Willis wonders about the PDO

Wondering Willis Eschenbach has another article on WUWT, this time he's wondering about the Pacific Decadal Oscillation. (I've written about some of his previous 'wonderings' such as here and here and here.)

He doesn't make as much of a fool of himself as he has on other occasions, but it doesn't look like he has bothered much with the scientific literature.  Willis writes:

I’ve hypothesized that the Pacific Decadal Oscillation (PDO) is another one of the complex interlocking emergent mechanisms which regulate the temperature and the heat content of the climate system.

I think that's his fancy way of saying that the PDO is an intricate part of the earth-climate system.  Well, duh! He also thinks he has 'discovered' an association between the PDO and ENSO.  He's right but he's most definitely not the first to do so.

This is from Newman et al:

The PDO is dependent upon ENSO on all timescales. To first order, the PDO can be considered the reddened response to both atmospheric noise and ENSO, resulting in more decadal variability than either. This null hypothesis needs to be considered when diagnosing and modeling ‘‘internal’’ decadal variability in the North Pacific. For example, the observed spatial pattern of Pacific SST decadal variability, with relatively higher amplitude in the extratropics than in the Tropics, should be at least partly a consequence of a reddened ENSO response....

...Finally, this work suggests that predicting the PDO may be directly related to the skill of forecasting ENSO. Given the 2-yr decorrelation timescale of the PDO and the possibility that ENSO may not be predictable beyond about 2 yr, so-called regime shifts of the PDO will not be apparent until years after they have occurred. For example, the recent long-term positive phase of the PDO may have simply resulted from the 1977–98 period being dominated by warm events in the Tropics, and the recent apparent ‘‘change’’ in phase of the PDO is an expected outcome of the cool tropical SST in the east Pacific of the last few years. Thus, with tropical SSTs having returned to warm conditions in 2002, the PDO has likewise become positive again. In the absence of a La Nin˜a this year, the PDO may be expected to remain positive in 2004. 

doi 

Incidentally, the PDO did remain positive through 2004.  Here is a chart showing the PDO (left axis) and global temperature anomaly (right axis), with ENSO years marked from 1950 onwards. (Click for larger version).

Source: JISAO and NASA

Constructal Law?

Willis also mentions the "Constructal Law" which a quick google appears at face value to be a quack attempt to popularise some airy fairy "unifying" notion or other.  The word "Law" in the title is a red flag but am I being unfairly dismissive? Does anyone have any more info on it before I waste time checking it out?

Using pressure to estimate temperature

As another example of how Wondering Willis spends too much time wondering and too little time reading the work of others, he writes:

PS—This discussion of pressure-based indices makes me think that there should be some way to use pressure as a proxy for the temperature. This might aid in such quests as identifying jumps in the temperature record, or UHI in the cities, or the like. So many drummers … so little time.

Pressure is often used as a proxy for temperature, including in various temperature reanalyses.  For example, if Willis had kept up with the literature he might have come across this paper in press, from the abstract (my bold):

We use a completely different approach to investigate global land warming over the 20th century. We have ignored all air temperature observations and instead inferred them from observations of barometric pressure, sea surface temperature, and sea-ice concentration using a physically-based data assimilation system called the 20th Century Reanalysis.

This independent dataset reproduces both annual variations and centennial trends in the temperature datasets, demonstrating the robustness of previous conclusions regarding global warming.

Compo et al (2013) Independent confirmation of global land warming without the use of station temperatures GRL doi: 10.1002/grl.50425

Funnily enough, WUWT put up an article by Bob Tisdale about the Compo paper (during which he has difficulty with anomalies), and this was the first comment - by tadchem  who says:

April 8, 2013 at 11:12 am  “…to investigate global land warming over the 20th century. We have ignored all air temperature observations and instead inferred them from”… (indirect measurements of secondary phenomena).

The exact OPPPOSITE of empirical science!  I’m surprised they didn’t mention the Tea Leaves or Tarot Cards.

Deniers are a peculiar mixed bag of odds and sods.  As I've said before, if people like Willis Eschenbach spent less time wondering and more time building on the knowledge of others, they might actually contribute something worthwhile instead of adding to the confusion of disinformation that is the bread and butter of WUWT.