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Ocean Heat Storage

  1. May 5, 2009 #1
    This paper "Earth's energy imbalance: Confirmation and implications. Science, 308, 1431-1435 Hansen et al" pdf available http://pubs.giss.nasa.gov/abstracts/2005/Hansen_etal_1.html" seems to have been very influential in research on climate change.

    The basic argument is that very little of the earth's heat is stored in the atmosphere and that the heat stored in the first 2.5 meters of the ocean is equivalent to the whole atmosphere. Therefore ocean heat storage is a more reliable tool to measure the radiative imbalances in our climate system than surface temperature changes.

    I've noticed that even researchers at the far end of climate debate from Hansen are starting to use the ocean heat storage metric in their papers.

    Part of this is probably driven by deployment of the Argo float system that has given us unprecedented capacity to measure changes in ocean temperatures down to 2000 meters.
    http://www.argo.ucsd.edu/" [Broken] . There are currently 3325 active Argo floats providing real time information about ocean conditions.
     
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  2. jcsd
  3. May 5, 2009 #2
    The recent Levitus et al 2009 paper may be a good read
    ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/PUBLICATIONS/grlheat08.pdf[/URL]
     
    Last edited by a moderator: Apr 24, 2017
  4. May 5, 2009 #3

    sylas

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    This is really interesting stuff… and with lots of unanswered questions which adds to the interest!

    It's long been known that the ocean's heat capacity is important; the problem has always been the computation to take it into account.

    The equivalence of heat storage for the atmosphere to about 2.5 meters of ocean is a back of the envelope calculation, using century old physics. Heat capacity of air is about 1000 kJ/kg; and for water is about 4000 kJ/kg. (Single digit accuracy) The atmosphere has a pressure of 1000 hPa, under gravity of 10 m/s^2; hence there is about 10,000 kg of atmosphere for each square meter of Earth's surface. That has the heat capacity of 2,500 kg of water. You get 2,500 kg of water per square meter with a depth of 2.5 m.

    Strictly speaking, this isn't a comparison with the whole ocean, but with atmosphere and ocean over a single square meter. To consider the whole Earth, you'd have to note that about 30% of the surface isn't ocean. Taking this into account, the heat capacity of the entire atmosphere is about the same as the heat capacity of the top 3.4m of the world ocean.

    That only tells you that the ocean is important, which has long been understood. The modeling of climate and weather has progressed steadily thanks to more detailed measurement of factors involved, better mathematical descriptions of the physics, and faster computers to actually handle the computations. A really helpful background historical summary of the progress in quantified understanding of weather and climate over the last century is at General Circulation Models of Climate, a chapter out of Spencer Weart's online book on the discovery of global warming.

    The paper you have cited by Hansen et. al. has been influential, not so much for persuading people to consider the ocean, but for a quantified estimate of it's impact in terms of the net energy flow currently going into the ocean.

    However, in my opinion the estimate given there is a substantial over estimate. They quote 0.85 W/m^2 +/- 0.15 net imbalance for the whole planet. But if you read the paper, it's clear this number is not a measurement, but based on the models. The actual measurements do indicate a positive imbalance, but substantially less. Climate models have been an enormous help in this whole field, but modeling of ocean circulation still has a ways to go before I'd put too much weight on this specific number.

    The research Chris has cited is a better guide, I think. The Argo floats you mention are a key part of this – although much of the issue there is sorting out teething problems with systematic measurement errors.

    Bottom line: the Leviticus et al paper estimate increasing heat content of the world ocean at roughly 4e21 J/year over recent decades, and this fits broadly with a range of empirical estimates.

    Crunch the numbers: a year is 3.15e7 seconds, and the Earth's surface is 5.1e14 m^2, and this works out to about 0.25 W/m^2 as the energy imbalance.

    I think this is a much more plausible value than the 0.85 used in Hansen et al (2005).

    Cheers -- sylas
     
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  5. May 5, 2009 #4
     
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  6. May 6, 2009 #5

    sylas

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    I'm not sure what you refer to. I've got the paper; you can refer to a figure or a page. I've not read it in great detail. I know some of the issues involved in this, but only from comparatively superficial reading of the associated literature. I'm not an expert.

