Background atmospheric CO₂ mixing ratios from individual flask air samples for American Samoa. Only measurements satisfying the data selection criteria fro background measurements are plotted. Consecutive background measurements are joined by lines. Background measurements interrupted by non-background measurements are not joined by lines.

Monthly atmospheric CO2 mixing ratios for American Samoa, expressed in parts per million (ppm) and
reported in the Scripps Institution of Oceanography X93 manometric mole fraction scale.  Annual values were
calculated by CDIAC for years with complete records.  Missing values are denoted by -99.99.




Year      Jan 	     Feb      Mar	April	  May	   June	     July      Aug     Sept	  Oct 	   Nov       Dec     Ann




1973    -99.99     -99.99   -99.99     -99.99   -99.99    -99.99    -99.99   330.32   330.28     330.08   330.09    330.29   -99.99
1974    330.63     331.15   331.30     331.08   331.37    331.13    330.52   330.61   330.77     331.05   330.45    329.98   330.84
1975    330.63     330.59   330.17     329.65   329.66    330.61    330.86   330.74   331.50     331.60   330.88    330.53   330.62
1976    330.48     330.54   330.81     331.18   331.43    331.15    330.99   331.53   331.91     332.20   332.63    332.96   331.48
1977    333.01     332.59   332.22     332.71   332.81    332.55    332.84   332.86   332.74     332.96   333.14    333.66   332.84
1978    334.04     333.77   334.37     334.48   334.26    334.83    334.50   334.20   334.38     334.51   334.38    334.14   334.32
1979    334.75     335.46   335.75     335.91   335.63    335.75    335.77   335.77   336.18     336.70   336.77    336.67   335.93
1980    337.37     338.00   337.68     337.65   338.33    338.55    338.44   338.48   338.35     338.25   338.56    338.94   338.22
1981    339.21     339.16   339.54     339.39   338.58    338.79    339.13   339.13   338.96     339.11   339.53    339.84   339.20
1982    340.49     340.89   340.65     340.16   339.69    339.79    340.50   340.88   340.45     340.05   340.28    340.75   340.38
1983    340.75     340.48   340.56     340.79   341.16    341.64    341.82   341.66   341.61     341.84   341.98    342.39   341.39
1984    342.98     343.08   342.88     342.37   341.98    342.34    342.76   343.05   343.15     343.07   343.37    344.02   342.92
1985    344.26     344.62   344.76     344.29   343.92    344.21    344.53   344.45   344.29     344.48   344.90    345.13   344.49
1986    345.45     345.66   345.50     345.17   345.39    346.11    345.77   345.31   345.62     345.89   346.01    346.09   345.66
1987    346.44     347.02   347.02     346.60   346.69    346.98    347.22   347.62   347.97     348.20   348.62    349.07   347.45
1988    349.39     349.49   349.87     350.53   350.30    349.89    350.02   350.07   349.87     350.26   350.82    351.32   350.15
1989    351.74     351.80   351.72     352.03   351.91    351.22    351.28   351.40   351.30     351.52   351.75    351.98   351.64
1990    352.20     352.28   352.87     352.85   352.30    352.50    352.77   352.90   352.87     352.84   353.12    353.59   352.76
1991    354.19     354.71   354.37     353.93   354.02    354.10    354.29   354.05   353.68     353.80   354.42    354.79   354.20
1992    354.41     354.69   354.78     354.49   354.60    354.91    355.39   355.34   355.05     355.03   355.04    355.30   354.92
1993    355.32     355.62   355.94     355.34   354.85    355.26    355.60   355.83   355.75     355.73   356.12    356.44   355.65