Typical (Average) El Nino, Traditional El Nino, and El Nino Modoki Events
Guest Post by Bob Tisdale
Recently, there have been a number of posts around the blogosphere about the current El Nino or about Sea Surface Temperatures (SST). Accompanying them are predictions by the authors of those posts or by commenters of a pending La Nina event. But the “typical” El Nino event is not followed by a La Nina event. Also, the current 2009/10 El Nino event is an El Nino Modoki; that is, simply, the area with elevated SST anomalies is located more towards the center of the tropical Pacific than a traditional El Nino event; and few La Nina events follow El Nino Modoki.
A number of months ago I noticed some of my visitors arrived from Google searches of “typical El Nino” or “average El Nino”. I prepared this post for them back then but got sidetracked and never posted it.
This post looks at the development and decay of the average El Nino, of the average traditional El Nino, and of the average El Nino Modoki. I’ve also segmented the data into two periods, before and after 1979 to illustrate the change in development and strength of El Nino events. Last, as references, are spaghetti plots of the development and decay of all El Nino events since 1950 (excluding the current El Nino, since it’s not complete). The post could also be used by those bloggers who like to make predictions or by those wanting to see whether prognostications have any basis in history.
THE AVERAGE EL NINO
Figure 1 illustrates the development and decay of the average El Nino event for the period of 1950 through 2007. It starts in January of the development year and ends in December of the following (decay) year. To create the graph, I averaged the SST anomaly (ONI) values for the 24 months associated with each official El Nino event identified on the CPC’s Oceanic Nino Index (ONI) webpage:
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml
The average El Nino reaches the +0.5 deg C threshold of an El Nino in late May, peaks in December, then quickly decays until it drops below the +0.5 deg C El Nino threshold in mid March. The SST anomalies of the average El Nino do drop below zero, but during the following ENSO season they do not cross the -0.5 deg C threshold for a La Nina event.
http://i39.tinypic.com/k3vuvo.png
Figure 1
BEFORE AND AFTER 1979
The frequency and magnitude of ENSO events changed about 1976. Between the mid-1940s and the mid-1970s, La Nina events dominated (with a period of El Nino dominance in the 1960s), and after, El Nino events were dominant. This can be illustrated with a long-term graph of NINO3.4 SST anomalies smoothed with a 121-month filter, Figure 2.
http://i43.tinypic.com/33agh3c.jpg
Figure 2
But studies such as Trenberth et al (2002) divide the data into periods before and after 1979, based on the development of El Nino events, so I’ve divided the data in this post at 1979. (The 1976/77 event was a weak traditional El Nino, and the 1977/78 El Nino was a weak El Nino Modoki.) Link to Trenberth et al (2002) “Evolution of El Nino–Southern Oscillation and global atmospheric surface temperatures”:
http://www.cgd.ucar.edu/cas/papers/2000JD000298.pdf
The average SST anomalies of the El Nino events before and after 1979 are shown in Figure 3. It comes as no surprise that El Nino events after 1979 are stronger and last longer than those before the cutoff year. Still, even in more recent decades, the average El Nino is not followed by a La Nina.
http://i40.tinypic.com/2wpto8w.png
Figure 3
TRADITIONAL EL NINO VERSUS EL NINO MODOKI
Central Pacific versus Eastern Pacific El Nino events are discussed in a number of recent papers. Ashok et al (2007) “El Nino Modoki and its Possible Teleconnection”… https://www.jamstec.go.jp/frcgc/research/d1/iod/publications/modoki-ashok.pdf
…provides an equation that can be used to identify El Nino Modoki:
“EMI= [SSTA]A-0.5*[SSTA]B-0.5*[SSTA]C …(1)
“The square bracket in Equation (1) represents the area-averaged SSTA over each of theregions A (165E-140W, 10S-10N), B (110W-70W, 15S-5N), and C (125E-145E, 10S-20N), respectively.”