    One of the problems has been systematic errors in Argo measurements. Most of that is probably ironed out, but it's an ongoing issue to sort out problems with Argo. In fact, I see that just yesterday there was a recall notice put out at the Argo site wanting to stop float deployment and bring in floats for repair to pressure sensors. Pressure sensors seem to have been something of a problem all along.

    This is a great experiment, but they are still sorting it all out as far as I can see. It's got great potential to help sort out ocean measurement.

    A part of this paper (Levitus et al 2009) has been to consider the impact of corrected Argo data from earlier systematic errors. They also seem to be working on identifying systematic errors in older "bathythermograph" measurements that I don't know about, but which are a crucial part of the longer instrument record.

    Argo is still new, so it can't tell you much about long term trend by itself. There certainly is real short term variation; there is also short term sampling errors. When you are dealing with incomplete data the short term variation is often hard to pin down. Furthermore, it's really the long term trend people are most interested in, at this point.

    As a general rule in ANY measurement of a trend of anything, you can't draw conclusions from a short sample. So sure, there is likely to be some real changes from year to year. The idea of a trend is to get a longer term picture that is not distorted by short term natural oscillations and variations.

    The other important recent reference is:
    That is an analysis of the instrument record up to 2003, but it is by the Argo floats research group and does use this new source of information. They obtain a trend in ocean heat content involving 16 +/- 3 *1022 J from 1961 to 2003; and that corresponds to a planetary energy imbalance of 0.24 W/m2 – very similar indeed to Levitus et al (2009).

    Cheers -- sylas
     
  7. May 6, 2009 #6
    I'm referring to figure 1 on page 2. From 2000 to 2004 it increases from 7x1022 to 13x1022 joules and it then flattens out.

    I just did a back of the envelope calculation based on the ocean storing 1.5x1022 joules a year. I figure that the human race uses about 5x1020 joules per year, so the ocean was storing 30 times as much energy as the human race was consuming.

    http://tonto.eia.doe.gov/ask/generalenergy_faqs.asp" [Broken]. There are 1055 joules in a BTU.
     
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  8. May 6, 2009 #7

    Xnn

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    From page 131. RF = Radiative Forcing

    http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf
     
  9. May 6, 2009 #8
    The other important recent reference is:
    That is an analysis of the instrument record up to 2003, but it is by the Argo floats research group and does use this new source of information. They obtain a trend in ocean heat content involving 16 +/- 3 *1022 J from 1961 to 2003; and that corresponds to a planetary energy imbalance of 0.24 W/m2 – very similar indeed to Levitus et al (2009).
    [/QUOTE]

    I found a free copy of the paper here http://www.astepback.com/GEP/Nature Higher Warming SLR rates.pdf".

    I'm not sure how much to read into their agreement with Levitus. It looks like they are working from the same datasets and may be using the same corrections.

    I don't know why they used the pre 1970 data. The 1 standard deviation band is so wide, that they might as well insert random numbers. I'm also a little concerned that they cut off their graph at 2003 when Leviticus includes data through 2008.
     
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  10. May 6, 2009 #9
    Sorry I messed up. The part above was from a post by sylas not me.
     
  11. May 6, 2009 #10

    sylas

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    OK. I see what you mean. Here's the same data as presented at the NOAA page for this research: Global Ocean Heat Content:
    heat_content55-07.gif
    The data being plotted here and in figure 1 of Levitus et al (2009) is in the "World Ocean" column of the file: ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/DATA_ANALYSIS/3M_HEAT_CONTENT/DATA/basin/3month/h22-w0-700m1-3.dat[/URL] (ftp, NOAA site). The rise you mean is from the data point for 2001 (5.073e22 J) to 2004 (12.154e22 J). You can also get at slightly more detailed 3-monthly data from the same pages.

