Some people cite scientists saying there is a “CO2 control knob” for Earth. No doubt there is, but due to the logarithmic effect of CO2, I think of it like a fine tuning knob, not the main station tuner. That said, a new data picture is emerging of an even bigger knob and lever; a nice bright yellow one.
A few months back, I found a website from NOAA that provides an algorithm and downloadable program for spotting regime shifts in time series data. It was designed by Sergei Rodionov of the NOAA Bering Climate and Ecosystem Center for the purpose of detecting shifts in the Pacific Decadal Oscillation.
Regime shifts are defined as rapid reorganizations of ecosystems from one relatively stable state to another. In the marine environment, regimes may last for several decades and shifts often appear to be associated with changes in the climate system. In the North Pacific, climate regimes are typically described using the concept of Pacific Decadal Oscillation. Regime shifts were also found in many other variables as demonstrated in the Data section of this website (select a variable and then click “Recent trends”).
But data is data, and the program doesn’t care if it is ecosystem data, temperature data, population data, or solar data. It just looks for and identifies abrupt changes that stabilize at a new level. For example, a useful application of the program is to look for shifts in weather data, such as that caused by the PDO. Here we can clearly see the great Pacific Climate Shift of 1976/77:
Another useful application is to use it to identify station moves that result in a temperature shift. It might also be applied to proxy data, such as ice core Oxygen 18 isotope data.
But the program was developed around the PDO. What drives the PDO? Many say the sun, though there are other factors too. It follows to reason then the we might be able to look for solar regime shifts in PDO driven temperature data.
Alan of AppInSys found the same application and has done just that, and the results are quite interesting. The correlation is well aligned, and it demonstrates the solar to PDO connection quite well. I’ll let him tell his story of discovery below. – Anthony
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Climate Regime Shifts
The notion that climate variations often occur in the form of ‘‘regimes’’ began to become appreciated in the 1990s. This paradigm was inspired in large part by the rapid change of the North Pacific climate around 1977 [e.g., Kerr, 1992] and the identification of other abrupt shifts in association with the Pacific Decadal Oscillation (PDO) [Mantua et al., 1997].” [http://www.beringclimate.noaa.gov/regimes/Regime_shift_algorithm.pdf]
Pacific Regime Shifts
Hare and Mantua, 2000 (“Empirical evidence for North Pacific regime shifts in 1977 and 1989”): “It is now widely accepted that a climatic regime shift transpired in the North Pacific Ocean in the winter of 1976–77. This regime shift has had far reaching consequences for the large marine ecosystems of the North Pacific. Despite the strength and scope of the changes initiated by the shift, it was 10–15 years before it was fully recognized. Subsequent research has suggested that this event was not unique in the historical record but merely the latest in a succession of climatic regime shifts. In this study, we assembled 100 environmental time series, 31 climatic and 69 biological, to determine if there is evidence for common regime signals in the 1965–1997 period of record. Our analysis reproduces previously documented features of the 1977 regime shift, and identifies a further shift in 1989 in some components of the North Pacific ecosystem. The 1989 changes were neither as pervasive as the 1977 changes nor did they signal a simple return to pre-1977 conditions.”
[http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V7B-41FTS3S-2…]
Overland et al “North Pacific regime shifts: Definitions, issues and recent transitions”
[http://www.pmel.noaa.gov/foci/publications/2008/overN667.pdf]: “climate variables for the North Pacific display shifts near 1977, 1989 and 1998.”
The following figure from the above paper show analysis of PDO and Victoria Index using the Rodionov regime detection algorithm. A regime shift is also detected around 1947-48.
The following figure shows regime shift detection for the summer PDO, showing shifts at 1948, 1976 and 1998.
[http://www.beringclimate.noaa.gov/data/Images/PDOs_FigRegime.html]
(For detailed information on the 1976/77 climate shift,
see: http://www.appinsys.com/GlobalWarming/The1976-78ClimateShift.htm)
Regime Shift Detection in Annual Temperature Anomaly Data
The NOAA Bering Climate web site provides the algorithm for regime shift detection developed by Sergei Rodionov [http://www.beringclimate.noaa.gov/regimes/index.html]. The following analyses use the Excel VBA regime change algorithm version 3.2 from this web site.