Ashok et al further describe the basis for their selection of El Nino Modoki events: “Based on the time series of the EMI shown in Figure 4a, we have identified seven typical El Niño Modoki events that lasted from boreal summer through boreal winter, peaking in one of these seasons (seasonal standard deviations for boreal summer and winter are 0.5ºC and 0.54ºC respectively). These typical El Niño Modoki events occurred in 1986, 1990, 1991, 1992, 1994, 2002, and 2004. Additionally, we identified a typical El Niño Modoki during the boreal winter of 1979-80 that lasted through the summer of 1980, though its amplitude fell below the threshold of 0.7 σ by then.” And they clarify with the footnote, “We call an El Niño Modoki event ‘typical’ when its amplitude of the index is equal to or greater than 0.7 σ, where σ is the seasonal standard deviation.”
Ashok et al appeared to use two definitions of an El Nino Modoki: first, the average of boreal summer through boreal winter for most events, and, second, the average of the boreal winter for the 1979 event. Using the average boreal summer through winter (June through February) El Nino Modoki Index and the boreal winter El Nino Modoki Index, Figure 4, as references, I’ve identified the typical El Nino Modoki events before 1979 (based primarily on the boreal winter data when they conflict). These along with traditional El Nino events are shown in Table 1, as are the breakdown of El Nino events after 1979.
http://i40.tinypic.com/16kc3kg.png
Figure 4
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http://i39.tinypic.com/24e7v2t.png
Table 1
Note 1: El Nino Modoki events identified by Ashok et al that do not qualify as official El Nino events on the ONI Index have been excluded.
Note 2: As illustrated in Table 1, there were more El Nino Modoki before 1979 than after, yet in press releases we’re advised that El Nino Modoki events are new, and that this NEW TYPE is resulting in a greater number of hurricanes with greater frequency and more potential to make landfall.” Refer to the press release…http://media-newswire.com/release_1094000.html…for the Hye-Mi Kim, et al (2009) paper “Impact of Shifting Patterns of Pacific Ocean Warming on North AtlanticTropical Cyclones”:
http://www.sciencemag.org/cgi/content/abstract/325/5936/77
The press release describes El Nino Modoki as “new” more than once. The “newness” of El Nino Modoki was also contradicted by data in my July 6, 2009 post There Is Nothing New About The El Nino Modoki.
Figure 5 compares the average El Nino Modoki and Traditional El Nino event since 1950. The typical Traditional El Nino is stronger than the El Nino Modoki and it results in a La Nina event, where the typical El Nino Modoki decays to a neutral SST anomaly of ~0.
http://i44.tinypic.com/5pkhn8.png
Figure 5
MORE COMPARISONS
Figures 6 through 9 provide further comparisons of El Nino Modoki and Traditional El Nino events before and after 1979. I won’t discuss these individually, other than to call your attention to the comparison of El Nino Modoki and Traditional El Nino events prior to 1979, Figure 8. Note that El Nino Modoki events were stronger and their durations were longer than Traditional El Nino events.
http://i41.tinypic.com/qz222u.png
Figure 6
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http://i41.tinypic.com/bk4ux.png
Figure 7
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http://i42.tinypic.com/dqzon.png
Figure 8
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http://i39.tinypic.com/elcfa0.png
Figure 9
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COMPARISONS OF INDIVIDUAL EL NINO EVENTS
Figure 10 compares the ONI SST anomalies for the 8 Traditional El Nino events from 1950 to 2007. Dashes are used to identify the El Nino events before 1979. Of the 8 Traditional events, only two El Nino events did not transition into La Nina events. The 1976/77 El Nino was followed by the 1977/78 El Nino Modoki.
http://i44.tinypic.com/jtxvg9.png
Figure 10
And the 1951/52 El Nino was not followed by a La Nina. The 1951/52 El Nino is also anomalous in that it peaks before the typical El Nino peak months of November, December, and January. However, looking at maps of ICOADS SST anomaly data (the basis for the Hadley Centre and NCDC’s SST data) for the tropical Pacific for October through December 1951 and for January 1952, Figure 11, we can see that there were few to no SST readings during those months in the NINO3.4 region (and most of the tropical Pacific for that matter), so the 1951/52 El Nino data could be considered suspect. (Always keep in mind that much of SST data before the eras of buoys and satellites are infilled.)