    This rise around 2003 is a part of the Argo data; it is not something that comes from trying to merge older data with new "better" data. I don't think you can draw any definite conclusions about a short term effect like this; it could be almost anything, from a calibration error to a real heat content jump to a measurement artifact of how floats are distributed with changing currents. The overall picture of increasing heat content, however, is pretty unambiguous. There are various short term oscillations in ocean currents and temperature distributions, like the ENSO oscillations with El Nino and La Nina. That's a real effect – not simply as a change in total heat content, but signal that can confound short term measures of heat content.

    In this data the whole trend is a strong positive, and there's shorter noise and up and down all along the timeseries. In the Domingues et al paper (2008) that I cited, you can see their figure 1 also showing a similar up surge. Since it is the same data being analysed, this isn't enough to tell how much is an artifact of measurement, and how much is a real difference in shift. The data files allow you to look at North and South Hemisphere separately, and at a 3-month series rather than annual data, and it looks a bit like there was at least some role for a fortuitous case of simultaneous upswings in both NH and SH throughout the year 2003 and a bit each side… but either NH or SH in isolation looks more like ongoing noisy variation and an increasing trend.


    [QUOTE]I just did a back of the envelope calculation based on the ocean storing 1.5x10[SUP]22[/SUP] joules a year. I figure that the human race uses about 5x10[SUP]20[/SUP] joules per year, so the ocean was storing 30 times as much energy as the human race was consuming.

    [PLAIN]http://tonto.eia.doe.gov/ask/generalenergy_faqs.asp" [Broken]. There are 1055 joules in a BTU.[/QUOTE]

    That sounds about right. The contribution of human activity by direct energy production is just about negligible. As far as the Earth is concerned, the only source of energy that matters is the Sun. That's why the greenhouse effect is so important. This isn't a source of energy – our actual energy input is tiny by comparison. The greenhouse effect has such a big impact because it alters how the Earth responds to the solar energy input.

    Cheers -- sylas
     
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  12. May 6, 2009 #11

    sylas

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    Of course. The thing is that this IS Argo data being used.

    It takes a lot of time and work to do these analyses. You can't just read off a value from Argo data. A global heat content figure is obtained by a lot of analysis of thousands of individual floats, along with all the issues of calibration and instrument drift and known errors with pressure sensors. Hence a paper submitted in 2007 is using data from some time prior to that.

    There's a slightly different focus in the two papers Levitus (2009) is particularly concerned with correcting errors in XBTs, whereas Domingues (2008) is particularly concerned with fixing problems with recently discovered problems with the Argo floats. The Levitus paper is a repeat of an older analysis, and has been updated to take into account the new Argo corrections amongst other things; and I guess they rely upon the Argo team for the corrections to systematic Argo errors. It appears so from the acknowledgements of the papers.

    I don't know how you conclude pre 1970 data is that bad. It certainly does not appear so to my analysis. The natural variation in measurement is very similar all along the series. You do have less trend prior to 1970, which is unsurprising. All the related data, on sea surface measures and sea level and so on, all indicate that the ocean has been warming substantially more since 1970 or so than prior. That's pretty definite.

    We'd like to know how much... and so pre-1970 data is of considerable interest. But the figure does not show any greater "randomness" before 1970 than after, and it fits well with other related data, like the SST record. I also ran a quick check of my own using confidence bounds based on the data only and a simple regression analysis. There's a little bit of extra amplitude to the short term variations through the 1980s, but only very minor and probably not significant. There's no indication at all of additional randomness prior to 1970.

    Cheers -- sylas
     
    Last edited: May 6, 2009
  13. May 6, 2009 #12
    Ignore the data points in figure 1 and look at the gray band marking the 1 std dev. If they are using it the way I'm familiar with, then the line is the measured value and the band represents where the is a 75% chance that actual value is. The pre 1970 data band is almost 3 times wider than the post 1970. You can fit any trend you want inside that band.

    This assumes the data actually following a Gaussian distribution.
     
  14. May 7, 2009 #13

    sylas

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    Ah! My apologies… I was still looking at figure 1 in Levitus et al (2009). In the Levitus analysis the error bars are not actually plotted, but they can be found at the download site.

