Component signals in the record of atmospheric carbon dioxide concentration at American Samoa

Variability in atmospheric CO/sub 2/ concentration over periods of 1-5 days at Cape Mutatula, American Samoa, was studied. The variability was found to be the result of the alternating influences of three air mass source regions. Partitioning of Samoa CO/sub 2/ data according to these air mass source regions revealed annual cycles in the partitioned data sets corresponding to those of the tropical South Pacific. The midlatitude southern hemisphere, and the tropical North Pacific regions.