Sea Ice

[William]

Crazy weather. Curious that sea ice is increasing.

Need to keep an eye on that. I would expect the weather will change again and sea ice will continue to change as it is predicted.

http://nsidc.org/data/seaice_index/i...timeseries.png

http://arctic-roos.org/observations/...i1_ice_ext.png

http://arctic.atmos.uiuc.edu/cryosph....antarctic.png

Curious that paleo-climatologists do not understand what causes the Dansgaard-Oeschger cycle. Planet warms up and then cools cyclically. During the cyclic warming and cooling there is the interesting so call polar see saw. Greenland ice sheet warms when the Antarctic ice sheet cools and visas a versa.

I will keep an eye out and see if there is any more data or perhaps a paper if the trend were to continue that might discuss a mechanism.

http://www.agu.org/pubs/crossref/200...PA000571.shtml

On the 1470-year pacing of Dansgaard-Oeschger warm events
The oxygen isotope record from the Greenland Ice Sheet Project 2 (GISP2) ice core was reanalyzed in the frequency and time domains. The prominent 1470-year spectral peak, which has been associated with the occurrence of Dansgaard-Oeschger interstadial events, is solely caused by Dansgaard-Oeschger events 5, 6, and 7. This result emphasizes the nonstationary character of the oxygen isotope time series. Nevertheless, a fundamental pacing period of ∼1470 years seems to control the timing of the onset of the Dansgaard-Oeschger events. A trapezoidal time series model is introduced which provides a template for the pacing of the Dansgaard-Oeschger events. Statistical analysis indicates only a ≤3% probability that the number of matches between observed and template-derived onsets of Dansgaard-Oeschger events between 13 and 46 kyr B.P. resulted by chance. During this interval the spacing of the Dansgaard-Oeschger onsets varied by ±20% around the fundamental 1470-year period and multiples thereof. The pacing seems unaffected by variations in the strength of North Atlantic Deep Water formation, suggesting that the thermohaline circulation was not the primary controlling factor of the pacing period.

http://www.agu.org/pubs/crossref/200...GL017115.shtml

Timing of abrupt climate change: A precise clock by Stefan Rahmstorf

Many paleoclimatic data reveal a approx. 1,500 year cyclicity of unknown origin. A crucial question is how stable and regular this cycle is. An analysis of the GISP2 ice core record from Greenland reveals that abrupt climate events appear to be paced by a 1,470-year cycle with a period that is probably stable to within a few percent; with 95% confidence the period is maintained to better than 12% over at least 23 cycles. This highly precise clock points to an origin outside the Earth system; oscillatory modes within the Earth system can be expected to be far more irregular in period.

[HenrikOlsen]

It's weather.
Don't be confused that it's not like last year.

[Tensor]

Crazy weather. Curious that sea ice is increasing.

Need to keep an eye on that. I would expect the weather will change again and sea ice will continue to change as it is predicted.

http://nsidc.org/data/seaice_index/i...timeseries.png

http://arctic-roos.org/observations/...i1_ice_ext.png

http://arctic.atmos.uiuc.edu/cryosph....antarctic.png

Curious that paleo-climatologists do not understand what causes the Dansgaard-Oeschger cycle. Planet warms up and then cools cyclically. During the cyclic warming and cooling there is the interesting so call polar see saw. Greenland ice sheet warms when the Antarctic ice sheet cools and visas a versa.

I will keep an eye out and see if there is any more data or perhaps a paper if the trend were to continue that might discuss a mechanism.

http://www.agu.org/pubs/crossref/200...PA000571.shtml

http://www.agu.org/pubs/crossref/200...GL017115.shtml

Here, I'll save you the trouble. This 2007 paper shows that a newer, more complete statistical analysis of the GISP2 and newer data in the North Greenland Ice Core Project's (NGRIP) Greenand Ice Core Chronology for 2005 (GICC05) show that the 1470 year pattern found in the older analysis, is below statistical noise. Or as the paper puts it:

For the NGRIP dating the recurrence times are indistinguishable from a random occurrence. This is also the case for the GISP2 dating

or

This distribution implies that there is no long term memory in the climate system or unknown 1470 years periodic forcing triggering the climate shifts. The assumption of the onsets being determined by a strictly periodic triggering (not activating at each period) masked by the dating uncertainty can with high significance be rejected

So worrying about a mechanism isn't necessary.

[Ara Pacis]

Crazy weather. Curious that sea ice is increasing.

Need to keep an eye on that. I would expect the weather will change again and sea ice will continue to change as it is predicted.

That happens in winter.

Why assume a cycle is extraterrestrial in cause?

[William]

Here, I'll save you the trouble. This 2007 paper shows that a newer, more complete statistical analysis of the GISP2 and newer data in the North Greenland Ice Core Project's (NGRIP) Greenand Ice Core Chronology for 2005 (GICC05) show that the 1470 year pattern found in the older analysis, is below statistical noise. Or as the paper puts it:

or



So worrying about a mechanism isn't necessary.

Tensor,
The 2007 paper notes there is a saw tooth change in temperature. The 2007 paper does not dispute the existence of the saw tooth temperature changes. Look at the graph in the paper. There are saw tooth changes in temperature. What the 2007 paper speculates is that the forcing function (which causes the saw tooth temperature change) is not a precise 1470 year external forcing function. Sure I would support that assertion. i.e. The timing of the external forcing changes and does not follow a precise 1470 year period. The authors of the 2007 paper do not acknowledge that there are cosmogenic isotope changes at the saw tooth temperatures changes. The cosmogenic isotope changes are caused by solar magnetic cycle changes.

The 2007 paper then speculates since the saw tooth changes in temperature do not follow a very precise 1470 year period (i.e. there is some variance) that the saw tooth change in temperature is caused by noise. That is pure speculation with no supporting data or logic to justify the conclusion. It should be noted that there are unexplained massive abrupt climate change events in the paleo-record. For example the Younger Dryas and the other Heinrich events. The massive and abrupt climate changes have a cause. After 20 years of research one by one the hypothesized mechanisms such as ocean currents and cyclic changes to the ice sheets have been eliminated.

The 2007 paper is appealing to the weather gods all working together to cause a cyclic saw tooth change in temperature. The 2007 paper does not dispute that there is a saw tooth change in temperature. There are saw tooth changes in temperature during glacial period and during the most recent interglacial period the Holocene.

So the question of mechanism is front and center. A single 2007 paper that states the cycle abrupt climate changes events are caused by "noise" with no logic, analysis, or data to support that assertion, does not solve the problem.



http://www.clim-past.net/3/129/2007/cp-3-129-2007.pdf

2 The 1470 years period
The DO events have a characteristic saw-tooth shape, beginning with a very abrupt transition from the glacial (stadial) state into the DO (interstadial) state (William: Stadial is the name for the cold period and interstadial is the name for the warm period. i.e. There is observed cyclic warming followed by cooling. The cycle warming and cooling are also called Bond events after Gerald Bond who found that they correlate with cosmogenic isotope changes.) This is followed by a gradual decrease in the 18O isotope ratio until eventually there is a smaller jump back into the stadial state. This strongly non-sinusoidal shape of the climate curve results in a large part of the spectral power in a signal being spilled into overtones, which can result in a lowering of a spectral peak below the noise level ...

Now here is a paper that notes there is correlation of high latitude Northern temperature with the length of the solar cycle (it gets colder at high Northern latitudes when the solar cycle is long and warmer then the cycle is short), with a 10 to 12 year delay in between the change in the solar cycle length and the change in the high latitude temperature. The authors of that paper are predicting a drop in high Northern latitude temperatures of 3C average and 6C in the winter due to change in the solar magnetic cycle from solar cycle 23 to 24.

www.hindawi.com/journals/amet/aip/543146.pdf

Solar activity and Svalbard temperatures

The long temperature series at Svalbard (Longyearbyen) show large variations and a positive trend since its start in 1912. During this period solar activity has increased, as indicated by shorter solar cycles. The temperature at Svalbard is negatively correlated with the length of the solar cycle. The strongest negative correlation is found with lags 10–12 years. The relations between the length of a solar cycle and the mean temperature in the following cycle are used to model Svalbard annual mean temperature and seasonal temperature variations.

These models can be applied as forecasting models. We predict an annual mean temperature decrease for Svalbard of 3.5C +/- 2C from solar cycle 23 to solar cycle 24 (2009--‐20) and a decrease in the winter temperature of ≈6 C.