    We need to bear in mind that everything in these figures is a calculation; including the error bars. There is no such thing as a direct measurement of the ocean's total heat content – it has to be inferred on the basis of many thousands of measurements and a whole heap of analysis. Both Levitus (2009) and Domingues (2008) are papers that are clearing up systematic errors in earlier measurements.

    Here is a copy of Figure 1 from Domingues (2008):
    ohc_domingues.jpg (image source: realclimate blog).
    What this shows are two older calculations and the new revision that Domingues et. al. have obtained, in black. The error bars shown here represent the one standard deviation of the Domingues et. al. analysis, and this does indicate that the analysis used is degraded for trends prior to 1970.

    One of the lines there in the Domingues paper, given in red, is from Levitus (2005).

    The first paper we’ve been using in this thread is Levitus (2009), introduced by Chris Colose. This is mainly concerned with cleaning up errors in the XBT datasets, and updating their previous and erroneous 2005 analysis. The figure 1 in Levitus (2009) does not include the error bars, but it does give a side-by-side comparison with their 2005 analysis, as shown in red in Domingues (2008). There are error bars in the datasets that I linked to previously. Hence I can plot them for you. This plot shows the annual OHC for the Levitus (2009) analysis, along with hi and lo limits corresponding to one standard error. The baseline is a bit different to the published figure… this is simply a somewhat arbitrary choice for a reference zero point.
    Levitus2008OHC%2Bstderr.GIF
    I've also plotted here the width of the standard error calculation independently above the main data plot, which gives a better idea of how the standard error develops over time.

    There are different error bars here in Levitus (2009) because they are different datasets and different calculations. Levitus is working mainly with XBT data. This is reasonably seen as a reduction in errors associated with the older dataset; but it is also likely that the error bars represent something a bit different in this case… the method error without explicit additional measurement error. That's fair enough in a downloaded dataset; it's probably method error that's more useful for other analysis. However, it remains the case that the two analyses by Levitus and Domingues are different analyses with their own associated error estimates. The 2009 analysis from Levitus et al is mostly somewhere in between their 2005 analysis and the Domingues analysis.

    I don't have direct access to the Domingues et al data -- it is available, but not as a direct download, and I haven't put in an order for it by email. But it looks like the big hump from the Levitus 2005 analysis is mostly gone in 2009. What's left of that hump still represents a difference between the two analyses.

    The Domingues 2008 error bars most probably include a larger measurement error component, not explicitly addressed in Levitus 2009. That's how I read it, in any case.

    A great summary of this ongoing work is available at the NASA earth observatory: Correcting Ocean Cooling. It tells the story of how the errors in the Argo floats were found and fixed, and gives a good insight into how difficult it all is. Although the article focuses on the Argo team, the final word of the article goes to Syd Levitus:
    "Models are not perfect," says Syd Levitus. "Data are not perfect. Theory isn't perfect. We shouldn't expect them to be. It's the combination of models, data, and theory that lead to improvements in our science, in our understanding of phenomena."

    Cheers -- sylas
     
  15. May 7, 2009 #14
    It appears the oceans have stopped warming. I am not sure that is cause for celebration.


    http://www.ingentaconnect.com/content/mscp/ene/2009/00000020/F0020001/art00008;jsessionid=1k9alnlpdhr7c.alice [Broken]

    Author: Loehle, Craig

    Source: Energy & Environment, Volume 20, Numbers 1-2, January 2009 , pp. 101-104(4)

    Cooling of the global ocean since 2003

    http://www.npr.org/templates/story/story.php?storyId=88520025
     
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  16. May 8, 2009 #15
    I found a copy of the paper here:

    http://www.ncasi.org/publications/Detail.aspx?id=3152"

    As far as I can tell, there is no data in the paper that isn't in the Leviticus paper we have been discussing. Frankly, I think, my earlier characterization of the data as essentially flat is more accurate. The trend they refer to overwhelmed by seasonal variations.

    I didn't think that was remarkable, since it was consistent with the surface temperature record with some lag.
     
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  17. May 8, 2009 #16
    A trend of minus -0.35 x 10^22 Joules/year for the period 2003 to 2008 is not essentially flat. A negative trend in the planet’s ocean temperature shows the planet is cooling. A clearer description than "a lack of warming of over the last few years" is the planet was been cooling from the period 2003 to present.

