eg Ramanathan
http://i255.photobucket.com/albums/hh133/mataraka/ramanathanco2x.jpg
Further to previous post maksimovich (12:54:47)
This has some interesting synergies with what Erl is suggesting.
Stratospheric dryness
“The mechanisms responsible for the extreme dryness of the stratosphere have been debated for decades. A key difficulty has been the lack of models which are able to reproduce the observations. Here we examine results from a new atmospheric chemistry general circulation model (ECHAM5/MESSy1) together with satellite observations. Our model results match observed temperatures in the tropical lower stratosphere and realistically represent recurrent features such as the semi-annual oscillation (SAO) and the quasi-biennual oscillation (QBO), indicating that dynamical and radiation processes are simulated accurately. The model reproduces the very low water vapor mixing ratios (1?2 ppmv) periodically observed at the tropical tropopause near 100 hPa, as well as the characteristic tape recorder signal up to about 10 hPa, providing evidence that the dehydration mechanism is well-captured, albeit that the model underestimates convective overshooting and consequent moistening events. Our results show that the entry of tropospheric air into the stratosphere at low latitudes is forced by large-scale wave dynamics; however, radiative cooling can regionally limit the upwelling or even cause downwelling. In the cold air above cumulonimbus anvils thin cirrus desiccates the air through the sedimentation of ice particles, similar to polar stratospheric clouds. Transport deeper into the stratosphere occurs in regions where radiative heating becomes dominant, to a large extent in the subtropics. During summer the stratosphere is moistened by the monsoon, most strongly over Southeast Asia.”
http://hal.archives-ouvertes.fr/hal-00302265/en/
Leif Svalgaard (08:36:39) :
“What you say is that T(global tropics, t) ~ T(200nPa SE P, t-12). This is what you should establish with a graph.”
This form of expression is lost on me. But is this the last graph in this post the one that you are after: erlhapp (23:35:33) :
http://i249.photobucket.com/albums/gg220/erlandlong/240-26030-40STemperatureVsSST20N-20.jpg
Leif Svalgaard (08:54:38) :
Is the failure of that heat to propagate downwards from the upper troposphere recognized in climate science? No.
In the extract you cite there is no evidence that ozone content of the upper troposphere varies strongly by latitude or that there is a failure of downward propagation of energy due to convection. Looks to me like they are inferring the downward heat flux and assuming it is surface effective. But to the extent that the energy is lost by convective decompression it is not effective in transferring heat downwards and a simple observation of the temperature curves below the heated layers reveal that it is not effective.
Leif Svalgaard (10:03:04) :
Sorry, that link is forcing an error in Firefox so I am unable to download.
But this statement I would contest:
“The reason why the effect at ground level is nearly zero is that the ozone’s absorption and radiation of infrared rays (from the Earth) is balanced, since the air temperature is almost the same as that of the Earth’s surface and there is no net absorption. At higher altitudes, where the temperature is lower, the net of infrared absorption by ozone is larger, making the greenhouse effect more efficient. Similarly, near the tropopause where the temperature of the atmosphere is at its lowest, the greenhouse effect of ozone is at its highest. In contrast, at higher altitudes in the stratosphere where the temperature is also higher, the net absorption of infrared rays by ozone is reduced, making the greenhouse effect negative above the middle layer of the stratosphere.”
This seems to be hand waving theory that ignores the distribution of ozone by latitude and the countervailing force of convection. The energy retention time is very different in the upper troposphere to that in the stratosphere where convection is attenuated. It is worthy of note that ozone is at a maximum at 30hPa and yet the observed temperature profile shows the strongest seasonal response of air temperature to outgoing radiation is at 100hPa. The absence of convection is the condition required for transfer energy in a downward direction. There is strong attenuation below 100hPa.
Leif Svalgaard (11:12:57) :
First let us note that the end statement in Joanna Haigh’s presentation is that
Solar UV does affect (tropospheric) climate. But, the author is at a loss to suggest how the solar signal is produced in the troposphere.
Secondly, there is no analysis of ozone by latitude or apparent recognition of its likely effect.
The other things I would note is that the study seems to be based upon a comparison between solar maximum and solar minimum. Both tend to produce La Nina conditions. No two solar minimums are the same and neither are solar maximums and the geomagnetic needle tells us that. Since we observe that 200hPa heating occurs on ENSO timescales, that timescales are a more appropriate interval for comparison of one period with another. That is elementary.
