******************************************************************* *** South Pole isotopic ratio of atmospheric 13C/12C (permil) *** *** averages of data adjusted to the 15th of each month *** *** *** *** Source: C.D. Keeling, A.F. Bollenbacher, and T.P. Whorf *** *** Carbon Dioxide Research Group *** *** Scripps Institution of Oceanography (SIO) *** *** University of California *** *** La Jolla, California USA 92093-0444 *** *** *** *** March 2005 *** *** *** ******************************************************************* Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ave FitAve 1977 99.999 99.999 -7.491 99.999 99.999 99.999 -7.431 99.999 -7.541 -7.486 -7.549 -7.507 99.999 99.999 1978 -7.499 -7.496 99.999 99.999 99.999 -7.559 -7.478 -7.501 -7.540 -7.550 -7.479 -7.484 99.999 -7.498 1979 -7.505 -7.474 -7.471 -7.417 -7.453 99.999 -7.458 -7.458 -7.417 -7.563 -7.454 -7.494 (-7.469) -7.478 1980 -7.509 -7.474 99.999 -7.530 -7.548 -7.510 -7.580 -7.583 -7.567 -7.582 99.999 -7.582 (-7.546) -7.543 1981 -7.593 99.999 -7.568 -7.561 -7.518 -7.569 -7.570 -7.540 -7.534 -7.568 -7.530 -7.601 (-7.559) -7.554 1982 99.999 -7.508 -7.513 -7.495 -7.467 -7.503 -7.555 -7.572 -7.556 -7.568 -7.554 -7.534 (-7.530) -7.537 1983 -7.518 -7.593 -7.586 99.999 -7.646 -7.662 -7.630 -7.665 -7.649 -7.658 -7.689 -7.692 (-7.632) -7.629 1984 -7.695 99.999 99.999 -7.672 -7.668 -7.645 99.999 -7.672 99.999 -7.702 -7.656 -7.646 99.999 -7.668 1985 -7.625 -7.620 99.999 -7.631 -7.612 -7.638 -7.636 -7.639 -7.632 -7.641 -7.640 -7.655 (-7.633) -7.637 1986 -7.662 -7.599 -7.592 -7.603 -7.589 -7.635 -7.629 -7.653 -7.658 -7.662 -7.661 -7.635 -7.631 -7.635 1987 -7.633 -7.638 -7.644 -7.650 -7.676 -7.669 -7.701 -7.712 -7.711 -7.716 -7.719 -7.749 -7.685 -7.683 1988 -7.715 -7.718 -7.712 -7.728 -7.734 -7.745 -7.760 -7.754 -7.783 -7.794 -7.828 -7.822 -7.758 -7.753 1989 99.999 -7.766 -7.694 -7.766 -7.761 -7.800 -7.803 -7.749 -7.819 -7.791 -7.774 -7.779 (-7.773) -7.783 1990 -7.802 -7.774 -7.784 -7.775 -7.765 -7.791 -7.797 -7.845 -7.825 -7.860 99.999 -7.785 (-7.801) -7.794 1991 99.999 -7.769 -7.741 -7.763 -7.758 -7.770 -7.781 -7.784 -7.798 -7.784 -7.802 -7.806 (-7.779) -7.781 1992 -7.779 -7.767 -7.742 -7.746 -7.767 -7.786 -7.791 -7.798 -7.807 -7.800 -7.792 -7.786 -7.780 -7.776 1993 -7.777 -7.731 -7.737 -7.720 -7.732 -7.729 -7.746 -7.766 -7.776 -7.773 -7.779 -7.775 -7.754 -7.761 1994 -7.772 -7.793 -7.792 -7.795 -7.766 -7.771 -7.785 -7.791 -7.828 -7.815 -7.842 -7.785 -7.795 -7.789 1995 -7.795 -7.798 -7.762 -7.769 -7.810 -7.805 -7.815 -7.849 -7.850 -7.876 -7.829 -7.850 -7.817 -7.822 1996 -7.832 -7.859 -7.884 -7.848 -7.888 -7.862 -7.854 -7.876 -7.891 -7.885 -7.883 -7.874 -7.870 -7.865 1997 -7.883 -7.858 -7.860 -7.836 -7.858 -7.845 -7.864 -7.874 -7.875 -7.881 -7.894 -7.891 -7.868 -7.875 1998 -7.892 -7.933 -7.937 -7.936 -7.955 -7.955 -7.976 -7.991 -8.004 -7.997 -8.003 -8.008 -7.965 -7.959 1999 -7.991 -8.034 -7.986 -7.983 -7.966 -7.989 -7.982 -7.980 -8.004 -8.012 -8.016 -8.004 -7.996 -7.996 2000 -7.999 -8.012 -8.004 -8.005 -7.978 -7.989 -7.993 -7.999 -8.004 -8.003 -8.004 -7.983 -7.998 -7.994 2001 -7.984 -7.980 -7.970 -7.966 -7.970 -7.996 -7.984 -7.994 -8.008 -8.028 -8.025 -8.017 -7.994 -7.993 2002 -8.011 -8.008 -7.995 -7.984 -7.987 -8.005 -8.003 -8.034 -8.037 -8.033 -8.057 -8.044 -8.016 -8.017 Monthly averages have been adjusted to the 15th of each month. Missing values are denoted by 99.999. Annual average data have been augmented (data in parentheses) when only 1 or 2 months are missing for that year, by substituting the monthly fit value(s) for missing (99.999) data and then averaging the 12 values. The month without data is still shown as 99.999 while this recomputed annual average is shown in parentheses. These monthly data have been adjusted from January 1992 to the present by adding -0.112 per mil.