    Both the atmosphere and the ocean appear to be cooling. (Which makes sense as sea ice is also increasing.)

    What is causing a significant five year cooling of the planet?

    Comment:
    The upper stratospheric temperature paper that was published in 2008 only used data up until 2003.

    rss_april_09.png

    uah_april_2009.png
     

    Attached Files:

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  18. May 8, 2009 #17

    sylas

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    Careful guys; this is descending into crackpottery and irrelevance. There's a reason the Earth Science forum requires peer-reviewed references for support of controvertial claims – there's a lot of flagrant nonsense out there.

    This thread is about the topic of Ocean Heat content. This is an excellent topic, and there are some genuine scientific puzzles and open questions here. Unfortunately, the thread risks being derailed into consideration of low grade popular caricatures of genuine science investigation.

    Specifically.
    • Loehle 2009 is not a legitimate peer-reviewed science paper. The available data is much better examined using the legitimate scientific papers already cited rather than distracting into fringe oddities.
    • Bizarre claims are being made with no reference. The claim that "sea ice is increasing", for example, is symptomatic of the extreme flight from reality that shows up so often in these debates.
    • Irrelevant distractions are showing up. For example, we have large and badly produced graphs of tropospheric temperature. That's not the ocean. (Not to mention that the data actually shows more warming than in the ocean. More below.)
    • There is no "significant five year cooling". Five years is a short variation, almost by definition a five year "trend" is not significant!

    More detail on each point.

    References from Energy and Environment

    Energy and Environment is not a science journal. It was set up by an English climate skeptic with no profession background in the topic. It doesn't show up in the recognized ranking systems and impact factors for scientific publications, anymore than OMNI or Readers Digest. The founder and main editor is Sonja Boehmer-Christiansen, an academic with background in geography, politics and policy – not science at all. The magazine has become a clearing house for easy publication of low grade material that can't get into a real science journal. Indeed, that was the aim. Boehmer-Christiansen apparently thinks there a bias against publishing work running counter to the mainstream science; but she's got it backwards. The mainstream is what it is because it has a bias against shoddy methodology and pseudoscience.

    This "journal" has a lot of currency OUTSIDE science, where it is eagerly lapped up by people who don't accept the basic findings of conventional climatologists. It's cited in blogs, pundits, congressional submissions, etc, etc… but it has very little circulation in university libraries.

    The paper by Craig Loehle (2009) would be okay as an undergraduate project, but the low level engaged is very obvious if you look at it side by side with a real science paper, such as Levitus (2009) or Domingues (2008) that has been used in the thread. Loehle's actual conclusions are rather weaker than his abstract suggests. The conclusion of the article is as follows:
    While the current study takes advantage of a globally consistent data source, a 4.5-year period of ocean cooling is not unexpected in terms of natural fluctuations. The problem of instrumental drift and bias is quite complicated, however, (Domingues et al. 2008; Gouretski and Koltermann 2007; Wijffels et al. 2008; Willis et al. 2004, 2008a) and it remains possible that the result of the present analysis is an artifact.

    Exactly so. The result is "not unexpected" in terms of natural fluctuations, and even worse – it remains possible that the result is an "artifact".

    The analysis in the paper is trite. It's nothing but an exercise in curve fitting, using a distinctly odd method for finding a trend. He fits a sine curve to the data as a way of handling the annual cycles, and then fits for an underlying linear slope, and also a linear change in amplitude. That pretty much ensures he's going to get results with limited meaning. It makes sense to have a linear trend over a long period of time, but a linear damping?!? Seriously, forget the Loehle paper. It's not going to be a part of the actual ongoing scientific work, and with good reason. Stick with the science journals. It's all the same data being used, and the science journals do it much better.

    Tropospheric temperature.

    We've got two huge graphs above, badly produced, talking about atmospheric trends.