It is interesting based on the above prediction of high North Latitude cooling that there is now an increase in Northern sea ice.

I would caution the person above who emphatically states the increase in Northern latitude sea ice is only weather rather than a change that is caused by the recent solar change. Taking a strong emotion position makes it very difficult to see the pros/cons of the competing hypothesis. Scientists are curious and have an open mind. How do we know how Northern sea ice has changed in the past? There are records in the past of significant reductions in North sea ice. It appears there has been cyclic changes to Northern sea in the past.

I fully support the assertion that the very, very, recent few months of increasing North sea ice data does not prove anything. A few months is not sufficient to even see if there is a change in the trend. What we have observed is there has been a change. That is interesting.

It is a fact that concurrent with the observed change in sea ice (the sea ice change could be just a temporary change, we do not know at this point in time what will happen in the future) there has been a significant change in the sun which has resulted in a 40% reduction in the solar wind and the weakest solar heliosphere ever measured using modern instruments. The solar specialists are predicted a further weakening of the solar magnetic cycle.

Will the changes in the solar magnetic cycle result in decreased high latitude Northern Latitude temperatures and a significant increase in Northern Latitude sea ice.

What I find exciting is it appears there will be an opportunity to answer that question, to see which hypothesis is or is not correct, and to resolve some of the fundamental scientific questions concerning climate parameters and the different mechanisms.

[Cougar]

The 2007 paper does not dispute the existence of the saw tooth temperature changes. Look at the graph in the paper.

Well, depending on how you scale your graph, you can make blips look like "sawtooths."

The timing of the external forcing changes and does not follow a precise 1470 year period.

Didn't you say it did at first?

The 2007 paper then speculates... that the saw tooth change in temperature is caused by noise. That is pure speculation with no supporting data or logic to justify the conclusion.

I'm not sure why you would say that. The pattern, whatever it is, is certainly subject to mathematical analysis. The question, apparently, is in the degree of measurement error, which includes, I would imagine, the interpretation of the measurement, since we're dealing with ice cores from a particular region of the Earth.

[Shaula]

The 2007 paper then speculates since the saw tooth changes in temperature do not follow a very precise 1470 year period (i.e. there is some variance) that the saw tooth change in temperature is caused by noise. That is pure speculation with no supporting data or logic to justify the conclusion

What that paper does is rigorously compare a range of models to the data and concludes that the data resembles the probabilistic models more closely than the forced models. It is not speculation - it is a series of comparisons of models with data in a statistical manner. You can say they used the wrong models, you can argue that they have not corrected the data in some way. What you cannot do is dismiss statistical techniques like this as speculation in a thread that is all about finding statistically significant patterns and changes in data.

[William]

Well, depending on how you scale your graph, you can make blips look like "sawtooths."



Didn't you say it did at first?



I'm not sure why you would say that. The pattern, whatever it is, is certainly subject to mathematical analysis. The question, apparently, is in the degree of measurement error, which includes, I would imagine, the interpretation of the measurement, since we're dealing with ice cores from a particular region of the Earth.

A) Looking at the Temperature Data - Large cyclic temperature changes

The temperature changes are very large. The temperature changes are saw tooth. Look at the data.

As I noted the 2007 paper does not dispute the proxy data. The 2007 paper is asserting without proof the saw tooth temperature changes which correlate with cosmogenic isotope changes are caused by “noise”. I am not sure what “noise” is.
This is a link to the Greenland ice sheet temperature data. The mechanism that they are appealing to is if all the weather factors align the planet can cyclically change in temperature.

Another hypothesis is cyclic changes to the sun. The word cyclic means the changes happen again and again. The timing of the cycle varies somewhat. The mystery of the solar cycle variance goes away if where to understand the solar mechanism rather than to appeal for internal "earth noise" cause the cyclic temperature changes.

ftp://ftp.ncdc.noaa.gov/pub/data/pal...rature2010.xls

The author of paper that predicts a cooling of Vs solar length paper, has the same data at his site which is a summary of the paleoclimatic data.

http://www.climate4you.com/images/GI...CA%20DomeC.gif

http://www.climate4you.com/

B) What Caused the Past Temperature Changes - i.e. Large Cyclic Temperature Changes
The large temperature changes have an average cyclic period of 1470 years.

Heinrich very, very, large temperature changes occur as one of the 1470 year temperature changes. The Heinrich events occur every 8000 year to 10,000 years. Between the Heinrich temperature events are multiple smaller 2C to 3C changes. Gerald Bond tracked 23 of the cycles and noted the Younger Dryas Heinrich event was one of the 1470 year events.

There are cosmogenic isotope changes at the temperature changes.

There is variance in the timing of the cosmogenic isotope changes. There is a beat of plus or minus 400 years in the cosmogenic isotope changes. The temperature changes occur when the cosmogenic isotope changes occur.

[William]

What that paper does is rigorously compare a range of models to the data and concludes that the data resembles the probabilistic models more closely than the forced models. It is not speculation - it is a series of comparisons of models with data in a statistical manner. You can say they used the wrong models, you can argue that they have not corrected the data in some way. What you cannot do is dismiss statistical techniques like this as speculation in a thread that is all about finding statistically significant patterns and changes in data.

See this comment: http://www.bautforum.com/showthread....06#post2010106

The 2007 paper provides no explanation for mechanism. Look at the data. There are large and very large saw tooth temperature changes. Spectral analysis (i.e. analyzing the data in the frequency domain rather than the time domain) shows there is variance in the timing of large and very large saw tooth temperature changes. It does not follow from that fact that the saw tooth temperature changes are caused by internal earth "noise".

Ask questions. What the heck is this "noise"?

Why are there cosmogenic isotope changes at the 23 climate change events. (Cosmogenic isotope changes are caused by solar magnetic cycle changes.)

[Shaula]

The 2007 paper provides no explanation for mechanism.

How is that relevant to their conclusions? To answer myself - it is utterly irrelevant to that paper. You seem to be missing my point - they tested certain models against the data and, for the models they tested, showed that the data better fitted a probabilistic model rather than a forced one. They did not test all models, they specifically did not say that it was due to noise. What they said was that the timing intervals were best approximated by the exponential distribution model. Simple deterministic forcing models failed. That does not mean that a hybrid or more complex forcing model will not be found. It does not mean that the triggers have to be random. It means, to reiterate the point again, that of the three models they tested the exponential probabilistic one best fitted the data.

Are you now saying that all patterns which have no obvious mechanism should be discounted and ignored? A lot of statisticians would be very upset at this idea. You cannot ignore statistics in favour of the easier path of explanations that make you feel warm and fuzzy, or tie in with a personal belief. Statistics exists to test your ideas against data - and in this case the simple forcing model failed.

The paper itself says that it is trying to help people find out an underlying mechanism by providing some analysis of the basic ideas. It is not trying to sell any one idea - it is providing measures of success of the simplest models in each class.

Edit - "Look at the data" is about the worst thing you can say to back up your argument. Humans are very good at picking up on patterns but far less good at assessing their significance or telling the difference between probabilistic and triggered events.

[William]

How is that relevant to their conclusions? To answer myself - it is utterly irrelevant to that paper. You seem to be missing my point - they tested certain models against the data and, for the models they tested, showed that the data better fitted a probabilistic model rather than a forced one. They did not test all models, they specifically did not say that it was due to noise. What they said was that the timing intervals were best approximated by the exponential distribution model. Simple deterministic forcing models failed. That does not mean that a hybrid or more complex forcing model will not be found. It does not mean that the triggers have to be random. It means, to reiterate the point again, that of the three models they tested the exponential probabilistic one best fitted the data.

Are you now saying that all patterns which have no obvious mechanism should be discounted and ignored? A lot of statisticians would be very upset at this idea. You cannot ignore statistics in favour of the easier path of explanations that make you feel warm and fuzzy, or tie in with a personal belief. Statistics exists to test your ideas against data - and in this case the simple forcing model failed.

The paper itself says that it is trying to help people find out an underlying mechanism by providing some analysis of the basic ideas. It is not trying to sell any one idea - it is providing measures of success of the simplest models in each class.

Edit - "Look at the data" is about the worst thing you can say to back up your argument. Humans are very good at picking up on patterns but far less good at assessing their significance or telling the difference between probabilistic and triggered events.

Shaula,

The point of this thread is we may very well have an opportunity to see which hypothesis is or is not correct. The following are logical reasons to support the assertion that there will be a significant increase in high latitude Northern sea ice.