The following figure shows the regime analysis of the HadCRUT3 annual global annual average temperature anomaly data from the Met Office Hadley Centre for 1895 to 2009 [http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/annual].
The analysis was run based on the mean using a significance level of 0.1, cut-off length of 10 and Huber weight parameter of 2 using red noise IP4 subsample size 6. Regime changes are identified in 1902, 1914, 1926, 1937, 1946, 1957, 1977, 1987, and 1997. Running the analysis based on the variance rather than the mean results in regime changes in the bold years listed above.
Regime Shift Relationship to Solar Cycle
The NASA Solar Physics web site provides the following figure showing sunspot area.
[http://solarscience.msfc.nasa.gov/SunspotCycle.shtml]
The following figure compares the Hadley (HadCrut3) monthly global average temperature (from [http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/]) overlaid with the regime change line (red line) shown previously, along with the sunspot area since 1900. The sunspot cycle is approximately 11 years. The sun’s magnetic field reverses with each sunspot cycle and thus after two sunspot cycles the magnetic field has completed a cycle – a Hale Cycle – and is back to where it started. Thus a complete magnetic sunspot cycle is approximately 22 years. The figure marks the onset of odd-numbered cycles with a vertical red line, even-numbered cycles with a green line.
From the figure above it can be seen that the regime changes correspond to the onset of solar cycles and occur when the “butterfly” is at its widest. The most significant warming regime shifts occur at the start of odd-numbered cycles (1937, 1957, 1977, 1997). Each odd-numbered cycle (red lines above) has resulted in a temperature-increase regime shift. Even-numbered cycles (green lines above) have been inconsistent, with some resulting in temperature-decrease regime shifts (1902, 1946) or minor temperature-increase shifts (1926, 1987).
An unusual one is the 1957 – 1966 cycle, which in the monthly data shown above visually looks like a temperature-increase shift in 1957 followed by a temperature-decrease shift in 1964 but the regime detection algorithm did not identify it. This is likely due to the use of annually averaged data in the regime detection algorithm.
The following figure shows the relative polarity of the Sun’s magnetic poles for recent sunspot cycles along with the solar magnetic flux [www.bu.edu/csp/nas/IHY_MagField.ppt]. The regime change periods are highlighted by the red and green boxes. Each one occurs on as the solar cycle is accelerating. The onset of an odd-numbered sunspot cycle (1977-78, 1997-98) results in the relative alignment of the Earth’s and the Sun’s magnetic fields (positive North pole on the Sun) allowing greater penetration of the geomagnetic storms into the Earth’s atmosphere. “Twenty times more solar particles cross the Earth’s leaky magnetic shield when the sun’s magnetic field is aligned with that of the Earth compared to when the two magnetic fields are oppositely directed” [http://www.nasa.gov/mission_pages/themis/news/themis_leaky_shield.html]
The following figure shows the longitudinally averaged solar magnetic field. This “magnetic butterfly diagram” shows that the sunspots are involved with transporting the field in its reversal. The Earth’s temperature regime shifts are indicated with the superimposed boxes – red on odd numbered solar cycles, green on even.
[http://solarphysics.livingreviews.org/open?pubNo=lrsp-2010-1&page=articlesu8.html]
The Earth’s temperature regime shift occurs as the solar magnetic field begins its reversal.
Solar Cycle 24
Solar cycle 24 is in its initial stage after getting off to a late start. An El Nino occurred in the first part of 2010. This may be the start of the next regime shift.
