Revisiting Bratcher and Giese (2002)
Guest Post by Bob Tisdale
INTRODUCTION
In a comment in the March 2009 SST Anomaly Update thread, Blogger DB reminded me of the Bratcher and Giese (2002) paper “Tropical Pacific Decadal Variability and Global Warming” [GEOPHYSICAL RESEARCH LETTERS, VOL. 29, NO. 19, 1918, doi:10.1029/2002GL015191, 2002].
Abstract:
“An analysis of ocean surface temperature records show that low frequency changes of tropical Pacific temperature lead global surface air temperature changes by about 4 years. Anomalies of tropical Pacific surface temperature are in turn preceded by subsurface temperature anomalies in the southern tropical Pacific by approximately 7 years. The results suggest that much of the decade to decade variations in global air temperature may be attributed to tropical Pacific decadal variability. The results also suggest that subsurface temperature anomalies in the southern tropical Pacific can be used as a predictor for decadal variations of global surface air temperature. Since the southern tropical Pacific temperature shows a distinct cooling over the last 8 years, the possibility exists that the warming trend in global surface air temperature observed since the late 1970’s may soon weaken.”
Link to GRL Abstract:
http://www.agu.org/pubs/crossref/2002/2002GL015191.shtml
Also refer to the copy of the Bratcher and Giese slide presentation:http://www.decvar.org/documents/CCR_workshop/bratcher.htm?PHPSESSID=df81bed52419c895efe9135099fb26e9
And theWorldClimateReport post on the study here:http://www.worldclimatereport.com/archive/previous_issues/vol8/v8n04/feature1.htm
And CO2Science did a write up here:http://www.co2science.org/articles/V6/N20/C1.php
As illustrated in Figure 1 (Figure 1 of Bratcher and Giese 2002), their comparison of Global Temperature Anomaly (GISTEMP) and NINO3 SST Anomaly (Simple Ocean Data Assimilation-SODA) ran from 1948 to 2000. The graph appears to be of annual (not monthly) data, with 5-year smoothing as discussed in the paper. The two questions that struck me were: How far back in time do the two datasets coincide and what would the updated graph look like? (The latter question was also part of DB’s comments.)
http://i40.tinypic.com/nyd7nn.jpg
Figure 1
The problem: the easily available SODA data through the KNMI Climate Explorer website only includes the years of 1958 to 2004. So I’ve substituted ERSST.v3b data in place of the SODA data. I’ve also used monthly instead of annual data.
UPDATING THE GLOBAL TEMPERATURE AND NINO3 SST ANOMALY COMPARISON
Figure 2 illustrates a reasonable facsimile of Cell A of the Bratcher and Giese comparison of Global Surface Temperature and NINO3 SST anomalies. It has been extended in time through February 2009. The global surface temperature data is GISTEMP and the NINO3 SST anomaly data is ERSST.v3b. Bratcher and Giese appear to use different base years than the ones used here (1971-2000), and, of course, the variability appears greater with the monthly data.
http://i44.tinypic.com/abjy9z.jpg
Figure 2
Figure 3 updates Cell B of the Bratcher and Giese Figure 1. Without accounting for volcanic aerosols, any attempt to determine the 4-year lag between NINO3 and Global Surface Temperatures as claimed by Bratcher and Giese would be difficult with these time-series graphs, including Figure 1. However, Global Temperatures do appear to respond gradually over time to the shift in NINO3 SST anomaly. Note the impact of the Pacific Climate Shift of 1976 on the smoothed NINO3 SST anomalies. It stands out in Figures 1, 2, and 3.
http://i44.tinypic.com/14uko7n.jpg
Figure 3
Based on the averages of the smoothed NINO3 SST anomalies for the periods of 1950 through 1975 and of 1978 to present, Figure 4, the magnitude of the 1976 shift in NINO3 SST anomalies is more than 0.4 Deg C. If one considers NINO3 SST anomalies as a forcing, then the rise of global temperatures from 1976 to the early 2000s would then appear to be a natural response to a natural variation.
http://i41.tinypic.com/9st6yw.jpg
Figure 4
EXTENDING THE COMPARISON BACK IN TIME
Figure 5 illustrates the NINO3 SST and global surface temperature anomalies from 1880 to present. Both datasets are smoothed with 61-month (5-year), running-average filters. Two things to consider when looking at the data before 1948: the discontinuity in the SST anomalies at 1945 would have impacted both datasets, and prior to 1914 and the opening of the Panama Canal, there were very few SST samples in the NINO regions. With those in mind, the fact the two datasets do seem to “track” is quite remarkable.