This comment starts with a link to an observed change in Northern sea ice. I fully support the assertion that a couple of months of observed increase in Northern sea ice does not prove anything. It is interesting however as the increase in sea ice is concurrent with a change in the sun. There is an observed past correlation with changes in the length of the solar magnetic cycle and temperatures in high latitude Northern regions. (See the link to the paper at the end of this comment.) A significant increase in high latitude northern sea ice is predicted by one hypothesis. It is not predicted by the competing hypothesis.

The solar wind speed has dropped 40% and is still low. The solar heliosphere (that is the name for pieces of the sun's magnetic field that are pushed off into space by the solar wind) is the weakest ever measured by modern instruments. The solar heliosphere deflects high speed protons which are called for historical reasons galactic cosmic rays GCR - the GCR are not rays but rather high speed protons. The "GCR", high speed protons, create muons - which is the name for an unstable negatively charge particle which is roughly 1000 times heavy that an electron.

Scientific discussion requires the ability to think of more than one hypothesis. What is the logic and observations that supports one hypothesis/mechanism over another. Scientific discussion requires logical analysis of the competing hypotheses/mechanisms based on current and past observations. Often a prediction and a new special condition/new change can be used to determine which hypothesis is or is not correct. The prediction is that there will be significant cooling of Northern high latitude regions. As most are aware the majority of the twentieth century warming was in Northern high latitude regions. Why is that so?

Comments:
- High speed GCR strike the earth's atmosphere creating muons which are negative charged particles which are a 1000 times heavy than electrons. The muons strike molecules in the atmosphere creating ions - ions is the name for atoms or molecules that are missing an electron. The ions cause low level clouds to form and change the optical properties of low level clouds. Ions also cause high level cirrus clouds to dissipate by causing larger ice particles to form in the cirrus cloud. The larger ice particles then drop to the surface of the planet. Low level clouds cool the planet by reflecting sunlight off into space. High level cirrus clouds warm the earth particularly at high latitude regions due to the greenhouse effect.
- An increase in the amount of cirrus clouds would cause the observed pattern of warming that we have observed in the 20th century. i.e. The 20th century warming is in specific regions. As others have noted the regions that have warmed in the twentieth century is not the regions that would be expected if the warming was caused by an increase in atmospheric CO2. If the warming was due to an increase in atmospheric CO2 the expected warming would be greatest in the tropics and there would have been similar warming in high latitude Northern and Southern regions, which is not observed.
- Interesting there has been no warming on the Antarctic ice sheet. An explanation for that observation is that due to the altitude of the surface of the Antarctic ice sheet (the Antarctic ice sheet has covered the tops of the Antarctic continent mountains) the temperature of the surface is so cold there is almost no moisture to create cirrus clouds. As there is almost no moisture to form the cirrus clouds over the Antarctic ice sheet the GCR's modulation of the amount of cirrus clouds would not have a significant affect on the temperature on the Antarctic ice sheet. This cyclic warming of the Greenland ice sheet and slight cooling of the Antarctic ice sheet is called the polar see-saw. The polar see-saw occurs during the Bond cycles.
- There is an observed delay of 10 to 12 years between when there is a change in the length of the solar cycle as to when there is cooling of the high latitude regions. That is very interesting based on GCR mechanism. The GCR change has occurred but for 10 to 12 years there is no observed change. A change in cirrus clouds will result in an immediate change in high latitude Northern temperatures. Staying with the GCR mechanism/hypothesis a delay would require a change which removes ions from the atmosphere. Interesting the earth's ionosphere dropped to the lowest level every measured when the GCR initially changed. The drop in the earth's ionosphere could not be explained by the reduction in solar wind speed or due to the reduction in solar total radiation (TSI). The drop in level of the earth's ionosphere is an unexplained anomaly.

The 2007 paper states that whatever is causing the cycle temperature changes of the planet varies in period around a mean period of 1470 year. The forcing function varies. The 2002 paper stated there is no known internal forcing function that can maintain a regular period across the interglacial period and into the glacial period (note feedbacks and other factors that affect weather are significantly different in the interglacial period as compared to glacial period.) Other authors have noted the sun is the most likely cause of the Bond cycle for half a dozen different logical reasons. (Including for example that there are cosmogenic isotope changes when the cycles occur.)

The 2007 paper could be used to support the assertion that for some unknown reason there is a particular configuration of wind and so on that could cyclically cause the planet to abruptly warm and then cool. The 2007 paper at most opens the door to consider the "noise" hypothesis which is some unknown configuration of winds and ocean currents can cause abrupt warming followed by abrupt cooling in both the interglacial period and in the glacial period. It does not disprove the alternative hypothesis which is solar changes cause what is observed.

I would assume you are aware of solar magnetic cycle changes. Do you understand that solar magnetic cycle changes cause cosmogenic isotope changes.

I said look at the climate change data as Cougar stated the scale of the graph had been blown up to exaggerate the magnitude of past cycles. That is not correct. The Bond cycles are large. The cycles have a mean period of 1470 years. As I stated the Younger Dryas abrupt cooling period is one of the Bond events. Google the Younger Dryas abrupt cooling period.


www.hindawi.com/journals/amet/aip/543146.pdf

Solar activity and Svalbard temperatures

The long temperature series at Svalbard (Longyearbyen) show large variations and a positive trend since its start in 1912. During this period solar activity has increased, as indicated by shorter solar cycles. The temperature at Svalbard is negatively correlated with the length of the solar cycle. The strongest negative correlation is found with lags 10–12 years. The relations between the length of a solar cycle and the mean temperature in the following cycle are used to model Svalbard annual mean temperature and seasonal temperature variations.

These models can be applied as forecasting models. We predict an annual mean temperature decrease for Svalbard of 3.5C +/- 2C from solar cycle 23 to solar cycle 24 (2009--‐20) and a decrease in the winter temperature of ≈6 C.

[Torsten]

Crazy weather. Curious that sea ice is increasing.

Need to keep an eye on that. I would expect the weather will change again and sea ice will continue to change as it is predicted.

http://nsidc.org/data/seaice_index/i...timeseries.png

http://arctic-roos.org/observations/...i1_ice_ext.png

http://arctic.atmos.uiuc.edu/cryosph....antarctic.png

Curious to me is that in posting all these charts there is not a link to the context provided by the people who publish the charts. For example, see 'Conditions in Context" here.

NSIDC
Over the past thirty years of satellite data, the day of the maximum has varied by over six weeks, occurring as early as mid-February and as late as the end of March. However, even with so much variability, there is a small trend towards later maximum ice extents. This year’s maximum ice extent continued that trend, occurring 12 days later than average.

It is not clear why the maximum ice extent would happen later, given that in general, ice extent is decreasing. One possibility is that the lower winter ice extents might make it easier for ice to continue growing later in the season. With lower winter extents, a late cold snap or northerly wind could spread ice southward over ocean that would normally be ice-covered at that point. Researchers do not expect the late maximum ice extent to strongly influence summer melt. The ice that grew late this winter is quite thin, and will melt rapidly as the sun rises higher in the sky and the air and water get warmer.

So, there is a trend to later maximum sea ice extent, despite a general decline in the volume of ice and the amount of multi year ice. The phenomenon is recognized, and there are attempts to explain it. Imagine that!

Curious that paleo-climatologists do not understand what causes the Dansgaard-Oeschger cycle. Planet warms up and then cools cyclically. During the cyclic warming and cooling there is the interesting so call polar see saw. Greenland ice sheet warms when the Antarctic ice sheet cools and visas a versa.

I will keep an eye out and see if there is any more data or perhaps a paper if the trend were to continue that might discuss a mechanism.

http://www.agu.org/pubs/crossref/200...PA000571.shtml

http://www.agu.org/pubs/crossref/200...GL017115.shtml

Curious that there is a paper linked from 2002, then another from 2003, but not the one I showed you here from 2005.

Possible solar origin of the 1,470-year glacial climate cycle demonstrated in a coupled model, Braun et al., 2005.

This is a good paper to know about as it only shows that the GCMs can reproduce the phenomenon, even if only as an effect of the external influence.

And of course, now we know about the one from 2007 that Tensor has linked and Shaula has commented on.

http://www.climate4you.com/images/GI...CA%20DomeC.gif

You've been shown that that is a deceptive and misleading chart. There was more commentary on that chart here. Why do you link to it?

[William]

Curious to me is that in posting all these charts there is not a link to the context provided by the people who publish the charts. For example, see 'Conditions in Context" here.


