[The spectral model for characterizing gaseous pollutants in the atmosphere]

Following Tukey's indications, the Authors propose the spectral model for the analysis of the temporal series related to the main pollutants of the atmosphere. In the paper the mathematical method's development is pointed out and its theoretical bases are emphasized, in particular about the basic passages; the formulas used in practice are no. (5), (6), (7) and (8). To exemplify the spectrum evaluation, the trends of the carbon monoxide (CO), relative to the summer and winter periods, are reported in frequency.