http://i42.tinypic.com/qod3bq.png
Figure 11
And Figure 12 is a comparison of the 10 El Nino Modoki events. I’ve also identified the earlier events with dashes. Of the 10 El Nino Modoki, only 2 events transitioned into La Nina events, the 1963/64 and 1994/95 El Nino events. The SST anomalies during the ENSO season following the 2004/05 El Nino dipped below the La Nina threshold, but did not remain there long enough to be considered an official La Nina.
http://i44.tinypic.com/72deeq.png
Figure 12
CLOSING COMMENT
Will a La Nina follow the 2009/10 El Nino? Considering that only 2 of 10 El Nino Modoki events since 1950 were followed by La Nina events, the odds are against it. But nature does provide surprises.
SOURCES
The ONI data is available through the NOAA CPC webpage:
http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml
The HADISST SST anomaly data used for the El Nino Modoki graph, and the ICOADS data used for the tropical Pacific SST maps are available through the KNMI Climate Explorer:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere
I also used the KNMI Climate Explorer to create the maps.
Bob,
Take a note of my temperature outlooks for this year and check them against measurements as the year progresses.
May above average especially from around the 20th.
June heatwave starting from around the 12th and another uplift from around the 27th.
July heatwave starting around mid month.
August starts warm but drops dramatically mid month, leading to much rain.
September starts on a warmer signal, uplifts mid month and gets hotter toward month end.
October starts on a very strong uplift, very warm month.
Looks like a classic Indian summer coming on.
November also starts on a hot note, an unusually mild November, very wet.
Ulric Lyons says:
May 2, 2010 at 6:00 pm
Precipitation outlooks are for the N.H. and are the inverse to the S.H. where the temperature uplifts during May/June/July will increase rainfall.
Gail Combs says:
May 2, 2010 at 3:46 pm
Take it a step further. As water warms it dissolves less CO2 (out gases)
That’s not neccesarily true. Henry’s Law predicts this, but Henry’s Law specifically excludes any reaction with the dissolved gas. In sea water, CO2 combines (reversabily) to form carbonic acid, and also reacts with Calcium ions to form Calcium Carbonate. There are undoubtedly other ions in sea water which react with CO2 – any of which stop Henry’s Law being accurate.
How CO2 reacts with rising temperature, then also depends on the thermal profile of all the side-reactions along with the “normal” dissolved gas. Has anyone done any experiments on this?
Gail Combs says:
May 2, 2010 at 3:11 pm
Another way is to use tilde-names (or whatever they should be called).
For El Ni˜o I typed El Ni˜o.
Some of the key ones are listed at my http://home.comcast.net/~ewerme/wuwt/
E.g. It reached 91°F (91°) at our property on Mt Cardigan today. Not appreciated, way too hot for brush cutting and hiking back uphill. It was only 86 south and lower at a Vantage Pro station (as opposed to cheap indoor/outdoor thermometer in the shade, but our property is on a south facing slope, and a south wind on a sunny day gets extra heat.
etudiant says: You wrote, “Your concept, that heat accumulates during Nina phases and is dissipated during Nino episodes, is very plausible.”
The concept of ENSO discharge/recharge has been around for at least a decade.
You wrote, “The NOAA data referenced by R Gates likewise shows a large increase since 1990 in ocean heat content.(more than 10*23 Joules for the top 700 meters).”