So, there is a trend to later maximum sea ice extent, despite a general decline in the volume of ice and the amount of multi year ice. The phenomenon is recognized, and there are attempts to explain it. Imagine that!

Curious that there is a paper linked from 2002, then another from 2003, but not the one I showed you here from 2005.

Possible solar origin of the 1,470-year glacial climate cycle demonstrated in a coupled model, Braun et al., 2005.

This is a good paper to know about as it only shows that the GCMs can reproduce the phenomenon, even if only as an effect of the external influence.

And of course, now we know about the one from 2007 that Tensor has linked and Shaula has commented on.


You've been shown that that is a deceptive and misleading chart. There was more commentary on that chart here. Why do you link to it?

William: The data in the chart is from Richard Alley's paper see the link above that is the source data. The fact the Greenland ice sheet temperature has increased and decreased in the past is pertinent to this discussion. That is specifically the subject of this thread. Past cyclic warming and cooling of high latitude Northern regions, the predicted cooling of high latitude northern regions due to the increase in the length of the solar cycle, and the recent increase in high latitude northern sea ice.

Torsten,

You miss the point of this thread. There is a specific predicted decrease in high Northern Latitude temperature that is caused by a change in solar cycle length with a 10 to 12 year delay. I fully support your skepticism that the recent increase in Northern sea ice does not prove the competing hypothesis is correct. If the solar length hypothesis is correct, however, we will see a significant decrease in high latitude Northern latitude temperatures and a significant increase in high latitude Northern sea ice. i.e. The high latitude Northern cooling will be significant and unequivocal to all observers.

I do not understand why you provide links to your past comments. Perhaps I am missing something. Your past comments do not address the scientific anomaly raised in this thread. Why was the majority of the twentieth century warming in the high latitude Northern regions? Based on my understanding of the CO2 warming mechanism there should be uniform warming due to the increase in atmospheric CO2 with the majority of the warming in the tropics. Perhaps I am missing something.

Your past comments do not appear to predict a sudden and significant cooling of high latitude Northern regions. Are you now predicting a sudden cooling of high latitude Northern regions? Would sudden cooling of high latitude Northern regions disprove your hypothesis?

I am saying that it appears that there will be observational data to prove or disprove the two different hypothesis/mechanisms. I provided a link to a paper that is predicting significant cooling of high latitude Northern regions.

Torsten said: "Curious to me is that in posting all these charts there is not a link to the context provided by the people who publish the charts. For example, see 'Conditions in Context" here."

Ice in the Bering Sea was the highest ever recorded. Alaska had the highest snowfall ever recorded. What are the conditions of context that disproves the observation that there has been a change in the high Northern regions?

I fully support your assertion that the 2012 high northern ice cover observations is evidence of a change not a trend as of yet.

http://nsidc.org/arcticseaicenews/20...g-melt-season/

Overview of Conditions
Arctic sea ice extent in March 2012 averaged 15.21 million square kilometers (5.87 million square miles). Ice extent this March ranked ninth lowest out of the 34 years of satellite data for the month, but it was the highest March average ice extent since 2008 and one of the higher March extents in the past decade.

[Tensor]

Tensor,
The 2007 paper notes there is a saw tooth change in temperature.

Snip...

they have no supporting data.[/B]

Shaula covered this rather nicely.

So the question of mechanism is front and center. A single paper 2007 paper

Actually, This paper , along with several other papers mentioned in it, have quite a bit more information. For example, see Svensson below for details on the problems with the GISP2. The rapid rise time and extension are not seen in the newer data

that states the cycle abrupt climate changes events are caused by "noise" with no logic, analysis, or data to support that assertion,

LOL, Oh William. You really need to read up on statistical analysis. And, besides, this paper did not say that the climate changes were caused by "noise", they said that there was no pattern above the noise. Meaning the data is a probabilistic model. [/QUOTE]

does not solve the problem.

http://www.clim-past.net/3/129/2007/cp-3-129-2007.pdf

2 The 1470 years period

snip..

below the noise level ...

Yeah, not so much. Using NGRIP's Greenland Ice Core Chronology (GICC05). See Svensson et al., 2006 :

"For example, the existence of the proposed 1470yr cycle depends on the exact timing and phasing of the onset of D–O events, and, as discussed above, this is exactly where we believe that the GISP2 time scale is inaccurate."

There's also the problem of the GISP2 of have problems with sometimes very thing layers.

Now here is a paper that notes there is correlation of high latitude Northern temperature with the length of the solar cycle (it gets colder at high Northern latitudes when the solar cycle is long and warmer then the cycle is short), with a 10 to 12 year delay in between the change in the solar cycle length and the change in the high latitude temperature. The authors of that paper are predicting a drop in high Northern latitude temperatures of 3C average and 6C in the winter due to change in the solar magnetic cycle from solar cycle 23 to 24.

www.hindawi.com/journals/amet/aip/543146.pdf

Actually, it says nothing about all high latitudes. It's specific to Svalbard. Interestingly, the temperatures at Svalbard have followed the following pattern 2009-2011:

Annual: +0.5, -0.5, +1
Spring: -0.5, +2, +1
Summer: +1, -1, +1.5
Autumn: +2.5, -2.5, +2.5
Winter: -2.5, +3, -5

The -5 is interesting as the arctic ice, instead of being blown to the north of the measuring station in 2011 by the prevailing winds, were, due to a change in the prevailing winds, blown into and around the harbor, close to the measuring station. Which many in Svalbard feel accounts for the large drop in 20111. Either way, the prediction in the paper isn't looking good at this point.

It is interesting based on the above prediction of high North Latitude cooling that there is now an increase in Northern sea ice.

Actually, this is wrong. The extent of arctic sea ice is larger than last year (by only .6 million kilometers), but the volume of sea ice is running at the same amount as 2011. This is due to the low extent of last summer’s minimum. While the extent has increased, much of the sea water that froze since the summer minimum is only 12-30 cm thick and will melt quickly.

It is a fact that concurrent with the observed change in sea ice (the sea ice change could be just a temporary change, we do not know at this point in time what will happen in the future) there has been a significant change in the sun which has resulted in a 40% reduction in the solar wind

This is just flat out false statement. What is it based on? This solar report , from March 26, 2003, shows the solar wind speed 349 and 430 km/sec. Yesterdays report showed the range between 335 and 423 km/s. You want to explain how a 7-14 km/s is a 40% drop? Especially since March 2003 was still a pretty active time for the sun. Today's wind has drop to the ~350 km/s. But sunspots and flux have gone way up.

and the weakest solar heliosphere ever measured using modern instruments.

Define mondern instruments. And provide a some support for that. 1900 and 1910 were lower, but it doesn't really matter. In a presentation on the Heliosphere Magnetic Field 1805-2010 Leif Svalgaard stated "There seems to be both a floor and a ceiling, and most importantly no long term trend since the 1830s. We hit the floor in 2008, and have been climbing since.

The solar specialists are predicted a further weakening of the solar magnetic cycle.

Some are, others aren't so sure. Some have checked data from the previous cycle and don’t see that much of a change.

Will the changes in the solar magnetic cycle result in decreased high latitude Northern Latitude temperatures and a significant increase in Northern Latitude sea ice.

Well, maybe at Svalbard. As long as ice isn’t blown into the harbor

What I find exciting is it appears there will be an opportunity to answer that question, to see which hypothesis is or is not correct, and to resolve some of the fundamental scientific questions concerning climate parameters and the different mechanisms.

Why didn't you just post this, instead of a bunch of wrong statements?

[Shaula]

William - your pictures are nice but they are just that. Pictures, verbal logic chains. Until you produce models that can be used to make predictions and then test these predictions against data then they are not all that useful, scientifically. Your attack on the 2007 paper seems to have been made on the grounds that the tests did not confirm your preconceptions. So instead of challenging your preconceptions, or thinking about what those tests mean you attacked the tests.

I have tried to explain what the paper means but you don't seem to be able to get over your interpretation of it as hostile to your ideas. It actually isn't. It is a useful piece of analysis you should be incorporating into your mental picture of what is happening. I don't really want to get into an on-line climate debate, they are rarely fun. I merely want to highlight that your dismissal of the paper is poor scientific practice.

And William?

I would assume you are aware of solar magnetic cycle changes. Do you understand that solar magnetic cycle changes cause cosmogenic isotope changes.