Climate Regime Shifts
[last update: 2010/07/04]
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“The notion that climate variations often occur in the form of ‘‘regimes’’ began to become appreciated in the 1990s. This paradigm was inspired in large part by the rapid change of the North Pacific climate around 1977 [e.g., Kerr, 1992] and the identification of other abrupt shifts in association with the Pacific Decadal Oscillation (PDO) [Mantua et al., 1997].” [http://www.beringclimate.noaa.gov/regimes/Regime_shift_algorithm.pdf]
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Pacific Regime Shifts
Hare and Mantua, 2000 (“Empirical evidence for North Pacific regime shifts in 1977 and 1989”): “It is now widely accepted that a climatic regime shift transpired in the North Pacific Ocean in the winter of 1976–77. This regime shift has had far reaching consequences for the large marine ecosystems of the North Pacific. Despite the strength and scope of the changes initiated by the shift, it was 10–15 years before it was fully recognized. Subsequent research has suggested that this event was not unique in the historical record but merely the latest in a succession of climatic regime shifts. In this study, we assembled 100 environmental time series, 31 climatic and 69 biological, to determine if there is evidence for common regime signals in the 1965–1997 period of record. Our analysis reproduces previously documented features of the 1977 regime shift, and identifies a further shift in 1989 in some components of the North Pacific ecosystem. The 1989 changes were neither as pervasive as the 1977 changes nor did they signal a simple return to pre-1977 conditions.” [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V7B-41FTS3S-2…]
Overland et al “North Pacific regime shifts: Definitions, issues and recent transitions” [http://www.pmel.noaa.gov/foci/publications/2008/overN667.pdf]: “climate variables for the North Pacific display shifts near 1977, 1989 and 1998.”
The following figure from the above paper show analysis of PDO and Victoria Index using the Rodionov regime detection algorithm. A regime shift is also detected around 1947-48.
The following figure shows regime shift detection for the summer PDO, showing shifts at 1948, 1976 and 1998. [http://www.beringclimate.noaa.gov/data/Images/PDOs_FigRegime.html]
(For detailed information on the 1976/77 climate shift, see: http://www.appinsys.com/GlobalWarming/The1976-78ClimateShift.htm)
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Regime Shift Detection in Annual Temperature Anomaly Data
The NOAA Bering Climate web site provides the algorithm for regime shift detection developed by Sergei Rodionov [http://www.beringclimate.noaa.gov/regimes/index.html]. The following analyses use the Excel VBA regime change algorithm version 3.2 from this web site.
The following figure shows the regime analysis of the HadCRUT3 annual global annual average temperature anomaly data from the Met Office Hadley Centre for 1895 to 2009 [http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/annual].
The analysis was run based on the mean using a significance level of 0.1, cut-off length of 10 and Huber weight parameter of 2 using red noise IP4 subsample size 6. Regime changes are identified in 1902, 1914, 1926, 1937, 1946, 1957, 1977, 1987, and 1997. Running the analysis based on the variance rather than the mean results in regime changes in the bold years listed above.
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Regime Shift Relationship to Solar Cycle
The NASA Solar Physics web site provides the following figure showing sunspot area. [http://solarscience.msfc.nasa.gov/SunspotCycle.shtml]
The following figure compares the Hadley (HadCrut3) monthly global average temperature (from [http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/]) overlaid with the regime change line (red line) shown previously, along with the sunspot area since 1900. The sunspot cycle is approximately 11 years. The sun’s magnetic field reverses with each sunspot cycle and thus after two sunspot cycles the magnetic field has completed a cycle – a Hale Cycle – and is back to where it started. Thus a complete magnetic sunspot cycle is approximately 22 years. The figure marks the onset of odd-numbered cycles with a vertical red line, even-numbered cycles with a green line.
From the figure above it can be seen that the regime changes correspond to the onset of solar cycles and occur when the “butterfly” is at its widest. The most significant warming regime shifts occur at the start of odd-numbered cycles (1937, 1957, 1977, 1997). Each odd-numbered cycle (red lines above) has resulted in a temperature-increase regime shift. Even-numbered cycles (green lines above) have been inconsistent, with some resulting in temperature-decrease regime shifts (1902, 1946) or minor temperature-increase shifts (1926, 1987).
An unusual one is the 1957 – 1966 cycle, which in the monthly data shown above visually looks like a temperature-increase shift in 1957 followed by a temperature-decrease shift in 1964 but the regime detection algorithm did not identify it. This is likely due to the use of annually averaged data in the regime detection algorithm.