I don’t think these studies will get very far without detailed observation of flux of UV at the tropopause. Secondly one needs to take into account the spatial variation in ozone content.
But, the elementary observation from historical data (of which we have plenty) is that the upper troposphere is rising and falling in temperature while local humidity is falling. By inference cloud cover has declined. If the upper troposphere suffered net warming (as it manifestly did in1978, cooling slowly thereafter) and suffered a continuing loss in relative humidity, as it has, upper atmosphere cloud will be less today than it was prior to 1978.
A point of information: The best measures of the distribution of ozone by latitude that I have seen are located at http://www.osdpd.noaa.gov/PSB/OZONE/OZONE.html The ‘TOAST’ maps are revealing.
An interesting sidelight to the observation of ozone dynamics in the southern hemisphere is that the atmospheric circulation there continuously depletes ozone in the SH stratosphere by bringing it towards the surface more vigorously than in the northern hemisphere. The profile of 200hPa temperature between the equator and Antarctica tells us that. This makes the southern hemisphere upper troposphere more reactive to UV than the northern.
Joanna Haigh concludes:
“The observed response of the stratosphere to solar variability results from: direct UV heating, changes in circulation/transport and interaction with ozone.”
In due course I think we will recognise that the word troposphere can be inserted in this statement without compromising the truth. Further, we will recognize that the dynamics in the upper troposphere due to direct UV heating give rise to the southern oscillation, the dynamic that adds heat to the ocean, or takes it away accounting for change in global temperature.
erlhapp (14:34:24) :
http://i249.photobucket.com/albums/gg220/erlandlong/240-26030-40STemperatureVsSST20N-20.jpg
does not show the relationship to my eyes. There is a standard way of judging this: computing the cross-correlation between the two series, then move one series over one year and compute the cross-correlation again, etc. To humor me, post or email the two time series and I’ll do the calculation.
First let us note that the end statement in Joanna Haigh’s presentation is that Solar UV does affect (tropospheric) climate. But, the author is at a loss to suggest how the solar signal is produced in the troposphere.
She gives a detailed mechanism on page 27. And you should not quote out of context and ‘contest’ careful calculations by saying they are ‘handwaving”. Page 12 and 15 should be clear enough to you. They show directly that there is no shortwave heating of the upper troposphere due to absorption by O3. And in the papers I cited there are lots of discussion of O3’s variation with latitude. This has been known and monitored for a long time. But, I give up [without nasty comments of horses that won’t drink]. I hope that I have given the general readership the information they need to make up their own mind.
Leif Svalgaard (11:12:57) :
As you can see on page 12 of
http://www.pmodwrc.ch/uvconf2007/presentations/speeches/session4/4_1%20Haigh%20PMODUV.pdf
there is no excess heating due to UV or other shortwave radiation upon O3 at 200 hPa [or in the troposphere as such].
Page 15 shows that even more explicitly [perhaps you could comment on this Figure]
My comment on that figure is that the diagram specifies no location. The only one of the three diagrams that does specify a location is on page 11. For the heating to be apparent the ozone must be present. There is much more ozone present at 30°-40°S in the troposphere than in ‘the tropics’, location unspecified.
Ozone absorbs UVB. Some UVB gets to the surface. I suspect it is being absorbed wherever ozone is present.
P27 The mechanism is based on a model ‘spin up’. When the modelers can explain and predict the southern oscillation, the dynamic that changes global temperature I will (cautiously) start to take notice of them.
Anomalous heating at 200hPa is a fact of life. The consequences in terms of local cloud cover and surface pressure with knock on effects in terms of the strength of the easterlies and the location of the convection zones are the essence of the Southern Oscillation. You can contest whether UV is responsible (and I suggest it is just the initiator with the consequent increase on OLR the reinforcer) but not on the basis of the diagrams that you refer me to.
But next time you take a flight, take a window seat, and take an interest in the cloud layers at various elevations and resist the temptation to drop the shade when you get to 8,000 metes. See how many minutes it takes to get sunburnt.