    This brings up a whole new topic. Fundamentally, the atmosphere shows MUCH more variation than the surface or the ocean, which puts bigger uncertainty on the trends. But in fact, the graphs Saul have provided do show an overall warming trend, along with a lot of up and down that is larger than at the surface.

    The regression trend for his RSS data is 0.155 C/decade warming, with 95% confidence bounds of 0.135 to 0.175. The trend in the UAH data is 0.128 C/decade, with 95% confidence bounds of 0.107 to 0.149. There's a pretty good working relationship between the RSS and UAH research groups. The scientific disagreements are the name of the game. Each group continues to work with the other in helping to find problems. The RSS website has a really nice little tool that allows you to compare all the various datasets involved. See Comparing RSS and UAH Atmospheric Temperatures to Adjusted Radiosonde Data. But take care to read the associated text; you get different trends when data is weighted by sampling to fit radiosonde data, probably because of the increased warming over the land.

    For what it is worth, the sea surface temperature trend over this same period is about 0.133 C/decade, with 95% confidence limits of about 0.121 to 0.144, using the standard HadSST2 dataset: here. The deeper ocean warms more slowly than this.

    This thread is about Ocean heat content.

    The measurement of tropospheric temperature is an ongoing active research question. As matters stand, this is mostly about measurements. There are some theoretical issues here about refining dynamic models of the atmosphere generally, but as matters stand the models are consistent with the wide range of plausible measurement. Furthermore, this all stands distinct from questions of what is causing the rising temperatures we observe. The primary modeling issues here would be the same whether warming was driven by greenhouse, or insolation, or albedo. Theoretical predictions are within the range of the available measurements, and ongoing work to resolve discrepancies between different data sets makes for lots of interesting and contrasting work in the scientific literature. But it's almost all about trying to nail down difficult measurements.

    The recent 5 year trend

    Anyone who talks about a five year climate trend doesn't understand trends.

    Over five years, the natural variation of climate and weather means you are necessarily looking at local variation. This is not a measure of "trend" at all, but of small scale local change. This is certainly interesting in its own right, but it isn't trend. A trend is something that extends over the time, and for climate and weather, the five year scale is dominated by natural oscillations. The long term trends show up only over longer periods.

    Nor is it particularly surprising that a number of climate indices show lower values recently. The major contributing factor for this is the ENSO oscillations -- El Nino, La Nina -- which have just been through a cool point after a high point about five years ago or so. A good discussion of this is
    • Fawcell, R (2007) http://www.amos.org.au/documents/item/82 [Broken], Bulletin of the Australian Meteorological and Oceanographic Society, Vol. 20, pp. 141-148.

    Sea ice

    The sea ice trends are strongly downwards in the Arctic, and about level in the Antarctic. Saul says:
    The above statements just don't make any sense. The actual trend for ocean and for atmosphere shows warming. Saul has mixed up a short term swing with a trend. That's just wrong, and fails to understand what "trend" means in the context of data with natural up and down variation. The oscillations are not trend, and the whole idea of trend is to abstract away from the short term variations. Trend is, by definition, not something you can find within spans of time dominated by oscillations.

    But the sea ice thing takes wrong to a whole new level.

    The sea ice talking point is symptomatic of the low level to which popular debate has sunk. What we actually have with sea ice is no significant trend in the Antarctic, and a very strong and unambiguous drop in the Arctic. You get the same thing with any actual scientific source of data, this is not ambiguous at all. There are good diagnostic timeseries for HadISST at the Hadley Centre.

    Recently, however, Washington Post columnist George Will produced an incredible piece of nonsense mentioning increasing sea ice. The fallout from this was interesting and IMO symptomatic of the low grade of popular debate. The Washington Post has since published a couple of much more sensible op-eds on this, specifically noting that George Will's conclusions contradict the actual scientific data. Some readers might think that this represents two sides of a scientific debate. It doesn't. It represents error and denial on one side and science on the other.

    Cheers -- sylas
     
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  19. May 8, 2009 #18
    Sylas,

    Name calling of the author, the publisher, and of others in the forum does not prove your point.

    Data indicates the planet (both hemispheres) was been cooling for the last 5 years. Ignoring the data does not change the data.

