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*** Station Alert, N.W.T. 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                                                  ***
***                                                             ***
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Year   Jan     Feb     Mar     Apr     May     Jun     Jul     Aug     Sep     Oct     Nov     Dec     Ave     FitAve

1985  99.999  99.999  99.999  99.999  -8.076  -7.940  -7.693  99.999  -7.466  -7.648  -7.942  -7.940  99.999  99.999
1986  -8.039  -8.065  -8.136  -8.064  -8.064  -7.919  -7.706  -7.356  -7.365  -7.598  -7.768  -7.813  -7.824  -7.829
1987  -7.905  -7.982  -8.131  -8.065  -8.093  -8.029  -7.790  -7.426  -7.373  -7.652  -7.820  -7.924  -7.849  -7.855
1988  -8.036  -8.088  -8.087  -8.260  -8.188  -8.290  -7.788  -7.578  99.999  99.999  99.999  99.999  99.999  -7.950
1989  -8.181  -8.326  -8.344  -8.161  -8.204  -8.186  -7.814  -7.637  -7.587  -7.790  -8.033  -8.163  -8.036  -8.024
1990  -8.192  -8.265  -8.289  -8.291  -8.291  -8.142  -7.749  -7.600  -7.627  -7.818  -8.029  -8.074  -8.031  -8.024
1991  -8.149  -8.201  -8.182  -8.239  -8.221  -8.133  -7.827  -7.511  -7.515  -7.719  -7.978  -8.118  -7.983  -8.004
1992  -8.255  -8.249  -8.358  -8.278  -8.322  -8.247  -7.804  -7.418  -7.441  -7.685  -7.959  -8.171  -8.016  -8.006
1993  -8.203  -8.182  -8.219  -8.265  -8.305  -8.097  -7.723  -7.451  -7.451  -7.691  -7.870  -8.039  -7.958  -7.973
1994  -8.186  -8.264  -8.280  -8.239  -8.246  -8.110  -7.816  -7.506  -7.498  -7.794  -7.992  -8.128  -8.005  -7.990
1995  -8.117  -8.197  -8.330  -8.313  -8.276  -8.183  -7.893  -7.502  -7.583  -7.772  -8.027  -8.215  -8.034  -8.040
1996  -8.214  -8.234  -8.355  -8.330  -8.384  -8.285  -8.016  -7.673  -7.582  -7.900  -8.132  -8.154  -8.105  -8.104
1997  -8.343  -8.523  -8.289  -8.312  -8.350  -8.259  -7.885  -7.626  -7.622  -7.880  -8.070  -8.186  -8.112  -8.114
1998  -8.296  -8.320  -8.381  -8.335  -8.402  -8.270  -7.996  -7.631  -7.788  -7.966  -8.210  -8.315  -8.159  -8.156
1999  -8.364  -8.464  -8.434  -8.485  -8.460  -8.339  -7.971  -7.687  -7.690  -7.933  -8.194  -8.338  -8.197  -8.195
2000  -8.350  -8.447  -8.411  -8.435  -8.479  -8.353  -7.974  -7.715  -7.693  -7.985  -8.139  -8.267  -8.187  -8.192
2001  -8.420  -8.413  -8.420  -8.467  -8.462  -8.347  -7.942  -7.674  -7.724  -7.948  -8.223  -8.279  -8.193  -8.189
2002  -8.398  -8.411  -8.427  -8.455  -8.455  -8.308  -8.061  -7.697  -7.765  -8.002  -8.179  -8.344  -8.208  -8.221


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.