The following figure shows the relative polarity of the Sun’s magnetic poles for recent sunspot cycles along with the solar magnetic flux [www.bu.edu/csp/nas/IHY_MagField.ppt]. The regime change periods are highlighted by the red and green boxes. Each one occurs on as the solar cycle is accelerating. The onset of an odd-numbered sunspot cycle (1977-78, 1997-98) results in the relative alignment of the Earth’s and the Sun’s magnetic fields (positive North pole on the Sun) allowing greater penetration of the geomagnetic storms into the Earth’s atmosphere. “Twenty times more solar particles cross the Earth’s leaky magnetic shield when the sun’s magnetic field is aligned with that of the Earth compared to when the two magnetic fields are oppositely directed” [http://www.nasa.gov/mission_pages/themis/news/themis_leaky_shield.html]
The following figure shows the longitudinally averaged solar magnetic field. This “magnetic butterfly diagram” shows that the sunspots are involved with transporting the field in its reversal. The Earth’s temperature regime shifts are indicated with the superimposed boxes – red on odd numbered solar cycles, green on even. [http://solarphysics.livingreviews.org/open?pubNo=lrsp-2010-1&page=articlesu8.html]
The Earth’s temperature regime shift occurs as the solar magnetic field begins its reversal.
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Solar Cycle 24
Solar cycle 24 is in its initial stage after getting off to a late start. An El Nino occurred in the first part of 2010. This may be the start of the next regime shift.
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Bob and Leif,
I have said several times that the response of the polar oscillations to the changes in solar activity is also affected by the oceanic oscillations. What matters is the balance between the two. The NCM should perhaps make that clearer earlier on but it is mentioned at various points and implicit in the steps I listed especially when one gets to the returning energy from the oceans on that 500/1000 year cycle.
The ITCZ moved latitudinally as the solar activity increased from LIA to date. That is the long term signal. It also seems to have moved MWP to LIA. You are looking at too short a period.
However much Leif feels ‘able’ to minimise solar variability in his reconstructions the fact is that the sun was less active during certain cold periods and has been more active during the recent warm period. At the same time the jets moved latitudinally and the globe warmed and cooled apparently with a high degree of correlation. Furthermore the ocean surfaces warmed and cooled to contribute to the overall interplay.
There is a logical scenario that fits all that and I have formulated it. You are entitled to hold a different view and/or to disbelieve it. Whether I am right or not remains to be seen and I am entitled to put it out there so that it can be compared with future real world events. They will be the arbiter not you and Bob who both keep reiterating the same flawed objections however often I counter them.
If you don’t like the evidence such as it is then that’s your problem.
Stephen Wilde says:
July 11, 2010 at 9:56 am
The ITCZ moved latitudinally as the solar activity increased from LIA to date.
To make that statement you need numbers. Plot the latitude of the ITCZ for each year [or whatever time resolution your data has) against time and [another plot] against solar activity. Show us the plots and then we can discuss.
that the sun was less active during certain cold periods
If I correlate random data with other random data, they will match during ‘certain’ periods [namely the ones where they match].
“If Stephens model does not include `seasonal variability` then it cannot be a climate model by definition, and would be useless for temperatures and jet stream position, and hydrology outlooks would be impossible.”
It is movement of the air circulation systems beyond normal seasonal variability that indicates changing global climates. On the basis of the limited data we have it appears that there is a 500/1000 year cycle of latitudinal shifts in the air circulation systems but of course are others. However that one has been the most important one for human civilisations for quite some time.
The shorter term cycles of sun and ocean obscure the pattern during the short period that we have had suitable monitoring equipment but the pattern is clear to anyone who watches weather and climate through a couple of PDO (or PDV) phases and then considers the fact of the far more substantial shifts from MWP to LIA to date.
It is not an insight that needs huge volumes of data to see the general significance but of course data is needed to supprt or refute the idea. We must wait and see.
No model or hypothesis that fails to account for the cyclical latitudinal shift of the air circulation systems over that specific time scale can have any validity.
Mine is the first that does so as far as I am aware. Any replacement must also encompass those latitudinal shifts in order for it to be taken seriously.
vukcevic:
Thanks for that. In the case of the UK it would make sense for the primary influence to shift from solar in summer to oceanic in winter because of our geographical situation.
We are in the mid latitudes on the edge of a continent and we tend to have the jets move poleward and equatorward above us on a seasonal basis. The sun controls the poles and the ocean controls the equatorial regions with the UK in the battleground.
Quite clearly the jets were much further south of the UK in the LIA and much further north of the UK in the late 20th century. It does not need reams of data to note that simple fact.
The difficult bit is fitting such changes into a logical scenario and then the data can follow because we now know what we are looking for. It should have been obvious some 20 years ago but something distracted the climate professionals.