I have a masters degree in physics, and did just about every module in astrophysics. My final year project was logging and analysing the solar cycle as we moved towards solar max. I took a range of measurements of solar properties and performed statistical analysis of their relationships to each other and some Earth-bound quantities. So yes, I am aware of solar magnetic cycles, thank you.

[William]

William - your pictures are nice but they are just that. Pictures, verbal logic chains. Until you produce models that can be used to make predictions and then test these predictions against data then they are not all that useful, scientifically. Your attack on the 2007 paper seems to have been made on the grounds that the tests did not confirm your preconceptions. So instead of challenging your preconceptions, or thinking about what those tests mean you attacked the tests.

I have tried to explain what the paper means but you don't seem to be able to get over your interpretation of it as hostile to your ideas. It actually isn't. It is a useful piece of analysis you should be incorporating into your mental picture of what is happening. I don't really want to get into an on-line climate debate, they are rarely fun. I merely want to highlight that your dismissal of the paper is poor scientific practice.

And William?

I have a masters degree in physics, and did just about every module in astrophysics. My final year project was logging and analysing the solar cycle as we moved towards solar max. I took a range of measurements of solar properties and performed statistical analysis of their relationships to each other and some Earth-bound quantities. So yes, I am aware of solar magnetic cycles, thank you.

Shaula,

Shaula could you please explain the "noise" hypothesis. Perhaps if you elaborated I could response.

[William]

Shaula covered this rather nicely.

Tensor,

Have you every heard of the polar sea-saw? That is the name for the cyclic change where the Antarctic ice sheet cools when the Greenland ice sheet warms.

http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt

This is a link to the satellite global temperature data.

Plot the data, global anomaly, Southern Polar, Northern Polar, Southern Polar, Southern Hemisphere, Northern Hemisphere, and tropics. Add a trend line to each of the plots.

The Southern Polar trend line is negative. The warming in the Northern Polar region is more than twice the global anomaly. The tropic anomaly is trending to zero.

That specific pattern has occurred before. Have a go at explaining that pattern using the CO2 mechanism.

Based on what has happened before the high latitude Northern region will cool due to the significant interruption in the solar magnetic cycle. Of I suppose you still have not acknowledged that there has been a significant interruption to the solar magnetic cycle.

Come on make a prediction.

I would assume, your prediction is that it is impossible for there to be cooling now of the high latitude Northern regions. Is that correct? Could you please answer my question.

Comment:
When one has no understanding what so ever of the mechanisms, the proxy data is quite confusing. When the forcing function occurs it has different effects depending on the region and latitude of the region.


Recent activity
The geomagnetic field was quiet to active on April 20. Solar wind speed at SOHO ranged between 299 and 364 km/s.

[William]

This "noise" hypothesis sounds very interesting. What specifically is causing the "noise". What is the forcing function? Why are there cosmogenic isotope changes during the abrupt climate changes?

Perhaps the "noise" is the explanation for why both hemispheres cool.

http://sheridan.geog.kent.edu/geog41066/7-Overpeck.pdf

ABRUPT CHANGE IN EARTH’S CLIMATE SYSTEM

Abrupt shifts between warm and cold states punctuate the interval between 20 to 75 ka) in the Greenland isotope record, with shifts of 5◦–15◦C occurring in decades or less (Figure 1). These alternations were identified in some of the earliest ice core isotopic studies [e.g., (22)] and were replicated and more precisely dated by subsequent work (23). Further analysis of diverse records has distinguished two types of millennial events (13). Dansgaard/Oeschger (D/O) events are alternations between warm (interstadial) and cold (stadial) states that recur approximately every 1500 years, although this rhythm is variable. Heinrich events are intervals of extreme cold contemporaneous with intervals of ice-rafted detritus in the northern North Atlantic (24–26); these recur irregularly on the order of ca. 10,000 years apart and are typically followed by the warmest D/O interstadials.

Both Heinrich and D/O events exhibit clear global impacts. These patterns have been summarized in several studies [e.g., (26, 34)]. Although the pattern of influence appears to differ between these types of anomaly, a clear interpretation of these differences, particularly in terms of distinguishing physical mechanisms, has not been developed. As Hemming (26) notes, different global patterns of impact may simply reflect proxy-specific or site-specific limitations such as sensitivity and response time. In general, however, a cold North Atlantic corresponds with a colder, drier Europe, weaker Asian summer monsoon, saltier northwestern tropical Pacific, drier northern South America, colder/wetter western North America, cooler eastern subtropical Pacific, and warmer South Atlantic and Antarctic. Table 1 summarizes the main impacts of a cold North Atlantic (stadial) on key regions and systems.

Abrupt tropical cooling ~8,000 years ago

"We drilled a sequence of exceptionally large, well-preserved Porites corals within an uplifted palaeo-reef in Alor, Indonesia, with Th-230 ages spanning the period 8400 to 7600 calendar years before present (Figure 2). The corals lie within the Western Pacific Warm Pool, which at present has the highest mean annual temperature in the world's ocean. Measurements of coral Sr/Ca and oxygen 18 isotopes at 5-year sampling increments for five of the fossil corals (310 annual growth increments) have yielded a semi-continuous record spanning the 8.2 ka event. The measurements (Figure 2) show that sea-surface temperatures were essentially the same as today from 8400 to 8100 years ago, followed by an abrupt ~3�C cooling over a period of ~100 years, reaching a minimum ~8000 years ago. The cooling calculated from coral oxygen 18 isotopes is similar to that derived from Sr/Ca. The exact timing of the termination of the cooling event is not yet known, but a coral dated as 7600 years shows sea-surface temperatures similar to those of today.

"

http://www.geo.arizona.edu/palynolog...00yrevent.html

The 8200-year Climate Event

This figure shows snow accumulation and isotopically inferred temperature records in the Greenland GISP2 ice core and a temperature record derived from oxygen isotope measurements of fossil shells in the sediments of Lake Ammersee, southern Germany. These records all show a major climatic instability event which occurred around 8200 years ago, during the Holocene. The event was large both in magnitude, as reflected by a temperature signal in Greenland of order 5 C, and in its geographical extent, as indicated by the close correlation of the signal in these two locations. The dramatic event is also seen in the methane record from Greenland (not shown here) indicating possible major shifts in hydrology and land cover in lower latitudes. source: Von Grafenstein et al (1998) Climate Dynamics, 14, 73-81.

The Bond events are the periods when there is cosmogenic isotope change.

http://en.wikipedia.org/wiki/1500-year_climate_cycle

List of Bond events
Most Bond events do not have a clear climate signal; some correspond to periods of cooling, others are coincident with aridification in some regions.
• ≈1,400 BP (Bond event 1) — roughly correlates with the Migration Period pessimum(450–900 AD)
• ≈2,800 BP (Bond event 2) — roughly correlates with the Iron Age Cold Epoch (900–300 BC)[8]
• ≈4,200 BP (Bond event 3) — correlates with the 4.2 kiloyear event
• ≈5,900 BP (Bond event 4) — correlates with the 5.9 kiloyear event
• ≈8,100 BP (Bond event 5) — correlates with the 8.2 kiloyear event
• ≈9,400 BP (Bond event 6) — correlates with the Erdalen event of glacier activity in Norway,[9] as well as with a cold event in China.[10]
• ≈10,300 BP (Bond event 7) — unnamed event
• ≈11,100 BP (Bond event 8) — coincides with the transition from the Younger Dryas to the boreal

http://www.esd.ornl.gov/projects/qen/transit.html

According to the marine records, the Eemian interglacial ended with a rapid cooling event about 110,000 years ago (e.g., Imbrie et al., 1984; Martinson et al., 1987), which also shows up in ice cores and pollen records from across Eurasia. From a relatively high resolution core in the North Atlantic. Adkins et al. (1997) suggested that the final cooling event took less than 400 years, and it might have been much more rapid.
The event at 8200 ka is the most striking sudden cooling event during the Holocene, giving widespread cool, dry conditions lasting perhaps 200 years before a rapid return to climates warmer and generally moister than the present. This event is clearly detectable in the Greenland ice cores, where the cooling seems to have been about half-way as severe as the Younger Dryas-to-Holocene difference (Alley et al., 1997; Mayewski et al., 1997). No detailed assessment of the speed of change involved seems to have been made within the literature (though it should be possible to make such assessments from the ice core record), but the short duration of these events at least suggests changes that took only a few decades or less to occur....