    I provided a paper that shows the planet's oceans (Total heat content.) have been cooling for the last 5 years.

    http://www.ingentaconnect.com/content/mscp/ene/2009/00000020/F0020001/art00008;jsessionid=1k9alnlpdhr7c.alice [Broken]

    http://www.npr.org/templates/story/story.php?storyId=88520025

    It is quite reasonable if the continents cool the oceans will also cool. Or alternatively if the oceans are cooling there will be an increase in sea ice and colder temperatures on land.
     
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  20. May 9, 2009 #19
  21. May 9, 2009 #20

    Energy & Environment is not an acceptable peer reviewed journal on this forum.

    This is the communique I received from Monique.

    You are drawing a conclusion that is not supported by the NPR article.
    That article states that the surface is not cooling.
    And ice is melting not growing. (With exceptions; Antarctic sea ice and high altitude glaciers experiencing increased precipitation patterns etc.)
    It would think that when the surface temperatures of the oceans oscillate from warm to cold, that warmer water displaces the cooler water that wells up from the bottom. I suspect that with PDO and ENSO being predominately negative, that some of the sea level rise is deep warming that is not being measured.
     
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  22. May 9, 2009 #21
    It is asserted the planet's oceans have cooled 2003-2008.

    Ocean surface temperatures support that assertion.

    http://data.giss.nasa.gov/gistemp/2008/Fig2b.gif [Broken]

    http://data.giss.nasa.gov/gistemp/2008/Fig2b.gif [Broken]
     
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  23. May 9, 2009 #22

    sylas

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    Responding to two posts in one.

    There was no name calling.

    Looking over my article, I am satisfied it was entirely fair. The critical remarks were properly focused on ideas and writings, without name calling applied to persons. I stand by them without hesitation, and will repeat them as appropriate. I am not attacking you personally when I refute your claims. Some of what you say is absurd and completely counter factual, well beyond legitimate scientific disagreement. I back up all such assertions. There's nothing personal intended with it; don't take this as animosity.

    When I want to make points of my own, I will use positive argument and direct reference to relevant sources from the mainstream of scientific literature and research. My previous post was cautioning against going off topic, and using unreliable material.

    I don't even need to make any case on what is and is not reliable as a reference. We already have guidelines here, which require you to use the peer-reviewed scientific literature. If you can't defend a particular hypothesis by showing that it is being argued within the mainstream of science this ought to be a red flag to you, frankly. In any case, that's the rules of the game.

    There is a fall in many climate indices over the last five years, and I have not ignored that at all. I have discussed it explicitly, just above and also in other threads. Short term temperature falls are a consequence largely of the ENSO oscillation, and I backed this up from the mainstream literature. In any case, it is an entirely unexceptional instance of natural variation similar to other rises and falls all along the last 40 years.

    The paper I cited for you above, Fawcett (2008) describes the measurement and impact of the southern oscillation (ENSO). There's a lot of work going into understanding and modeling this important source of interannual change. That it exists, and has a strong influence on short term trend, is basic data.

    The data shows a definite warming trend on scales where trend is meaningful, and it shows lots of short term variation above and below the underlying trend. A five year span is much too short to show "trend", but the variation is there and actively investigated in the literature. The last five years shows nothing exceptional by comparison with the previous thirty. Short term variations like this are actively studied in the literature.

    This sidetrack into sea ice is just silly. The diagrams you linked show precisely what I mentioned before – a strong trend of decreasing ice cover in the Arctic, and no significant trend in the Antarctic. That you see increasing ice cover is surreal. You must be looking at "winter" in isolation, I think. There is an increase in sea ice in winter.

    The data shows a strong and unambiguous down trend in sea ice cover, in the Arctic. The Arctic also shows an exceptionally high rate of warming, including the last five years. There is natural variation, just like anywhere else, and individual years can be either up or down, but the Arctic warming is several times stronger than at lower latitudes, and the five year trend is upwards as well.