http://i40.tinypic.com/333d9pg.jpg
Figure 5
The NINO3 data was still noisy with the 61-month smoothing, so I changed to a 121-month filter in Figure 6. This seems to aid in illustrating the influence of NINO3 SST anomalies on global surface temperature. ENSO appears to dictate whether global surface temperatures rise or fall over decadal periods. It also illustrates a gradual “ramp up” required to overcome global thermal inertia.
http://i39.tinypic.com/1492ohi.jpg
Figure 6
There’s a mismatch with those two datasets. The NINO3 SST anomalies are based on ERSST.v3b data, while GISS uses HADSST data prior to November 1981 for their global surface temperature product. So let’s look at matching data.
NINO3 AND GLOBAL SST ANOMALIES USING ERSST.v3b DATA
In Figure 7, the GISS Global Surface Temperature data has been replaced by ERSST.v3b Global SST Anomaly data. The most significant difference between the GISTEMP Global Surface Temperature and the ERSST.v3b SST data can be found between ~1880 and 1900. Note how the drop in the temperature from 1880 to 1900 is exaggerated in the ERSST.v3b Global SST anomaly data.
Note also how the effect of NINO3 SST anomalies on Global SST anomalies is still clear after 1914. This is especially true following the shift in NINO3 SST anomalies in 1976.
http://i43.tinypic.com/34e6ow7.jpg
Figure 7
THE SECOND CONCLUSION OF BRATCHER AND GIESE 2002
As noted earlier, Bratcher and Giese wrote in the Abstract, “Anomalies of tropical Pacific surface temperature are in turn preceded by subsurface temperature anomalies in the southern tropical Pacific by approximately 7 years.” They illustrated this lag in their Figure 3, my Figure 8.
http://i39.tinypic.com/w970ao.jpg
Figure 8
In the body of the paper, Bratcher and Giese discuss and illustrate the lag between the subsurface Tropical Pacific temperature and NINO3 SST anomalies. I am not trying to undermine that in any way. But the second problem I encountered while trying to update the Bratcher and Giese 2002 paper was the availability of Subsurface Temperature data for the Tropical Pacific Ocean. Simple Ocean Data Assimilation (SODA) data through KNMI does not include the subsurface temperature data.
It was my original intent to end the comparisons here, which is why the graphs are titled “Revisiting Part of Bratcher & Giese 2002”, but then it struck me that this would be a good time to illustrate a possible influence of the Southern Ocean on ENSO.
COMPARING SST ANOMALIES FOR THE SOUTHEAST PACIFIC ACC AND NINO3
Figure 9 shows the locations of NINO3 region and the portion of the Antarctic Circumpolar Current (ACC) in the extreme Southeast Pacific used in the following comparison. Note how the Humboldt Current carries waters from the ACC along the coasts of Chile and Peru and up to the eastern equatorial Pacific. The SST anomalies of the Southeast Pacific ACC should have an influence on NINO3 SST anomalies.
http://i39.tinypic.com/ziqgkj.jpg
Figure 9
Figure 10 is a comparison of NINO3 and Southeast Pacific ACC SST anomalies. Again, both datasets have been smoothed with 121-month filters. From 1940 to present, there is a reasonable agreement between the two datasets, indicating that the underlying SST for the equatorial Pacific is impacted by the ACC and Southern Ocean SST anomalies. There does not appear to be the 7-year lag suggested by Bratcher and Giese, though.
I found the correlation between the Southeast Pacific ACC and NINO3 SST anomalies interesting, but not conclusive. And I have no explanation for the divergence between the two datasets from ~1915 to 1945. Did the North Pacific have a greater influence during those times? I can’t say. I’ll have to investigate that and the SST anomalies along the Humboldt Current in a future post to try to determine the reason for the disagreement during that period.
http://i40.tinypic.com/fw29p5.jpg
Figure 10
YET ANOTHER POST ABOUT GLOBAL TEMPERATURE RESPONSE TO ENSO
In my series of posts “Can El Nino Events Explain All of the Warming Since 1976?” I illustrated the processes that cause step changes in the East Indian and West Pacific SST anomalies, which in turn result in increased global SST anomalies. Refer to:
–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
–Supplement To “Can El Nino Events Explain All Of The Warming Since 1976?”