@ur momisuglyStephen Fisher Wilde says:
July 11, 2010 at 9:56 am
“The ITCZ moved latitudinally as the solar activity increased from LIA to date. That is the long term signal. It also seems to have moved MWP to LIA. You are looking at too short a period.@ur momisugly
What about from the depth of Maunder to the very warm 1730/40`s, or even the huge changes in jet stream lattitude year to year. Seasonal differences are larger than the range of any percieved cycle. MWP and LIA are event clusters, there is no long cycle as such.
Leif:
http://iopscience.iop.org/1755-1315/6/7/072010/pdf/ees9_6_072010.pdf
“Specifically, our data indicate
that the ITCZ was 500 km closer to the equator during the LIA than it is today and that it was south of its
present position (7 degN) for the last 1,000 years.”
As I say, it moves equatorward with all the other air circulation systems when the globe is cooling and poleward when the globe is warming.
And it’s dated 11th July 2010 so it’s obviously been put up by a higher power just for you 🙂
@Stephen Fisher Wilde says:
July 11, 2010 at 10:40 am
“It is movement of the air circulation systems beyond normal seasonal variability that indicates changing global climates.”
Easier described as warmer N.H. winters at higher lattitues due to higher solar wind speed in those months, ie. the Modern winter = global warming, this determines air circulation changes. It changes dramatically from year to year, and is not a slow creeping cycle.
Stephen Wilde says:
July 11, 2010 at 11:00 am
“Specifically, our data indicate that the ITCZ was 500 km closer to the equator during the LIA than it is today and that it was south of its present position (7 degN) for the last 1,000 years.”
They say that it has moved steadily north during the past 1000 years, so no cyclic variation [that would make MWP like today]. Get the data, plot them up, then it becomes easier to see.
Ulric asked:
“What about from the depth of Maunder to the very warm 1730/40`s, or even the huge changes in jet stream lattitude year to year. Seasonal differences are larger than the range of any percieved cycle. MWP and LIA are event clusters, there is no long cycle as such.”
That’s why one needs to propose an interplay between two forces that sometimes oppose and sometimes supplement one another.
A warm period during the LIA would be a period when a pulse of warmth from the oceans overcame the effect of the quiet sun pushing the air circulation systems equatorward. The same in reverse for cold periods during the MWP.
All imposed on top of normal seasonal variability and any chaotic variability.
The routes of the jets do move greatly during each year and from year to year but the background cycle dictates how much room for manouvre the jets have. At the top of a warm cycle the jets are pushed towards the poles and cannot loop about so much. At the bottom of a cool cycle they loop about a lot more. We are currently either juststarting to come down from the top of a warm cycle or possibly experiencing a cooler phase just before the top of the next warm peak.
In the light of that Marshall Island evidence we should take another step.
There is a circulation in the stratosphere (the Brewer Dobson Circulation). It has been noted primarily in connection with ozone transport from tropics to poles but the underlying feature is a slow movement of air from above the convective cloud tops of the ITCZ to above the poles.
http://www.atmosp.physics.utoronto.ca/MAM/jones_Brewer_Dobson.pdf
Thus it involves both the low pressure systems above the ITCZ and the generally high pressure systems above the poles.
Clearly that circulation must vary since nothing in nature is static. Interestingly it is a very slow process so any changes associated with it will also be very slow.
I propose that the rates of energy release from the oceans affect that circulation from below and the energy flux from stratosphere to space affects it from above so that it slowly changes speed over time. Both the solar and oceanic influences are capable of either speeding it up or slowing it down such that there is a constant interplay.
The slowness of the circulation smooths out most of the high frequency solar and oceanic oscillations to give a slow 500 year cycle of movement of the ITCZ and other air circulation systems. First 500 years poleward and then 500 years equatorward. No doubt that too can change over enough time.
Although that slow change over time gradually changes regional climates by shifting the air circulation systems latitudinally the higher frequency solar and oceanic variations busily affect day to day weather within the existing climate zones at any given moment and often hide the underlying trend for long periods at a time.
As to how solar effects speed up or slow down the Brewer Dobson Circulation is another matter and I have suggested some possibilities elsewhere.