...The Younger Dryas cold event at about 12,900-11,500 years ago seems to have had the general features of a Heinrich Event, and may in fact be regarded as the most recent of these (Severinghaus et al. 1998). The sudden onset and ending of the Younger Dryas has been studied in particular detail in the ice core and sediment records on land and in the sea (e.g., Bjoerck et al., 1996), and it might be representative of other Heinrich events.

http://earthobservatory.nasa.gov/New...w.php?id=24476

Glacial Records Depict Ice Age Climate in Synch Worldwide
An answer to the long-standing riddle of whether the Earth’s ice ages occurred simultaneously in both the Southern and Northern hemispheres is emerging from the glacial deposits found in the high desert east of the Andes.
“During the last two times in Earth’s history when glaciation occurred in North America, the Andes also had major glacial periods,” says Kaplan.

The results address a major debate in the scientific community, according to Singer and Kaplan, because they seem to undermine a widely held idea that global redistribution of heat through the oceans is the primary mechanism that drove major climate shifts of the past.

The implications of the new work, say the authors of the study, support a different hypothesis: that rapid cooling of the Earth’s atmosphere synchronized climate change around the globe during each of the last two glacial epochs.
“Because the Earth is oriented in space in such a way that the hemispheres are out of phase in terms of the amount of solar radiation they receive, it is surprising to find that the climate in the Southern Hemisphere cooled off repeatedly during a period when it received its largest dose of solar radiation,” says Singer. “Moreover, this rapid synchronization of atmospheric temperature between the polar hemispheres appears to have occurred during both of the last major ice ages that gripped the Earth.”

[William]

I would suspect that it will be a number of months until there is sufficient data to see a change. We are looking out for any evidence of a slow down in the solar magnetic cycle. We are also looking for any evidence of cooling in high latitude Northern regions. Might also have a look out for any unusual changes in weather. Bering sea ice in the winter 2011/2012 has the highest ever measured. Snowfall in Alaska was the highest ever measured. That type of thing might be interpreted as first evidence of the start of a change.

http://arctic-roos.org/observations/...i1_ice_ext.png

[Tensor]

This "noise" hypothesis sounds very interesting. What specifically is causing the "noise". What is the forcing function? Why are there cosmogenic isotope changes during the abrupt climate changes?

Perhaps the "noise" is the explanation for why both hemispheres cool.

Not sure what any of this has to do with the sea ice. The sea ice is disappearing due to the warming caused mostly by the increase in CO2. Some quotes from this article.

The average thickness of the Arctic sea ice cover is declining because it is rapidly losing its thick component, the multi-year ice. At the same time, the surface temperature in the Arctic is going up, which results in a shorter ice-forming season.

Perennial” sea ice – all that which has survived at least one summer, including multi-year ice – is shrinking at a rate of 12.2 percent in extent and 13.5 percent in area, per decade. This, NASA says, demonstrates that the oldest ice is shrinking fastest

NASA says 2012 recorded the second-lowest extent ever recorded. Even then, the last decade’s decline suggests an accelerating trend.

[Torsten]

You miss the point of this thread. There is a specific predicted decrease in high Northern Latitude temperature that is caused by a change in solar cycle length with a 10 to 12 year delay.

I think you mean there is a specific prediction for Svalbard.

I do not understand why you provide links to your past comments. Perhaps I am missing something.

Yes, you are missing something, so I'll explain it to you. Regarding my first link to an older post: You trotted out the same papers on a topic as you have done one or more times in the past. However, as part of the previous discussion I showed you a paper that presented further research into that topic. But for reasons only you can answer, you chose to ignore that paper in this latest presentation of your idea. You treated the topic as if all research into it ended in 2003. And then you missed the 2007 paper that Tensor brought into the discussion.

Next, you linked to that wretched chart on Humlum's site. Everytime you do that, I will point out that it is based on unscientific reasoning, that it is purposely deceptive and misleading, and I will point out that you have already been shown this. It doesn't belong in here except as an object of derision and ridicule.

Your past comments do not address the scientific anomaly raised in this thread.

When you ignore key parts of the story (ie, Braun et al, 2005) then you will be reminded of them. I think you posted Humlum's chart because it purports to show the temperature record at the Greenland summit. But it ignores the best possible data for the modern rise (which I explained in my past comment) and it is incomplete on the CO2 story. And you didn't answer my question on why you posted it in this thread. I have to conclude that you think it is a fair representation, despite my detailed explanation of why it is a piece of garbage.

Why was the majority of the twentieth century warming in the high latitude Northern regions? Based on my understanding of the CO2 warming mechanism there should be uniform warming due to the increase in atmospheric CO2 with the majority of the warming in the tropics. Perhaps I am missing something.

Well, your understanding is wrong, and yes, you're missing a key prediction of the general circulation models. Greater warming at high northern latitudes has been predicted and understood since at least 1975. And once again, I will point you to an earlier discussion we had on this topic. I don't feel like reposting the links, so go here for the details.

Your past comments do not appear to predict a sudden and significant cooling of high latitude Northern regions. Are you now predicting a sudden cooling of high latitude Northern regions? Would sudden cooling of high latitude Northern regions disprove your hypothesis?

I'm not making specific short term predictions of anything. I expect noise in average annual temperature data, and in sea ice extent data. But I expect the trends we've been observing (expressed statistically and not "eyeballed") to continue because of the CO2 mechanism.

I am saying that it appears that there will be observational data to prove or disprove the two different hypothesis/mechanisms. I provided a link to a paper that is predicting significant cooling of high latitude Northern regions.

Again, I think the prediction is specific to Svalbard.

Ice in the Bering Sea was the highest ever recorded. Alaska had the highest snowfall ever recorded.

So what? The Barents Sea recorded a record low area this winter: chart

again, from NSIDC
High ice extent in the Bering Sea
In the Bering Sea, off Alaska, ice extent reached a record high for the month of March. Persistent winds pushed the sea ice southward and froze more seawater into ice.

As winds from the north pushed Arctic ice southward through the Bering Strait, the ice locked together and formed a structurally continuous band known as an ice arch, which acts a bit like a keystone arch in a building. The ice arch temporarily held back the ice behind it, but as the winds continued, the arch failed along its southern edge, and ice cascaded south through the strait into the Bering Sea. Sea ice also piled up on the northern coast of St. Lawrence Island, streaming southward on either side of it.

What are the conditions of context that disproves the observation that there has been a change in the high Northern regions?

You've been writing of imminent cooling or cooling underway, and calling it a "change", for about as long as you've been posting here. Remember how the summer minimum ice extent was a record low in 2007? Then in 2008 it ended up higher, and higher again in 2009. Look at what you wrote in December 2009, here. Perhaps your idea can explain what happened to the 2010 and 2011 values in this chart.

This current thread is a repeat of the same old posting pattern.

I fully support your assertion that the 2012 high northern ice cover observations is evidence of a change not a trend as of yet.

I don't know what this is supposed to mean.

[Shaula]

Shaula could you please explain the "noise" hypothesis. Perhaps if you elaborated I could response.

Again you missed my point. And that of the 2007 which is all I am defending here. They were not putting forwards a mechanism.

What they did was test 3 basic predictive mathematical models (NOT physics based or phenomenological models) against the data to see which worked best. The 3 cases were examples of Simple probabilistic models, Simple forced models and Stochastic resonance models. Of these three the simple probabilistic model fitted the interval data the best. That is all it was saying.

Your dismissal of the paper for not providing a mechanism as it lacking all logic is terrible science. That is the only point I am trying to get across. I do not believe that I, or the paper authors, have been proposing actual mechanisms. What they are doing is looking at the simplest, purest mathematical models to draw some basic conclusions. In fact you can sum their paper up as: "Simplistic models cannot explain the periodicity in this data any better than a basic random process".

In short: I am not arguing against your idea and not for it. All I am doing is arguing against your use of papers. You dismissed the paper for invalid reasons instead of trying to see what it actually meant for your idea.

[noncryptic]

Doesn't an increase in northern sea ice fit the idea that due to melting of arctic ice the gulf stream slows down, which would results in less warm water being transported to the arctic, which in turn would result in cooling of the north Atlantic area? (which would be rather different than global warming turning into global cooling)

[William]

Again you missed my point. And that of the 2007 which is all I am defending here. They were not putting forwards a mechanism.

What they did was test 3 basic predictive mathematical models (NOT physics based or phenomenological models) against the data to see which worked best. The 3 cases were examples of Simple probabilistic models, Simple forced models and Stochastic resonance models. Of these three the simple probabilistic model fitted the interval data the best. That is all it was saying.

