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*** Atmospheric CO2 concentrations (ppmv) derived from flask air   ***
*** samples collected at Casey Station, Antarctica                 ***
*** Source: L.P. Steele                                            ***
***              P.B. Krummel                                      ***  
***              R. L. Langenfelds,                                ***
***              Atmospheric, Research, Commonwealth Scientific,   ***
***              And Industrial Research Organisation,             ***
***              Aspendale, Victoria,                              *** 
***              Australia  3195                                   ***                   
***                                                                ***   
*** August 2007                                                    ***
***                                                                ***
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Month	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Ann. Ave
1997							361.27	361.68	362.07	362.23	362.09	362.15	
1998	362.28	362.37	362.65	362.96	363.12	363.51	364.13	364.67	364.98	365.06	364.91	364.78	363.79
1999	364.75	364.67	364.55	364.36	364.75	365.61	365.98	366.15	366.28	366.35	366.63	366.41	365.54
2000	365.95	366.01	366.26	366.33									
2001													
2002	368.83	369.12	369.52	369.46	369.37	369.89	370.63	371.19	371.66	371.84	371.86	371.90	370.44
2003	371.75	371.61	371.68	371.81	372.05	372.49	373.08	373.67	373.88	373.63	373.15	373.13	372.66
2004	373.42	373.45	373.58	373.72	373.98	374.57	375.07	375.50	375.76	375.73	375.72	375.51	374.67
2005	375.08	374.97	375.16	375.40	375.75	376.39	377.04	377.42	377.61	377.68	377.75	377.64	376.49
2006	377.22	377.01	377.17	377.45	377.73	378.15	378.73	378.98	378.98	379.24	379.38	379.03	378.26

Monthly values are expressed in parts per million (ppm) and reported in the WMO CO2 
Mole Fraction Scale (Zhao et al., 1997, J. Geophys. Res. 102 , 5885-5894). Calibration 
details are discussed by Francey et al. (2003).  Monthly values are calculated as the 
mean of the daily values from a smooth curve fit to the data using 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.