“Leif Svalgaard says:
July 11, 2010 at 11:08 am
Stephen Wilde says:
July 11, 2010 at 11:00 am
“Specifically, our data indicate that the ITCZ was 500 km closer to the equator during the LIA than it is today and that it was south of its present position (7 degN) for the last 1,000 years.”
They say that it has moved steadily north during the past 1000 years, so no cyclic variation [that would make MWP like today]. Get the data, plot them up, then it becomes easier to see.”
No Leif. They say it is now 500km further north than it was during the LIA about 500 years ago.
They also say it has been south of the current position since 1000 years ago. That means that 1000 years ago it was about where it is now and in the meantime it first moved 500km south and has since moved 500km back north.
Thus the MWP was like today and there is the cycle I require.
As for analysing their data there is no need. The logical implications are clear as day.
Stephen Wilde says:
July 11, 2010 at 12:12 pm
That means that 1000 years ago it was about where it is now
They don’t say that. You may interpret it that way. The only way to be sure is to plot the actual data, so please do.
Leif Svalgaard says:
July 11, 2010 at 12:53 pm
The only way to be sure is to plot the actual data, so please do.
It seems that only the abstract is available and that there is no data to plot.
Sorry, Leif but it’s time for you to spend more time on something before commenting:
“The establishment of defensively-oriented settlements
throughout much of the tropical Indo-Pacific region after 1000 A.D. supports the notion of a widespread climatic change that we suggest may have been the equatorward movement and southerly positioning of the ITCZ from 1000-1650 A.D.”
Thus from 1000 AD to 1650 AD the ITCZ was moving south resulting in societal problems and warfare. In 1000 it was clearly about where it is now.
“Since that time the ITCZ has moved north by 500 km, an average rate of 1.4
km/yr.”
From 1650 to date it has moved to it’s present position.
My interpretation is correct. They do say what I said they say.
In any event I have no access to their data nor the skills to process it. Nevertheless the implications are crystal clear.
Stephen Wilde says:
July 11, 2010 at 1:24 pm
“The establishment of defensively-oriented settlements
throughout much of the tropical Indo-Pacific region after 1000 A.D. supports the notion of a widespread climatic change that we suggest may have been the equatorward movement and southerly positioning of the ITCZ from 1000-1650 A.D.”
Suppose the ITCZ was in the southern hemisphere in 1000, and have moved north 1000-1650 until it reached the equator about the time of the LIA, and have since moved a further 500 km [~5 degrees] north. That would be consistent with their statement.
@Stephen Fisher Wilde says:
July 11, 2010 at 11:09 am
“A warm period during the LIA would be a period when a pulse of warmth from the oceans overcame the effect of the quiet sun pushing the air circulation systems equatorward. The same in reverse for cold periods during the MWP.”
Totaly ridiculous. I`ll give you some more extreme examples; the coldest winter on CET, 1684, two years later is a Junuary of 6.0C and a yearly average of 10.13. 1708 January is 6.0C and the years average is 9.67, this is followed by another of the hardest LIA winters in 1709. These, and nearly all the coldest winters on CET, show above normal temp`s within 3 to 4 months after the cold episode, this is the true and very typical nature of temp` change through the LIA, it`s completely composed of short term changes, which can be mapped absolutely by short term solar changes at a monthly and less definition. The oceans follow the same solar signal, but with a small lag, eg. extra warmth Mar/Apr 2009 gave a peak in SST`s in July, the SST response to the cold N.H. winter also showed a delay, see how long it takes for SST`s to recover with the recent strong warming episodes.
“All imposed on top of normal seasonal variability and any chaotic variability.
The routes of the jets do move greatly during each year and from year to year but the background cycle dictates how much room for manouvre the jets have.”
The variability is not chaotic.
Seasonal extremes dictate the limits, variations in seasonal behavior could be seen to have quasi cyclic nature, (no background cycle) but it would be very folly to predict on this basis as exceptions in any given year are often very contrary to accepted cycle(s) phase.
All imposed on top of normal seasonal variability and any chaotic variability.
@Leif Svalgaard says:
July 11, 2010 at 1:41 pm
Stephen Wilde says:
July 11, 2010 at 1:24 pm
“The establishment of defensively-oriented settlements
_______________________________________
It would be handy to see some precipitation records/proxies for the Marshall Islands going back some centuries rather than rely on this sort of evidence.
