TIME SERIES CHARACTERIZATION OF CONTINUOUS CARBON MONOXIDE MEASUREMENTS.

A time series of one- and eight-hour carbon monoxide concentrations, corresponding to the time periods of the ambient air quality standards, were examined to determine the degree of serial dependence, or autocorrelation, the persistence of this dependence, and the presence of cyclical patterns in the autocorrelation functions. The equivalent number of independent measurements for various time periods contained in a continuous record were determined, using a ratio of variance test.