One of the maddening aspects of climatology as a science is in the cavalier treatment of data and in particular the potential loss of information through filtering. A group of scientists at NASA JPL (Perigaud et al) have pointed out how reckless it is to remove what are considered errors (or *nuisance parameters*) in time-series by assuming that they relate to known tidal or seasonal factors and so can be safely filtered out and ignored. The problem is that this is only safe **IF** those factors relate to an independent process and don't also cause non-linear interactions with the rest of the data. So if a model predicts a linear component and non-linear component, it's not helping to hide the linear portion from the analysis.
This extends to filtering annual data. I just found out how NINO3.4 data is filtered to remove the annual data, and that the filtering is over-zealous in that it removes all annual harmonics as well. Worse yet, the weighting of these harmonics changes over time, which means that they are removing other parts of the spectrum not related to the annual signal. Found in an "ensostuff" subdirectory:
This makes me cringe now that I take a look at the portion of the filtered data (which I independently extracted, shown below) and notice how well it matches to the annual impulse I am applying in the ENSO model. The impulse, which is required to amplify the tidal cycles, is now clearly phase correlated to the observed annual temperature cycling.
This may sound like an innocent error correction but this eliminates the possibility of tracking correlations, which is the core of any science that does not allow experimental control or laboratory experimentation. Perhaps an example of climate scientists shooting themselves in the foot!
Without controlled experiments available, earth sciences advancements are glacial in progress, so you have to have patience. How Murray Gell-Mann described the process [in an interview](https://scienceblogs.com/pontiff/2009/09/16/gell-mann-on-conventional-wisd):
> "Battles of new ideas against conventional wisdom are common in science, aren't they?"
> "It's very interesting how these certain negative principles get embedded in science sometimes. Most challenges to scientific orthodoxy are wrong. A lot of them are crank. But it happens from time to time that a challenge to scientific orthodoxy is actually right. And the people who make that challenge face a terrible situation. Getting heard, getting believed, getting taken seriously and so on. And I've lived through a lot of those, some of them with my own work, but also with other people's very important work. Let's take continental drift, for example. American geologists were absolutely convinced, almost all of them, that continental drift was rubbish. The reason is that the mechanisms that were put forward for it were unsatisfactory. But that's no reason to disregard a phenomenon. Because the theories people have put forward about the phenomenon are unsatisfactory, that doesn't mean the phenomenon doesn't exist. But that's what most American geologists did until finally their noses were rubbed in continental drift in 1962, '63 and so on when they found the stripes in the mid-ocean, and so it was perfectly clear that there had to be continental drift, and it was associated then with a model that people could believe, namely plate tectonics. But the phenomenon was still there. It was there before plate tectonics. The fact that they hadn't found the mechanism didn't mean the phenomenon wasn't there. Continental drift was actually real. And evidence was accumulating for it. At Caltech the physicists imported Teddy Bullard to talk about his work and Patrick Blackett to talk about his work, these had to do with paleoclimate evidence for continental drift and paleomagnetism evidence for continental drift. And as that evidence accumulated, the American geologists voted more and more strongly for the idea that continental drift didn't exist. **The more the evidence was there, the less they believed it.** Finally in 1962 and 1963 they had to accept it and they accepted it along with a successful model presented by plate tectonics...."
This was the telling passage of the Gell-Mann interview, which is easily missed on first read -- *"The more the evidence was there, the less they believed it"*
Did he really mean that? The more the accumulation of evidence, the stronger the resistance? (The full interview is available on [Science News to subscribers](https://www.sciencenews.org/article/interview-murray-gell-mann)).