The NOAA NCDC data is the same data used in my OHC posts. I just break it down into subsets that can be explained. Refer to:
http://bobtisdale.blogspot.com/2009/09/enso-dominates-nodc-ocean-heat-content.html
And:
http://bobtisdale.blogspot.com/2009/10/north-atlantic-ocean-heat-content-0-700.html
And:
http://bobtisdale.blogspot.com/2009/12/north-pacific-ocean-heat-content-shift.html
You wrote, “The Trenberth chart you posted…”
I didn’t post a Trenberth chart. The italics in the comment by phlogiston you read are misplaced.
phlogiston: To have THC, the surface water has to be more dense than the water at depth.
This is so good I have to repeat again.
Well said, Rob. Very eloquent…
Chris
Norfolk Virginia USA
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rbateman says:
May 2, 2010 at 11:02 am
“If, my skeptical counterpart friend, the world were composed of airport tarmacs, M as in METAR mistranscribings, pal-reviewed paper circular reasonings, IPCC National Inquirer style findings, gridded GISS anomalies, catastrophical sea level rises of a few millimeters in a world populated by ants, a trace gas with magical powers of ten thousand times the ordinary water molecule and a Super-Methane molecule that no biologic species or physical process could break down, then yes, the dire consequential model holds water.
Such a theory has all the technological advatages of the TRS-80 computer as of today, May 02, 2010.
Let me ask you a question:
Do the climate models run you, or do you run the models?”
OT: Don’t bet on any sunspot reporting integrity.
http://sidc.oma.be/images/combimap800.png
Catania reports 4 regions.
http://www.swpc.noaa.gov/ftpdir/latest/DSD.txt
swpc/noaa counts 3 new regions.
SOHO MDI shows 1 for 05/02/2010
A check of GONG images shows only the one spotted region for the day.
Perhaps someone has a fistful of SDO images and is counting things no one has seen before?
rbateman says:
May 2, 2010 at 9:07 pm
OT: Don’t bet on any sunspot reporting integrity.
http://sidc.oma.be/images/combimap800.png
Catania reports 4 regions.
http://www.swpc.noaa.gov/ftpdir/latest/DSD.txt
swpc/noaa counts 3 new regions.
SOHO MDI shows 1 for 05/02/2010
A check of GONG images shows only the one spotted region for the day.
Perhaps someone has a fistful of SDO images and is counting things no one has seen before?
_______________________________________________________________________
Layman’s Sunspot Count site was saying the same thing:
“2010/05/02 05:29 There is lots more continuing speck activity that NOAA and now to some extent the SIDC are having a field day with. During these unusual times the scientific record is being butchered. 1064 achieved 13 pixels and only lasted a few hours, there are 2 other regions that may attract attention from NOAA that are not measurable so far.
The NOAA monthly mean for April is 11.2. The SIDC coming in at 7.9 which is suggesting a shift from their normally conservative recording. The Layman’s April count will be much lower this month. Full update in the next 24-48 hours. Meanwhile the Layman spotless streak is at 25 days.”
I check there for the sunspot count since they have made an effort to match their measurements to that of the historical record. Counting specks that last for a few hours means the “modern count” can not be compared to historical counts.
However you look at it the sun is still in a funk. With luck we will not have Iceland’s Katla volcano adding to the problem but the earthquake on April 28 suggest she is awakening. The news report did not define “significant earthquake” in the story. http://scienceray.com/earth-sciences/icelands-katla-volcano-new-seismic-activity-42810-eruption-imminent/
I found the “significant earthquake” at the Katla volcano in Iceland on April 28, 2010: “… Additionally, within the caldera of the Katla volcano, an Ml 1.7 earthquake occurred at 15:28 GMT at ~6 km depth….” http://en.vedur.is/media/jar/Eyjafjallajokull_status_2010-04-28_IES_IMO.pdf
Gail Combs says:
May 2, 2010 at 10:02 pm
“However you look at it the sun is still in a funk.”
With recent class C x-ray flares and high solar wind velocity levels that we have not seen for a few years… very funky.
Laymans count(G.Sharp) is expecting a weak cycle, I would have thought SSN 71 on Feb 8th is already too shocking to bear, especially this early in the cycle!