–Supplement 2 To “Can El Nino Events Explain All Of The Warming Since 1976?”
I illustrated the similar impacts of significant ENSO events on the North Atlantic Ocean in There Are Also El Nino-Induced Step Changes In The North Atlantic.
I’ve shown how Global Surface Temperature time-series data can be replicated using natural variables in Reproducing Global Temperature Anomalies With Natural Forcings. In that post, a running total of NINO3.4 SST anomalies establishes the underlying curve.
Based on the findings of Bratcher and Giese 2002, this post presents yet another way to illustrate that ENSO dictates long-term Global Surface Temperature Anomalies.
CLOSING REMARKS – THE BIG IFS
-IF the 5-year smoothing used by Bratcher and Giese (or the 61- and 121-month smoothing that I used) reflects the underlying NINO SST anomalies, and
-IF global temperatures do respond as implied by the correlation of the NINO3 SST anomalies and Global Surface Temperature anomalies as shown in the preceding and as discussed in Bratcher and Giese 2002, and
-IF NINO3 SST anomalies continue to follow the Southern Ocean and ACC SST anomalies,
-THEN Global Surface Temperatures should continue to decrease in response.
Will these natural variations overwhelm any anthropogenic sources of warming and drive global temperatures down, as opposed to only flattening the curve as it has recently and as it had from the 1940s to the late 1970s? Only time will tell.
SOURCE
The GISS Global Surface Temperature anomaly data and the ERSST.v3b SST anomaly data are available through the KNMI Climate Explorer website:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere
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This is an excellent analysis and the last sentence in the conclusion is irrefutable, though some would suggest that the outcome is settled. We live in interesting times. Great post!
Figure 9 was interesting to show the ACC becoming the North then West Humboldt current then mixing in the NINO3 sampling area in its westward journey.
I wonder if http://www.bom.gov.au/climate/enso/sst_weekly.gif is showing an embryonic El Nino ?
And IF the Sun continues to be out to lunch, there’s another factor.
Something tells me that it’s the Sun that warms the oceans.
Bob,
“…the magnitude of the 1976 shift in NINO3 SST anomalies is more than 0.4 Deg C”
What is the physical basis for this injection of the energy into NINO-3 in 1976 and why has it not dissipated?
“If one considers NINO3 SST anomalies as a forcing, then the rise of global temperatures from 1976 to the early 2000s would then appear to be a natural response to a natural variation.”
I don’t see how there can be an energy balance that would allow a 0.4C change in an area of the Pacific to cause the entire climate of the world to be raised by the same amount. Please explain.
Fig. 4: Step change in 1976. Moved the weather station?
Robert, of course it’s the Sun that warms the oceans. The Sun warms the oceans. It even warms the land. And melts ice. The question is what causes the variations and trends in temperature. The Sun, when measured outside of Earth’s atmosphere, is a steady state entity compared to the Earth. The Earth, on the other hand, is filled with variations. You can even see these variations from outside the atmosphere looking in. It looks nothing like a steady state ball. If there were a tongue we could put a thermometer under and measure both the Earth and the Sun, the Sun’s temp would be fairly steady. Earth’s temp would bounce and ping around. The only orb that varies to the degree that the temperature varies is the Earth. Therefore there is something about Earth that takes the heat from the Sun and causes it to jitter about and trend up and down.
I was comparing between the Sun, moom and Earth. The Earth is a source of much variation. The Sun and moon, not so much. Other planets also demonstrate a great deal more variability than the Sun does.
Keep in mind, the oceans are a heat sink, the atmosphere is not by many orders of magnitude. Neither is land.
Based on what I’ve learned apart from the arguments for and against the theoretical and hypothetical aspects of atmospheric processes affecting “climate change”, the atmosphere has not been heating up as climate models dictate, but the surface has warmed slightly. As such, it is indicative of more sunlight reaching the surface, both land and ocean, warming our living environment we so enjoy with the net result being a much more bountiful supply of food and plant life.
SST is a reflection of the total heat content of the oceans but because it is so variable it is difficult to assess. However if the data shows SST are falling uniformly it would seem logical OHC is as well and that can mean only one thing.
