Open Mind

I’ve been quite busy with the Thanksgiving holiday, and with two research papers I’m collaborating on, so my plan to post about the effect of astronomical cycles on ice ages has taken longer than hoped. I’m grateful to readers who are patient enough to keep watching, and I promise some time this week I’ll have it ready, and posted.

In the meantime, there’s something else I’d like to mention. Recently Eric Steig at RealClimate reviewed Mark Lynas’ book Six Degrees. At the end of his review Steig asks,
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The question arose recently, how does the total energy received by the earth depend on the eccentricity of earth’s orbit? I’d like to show how this is derived. I’d also like to show the entire impact of eccentricity, precession, and obliquity (the tilt of earth’s axis) on how incoming solar energy is distributed around the planet. But since there seems to be a request for the eccentricity piece, I’ll start with just that.

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As I write this, I’m watching the program Naked Science on the National Geographic channel. The episode is titled “Glacier Meltdown,” and that’s a subject of interest to me.

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This last January showed a strong el Nino, leading to the largest monthly global temperature anomaly ever recorded (according to NASA GISS), 0.87 deg.C. This caused researchers at the Hadley Centre for Climate Change Research to announce that 2007 would probably break the record for hottest year ever.

I said at the time that I thought the pronouncement was premature, because sometimes el Nino lasts a good long time (like 1998) but sometimes it’s very brief. The 2007 el Nino turned out to be brief, and it’s very unlikely that 2007 will break the record after all. The good people at the Hadley Centre will end up with egg on their faces. Even so, 2007 will turn out to be one of the hottest on record. Although it’s not yet complete, let’s use NASA GISS analysis to estimate where it will fall on the all-time-hottest-years list. The ten hottest complete years ever recorded, with their average temperature anomalies, are:

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No, this isn’t about a movie starring Robert de Niro and Billy Crystal (although I do like that movie — especially the cameo appearance by Tony Bennett).

Sooner or later, just about every scientist has to deal with numerical data. That’s one of the good things about being a mathematician; everybody needs us. A lot of scientists (especially in the physical sciences) are talented mathematicians themselves and even make contributions to the study of statistics, devising ingenious new methods of analysis. A lot of scientists go astray, either because they don’t appreciate the subtleties of the analysis method they apply, or because they don’t know the right method to choose.

Because global warming is a prominent environmental and political issue, it has brought scientific data under the scrutiny of the general public. Those who viewed Al Gore’s An Inconvenient Truth probably never saw a movie with so many graphs in it! But one of the lessons of mathematics is that if we’re not careful, the numbers can lead us to the wrong conclusion. I think it was Mark Twain who said there are three kinds of lies: lies, damned lies, and statistics.

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I recently mentioned that the timing of snowmelt runoff affects drought conditions in the American southwest. This harkens back to early this year, when I had communications with Pat Neuman, a retired hydrologist working in the midwest. He communicated to me that his studies of snowmelt runoff timing in the Red River (and other midwestern) basin indicated that it was coming earlier and earlier in the year. I even posted on the topic.

I thought I’d show an example, using streamflow for the Red River as measured at Fargo, ND. This is not the Red River of movie fame, it’s more properly called the “Red River of the North,” and forms the boundary between North Dakota and Minnesota. For each year, the data are the day of the year for the beginning of snowmelt runoff measured at Fargo, ND.

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