Friday, April 13, 2007

Rabett Reads....

Eli has been to the library. He has been reading Tellus 28 (1976) 552, in which Keeling Adams, Ekdahl and Guenther do it right. They describe their measurements of CO2 at the South Pole. Comparing how Fonselius, Koroleff and Buch grabbed their samples


to that of Keeling and Co. is the difference between Moe Howard and Einstein.

FKB used a small 250 cc cylinder filled with air one end of which is connected to a rubber bulb. They opened both stopcocks and held the bulb outstretched in Mr. Roland Ploennige's arm and pumped the thing a 150-200 times. There are huge problems, not the least of which is the presence of Mr. Roland playing the air bassoon which Eli commented on.

It is instructive to compare this with the care and thought that went into the South Pole sampling:

Five liter spherical glass flasks, previously evacuated to a pressure below 1 micrometer of mercury, were exposed by opening a greased stopcock so that air expanded into the flask. In the earlier years of the program, two flasks were routinely exposed on the same day; after 1964 this number was increased to three.

Although this procedure is simple to execute, special precautions must be consistently observed to avoid contaminating a high proportion of the samples. The sample taker, to minimize contamination from his own breath, was instructed to sample only when the wind was at least 5 knots. After first breathing normally near the site for some moments, he exhales, then inhales slightly, and finally, without exhaling again, walks 10 steps into the wind, where he takes the sample. He should have a clear idea of the wind direction and be certain that no local source of CO2, even another human being is upwind.

According to our current instructions, in force since 1962, the flask, after exposure to air, is brought indoors and the stopcock is slowly warmed and turned back and forth to work out any streaks in the grease. The flask is then repacked immediately to avoid prolonged exposure to light. . . .

Only one member of the South Pole field party was designated each year to take samples. Prior to arrival in Antarctica, he received two days of instruction from Scripps personnel. The results of his practice sampling were determined by gas analysis while he was still undergoing training.
Now you ask why Keeling took care to repack the sampling flasks...well from 1960 to 62
the flasks, after exposure to air, were hung on a wall and repacked only when a dozen had accumulated. Photo-oxidation of the hydrocarbon stopcock grease occurred in the hanging flasks and rendered useless all but the last pair of each dozen
Fortunately, a continuous, IR monitor was operated between 1960 and 1963.

3 comments:

Anonymous said...

It's Saturday. Guess it's time for the weekend laundry. For further example, see also Roger Pielke Jr. who is touting his latest paper.

http://sciencepolicy.colorado.edu/admin/publication_files/resource-2517-2007.14.pdf

When you dig down in the reference section, you'll find a series of citations for papers that have not gone through peer review. Many of them have been been written by Roger Pielke Jr.

I guess that's how you make a name for yourself.

1. Create a body of grey literature.

2. Launder grey lit. through a peer-reviewed article.

3. Trumpet peer-reviewed paper on blog.

4. Wait for emails from journalists.

guthrie said...

Thats cool. Wish I had proper journal access.

Anonymous said...

guthrie, you can find a copy of the article and read it for yourself on Pielke Jr.'s blog.

He always runs pre-release copies of anything he writes to drum up media attention.