It appears understanding the oceans is the key to how warm the earth was, is and will be, not counting molecules of CO2 which has yet to be proven to have anything but a negligible if not immeasurable net effect on surface temperature or OHC. If the oceans are not warming, there is no “global” warming.
Thanks Bob Tisdale for yet another informative analysis on oceans.
My 2c
Tom P (19:41:18) : “ I don’t see how there can be an energy balance that would allow a 0.4C change in an area of the Pacific to cause the entire climate of the world to be raised by the same amount.”
I’m having trouble with “energy balance” and “climate … raised by the same amount”
Seems Earth, climate-wise, is in a continual state of dynamic imbalance. For example when the warm water in the W. Pac. Ocean sloshes back eastward there has to be a whole lot of adjustments to follow. When the PDO switches one way or the other – adjustments follow. These things might be called a “balancing act” but not ever balanced.
As to the “same amount” phrase, I think equating many climate situations all over the world to an average temperature is a too simplifying concept.
Put one foot in a bucket of ice water and one in a bucket of hot water. On average you should feel normal. Now switch feet and buckets. Notice any difference?
I’ve been hoping that this year will see a pronounced cooling, and that the current lag in the retreat of arctic ice will continue, as it would pour cold water on the hotheads and defer destructive legislation. And I’ve been suspecting that such an unexpected upset would occur, because that’s the sort of banana-peel the Pranksters Above like to lay out for movements with their nose in the air.
This post reinforces my hope, and strengthens my anticipation, that that is what is to come.
On the Bloomberg channel they had an interview with a trader from the Blackmont firm; one Mr. Yves Lemoureux who was projecting what they thought would happen in various markets. Almost fell out of my chair when he said, roughly, “I’ve been watching sunspots. Look up the Maunder Minimum in Google. If we continue having low sunspots for another year like this, we will have a run up in the price of grains. It’s a cumulative effect. There is a correlation between sunspots and grain production. DBA is a good buy, with a double bottom in place” (DBA is an agricultural commodity basket Exchange Traded Fund.)
Wonder if he follows the PDO too?
Very interesting. Real traders betting real money against AGW based on a historical inverse correlation between sunspots and grain production (i.e. dead sunspots meaning cold). Wonder where I’ve heard that before? 😉
Tom P: You asked, “What is the physical basis for this injection of the energy into NINO-3 in 1976 and why has it not dissipated?”
The 1976 Pacific Climate Shift did not only effect the NINO3 region; SST anomalies shifted in the entire eastern Pacific. Refer to my post on “The 1976 Pacific Climate Shift.” In it I examined trends before and after 1976.
http://bobtisdale.blogspot.com/2008/10/1976-pacific-climate-shift.html
Trenberth and Stepaniak created the Trans Nino Index (TNI) to illustrate that the development of ENSO events shifted at that time as well. Refer to “Indices of El Nino Evolution” (2001):
http://ams.allenpress.com/perlserv/?request=get-document&issn=1520-0442&volume=014&issue=08&page=1697
What caused the shift? There are as many theories on what caused the 1976 Pacific Climate Shift as there are papers. Bratcher and Giese suggest in the referenced paper that the origin is the tropical South Pacific.
You wrote, “I don’t see how there can be an energy balance that would allow a 0.4C change in an area of the Pacific to cause the entire climate of the world to be raised by the same amount. Please explain.”
I did not state that the Pacific caused the entire climate of the world to be raised by the same amount. The fact that the “before and after” NINO3 SST anomaly averages in Figure 4 also agree with the global temperature values in 1976 and in the 2000s is coincidental. But now that you raised it… The frequency and magnitude of El Nino events increased after 1976. I discussed the processes by which ENSO events could be responsible for all of the warming in the posts with the title “Can El Nino Events Explain All of the Warming Since 1976?” Refer to the links after Figure 10 above.
El Nino events redistribute heat from the equatorial Pacific so that it can be dissipated more easily at high latitudes. The 1997/98 El Nino did a great job of raising Arctic temperatures. Heat from that El Nino lingered until the El Ninos of 2002/03, 2004/05, and 2006/07 bumped Arctic temperatures up some more. But not all of the heat is redistributed from the Tropical Pacific to high latitudes. Part of the warm water that travels eastward during an El Nino “sloshes” back to the Pacific Warm Pool. And to compound things and add more heat to the Pacific Warm Pool, cloud cover over the Pacific Warm Pool drops during an El Nino, causing additional heating there and adding more fuel for the next El Nino. Refer to my post “What Causes Sea Surface Temperature (SST) To Rise”:
http://bobtisdale.blogspot.com/2009/02/what-causes-sea-surface-temperature-sst.html
Terrific post, thanks Bob. Just following up on your reply to Tom P, would a run of La Nina’s have the opposite effect, creating more cloud over the PWP and so reinforcing a longer term cooling trend? Is there any evidence of that happening and is there reliable cloud cover data for this area of the planet so vital to the Earth’s energy budget?
