Posted by: Carl | August 18, 2009

Sea Level Data Exposes El Nino’s Secret

The climate science community tells us that the El Nino/Southern Oscillation (ENSO) is merely a redistribution of heat.  Sea level data tells us otherwise.  The graph below shows detrended sea level data from the University of Colorado, which is available for the period 1993-2008.

Detrended sea level v nino 3.4

If ENSO is non-radiative, it should not influence sea level, which is a metric of the heat content of the oceans (in addition to glacial melt).  However, the graph above clearly shows that ENSO is influencing the heat content of the oceans.  Very basic analysis of sea level data makes it incredibly obvious that ENSO is a radiative oscillation that has the potential to cause long-term climate change.

In this past, I have suggested that only the 1976/7, 1986/7, and 1997/8 El Nino events were radiative, a position that I now believe is false.  This point of view came from the examination of gridded sea surface temperature data.  Erl has, through an examination of gridded atmospheric data, always contended that ENSO is always radiative.  Gridded sea level data resolves the seeming discontinuity between these two viewpoints.  As Nino 3.4 anomalies swing between negative and positive values, the tropical ocean integrates the values as cloud cover rises and falls.  This has produced consistently increasing sea levels in the tropics as El Nino conditions have been prevalent, as shown in the graph below.

tropical sea level v enso

However, the increasing heat remains mostly in the tropics until it is released poleward by strong El Ninos, like the 1986/7 and 1997/8 El Ninos.  The effect of the 1997/8 El Nino on the poleward transport of heat can be seen in the graphs below.

SH sea levelNH SEA LEVEL

Once the heat is released from the tropics, it appears at the surface and in the temperature record, creating the observed “step-changes” in global temperature.

enso adj sst-3

ERSST v3b Nino 3.4 (scale: 1/11) subtracted from ERSST v3b global SST, lag=2 months

You’d think that after $79 billion dollars of government-funded research just in the United States, someone would have bothered to detrend sea level data to discover that ENSO is radiative.  The apocalyptic conclusions of climate scientists have come before a serious effort has been put into understanding the basics of climate.  Climate science truly needs to be rebuilt from the bottom up.


Global Sea Level Timeseries: University of Colorado

Gridded Sea Level: CLS ENACT Analysis

Nino 3.4 Timeseries: ERSST.v3b

Gridded Sea Surface Temperature: ERSST.v3b

All data available at KNMI Climate Explorer.



  1. One thing I had done awhile back was smoothed the data from Oulu neutron monitor out 6 years. When done like this it is very clear that there is a rise going on at the same time as the 76-78 86-87 and 97-98 el ninio’s. We also have a rise going on right now which would point to an el ninio event happening as we speak, which I do believe is. For the record I chose 6 years based on the difference between the super dip in the Oulu record and the 97/98 el-ninio.

  2. Carl, “sea level, which is a metric of the heat content of the oceans (in addition to glacial melt).”

    This is far too simple. Sea level is influenced by numerous factors. The ocean heat content is only part of that. None of this effects your conclusions, since those influences are generally only important to the long term, but I thought it would be important to note that you are falling into a misconception here.

    Of course you realize that the easy response is that the “radiative” characteristics must just be feedbacks on the temperature change. I don’t think that’s the case, but that is what they will say.

  3. Andrew, you make a good point. I graphed the detrended sea level data against SST, and the correlation is not as strong, with SST lagging the change in sea level (as one would expect). Also, the high values of sea level during the period 1993-95 are not consistent with SST data, as Mt. Pinatubo was still exerting influence on the temperature record. They are much more consistent with ENSO, which had relatively high values around that time.

  4. Idea for a future post:
    It would be interesting to see pairwise-contrasts of detrended sea-level for Atlantic, Indian, & Pacific (i.e. Atlantic minus Indian, Atlantic minus Pacific, & Indian minus Pacific). This is what I had in mind when I suggested the detrending & comparison with ENSO to Bob Tisdale awhile back. (I would immediately take up the task if the series were (conveniently) monthly, but my understanding from Bob’s earlier write-up is that there is messy spacing, so I’ll wait until a day freer of competing interests.)

  5. Very thought provoking Carl. Have you thought of doing the energy budget calculations to check the actual heat transfers? Obviously it would need to match up various elements, the radiative imbalance recently mentioned by Douglass, the heat needed to increase ocean level (short term), the fraction accumulated throughout and the meridional transfer during super-El Nino’s. That one way to verify this is not just correlations.

  6. He has erected a multitude of New Offices, and sent hither swarms of Officers to harass our people, and eat out their substance.

    Thomas Jefferson in the Declaration of Independence in reference to King George III.

    We would do well to read it again.

    This is in reference to the propsed new agency on climate change. Fox News 2/08/2001

  7. Of course ENSO is associated with radiative transfer. That isn’t news. There are some good papers (Park et al. 2006, Pavlakis et al. 2007, etc.) from several years ago exploring the dynamical processes.

    So in response to your blog, the research you’re demanding has already been done. And it doesn’t contradict the notion of anthropogenic climate change. I recommend reading a bit before blogging. It might expand your mind.

    In a side note, its fun to play with statistics, isn’t it?

  8. The comment by Ao is unkind. But that is, I suppose, to be expected. People are not at ease with suspending belief as much as suspending disbelief.
    A few years ago, secretary general of a broadcasting union extorted the member broadcasters not to give air-time to “these skeptics”. Given this attitude from scientific journals and mainstream media, people have no access to alternative hypothesis or recalcitrant data that does not fit in with “expert” viewpoints. Except in blogs like this. But I do wish that this pages become more structured and appear in the form of a book – as a pdf file if not printed and published for sale.

  9. […] Sea Level Data Exposes El Nino’s Secret « Climate Change […]

  10. […] to Carl Wolk of the website “Climate Change by Erl Happ and Carl Wolk” for his post “Sea Level Data Exposes El Nino’s Secret.” It gave me the idea for this post, which exposed a few secrets of the monotonous rise in the […]

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