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*** Delta C-13 values (per mil) derived from CO2 in flask air      ***
*** samples collected at Alert, NWT, Canada                        ***
*** Source: C. E. Allison                                          ***
***              R. J. Francey                                     ***
***              P. B. Krummel                                     ***  
***              Atmospheric, Research, Commonwealth Scientific,   ***
***              And Industrial Research Organisation,             ***
***              Aspendale, Victoria,                              *** 
***              Australia  3195                                   ***                   
***                                                                ***   
*** September 2003                                                 ***
***                                                                ***
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	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Ann. Ave.

1991						-8.285	-7.911	-7.609	-7.635	-7.875	-8.11	-8.346	
1992	-8.414	-8.301	-8.295	-8.332	-8.324	-8.208	-7.841	-7.482	-7.498	-7.737	-7.988	-8.154	-8.048
1993	-8.153	-8.144	-8.213	-8.272	-8.277	-8.126	-7.802	-7.529	-7.577	-7.813	-7.934	-8.034	-7.990
1994	-8.122	-8.175	-8.248	-8.275	-8.256	-8.12	-7.802	-7.535	-7.593	-7.826	-8.019	-8.179	-8.013
1995	-8.279	-8.298	-8.29	-8.287	-8.274	-8.122	-7.787	-7.581	-7.633	-7.841	-8.069	-8.183	-8.054
1996	-8.249	-8.329	-8.34	-8.316	-8.34	-8.258	-7.975	-7.676	-7.636	-7.878	-8.106	-8.191	-8.108
1997	-8.276	-8.326	-8.316	-8.323	-8.336	-8.253	-7.945	-7.619	-7.628	-7.867	-8.074	-8.199	-8.097
1998	-8.311	-8.384	-8.352	-8.321	-8.371	-8.264	-7.924	-7.66	-7.703	-7.955	-8.202	-8.317	-8.147
1999	-8.364	-8.418	-8.437	-8.444	-8.446	-8.314	-7.948	-7.651	-7.698	-7.919	-8.141	-8.269	-8.171
2000	-8.353	-8.43	-8.436	-8.423	-8.44	-8.279	-7.937	-7.685	-7.7	-7.931	-8.128	-8.257	-8.167
2001	-8.379	-8.406	-8.411	-8.456	-8.465	-8.274	-7.922	-7.675	-7.685	-7.967	-8.25	-8.328	-8.185


Monthly values (per mil) are reported on the international VPDB-CO2 scale. Monthly values were 
calculated as the mean of the daily values from a smooth curve fit to the data using the curve-
fitting routines described by Thoning et al., 1989 (J. Geophys Res. 94, 8549-8565).  Annual 
values are the arithmetic means of the 12 monthly values.