And I guess that is where we finish up on this occasion. Thank you for your willingness to participate. Thanks to the umpire, the ball boys and the linesmen, few though they may be.
maksimovich (13:00:45) :
“In the cold air above cumulonimbus anvils thin cirrus desiccates the air through the sedimentation of ice particles, similar to polar stratospheric clouds. Transport deeper into the stratosphere occurs in regions where radiative heating becomes dominant, to a large extent in the subtropics.”
Yes, the mount of cirrus is greatest where convective clouds feed moisture into the upper atmosphere. The humidity levels at 300hPa tend to be greater than at 400-500hPa. The surface area to volume in an ice cloud is enormous and that speeds crystallization. The same dynamic affects all crystallization reactions including tartrate in wine, that I am familiar with. So this will dry the atmosphere. But, cut off the supply of moisture as happens above the warm pool in an El Nino event or warm the upper atmosphere by whatever means and the crystallization will not occur.
erlhapp (20:01:37) :
My comment on that figure is that the diagram specifies no location. The only one of the three diagrams that does specify a location is on page 11. For the heating to be apparent the ozone must be present. There is much more ozone present at 30°-40°S in the troposphere than in ‘the tropics’, location unspecified.
It does indirectly, as the solar zenith angle was set at 53 degrees corresponding to a mean latitude of 37 degrees. In any event, the O3 concentration does not vary that much [factor of two] with latitude, so that scale the curve on page 15 would vary by a factor of two which will not even be visible.
Ozone absorbs UVB. Some UVB gets to the surface. I suspect it is being absorbed wherever ozone is present.
You do not understand the simple physics: the heating depends on the product of three factors: the UV flux, the O3 concentration, and the absorption coefficient for UVB. At 200 hPa all these are small, and the product of three small quantities is very small. That is the reason for the UV heating going to near zero below 100 hPa.
Anomalous heating at 200hPa is a fact of life.
It is not ‘anomalous’, it is a natural consequence of the fact that O3 is a very efficient greenhouse gas
local cloud cover and surface pressure with knock on effects in terms of the strength of the easterlies and the location of the convection zones are the essence of the Southern Oscillation.
You mistakenly assume that this is disputed. What I show you is just that your specific mechanism for this is not at work. That is all.
Thanks for sending the email with the temperature data. I had already simply read off the values from your graph [in millimeters without converting to degrees, which is not necessary for correlation analysis]. The result of my analysis is here: http://www.leif.org/research/200%20hPa%20versus%20SST%20in%20tropics.pdf The conclusion is that there is no lag.
Leif Svalgaard (21:55:29) :
“You do not understand the simple physics: the heating depends on the product of three factors: the UV flux, the O3 concentration, and the absorption coefficient for UVB. At 200 hPa all these are small, and the product of three small quantities is very small. That is the reason for the UV heating going to near zero below 100 hPa.”
What varies is the ozone concentration at 200hPa and no ‘universal curve’ will be valid in this circumstance. The physics is no problem, the quantification is the problem.
How do you explain the peak in variability in 100hPa, 150hPa and 200hPa in March and September in the historical data. This suggests to me that UV flux is greater at the equinox. That would explain the peak in temperatures at 1hPa at the same time. There can be no argument surely about what is causing that peak. How does your universal curve apply in this situation? Do you just shift it down a bit for these times. How much?
Thanks for your analysis of 200hPa temperature in the SE Pacific versus Tropical SST Leif. You are a skilled practitioner. I am no statistician. But I have had a careful look at the data and I look at these things from a practical point of view. I see 11 occasions where the peaks unambiguously belong together. The rest I discard. Of the 11, the timing of peaks matches exactly in five cases. In the other seven cases 200hPa temperature leads TSST.
But, if I am choosing a series to predict ENSO events I would be looking at sea surface pressure in the South East Pacific where the lead is more regular both in the upturn and the downturn.
For the interested reader, you can see the relationship between surface pressure in the south east pacific and tropical sea surface temperature 20N to 20S latitude in figure 6 at http://climatechange1.wordpress.com/2009/01/02/the-southern-oscillation-and-the-sun-2/
Like a sculptor who can feel the finished work within the marble.
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“Like a sculptor who can feel the finished work within the marble.”
Instinct and talent and other intangibles, indeed. Was Newton greater than Michelangelo? I doubt it.