The full text is exactly the same article;
http://iopscience.iop.org/1755-1315/6/7/072010/pdf/1755-1315_6_7_072010.pdf
Ulric Lyons says:
July 11, 2010 at 2:25 pm
The full text is exactly the same article
The lead author [Sachs] has more on his website:
http://faculty.washington.edu/jsachs/lab/www/Sachs-TropPac_ITCZ_0-1ka-NaGeo09.pdf
He speculates that the temperature of the Northern Hemisphere controls where the ITCZ is.
Here is the usual explanation:
http://suprememastertv.com/bbs/board.php?bo_table=sos&wr_id=1054&goto_url=&sca=sos_3&url=link1_0
due to AGW.
@Leif Svalgaard says:
July 11, 2010 at 3:13 pm
“Here is the usual explanation:
due to AGW.”
The study period suggests TSI changes over the last millenium.
What I don`t get is if the Galapagos were wetter during the LIA, then why wasn`t Christmas Island too?
Ulric Lyons says:
July 11, 2010 at 4:24 pm
The study period suggests TSI changes over the last millenium.
Yeah, they used Bard’s reconstruction which is not in tune with more modern work.
Bob Tisdale says:
July 11, 2010 at 6:17 am
How do you account for the impacts of ENSO on jet stream position, since ENSO does not correlate with solar cycles
Hi Bob,
I think you’ve said before that el nino is closely linked with ENSO.
Using this list of 24 el nino years since 1900 http://apollo.lsc.vsc.edu/classes/met130/notes/chapter10/elnino.html I plotted them against the solar cycles. I found that:
12 occurred within a year of minimum
8 occurred on the declining part of the cycle
4 occurred near the peak of the cycle. 2 of these were low cycles following high ones.
I think this shows that ENSO is linked with solar cycles, though I always welcome your well informed opinion.
Cheers
“Leif Svalgaard says:
July 11, 2010 at 1:41 pm
Stephen Wilde says:
July 11, 2010 at 1:24 pm
“The establishment of defensively-oriented settlements
throughout much of the tropical Indo-Pacific region after 1000 A.D. supports the notion of a widespread climatic change that we suggest may have been the equatorward movement and southerly positioning of the ITCZ from 1000-1650 A.D.”
Suppose the ITCZ was in the southern hemisphere in 1000, and have moved north 1000-1650 until it reached the equator about the time of the LIA, and have since moved a further 500 km [~5 degrees] north. That would be consistent with their statement.”
Has the ITCZ ever been south of the equator ?
My impression is that it is always to the north because most of the oceans are to the south and their effect pushes it north of the equator.
tallbloke: You replied, “I think this shows that ENSO is linked with solar cycles, though I always welcome your well informed opinion.”
But your stats could also be interpreted as random behavior of a chaotic oscillation (ENSO) versus a periodic one (solar), could it not?
@Bob Tisdale says:
July 11, 2010 at 6:17 am
Bob Tisdale says:
July 11, 2010 at 6:17 am
“I’ve never heard of the “17yr coronal hole cycle (and half cycle)”. I don’t believe I’ve ever heard Leif discuss it or seen it discussed on a thread in which he is commenting.”
Here are two; http://wattsupwiththat.com/2010/06/04/new-scafetta-paper-his-celestial-model-outperforms-giss/#comment-405845
http://wattsupwiththat.com/2010/05/15/hey-dude-where%e2%80%99s-my-solar-ramp-up/#comment-391923
Bob Tisdale says:
July 12, 2010 at 2:32 am
tallbloke: You replied, “I think this shows that ENSO is linked with solar cycles, though I always welcome your well informed opinion.”
But your stats could also be interpreted as random behavior of a chaotic oscillation (ENSO) versus a periodic one (solar), could it not?
Personally, I think chaos is mostly jumbled up things we haven’t untangled yet. Have you got a reliable longer list of El ninos I can test against more solar cycles? The more samples we test, on a longer timescale the more certain the outcome.
For example, the 14c curve could be a combination of a 6600 year and a 2245 year cycle, with short term variation due to lots of other short term cycles or ‘random’ events such as volccanos. (On the long term, volcanicity it cyclic too however.)
http://cyclesresearchinstitute.files.wordpress.com/2010/06/ssnrec-2-cycles-fit.png