Keith Minto: You asked, “I wonder if http://www.bom.gov.au/climate/enso/sst_weekly.gif is showing an embryonic El Nino ?”
Warm anomalies show up at times. They come and go. Could it be an indicator of the start of the next El Nino? It’s possible. I don’t rule out anything. However, the Unisys SST anomaly map is still showing light La Nina conditions over the NINO3.4 region.
http://weather.unisys.com/surface/sst_anom.html
An El Nino originates with a slackening of the Pacific trade winds, which causes more water than normal to travel eastward along the Equatorial Counter Current. Since there’s a steep SST gradient along the equatorial Pacific, (higher in the west than in the east) the change in direction of flow causes the above normal temperatures. During significant El Ninos, much of the warm water from the Pacific Warm Pool travels east as well. I illustrated this process in a post called “Equatorial Currents Before, During, and After The 1997/98 El Nino.” Refer to the video at the bottom of the page:
http://bobtisdale.blogspot.com/2009/02/equatorial-currents-before-during-and.html
E.M.Smith (00:24:18) :
On the Bloomberg channel they had an interview with a trader from the Blackmont firm; one Mr. Yves Lemoureux who was projecting what they thought would happen in various markets. Almost fell out of my chair when he said, roughly, “I’ve been watching sunspots. Look up the Maunder Minimum in Google. If we continue having low sunspots for another year like this, we will have a run up in the price of grains. It’s a cumulative effect. There is a correlation between sunspots and grain production. DBA is a good buy, with a double bottom in place” (DBA is an agricultural commodity basket Exchange Traded Fund.)
Wonder if he follows the PDO too?
Very interesting. Real traders betting real money against AGW based on a historical inverse correlation between sunspots and grain production (i.e. dead sunspots meaning cold). Wonder where I’ve heard that before? 😉
Very, very interesting, so I checked that. And you are right!
I found
Lomoureux Sees ‘One More Drop’ for Stocks, Likes Uranium
http://www.bloomberg.com/apps/news?pid=newsarchive&sid=aWo1xANcdNco
He talks about sunspots and the Maunder Minimum about 6 minutes into the interview.
Great post.
DR said “It appears understanding the oceans is the key to how warm the earth was, is and will be….” How true.
Water, in all it’s forms, governs our climate.
How true. Remember, according to the Mauna Loa CO2 data, the oceans annually inhale three times mans emissions of CO2.
Also, consider the endo and exothermic properties of water.
380 molucules for every 1 000 000 molecules of our atmosphere will not send the earth to some tipping point.
Tallbloke: You asked, “would a run of La Nina’s have the opposite effect, creating more cloud over the PWP and so reinforcing a longer term cooling trend?”
I would think just the opposite. The cloud amount follows the warm water. A decrease in temperature means less cloud amount. It was the variation in total cloud amount over the PWP during an El Nino that I was referring to in my comment to Tom P. The SST in the PWP drops during an El Nino, as the warm water sloshes east. This causes the drop in total cloud amount, which adds more heat to the PWP than would have occurred had there been no change in cloud cover.
You also asked, “…is there reliable cloud cover data for this area of the planet so vital to the Earth’s energy budget?”
There are at least two sources of cloud cover/amount data. COADS cloud cover data is based on observations and ISCCP cloud data is satellite based. The ISCCP has multiple variables but the data has only been available since 1983. Of course, the accuracy of both datasets has been questioned. I don’t recall the specifics.
KNMI Climate Explorer has both the COADS cloud cover and ISCCP cloud amount data, but the ISCCP data (available a three levels plus total) through KNMI hasn’t been updated since 2006. So I can’t comment how the cloud amounts are reacting to the La Nina conditions of this year and last.