It’s possible to bet on the monthly GISStemp anomalies at https://www.intrade.com. For instance, the last odds that the May anomaly will exceed .55 was 50%. The last odds that the June and July anomalies will exceed .50 was also 50%. Bets for future months will become available as time marches on.
Gail Combs
This is probably not the right track to discuss volcanoes as the topic is whether La Nina’s always follow EL Nino’s , but in a way they are realted as extra ash in the atmosphere can cool the Pacific and enhance the possibilty of a La Nina . I just wanted to comment about your obseravations about Katla. Although there is some activity there , my personal obseravations is that the area that perhaps we should be more concerned about is the Kamatcka Peninsula.
The reasons why I primarily focus on Kamchatka Peninsula and Kurile Islands [especially Kurile Lake ]volcanoes in Russia and not the Katla volcano in Iceland is as follows;
Second only to South America in number of volcanoes
Leads the world in number of past eruptions and number of major eruptions [4 and higher VEI]
Highest number of explosive volcanoes
No level 5 eruptions for 54 years [last 1956]
No level 6 eruptions for 1770 years [last 240 AD]
No level 7 eruptions for 8450 years [last 6440 BC]
The Kurile Lake eruption of 6440 BC was also preceded by a quiet period of about 1500 years
There were 16 eruptions [level 4 and higher ] during the past 20th century there and the last one was only last year at Kurile Islands. During 2010 there 4 volcanoes erupting in this area.
This area is overdue for a major eruption at any time . The last level 7 eruption at Kurile lake put 140-170 km/3 of material into the air and send ash thousands of miles to the mainland of Asia.
Bob Tisdale says:
May 2, 2010 at 2:15 pm
An El Nino event releases more heat than normal from the tropical Pacific, …
As I said in other posts, this was not a normal El Niño, because during SH summer, warm waters were only in 3-4 region, but also in southern CENTRAL pacific (lat 48°S) and nothing along 1-2 Niño areas, while the usual south-north cold Humboldt´s current were running normaly driven by the pacific counterclockwise anticyclone.
Only afterwards waters in 1-2 region began showing a little positive anomaly.
http://weather.unisys.com/surface/sst_anom.html
How strange is this?, Has it happened before?
The weekly Nino region SSTs have been updated.
For the week ending April 28th,
Nino 1,2: 0.3C
Nino 3: 0.5C
Nino 3.4: 0.5C
Nino 4: 0.8C
Nino 3.4 should be around 0.7C for April, down from 1.14C in March and 1.82C in the December peak.
http://www.cpc.ncep.noaa.gov/data/indices/wksst.for
The SST map for May 3rd is showing some below-normal patches in the Nino 3.4 region and a continued decline overall.
http://www.osdpd.noaa.gov/data/sst/anomaly/2010/anomnight.5.3.2010.gif
Out-going-Long-wave Radiation shows that the El Nino has probably finished dumping its heat into the atmosphere now.
http://cawcr.gov.au/bmrc/clfor/cfstaff/matw/maproom/OLR/ts.r11.l.gif
http://cawcr.gov.au/bmrc/clfor/cfstaff/matw/maproom/OLR/ts.r4.l.gif
There has got to be a lot of uncertainty in all of this. I would suggest reading Klaus Wolter on a regular basis:
http://www.esrl.noaa.gov/psd/people/klaus.wolter/SWcasts/index.html
http://www.esrl.noaa.gov/psd/people/klaus.wolter/MEI/index.html
The IRI models chart, which Wolter links here
http://www.esrl.noaa.gov/psd/people/klaus.wolter/SWcasts/IRI.apr10.gif
shows the broad range of uncertainty. His narrative:
“At this point, ALL models show a more or less continuous decline over the next four seasons into ENSO-neutral territory, with five models (four of them dynamical) crossing below -0.5C. After the summer seaason (JAS), three statistical models maintain borderline weak El Niño conditions (near or below +0.5C), while the majority of models slowly drifts further down, leading to about half of them predicting at least weak La Niña conditions by the end of 2010, with the rest remaining near-neutral. While not as big a gap as last year, the difference between statistical and dynamical models is widening again, currently averaging 0.4C higher for the former models than the latter ones.”
