********************************************************************
*** Atmospheric CO2-curve values (ppmv) derived from flask air   ***
*** samples collected at Alert, Northwest Territiries, Canada    *** 
***                                                              ***
*** Source: R. F. Keeling, S. C. Piper, A. F. Bollenbacher       ***
***             and S. J. Walker                                 ***
***         Carbon Dioxide Research Group                        ***
***         Scripps Institution of Oceanography (SIO)            ***
***         University of California                             ***
***         La Jolla, California USA 92093-0444                  ***
***                                                              ***
*** May 2008                                                     ***
********************************************************************

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Ann. Ave.
1985						350.11	344.04	337.99	338.49	343.09	347.36	350.04	
1986	351.49	352.22	352.73	353.00	353.25	351.45	345.30	339.17	339.61	344.16	348.39	351.04	348.48
1987	352.48	353.24	353.79	354.14	354.48	352.78	346.74	340.71	341.29	346.00	350.39	353.20	349.94
1988	354.77	355.65	356.32	356.77	357.19	355.49	349.46	343.56	344.27	349.05	353.46	356.25	352.69
1989	357.79	358.60	359.16	359.48	359.77	357.99	351.80	345.64	346.11	350.76	355.05	357.72	354.99
1990	359.12	359.79	360.24	360.45	360.64	358.78	352.52	346.31	346.80	351.51	355.88	358.63	355.89
1991	360.14	360.91	361.46	361.77	362.06	360.27	354.05	347.84	348.35	353.06	357.41	360.11	357.29
1992	361.53	362.19	362.63	362.80	362.92	360.88	354.42	348.11	348.56	353.18	357.44	360.10	357.90
1993	361.49	362.15	362.60	362.81	363.00	361.10	354.75	348.45	348.94	353.70	358.15	360.96	358.18
1994	362.52	363.34	363.93	364.27	364.60	362.81	356.54	350.29	350.84	355.66	360.13	362.95	359.82
1995	364.49	365.31	365.88	366.24	366.57	364.80	358.52	352.28	352.87	357.75	362.27	365.12	361.84
1996	366.68	367.50	368.09	368.42	368.71	366.79	360.37	354.06	354.60	359.35	363.72	366.43	363.73
1997	367.86	368.56	369.04	369.30	369.56	367.70	361.31	354.97	355.53	360.43	364.99	367.90	364.76
1998	369.51	370.41	371.06	371.51	371.95	370.26	364.00	357.76	358.43	363.42	368.03	370.92	367.27
1999	372.49	373.27	373.81	374.08	374.33	372.41	365.92	359.46	359.97	364.85	369.39	372.24	369.35
2000	373.78	374.58	375.16	375.48	375.77	373.83	367.33	360.97	361.59	366.51	371.05	373.90	370.83
2001	375.44	376.22	376.76	377.06	377.33	375.42	368.89	362.38	362.90	367.82	372.39	375.26	372.32
2002	376.82	377.64	378.22	378.58	378.93	377.12	370.68	364.28	364.94	370.02	374.75	377.77	374.15
2003	379.47	380.42	381.11	381.56	381.97	380.17	373.69	367.21	367.78	372.76	377.37	380.25	376.98
2004	381.78	382.54	383.08	383.35	383.61	381.59	374.94	368.44	369.06	374.06	378.69	381.62	378.56
2005	383.23	384.09	384.71	385.10	385.47	383.64	377.11	370.62	371.27	376.38	381.14	384.17	380.58
2006	385.86	386.79	387.47	387.92	388.34	386.53	379.98	373.43	374.01	379.06	383.71	386.61	383.31
2007	388.13	388.88	389.38	389.63	389.87	387.89	381.20	374.57	375.15	380.27	385.05	388.10	384.84

Values above are taken from a curve consisting of 4 harmonics plus a stiff spline and a linear gain factor, fit
to monthly concentration values adjusted to represent 2400 hours on the 15th day of each month. Data used to
derive this curve are shown in the accompanying graph.  Units are parts per million by volume (ppmv) expressed 
in the 2003A SIO manometric mole fraction scale. The "annual average" is the arithmetic mean of the twelve
monthly values.