Month: January 2014

What missing heat?

/ Paul Pukite (@whut) / 40 Comments

[mathjax]As with the discussion about the “pause” in global surface temperatures, much consternation exists about the so-called “missing heat” in the earth’s energy budget.

There are three pieces of the puzzle regarding this issue, which collectively have to fit together for us to be able to make sense about the net energy flow.

  1. The surface temperature time series, see the CSALT model
  2. Heat sinking via ocean heat content diffusion, see the OHC model
  3. The land and ocean surface temperatures have an interaction where they can exchange energy

We have an excellent start on the first two but the last requires a fresh analysis.   Understanding the exchange of energy is crucial to not getting twisted up in knots trying to explain any perceived deficit in heat accounting.

Consider Figure 1 below where the energy fluxes are shown at a level of detail appropriate for book-keeping.  On the left side, we have an energy balance of incoming flux perturbation (Li)  and outgoing flux (Lo) for the land area (we don’t consider the existing balance as we assume that is already in a steady state).  On the right side we do the same for the sea or ocean area (Si and So).

The question is how do we proceed if we don’t have direct knowledge of all the parameters.  The first guess is that they have to be inferred collectively. The complicating factor is that the sea both absorbs thermal energy (heat) into the bulk shown as the OHC arrow, and that some fraction of the latent and radiative heat emitted by the sea surface transfers over to the land.  There is little doubt that this occurs as the Pacific Ocean-originating El Nino events do impact the land, while regular seasonal monsoons work to redistribute enormous amounts as rain originating from the ocean and delivered to the land as moist latent energy. So the question mark in the figure indicates where we need to estimate this split.

Fig 1: Schematic of energy flow necessary to balance the budget.

Solving this problem would make an excellent homework assignment and perfect for a class in climate science.  Let’s give it a try.

 

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Projection Training Intervals for CSALT Model

/ Paul Pukite (@whut) / 8 Comments

DC commented in the previous post that a training interval can be used to evaluate the feasibility of making projections of the CSALT model. His initial attempts hold great  promise as shown here.  One can see that the infamous “pause” or “hiatus” in global surface temperature is easily predicted using DC’s training interval up to 1990.

Figure 1 below is my attempt at doing the projections with a more sophisticated version of the CSALT model.  The top chart is the model fit using all available data, and below that is a succession of projections with training intervals that end in 1990, 1980, 1970, 1960, and 1950.  Each successive chart uses fewer data points yet appears to hold fast to a credible projection, signifying the invariance of the model across the years.

Fig 1 : Set of training runs with temperature projection, the Green curve is the GISS data and Blue curve is the CSALT model.. The end of the training period is the upward pointing red arrow. The future temperature projections cover the interval spanned by the horizontal arrow. The correction term shown is for the WWII years where temperature readings were hot by a factor of 0.14 C.

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Reverse Forecasting via the CSALT model

/ Paul Pukite (@whut) / 10 Comments

DC of the Oil Peak Climate blog suggested that reverse forecasting to earlier dates using the CSALT model may be an interesting experiment.  Considering the growing sophistication of the model, I tend to agree.

The contributing factors to CSALT are a mix of empirical forcing terms and several periodic elements suggested by climate scientists with an interest in tidal and solar topics,  including Keeling from Scripps [1], R.Ray from NASA Goddard [2], Dickey from NASA JPL [3], and going back to Brier in 1968 [4]. These fall under the category of orbital influences discussed in a previous post.   Selecting the periods of the principle orbital most commonly cited, we get the staggered view of the individual contributions shown in Figure 2.  (see http://entroplet.com/context_salt_model/navigate for an interactive version)

Figure 1 : Contributions of the various thermodynamic factors to the CSALT model of global average surface temperature. The “sme” term represents the Sun-Moon-Earth alignment harmonic of 9 years.

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