    Note that the extent of ice cover is not defined only by temperature. For example, the immediate cause of exceptionally low levels of ice in the summer of 2007 is wind pushing back the boundary. This made 2007 an outlier, with a minimum in sea ice well below the main trend of reducing cover. 2008 bounced back a bit – though it was still the second smallest summer ice extent on record. Actual scientists measure temperature. They don't make clueless inferences from sea ice cover in isolation of any thought for effects of precipitation, wind and currents. Ref: NASA press release: NASA Examines Arctic Sea Ice Changes Leading to Record Low in 2007.

    Sea ice cover says very little about total ocean heat content. There's a small contribution, but ocean heat content is overwhelming driven by the the major oceans where sea ice is not a factor. There are genuine and unresolved open questions about heat content of the ocean. Stay tuned. Josh Willis -- one of the main Argo researchers -- will have some new papers coming out pretty soon, that will be much more relevant.

    And the next post:
    You should read the text, as well as look at the diagram. The diagram you've reproduced shows both the longer warming trend, and the shorter up and down variations, with a fall in temperature in recent years.

    You are using the http://data.giss.nasa.gov/gistemp/2008/ [Broken], from the Goddard Institute for Space Studies, which is one of the leading research groups on world climate modeling and monitoring. Co-incidentally I was in the middle of preparing a reply using this very summation when you posted the diagram.

    The summation starts out by noting that 2008 was the coldest year since 2000, and also one of the 10 hottest years on record -- ALL of which have occurred since 1997. That's a quick insight right there into the nature of both the long term trend and the short term variation. The conclusion of the summation repeats what I have been explained to you here as well.
    Summary: The Southern Oscillation and increasing GHGs continue to be, respectively, the dominant factors affecting interannual and decadal temperature change. Solar irradiance has a non-negligible effect on global temperature [see, e.g., ref. 7, which empirically estimates a somewhat larger solar cycle effect than that estimated by others who have teased a solar effect out of data with different methods]. Given our expectation of the next El Niño beginning in 2009 or 2010, it still seems likely that a new global temperature record will be set within the next 1-2 years, despite the moderate negative effect of the reduced solar irradiance.​

    That "southern oscillation" is ENSO -- precisely what I also identified as the major cause for a short term drop in temperature. Here's the recent timeseries for the index:
    ts.gif
    If you compare this plot with your extracted plot of temperatures, the similar features are striking.

    Cheers -- sylas
     
    Last edited by a moderator: May 4, 2017
  24. May 9, 2009 #23
    The Southern Sea ice anomaly is the highest in the 45 year period shown. The anomaly is high in both spring and in winter.

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.anom.south.jpg

    The Argo ocean temperature data 2003 to 2008 shows cooling if the data is not adjusted.

    The paper you quote shows flat ocean temperatures 1957 to 1990 and then a large increase which again flattens 2003 to 2008.

    You provide no explanation as to why there is a sudden hockey stick warming for the period 1990 to 2003. Why was there no warming prior to 1990? Why has the warming suddenly stopped?

    ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/PUBLICATIONS/grlheat08.pdf[/URL]

    The global sea surface temperature shows cooling 2003 to present which supports the cooling interpretation of the Argo’s data.

    I standby the assertion: the planet is cooling, the cooling trend will accelerate.

    New data will either prove or disprove that assertion.
     
    Last edited by a moderator: Apr 24, 2017
  25. May 9, 2009 #24
    What do you mean, "if the data is not adjusted"?

    It actually shows a positive trend from 1955-1990, followed by a steep warming trend from 1990-2000, and then a very large spike from 2001-2004, and then a leveling off.
     
    Last edited by a moderator: Apr 24, 2017
  26. May 9, 2009 #25
    Skyhunter.

    The ocean surface temperatures are colder each year after 2003. i.e. 2003 is the warmest year in the period. That is the definition of cooling. If the ocean surface is warming the temperature increases.

    What is your definition of warming?


    2003 0.4792
    2004 0.4642
    2005 0.4722
    2006 0.4537
    2007 0.3784
    2008 0.3714

    2008 is the coldest year of the 21st century.

    http://data.giss.nasa.gov/gistemp/2008/Fig2b.gif [Broken]
     
    Last edited by a moderator: May 4, 2017
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