Bob,
Thanks for your response. A very strong contender for the 1976 step would be a permanent change in the vertical currents of the tropical Pacific:
http://www.sciencemag.org/cgi/content/abstract/281/5374/240
But there obviously must be an increased energy input to support this warming, and as you quite rightly say in ““What Causes Sea Surface Temperature (SST) To Rise” the ultimate source of energy necessary to raise SSTs has be an increase in solar contribution. The oceans are not overall sources of energy, though they can act to capture, store, distribute and dissipate energy from other sources.
Hence to understand the rise in temperatures we need to understand the changes in the solar forcing. Attempting to explain the upwards trend in global temperatures with reference to the oceans alone is the equivalent of trying to understand the temperature of a car engine through consideration of just the water in the cooling system!
So we are left with explaining why the solar input has changed. Again you rightly say that changes in total solar irradiance are insignificant.
Nearly all your subsequent analysis on your website and all in this article is about distributional processes, so these cannot explain the overall increase in temperature. But you mention one possibility on your website – that it is the cloud cover over the Pacific which is driving a change in the solar forcing and therefore injecting the required energy into the system.
As I am sure you are aware, Roy Spencer has a very similar idea, though he is
having difficulty getting his work published. This might be related to the difficulty in justifying his selection of parameters to try to match the PDO time series to the temperature data. Maybe you could give him a hand?
Bob,
Thanks for your response. My reply seems to have run foul of the spam filter…
In case it doesn’t resurface, I’ll summarise briefly:
If as you quite rightly say in “What Causes Sea Surface Temperature (SST) To Rise” the underlying cause of this rise is a change in the solar input, what do you think is changing this solar forcing and how does it account for the size of the measured global warming?
From the graphs, the Southeast Pacific ACC SST anomaly appears to precede and drive the Ninho 3 anomaly.
So please, please, please could somebody graph solar activity / sunspot number against the Southeast Pacific ACC SST anomaly. (Or, the icing on the cake, cosmic ray activity against the Southeast Pacific ACC SST anomaly.)
This would then confirm or disprove the following fairly reasonable hyothesis:
1. Solar activity inversely drives cosmic ray flux at the earth’s atmosphere.
2. Cosmic ray flux drives nucleation in the earth’s atmosphere. This effect being most noticeable in the southern oceans, where the lack of land mass fails to provide dust bourne nucleation.
3. Increased nucleation in the southern oceans provides increased cloud cover and significant changes in temperature.
3a. Proximity of the southern oceans to Antartica provides a strong reinforcing mechanism via increased ice cover and albedo effects.
4. Southern ocean temperature leaks up north to drive overall Pacific temperature.
5. Pacific temperature drives world surface temperature.
6. Bob’s your uncle.
Robert Bateman (19:36:07) :
And IF the Sun continues to be out to lunch, there’s another factor.
Something tells me that it’s the Sun that warms the oceans.
I agree with you.
Based on 50+ years of observation, I’ve noticed a positive correlation between sunshine and temperature. Furthermore, it seems to follow a short term 24 hour cycle, and a longer term 365 day cycle. These temperature cycles also seem to be perturbed by cloud cover and winds. Winds from the north correlate with dropping temperature, and wind from the south correlates with rising temperature.
During the summer, I’ve also noticed a correlation between number of high sunlight summer days and swimming pool and lake water temperature. It seems that as the number of days increases, so does the temperature of the water in the pool.
I’ve noticed similar correlations with soil temperature.
My theory is that the Sun does heat exposed water. Being a system type, my corollary to the theory is that Solar energy does drive climate.
Here’s a prediction based on my theory, on a short enough time scale we can evaluate it over the few months:
If the current low level of Solar activity continues, then: A. This summer we will observe lower than average temperatures. B. The growing season will start later than average, end end sooner than average.
On another thread, I presented a rough calculation of the staggering amount of energy change in the Central Pacific involved in just 1 watt/sm fluctuation in TSI, and added that included other external sources only increased the amount. Another poster pointed out that geothermal also contributed.
Silly me. I thought science began with observation.
I should have added, if my predictions pan out, can we then accept that:
1. I’ve collected observations.
2. Formulated a theory based on observation.
3. Used the theory to make predictions.
4. The predictions were correct.
And therefore the Sun does affect climate.
Could we then all agree on that and maybe work toward building climate models based on Old Science understanding of THERMODYNAMICS AND ENERGY BALANCE?