Your dismissal of the paper for not providing a mechanism as it lacking all logic is terrible science. That is the only point I am trying to get across. I do not believe that I, or the paper authors, have been proposing actual mechanisms. What they are doing is looking at the simplest, purest mathematical models to draw some basic conclusions. In fact you can sum their paper up as: "Simplistic models cannot explain the periodicity in this data any better than a basic random process".

In short: I am not arguing against your idea and not for it. All I am doing is arguing against your use of papers. You dismissed the paper for invalid reasons instead of trying to see what it actually meant for your idea.

Shaula,

You miss my point. Each time there is a climate change there are cosmogenic isotope changes. Solar magnetic cycle changes can also be chaotic, or at least appear to be chaotic if one does not understand all of the factors that affect the solar magnetic cycle. Solar physicists have noted the sun changes pseudo cyclically. That is to say there are multiple factors affecting the solar magnetic cycle which makes the frequency of the cycle shift. If the external forcing function is chaotic it is not ruled out by the 2007 paper. The 2007 paper as you note does not discuss mechanisms.

What you are also missing is the climate change events come in small, medium, large, and super large. Paleoclimatic scientists do not have a physical explanation for the large and super large climate change events. The change is too rapid and too large to be caused by internal forcing functions or at least known internal forcing functions. An example is the 8200 year before present and the Younger Dryas cooling event or the termination of the last interglacial.

The paleo climatic researcher appeal to changes in the North Atlantic drift current as possible forcing function. However there are multiple instances of large climate change events where there no correlation with changes in the ocean currents. The Younger Dryas super large climate change event also does not correlate with an ocean current change.

There are three points in this thread. 1) One there is a prediction of cooling when the solar magnetic cycle length changes. 2) The second is the solar magnetic cycle has changed. 3) The third is there is suddenly an increase in sea ice in the high latitude regions.

Solar activity and Svalbard temperatures

The long temperature series at Svalbard (Longyearbyen) show large variations and a positive trend since its start in 1912. During this period solar activity has increased, as indicated by shorter solar cycles. The temperature at Svalbard is negatively correlated with the length of the solar cycle. The strongest negative correlation is found with lags 10–12 years. The relations between the length of a solar cycle and the mean temperature in the following cycle are used to model Svalbard annual mean temperature and seasonal temperature variations.

These models can be applied as forecasting models. We predict an annual mean temperature decrease for Svalbard of 3.5C +/- 2C from solar cycle 23 to solar cycle 24 (2009--‐20) and a decrease in the winter temperature of ≈6 C.

Tensor is missing the obvious, that it does not seem possible to isolate cooling to Svalbard. Long term data is only available at Svalbard. Svalbard cooled in the past after a 10 to 12 year delay when there was a change in the length of the solar magnetic cycle. There was in the winter 2011/2012 the largest extent of ice ever measured in the Bering sea. Alaska had the highest snowfall ever measured. Alaska and the Bering sea are high Northern latitude regions that which are longitudinally separated from Svalbard.



http://www.agu.org/pubs/crossref/200...PA000571.shtml

On the 1470-year pacing of Dansgaard-Oeschger warm events
The oxygen isotope record from the Greenland Ice Sheet Project 2 (GISP2) ice core was reanalyzed in the frequency and time domains. The prominent 1470-year spectral peak, which has been associated with the occurrence of Dansgaard-Oeschger interstadial events, is solely caused by Dansgaard-Oeschger events 5, 6, and 7. This result emphasizes the nonstationary character of the oxygen isotope time series. Nevertheless, a fundamental pacing period of ∼1470 years seems to control the timing of the onset of the Dansgaard-Oeschger events. A trapezoidal time series model is introduced which provides a template for the pacing of the Dansgaard-Oeschger events. Statistical analysis indicates only a ≤3% probability that the number of matches between observed and template-derived onsets of Dansgaard-Oeschger events between 13 and 46 kyr B.P. resulted by chance. During this interval the spacing of the Dansgaard-Oeschger onsets varied by ±20% around the fundamental 1470-year period and multiples thereof. The pacing seems unaffected by variations in the strength of North Atlantic Deep Water formation, suggesting that the thermohaline circulation was not the primary controlling factor of the pacing period.

I do not see the phrase: "Simplistic models cannot explain the periodicity in this data any better than a basic random process" in the author's conclusion. I do not see anything in the authors conclusion that would rule out the sun as the forcing function. The sun is not a simplistic forcing function.

The assumption of the onsets being determined by a strictly periodic triggering (not activating at each period) masked by the dating uncertainty can with high significance be rejected (Figs. 3c, d) A remarkable exception for the rejection is the situation where DO9 is omitted for the GISP2 time scale. The relatively strong periodicity in that case is, however, not preserved in the newer NGRIP dating. By the nature of the statistical test we can only reject the hypothesis of a periodic component when the period is sufficiently above the noise level. For SR models with too low a strength of the periodic component, the period would with high probability not be detected in comparison to detecting a spurious coincidental periodicity in the sample (Figs. 3e, f). Whether or not the record shows a truly periodic beating has strong implications for identifying the underlying cause. If the recurrence is periodic it suggests an external cause. If the recurrence of DO events is not periodic it points to triggering mechanisms internal to the climate system being manifested at the millennial timescale.

Tensor,
Ole Humlum seems to have valid qualifications. The data he is presenting is from published papers. I linked to his site for the Greenland ice sheet temperature data as it is pertain to this discussion. The Greenland Ice sheet temperature graph that Ole Humlum displays at his site is from Richard Alley's paper. Doctor Ole Humlum also has links to the original data from the papers which I found helpful.

Bibliography; Ole Humlum
Last updated March 20, 2012.
Thesis (3):
Humlum, O. 1975. Geomorfologiske studier i Vernagtferner-området, Østrig (Geomorphological Studies in the Vernagtferner-area, Tirol, Austria). Med særlig Hensyntagen til nogle principielle glacialmorfologiske problemstillinger, der supplerende belyses ved iagttagelser fra andre recente eller tidligere nedisningsområder. Afløsningsopgave ved Naturvidenskabelig Embedseksamen, M.Sc.Thesis, Geogr.Inst., Kbh.Univ., 769 p.
Humlum, O. 1976. Sorø-Stenlille egnens glacialmorfologi (Glacial geomorphology of the Sorø-Stenlille area, Zealand, Denmark). Med særligt henblik på landskabsudviklingen og eksisterende glacialmorfologiske undersøgelsesmetoders tolkningskapacitet. Besvarelse af prisspørgsmål i Naturgeografi for året 1974 ved Københavns Universitet, Prize essay submitted to The University of Copenhagen, 383 p., awarded the University of Copenhagen Gold Medal, november 1976.
Humlum, O. 1979. Glacial transport, erosion and deposition; a general glacial-geomorphological theory for processes, sediments and landforms (in Danish). Ph.D. Thesis, Institute of Geography, University of Copenhagen, 361 p.

[Tensor]

This one was pretty funny. I'll get to the rest later.

Tensor is missing the obvious,

I am?

that it does not seem possible to isolate cooling to Svalbard.

It doesn't? Hmmmmmm....

Long term data is only available at Svalbard. Svalbard cooled in the past after a 10 to 12 year delay when there was a change in the length of the solar magnetic cycle. There was in the winter 2011/2012 the largest extent of ice ever measured in the Bering sea. Alaska had the highest snowfall ever measured.

And the Barents sea had the lowest Ice cover ever.

Alaska and the Bering sea are high Northern latitude regions that which are longitudinally separated from Svalbard.

Yeah, and Svalbard's SE beaches are on the Barents sea. So, you say I'm missing the obvious that it does not seem possible to isolate Svalbard from the rests of the high norther latitude. Then why if Alaska and the seas south of it are having such as deep, cold winter, are Svalbard and the seas southeast of it have a milder winter? It seems obvious to me that Svalbard and the Barents sea is somehow isolated from Alaska and the Bering sea.

Tensor,
Ole Humlum seems to have valid qualifications. The data he is presenting is from published papers. I linked to his site for the Greenland ice sheet temperature data as it is pertain to this discussion. The Greenland Ice sheet temperature graph that Ole Humlum displays at his site is from Richard Alley's paper. Doctor Ole Humlum also has links to the original data from the papers which I found helpful.

Your link did not work. And besides, that original data has been superseded by the CIGC 2005 data. The original data has been recognized as having some problems.

