Environment & Energy

...in my files, the average reading for every weekly average going back to the week beginning, May 25, 1975, as of this reading, for 2,654 weeks. Of these, only 7 were based on a single reading for the week, and one was missing presumably because of the ignorant Orange Pedophile's shutdown.

There were notes during the weeks that they could not operate at the Observatory normal site that the location of the instruments was different. (I didn't record that in my spreadsheet, but probably should have.)

The scientists working in this lab are very, very, very serious people.

In analytical chemistry of high quality, statistical rules are rigorously applied; these involve generally precision (the spread of data, i.e. repeatability in a series of measurements within a given time frame) and accuracy, (comparison with carefully prepared standards of scrupulously dried air). On these grounds a measurement can be rejected, and so there are many weeks where the weekly average is represented by fewer than 7 daily data points, themselves averages of readings throughout the day. The statistical tests for data inclusion are rigorous. A day can be rejected based on the number of data points meeting statistical criteria. This is high end stuff. Of the 2,654 weekly data points, 1,810 are based on a 7 day average, about 68%.

A cavity ring down spectrometer is a Fourier transform device. It records the decay of a signal for emission at a known wave length characteristic of the gas, generated by a laser pulse over time and transforms it into a concentration measurement.

The website has a very nice and impressive description of the procedures utilized.