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*** Point Barrow, Alaska 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

1982  99.999  99.999  99.999  -8.012  -8.014  -7.925  -7.587  -7.181  -7.354  -7.554  -7.806  -7.887  99.999  99.999
1983  -7.922  -7.934  -7.942  -7.962  -8.020  -8.047  -7.593  -7.198  -7.242  -7.633  -7.830  -8.021  -7.779  -7.799
1984  -8.151  -8.086  -8.142  -8.121  -8.104  -8.066  -7.562  -7.232  -7.352  -7.678  -7.750  -7.946  -7.849  -7.837
1985  -7.990  -7.903  -8.014  -8.058  -8.168  -7.982  -7.672  -7.337  -7.412  -7.700  -7.871  -7.928  -7.836  -7.840
1986  -7.984  -8.058  99.999  -8.153  -8.060  -7.978  -7.597  -7.209  -7.531  -7.773  -7.761  -7.945 (-7.846) -7.850
1987  -8.096  -8.075  -8.088  -8.056  -8.075  -8.107  -7.708  -7.304  -7.421  -7.628  -7.847  -7.971  -7.865  -7.869
1988  -8.082  -8.227  -8.185  -8.150  -8.159  -8.103  -7.723  -7.487  -7.611  -7.845  99.999  99.999 (-7.979) -7.971
1989  99.999  99.999  -8.362  -8.324  -8.323  99.999  -7.900  99.999  -7.522  -7.817  -8.065  -8.194  99.999  -8.065
1990  -8.225  -8.274  -8.367  -8.316  -8.457  -8.131  99.999  -7.590  -7.541  -7.749  -7.971  -8.118 (-8.047) -8.059
1991  -8.290  -8.313  -8.369  -8.275  -8.279  -8.141  -7.813  -7.446  -7.538  -7.888  -7.984  -8.135  -8.039  -8.028
1992  -8.231  -8.231  -8.228  -8.264  -8.261  -8.189  -7.809  -7.485  -7.485  -7.775  -7.946  -8.125  -8.002  -8.001
1993  -8.214  -8.205  -8.272  -8.253  -8.266  -8.105  -7.632  -7.473  -7.700  -7.771  -7.981  -8.147  -8.002  -7.993
1994  -8.170  -8.278  -8.329  -8.274  -8.244  -8.183  -7.754  -7.454  -7.487  -7.789  -7.936  -8.221  -8.010  -8.013
1995  -8.185  -8.308  -8.292  -8.309  -8.244  -8.179  -7.829  -7.508  -7.607  -7.816  -8.089  -8.197  -8.047  -8.048
1996  -8.292  -8.344  -8.316  -8.315  -8.410  -8.309  99.999  -7.586  -7.652  -7.950  -8.002  -8.230 (-8.106) -8.101
1997  -8.391  -8.341  -8.274  -8.384  -8.326  -8.312  -7.939  -7.536  -7.706  -7.881  -8.128  -8.189  -8.117  -8.108
1998  -8.312  -8.457  -8.348  -8.368  -8.403  -8.345  -7.806  -7.543  99.999  -8.015  -8.208  -8.380 (-8.158) -8.156
1999  -8.465  -8.407  -8.431  -8.440  -8.487  -8.390  99.999  -7.655  -7.733  -7.941  99.999  -8.324 (-8.203) -8.208
2000  -8.417  -8.519  -8.425  -8.463  -8.518  -8.317  -7.937  -7.700  -7.783  -7.982  -8.142  -8.285  -8.207  -8.203
2001  -8.375  -8.431  -8.416  -8.475  -8.471  -8.388  -7.980  -7.612  -7.752  -8.115  -8.202  -8.391  -8.217  -8.213
2002  -8.486  -8.434  -8.490  -8.451  -8.484  99.999  -8.028  -7.646  -7.872  -8.038  -8.256  -8.345 (-8.245) -8.248


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.