All of this reminds me of Lambeck, K. and Cazenave, A., 1976. Long Term Variations in the Length of Day and Climate Change, Geophysical Journal International Vol 26 Issue No 3 pps 555 to 573.
THey not only report the global cooling of the 1960s and 70s they explained it by a decrease in the earth’s rotation AND noting the planet had started to spin faster, they predicted the imminent global warming. They used sound geiphysical science for the lot!! Surely a Nobel Prize is in order.
Lambeck and Cazenave (1976) reported that there is an established relationship between the Earth’s decadal variable rotation and climate dynamics. As LoD shortens, (i.e. the Earth rotates faster) the planet warms; in contrast, as LoD lengthens, the planet cools. There is a time lag of most likely six years between the change in the Earth’s rotation and global temperature changes.
They found that:
“The long-period (greater than about 10 yr) variations in the length-of-day (LoD) observed since 1820 show a marked similarity with variations observed in various climatic indices; periods of acceleration of the Earth corresponding to years of increasing intensity of the zonal circulation and to global-surface warming: periods of deceleration corresponding to years of decreasing zonal-circulation intensity and to a global decrease in surface temperatures. The long-period atmospheric excitation functions for near-surface geostrophic winds, for changes in the atmospheric mass distribution and for eustatic variations in sea level have been evaluated and correlate well with the observed changes in the LoD.“
They argued that the cooling of that the planet experienced in the 1960s arose from a slowing of the Earth’s rotation:
“if the hypothesis [that decadal rotation decrease (increase) results in planetary cooling (warming)] is accepted then the continuing deceleration of[the rotating Earth] for the last 10 yr suggests that the present period of decreasing average global temperature will continue for at least another 5-10 yr.”
Lambeck and Cazenave (1976) predicted that the cooling would come to an end by the mid 1970s and be followed by a period of global warming because they discovered that the planet’s rate of rotation began to accelerate from 1972:
“Perhaps a slight comfort in this gloomy trend is that in 1972 the LoD showed a sharp positive acceleration that has persisted until the present, although it is impossible to say if this trend will continue as it did at the turn of the century or whether it is only a small perturbation in the more general decelerating trend.”
Recent data shows that the rate of rotation has been de-accelerating since the early 1990s, (and before that from the peak of the 1970s) indicating that the planet will cool.
I think that the observational record since 1820 provided a sound foundation for the hypothesis that for time periods equal to or greater than a decade, planetary rotation drives climate: a decadal rotation decrease (increase) results in planetary cooling (warming).
This hypothesis has been corroborated by subsequent research, for example, Morner (1987 and 1995). He reported that there was a causal chain-relation between sunspot activity, solar wind strength, Earth’s rotation rate, oceanic surface circulation, atmospheric angular momentum and regional climatic changes on a decadal time-scale.
Tom P: You asked, “…what do you think is changing this solar forcing and how does it account for the size of the measured global warming?”
I wrote a post a few weeks ago that will hopefully help answer the first part of that two-part question.
http://bobtisdale.blogspot.com/2009/04/did-decrease-in-total-cloud-amount-fuel.html
While my post deals with the possibility that a significant drop in cloud amount over the tropical Pacific fueled the 1997/98 El Nino, the decrease in cloud amount there began ~1985 according to the ISCCP data, so that would have aided the 1986/87/88, the 1991/92, and the 1994/95 El Nino events also. Unfortunately, that ISCCP dataset began in 1983, so we really don’t know what the values were before then.
In summary, a decrease in cloud amount causes an increase in Downwelling Shortwave Radiation (Visible Light). Pavlakis et al discussed this in their 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
With the decrease in cloud amount fueling the El Ninos, I believe I’ve then answered the second part of your question with the posts titled “Can El Nino Events Explain All of the Warming Since 1976?” Links are above and here:
http://bobtisdale.blogspot.com/2009/01/can-el-nino-events-explain-all-of.html
http://bobtisdale.blogspot.com/2009/01/can-el-nino-events-explain-all-of_11.html
http://bobtisdale.blogspot.com/2009/01/supplement-to-can-enso-events-explain.html
http://bobtisdale.blogspot.com/2009/01/supplement-2-to-can-enso-events-explain.html
E.M.Smith (00:24:18) :
Follow his advice without any doubt. These guys know more about climate than a thousand “new age” modellers or climatologists.
That is the best forecast, it is about their living or dying. Merchants always know more; be sure grain prices will increase.