That last sentence bears noting. Bob’s analysis is basically statistical, and the statistical analyses show less cooling going into the latter part of this year. While I wouldn’t bet on La Nina this year, I wouldn’t bet against it, either. But I would bet on La Nina before we see another El Nino.
Guest Post by Bob Tisdale
History suggests: don’t bet on La Nina this year.
If I were gambling man I would take odds on there being La Niña conditions by the end of the year.
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/wkxzteq.shtml
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt
http://www.bom.gov.au/climate/enso/soi.txt
An episode of La Niña is defined as a period of at least 5 months of La Niña conditions. If this definition is the same as what you call an event then all bets are off. :-}
From my understanding of some AGW skeptics arguments, the climate shift that occurred in 76/77 is now shifting back to a cooler period, and the whole rise in temps that we saw since that time (and associated cycles of stronger El Ninos) is all a normal cyclical event and in no way connected to AGW. Is that correct my skeptical friends?
There’s an elephant in the room. Looking at it from a global temperature perspective we need to see what conditions conspired to produce the 1997-1998 spike.
Here is an overlay of ENSO and AMO.
http://i599.photobucket.com/albums/tt74/MartinGAtkins/AMO-NINO.png
If we are to place our trust in pretty patterns then a positive AMO may yet have more time to run.
http://i599.photobucket.com/albums/tt74/MartinGAtkins/AMO.png
Do you see anymore strong El Niño events on the horizon?
.
phlogiston: I reread my realier reply and decided it was poorly written. I wrote, To have THC, the surface water has to be more dense than the water at depth. (That was terrible.) I should have written: To have THC, the surface water at high latitudes in the North Atlantic must sink and in order to do that it has to be more dense than the water at depth. (Much better.)
I’ll repeat a previous commenter (R. de Haan) and mention that Joe Bastardi of Accuweather is calling for La Nina to occur. But as a slight correction to R. de Haan, JB thinks that the La Nina will start Fall of 2010. As mention by commenter Basil, most of the dynamic models are calling for La Nina type conditions by summer’s end:
http://iri.columbia.edu/climate/ENSO/currentinfo/SST_table.html
Basil raises an important point about the hazards of the statistical approach. Plainly & flatly: The assumptions that underpin the approach do NOT hold. (That doesn’t mean insight cannot be gained by the exercise – quite the contrary.)
The coherence between SOI & QBO is nothing to scoff at — 2nd panel here:
http://www.sfu.ca/~plv/100204.PNG
Until something better comes along, 2.37 years seems to be a useful crude rule of thumb (but definitely don’t assume symmetrical cycles and don’t assume the pattern will go on indefinitely).
Bob, I’ve summarized more variables that show a “60 year” (as folks claim) pattern:
http://www.sfu.ca/~plv/CumuSumCombo.png
[ Definitions here http://www.sfu.ca/~plv/VolcanoStratosphereSLAM.htm or here http://www.sfu.ca/~plv/60yearCycles.htm .]
Something else that might interest you:
The following plot features -SOI (-Southern Oscillation Index) for AUGUST:
http://www.sfu.ca/~plv/-SOI_August.png
Red represents interannual -SOI (so + indicates El Nino dominance).
Black is the cumulative effect.
When ice is thick, water under it is insulated from the atmosphere, so the Arctic Ocean is essentially continental (from an atmospheric perspective). The most damage can be done if the timing of blasts is right.
Also, have you ever taken a look at IVI2? http://www.sfu.ca/~plv/IVI2_SOI.png [Note: The summary of SOI in the plot is flipped-over (+El Nino, -La Nina), detrended & decadal-timescale. Link to the IVI2 data can be found in the data section here.]