[Shaula]

I do not see anything in the authors conclusion that would rule out the sun as the forcing function. The sun is not a simplistic forcing function.

Which was my whole point all along. There is a lot of logic in that paper, it is a good one. The lack of a mechanism is totally irrelevant. They are testing some simple classes of predictive model, not phenomenological ones. You jumped on the paper, misinterpreted it as a challenge to your ideas (it was not) and started trashing it. Which is poor science.

All that paper did was rule out the most simple models, it is a framework to test more complex ones with. That is all. I have not been missing your point at all - I know what you are arguing for. I just don't really want to engage on it. What I wanted to do was make sure you were rigorous in your use of these papers.

[Tensor]

Tensor,

Have you

snip...

Have a go at explaining that pattern using the CO2 mechanism.

I notice that ignored all the questions I asked and refutations I provided in my last post. How about we go back to them?

You provided a link to a paper claiming 1470 year D-O cycles. I presented several papers. One that showed that the cycles were best explained by exponential distribution, not one based on simple forcing. I then provided two papers, on the newer, with better data, NGRIP’s, GICC05 dating. These papers showed that the GISP2 dating was not as accurate and the D-O events didn’t rise or tail as the GISP2 data showed. The combination of these papers means that the original paper you presented, is falsified. That doesn't mean the forcing can't be the sun, but the data in the GISP2 is suspect. Yet, you don’t mention it, nor even try to refute the papers. You simply go off in another direction.

Based on what has happened before the high latitude Northern region will cool

You presented this paper and nowhere in that paper do they claim that the high lattitude northern region will cool, only that Svalbard will cool.

The funny part is that the annual and all but one of the seasonal temperatures have INCREASED since that paper has come out. Even though the paper predicted a drop in temperatures. The deep winter temperature dropped 5 degrees, but then in 2011, the harbor, near where the temperatures are measured was frozen over, due to ice being blown into the harbor by prevailing winds. This doesn’t happen too often, but does explain the large drop. But, again, you didn’t acknowledge that, or try to refute it, just move off in another direction.

due to the significant interruption in the solar magnetic cycle.

Neither do they claim an interruption in the solar magnetic cycle. Perhaps you can point it out in the paper for me?

Of I suppose you still have not acknowledged that there has been a significant interruption to the solar magnetic cycle.

There is an open thread for that discussion. I owe a post to that other thread But no, I don't think there is one. .

Could you please answer my question.

Why would you demand I answer your questions, when you haven’t answered mine?

Comment:
When one has no understanding what so ever of the mechanisms, the proxy data is quite confusing. When the forcing function occurs it has different effects depending on the region and latitude of the region.

I'm not sure why you think you don't have an understanding of the mechanisms, but I'll go to several other things in my last post.

You have no comment on the refutation of your claim that arctic sea ice is increasing. It has a greater extent than last year, but the volume is the same as last year, due to the ice being thinner.

I asked several questions on you claim that the heliosphere is the weakest ever measured by modern instruments. You ignored the questions, and had no comment on Leif Svalgaard’s comment about there being no long term trend since the 1830s.

Then, there was your claim that there has been a 40% reduction in the solar wind. I pointed out that on March 26, 2003, the solar wind was between 349 and 430 km/s. Then pointed out that the solar wind on April 19 of this year, the solar wind was between 335 and 423 km/s. I asked you to explain how a drop of 7-14 km/s was a 40% drop, there was no answer, except to state the following:

Recent activity
The geomagnetic field was quiet to active on April 20. Solar wind speed at SOHO ranged between 299 and 364 km/s.

Which means, what? After all, look at April 9 2005 . “The geomagnetic field was quiet on April 9. Solar wind speed ranged between 294 and 338 km/sec.” Back in 2005, the Solar wind speed was even lower than yesterday, by 5-26 km/s. You want to explain how that represents a 40% drop to us? Since you didn’t do it last time?

[Torsten]

Crazy weather. Curious that sea ice is increasing.

Need to keep an eye on that. I would expect the weather will change again and sea ice will continue to change as it is predicted.

http://nsidc.org/data/seaice_index/i...timeseries.png

http://arctic-roos.org/observations/...i1_ice_ext.png

http://arctic.atmos.uiuc.edu/cryosph....antarctic.png

At the time of your post, sea ice was not increasing in the arctic, although the anomaly from the 1979-2008 mean may have been increasing due to the phenomenon of maximum extent happening later in the year, as I mentioned in an earlier post. For your reference I have archived a copy of your first chart as it appeared a couple of days ago, here.

The equivalent chart for the antarctic shows ice increasing at this time of year and also that it is above the 1979-2008 mean, which would yield a positive anomaly.

Your second chart shows more-or-less the same thing as your first, with the data processed and displayed somewhat differently by a different agency.

Your third chart shows the anomaly for the antarctic. I didn't think to record the value on the day you linked to it, but for today it is 0.774 million sq. km. (Copy of chart archived here.) For the arctic, the anomaly today is -0.173 million sq km. (Copy of chart archived here.)

If you add them the value is a net positive anomaly of 0.6 million square km of ice.

I think this is what you were trying to convey with that opening post. Please correct me if I'm wrong.

However, these are again just single dates. So the following chart, which I obtained from this page at NSIDC, shows the trends for both hemispheres on one chart:



As you can see, the losses in the arctic far exceed any gains in the antarctic.

Another point I want to make is that this slow drift to a later date for maximum arctic ice in the last few years has not changed the trend for minimum ice levels reached in September.

I made the following chart from monthly data acquired from NSIDC:



The maximum amount of ice in the satellite record usually occurs in March, but there were two years when it happened in February. The data trend down for both months. The green triangles in the lower part of the chart show the average values for the month of September, and the line is a quadratic fit based on year.

The red points and line in the middle show the difference between the maximum reached in February/March and the low in September. This value has been increasing over time. What it indicates is that a large area of the arctic refreezes each winter, but it can't be very substantial ice because the amount that disappears by September is getting larger. My conclusion is that your pointing to ice extent values at this time of year is a pretty useless indicator of anything.

Plot the data, global anomaly, Southern Polar, Northern Polar, Southern Polar, Southern Hemisphere, Northern Hemisphere, and tropics. Add a trend line to each of the plots.

I find this suggestion to plot data humorous, because in all the years we've been discussing these topics I cannot remember you linking even once to a chart that you yourself have made from data found online.

Come on make a prediction.

Okay. The following rationale is not original, but the method makes sense to me so I will use it to make a prediction for the amount of arctic ice in September:

The monthly average ice extent for September, as published by NSIDC here, has shown an accelerating downward trend. In the above chart I presented a quadratic fit to the data. I think that if that trend is extrapolated one year into the future it serves as a reasonable prediction of the September average ice extent. I'm not expecting a radical change in temperatures due to a changing sun, but I expect weather to be a factor, as it has been in other years. So when I calculate the regression, I'll use the standard error of the estimate to calculate error bounds on my prediction. In the following chart, I've plotted the actual values that occured each September, and I've also plotted the values that I would have extrapolated for each year based on the records that were available at the end of each previous melt season. You can see that for seven of the last 11 years this method overestimated the amount of September ice extent.

So, my prediction is for 4.45 +/- 0.90 million square km average ice extent for September 2012, as reported by NSIDC. The error range may seem wide, but that's the best I can do with this method.



Now, how about you provide us with a hard estimate?

[Ari Jokimaki]

There's a new study out on Arctic sea ice (no surprises there, as there are new studies on the issue every week):

Observations reveal external driver for Arctic sea-ice retreat - Notz & Marotzke (2012)

They present very strong statement in their absract:

"Our results hence show that the observed evolution of Arctic sea-ice extent is consistent with the claim that virtually certainly the impact of an anthropogenic climate change is observable in Arctic sea ice already today."

[Tensor]

There's a new study out on Arctic sea ice (no surprises there, as there are new studies on the issue every week):

Observations reveal external driver for Arctic sea-ice retreat - Notz & Marotzke (2012)

That's a nice find Ari. Thanks for bringing it to our attention.

They present very strong statement in their absract:

"Our results hence show that the observed evolution of Arctic sea-ice extent is consistent with the claim that virtually certainly the impact of an anthropogenic climate change is observable in Arctic sea ice already today."

That IS a very strong statement. But, the data, and the correlation between the data justifies it. One of the things I liked was all the work they went through to make sure there was consistency across the different data sets. Along with the work they did checking the various models.