Archive for March, 2010

The Winter That Was

March 30, 2010

With March drawing to a close, Winter should now be safely behind us. For people in much of the US it has doubtless been a long one. Here in Florida it obviously is always warmer than where the rest of you are, but for me it was long enough-interestingly, the summer of 2009 was very hot here, so sort of a swing between extremes we’ve had. I decided to make some comments on the winter that has just passed because from a climate/weather standpoint it was very interesting. Not so much for what it says about warming (not much at all if anything) but for the particular pattern we’ve just seen.

There can be little doubt that this last winter was a crazy one-plenty of warmth hid at the poles where nobody would have noticed if they went by their experiences alone. When talking about large scale patterns, one can almost make out the path of the Jet Stream in the NH where a surprising dent was made in the Siberian Hotspot, bent southward over the Pacific and gave a classic “El Nino” pattern (that’s possibly debatable) in the US, and drifted North up to Europe looping back to Siberia. Outside of that cold belt it was relatively warm in most places, with a classic negative Arctic Oscillation “blocking” Highs pattern. The reason this winter is interesting, to me, is that it illustrates the role of ocean and atmospheric dynamics in causing variations in seasonal weather. My (heretical) conjecture is that the right pattern of such dynamics can result in “global warming” and also “global cooling”, and that the potential that such dynamics have to cause long term changes in climate has not been considered thoroughly enough by those claiming they can “attribute” the observed changes.

Statistics is good, Statistics is bad, the way you do it matters.

March 20, 2010

Some blogs have been discussing a recent article claiming that statistics is a bad way to do science. See here and here. I have to say that I completely agree with Lubos about the importance of statistical methods. I think I will elaborate on why I think statistics is important in doing science.

Suppose we have two hypotheses, only one of which can be correct. Suppose that these hypotheses both allow a certain observed phenomena to occur, but one suggests that such a phenomena should be exceedingly rare while the other suggest it should be fairly common. Obviously we can’t say that the latter hypothesis is proven because the former hypothesis is less likely to reproduce the observed results. But I think any rational person would say that the latter hypothesis is more likely to be correct. Statistics is importance because it allows us to quantify the probabilities involved so that we can make a judgment about such issues.

However, statistics can be misused. As Lubos says it is clear that sometimes people don’t use the right null hypotheses, they don’t use realistic assumptions about the probability distribution, etc. The reason this blog exists is because in my mind climate science is full of misapplication of statistics of precisely that nature, in particular the failure to do tests on realistic null hypotheses. But statistics is not at fault here. When something goes wrong with statistics, it is because the user did something wrong, not because the system itself is fundamentally flawed. Indeed, since it is basically math, it cannot, itself, be wrong. But as anyone who has taken a math course knows, that mathematics is more infallible than the Pope* doesn’t prevent you from getting less than a perfect grade.

*I understand that not everyone is likely to appreciate this joke, but I like to use hyperbolic examples and this was the best example I could think of.

ENSO effects on US climate/weather?

March 18, 2010

By using the Southern Oscillation Index and identifying the twenty most negative and positive SOI years (re-centered on the mean of the entire dataset) from 1895-2009, and ESRL’s climate division composite page I decided to see if I could find some of the various frequently talked about El Nino/La Nina effects on the US. First, let’s have a look at temperatures.

El Nino is on the top, La Nina on the bottom. This more or less confirms some of the claims that El Nino leads to cooler weather in the southeast, although there are some differences in that the effect seems stronger in the western part of the South (the same for La Nina). Florida is notably warmer during El Nino’s than I’ve seen in other comparisons. So the relationship appears to show key differences, indicating that the link between El Nino and US weather may be less certain than sometimes portrayed.

With regard to Precipation:

El Nino appears to tend to be wetter in the South and Midwest, and drier area from the Mid-Atlantic to the Mississippi, with this pattern reversed in La Nina. I am unaware of what tends to be claimed for precipitation but notably many places in the US appear to have average precipitation in El Nino years and La Ninas, suggesting that little effect is present.

Drought Causes Senate Democrats

March 12, 2010

The following is a joke.

Recent work that I have just done has uncovered a new, important connection between politics and climate in the US. It appears that whenever the US is unusually dry over a large area, either at the same time or not long afterward, Democrats gain more power in the Senate. This has implications for Global Warming. If warming causes drought to become more widespread, Democrats will surely enter a period of dominance in the Senate. Even a wacko denier like me finds this a frightening prospect. On the other hand, if droughts become less widespread, Democrats will probably have difficulty attaining and maintaining majorities in the Senate. This prospect is surely much more desirable, and even implies a positive feedback, as Republicans are a well known leading cause of Global Warming. Of course, I imagine that environmentalists find that possibility to be disturbing.

UAH is going to version 5.3

March 5, 2010

The new version does not change the trend but does eliminate the annual cycle differences due to the AMSU’s. It is not up at the ftp site yet it seems-there is usually a slight delay between when that happens and when Roy announces the new anomalies.

I’m going to wait a while before I test how this may impact recent analyses I’ve done. Mostly because I’ll want the updated anomalies from the whole record. Note also that the “extreme” warmth noted last month that was supposedly the “return of global warming” is not so obvious anymore.

IJOC Sucks (More Climate Gatekeeping!)

March 3, 2010

As some of you may know, in 2007, Ross McKitrick and Pat Michaels published a paper which showed that there was statistical evidence of uncorrected biases in land surface temperature data. You may also know that realclimatescientist Gavin Schmidt published a paper which claimed their result (and the results of a pair of Dutch meteorologists) was spurious. Well, you may or may not know that Ross McKitrick and Nicholas Nierenberg tried to continue this dialogue going on the the journal International Journal of Climatology. However, in true climategate form, it was rejected in spite of showing that Schmidt’s claim was just wrong. They weren’t even allowed to respond formally to their referees! This is just outrageous and smacks of a pre-climategate mentality. Well they did respond to the ridiculous complaints of the referees anyway. Did Schmidt’s paper get a similarly difficult review? Almost certainly not, as one of the reviewers of his paper defending the surface temperature record was surface record compiler and climategate chief sinner Phil Jones.

Reference.

Did They See It Coming?

March 1, 2010

Chick Keller is a master cheerleader for climate concerns-and climate science. In a whiny post over at RP Sr’s he makes several claims, but this one is just odd:

Global temperatures haven’t warmed appreciably in the past 8 years (ya gotta ignore 1998 cuz it’s a big  ENSO spike not part of the trend). This is not so much evidence that modelers etc don’t know what they’re doing (it was actually predicted rather well before it happened) as it is a splendid chance to study aspects  of climate variability without “contamination” of the signal by ENSO and volcanos.

 Do begin with, ignoring 1998, you can go back to 1997 and not find warming (Phil Jones actually says that significant warming requires going back before 1995) and 1997 is not an ENSO spike. Second, ENSO is not “contamination”-it’s a part of the climate system’s evolution, so fundamentally so that even the period he speaks of is not “free” of ENSO effects. Lastly, I don’t know of anyone who said ahead of time that warming would stop for twelve (not eight) years. Nobody. If Chick knows someone who predicted that, I’d love to see his evidence.

One should never claim something was predicted ahead of time without proof that such a prediction was actually made. Otherwise you are just blowing smoke.