Enneagram, in response to my comment, “An El Nino event releases more heat than normal from the tropical Pacific…” you replied, “As I said in other posts, this was not a normal El Niño, because during SH summer, warm waters were only in 3-4 region, but also in southern CENTRAL pacific (lat 48°S) and nothing along 1-2 Niño areas…”
Agreed. As this post notes, the 2009/201o El Nino is an El Nino Modoki. And let me clarify what you quoted. An El Nino event (both types, El Nino Modoki and Traditional El Nino) releases more heat from the tropical Pacific than normal (ENSO neutral) conditions.
Also, I discussed the hotspot in the South Pacific in the following posts. It is not unusual. Refer to:
http://bobtisdale.blogspot.com/2010/01/south-pacific-hot-spot.html
And:
http://bobtisdale.blogspot.com/2010/01/south-pacific-sst-patterns.html
Regards
El Nino is transitioning to ENSO Neutral!
http://motls.blogspot.com/2010/05/el-nino-is-transitioning-to-enso.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+LuboMotlsReferenceFrame+%28Lubos+Motl%27s+reference+frame%29
Roger Knights says:
May 3, 2010 at 5:17 am
“It’s possible to bet on the monthly GISStemp anomalies”
Would it not be better if everyone knew what was coming, rather than me keeping schtum and making a few bob down the bookies? I might have the odd period of uncertainty, but my forecasts achieved 49/52 weeks correct last year. The warmer mid November 2 week period that neither I or Piers forecast, I have successfully diagnosed, and with this new detail, predicted the strong solar activity at the start of April. This years forecast is pretty much deterministic apart from one week in particular where I am still working on some uncertainties.
John Finn says:
May 2, 2010 at 12:38 am
“You make the mistake of thinking that the AGW crowd denies solar variability. On the contrary they rely on solar variability to explain past climate fluctuations. Without them they would have to admit they don’t know. If the Lockwood paper (your link) is correct then the AGW case is strengthened”
The problem with this argument is that the AGW crowd believes that solar forcing of atmospheric temperature must be nearly immediate and is entirely dependent on the slight variations of solar intensity. This view is extremely narrow minded and in contrast to the undeniable complexity of the climate system.
Most of the solar radiation reaching the Earth (light) has very little direct impact on the atmospheric temperature. The energy passes through the atmosphere and impacts the Earth’s surface, which is primarily ocean. The additional energy in the world’s oceans is not released immediately into the atmosphere, but is regulated by multi-decadal ocean cycles. For example, a slight increase in the amount of solar energy reaching the ocean surface would may not manifest in a warmer atmosphere until the ocean enters a warm phase of its natural cycle. If the ocean is in its cool phase, global cooling of the atmosphere will result, even if the sun is more active.
Overall, the sun was more active in the 20th century than anytime in the last 500 years, but global warming did not take place except when the Pacific Decadal Oscillation was in its warm phase. The additional solar energy stored in the Pacific from a more active sun was only detectable at these times. During the mid 20th Century, when the sun was at its peak intensity and CO2 forcing was increasing rapidly (which IS a direct forcing on the atmosphere) we had global cooling because the PDO was in its cool phase.
In a nutshell, the solar impact on climate is cumulative and likely continues for many years (perhaps decades) after the trend in solar radiation changes, but its impact is embedded in the ocean cycles. That is why we continued to warm during the late 20th Century, even as the solar intensity began to wain. Now, as the sun continues to quiet down and the PDO appears to be shifting to its cool phase, global cooling is imminent. CO2 is simply a minor player in all of this.
The AGW crowd may rely on solar forcing to keep their theory from appearing totally without merit, but they do not attempt to really understand how that forcing manifests in the atmosphere. If they did, their theory would be without merit. They are walking a knifes edge, and they are coming to the end of the blade.
R. de Haan: Thanks for the link to Lubos’s post, but NINO3.4 SST anomalies have actually reached ENSO-neutral range, i.e., it dropped below 0.5 deg C last week.
http://bobtisdale.blogspot.com/2010/05/nino34-sst-anomalies-in-neutral.html