******************************************************************** *** Atmospheric CO2-curve values (ppmv) derived from flask air *** *** samples collected at La Jolla Pier, California, USA *** *** *** *** 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. 1969 329.23 329.49 330.14 330.17 328.35 324.67 321.49 321.98 324.63 326.66 327.78 1970 328.60 328.91 329.30 330.09 330.23 328.49 324.86 321.73 322.28 325.03 327.14 328.33 327.08 1971 329.22 329.58 330.01 330.85 331.03 329.30 325.66 322.51 323.08 325.88 328.01 329.21 327.86 1972 330.10 330.46 330.90 331.73 331.85 330.04 326.32 323.16 323.78 326.60 328.76 330.01 328.64 1973 330.96 331.39 331.89 332.82 333.08 331.40 327.77 324.64 325.33 328.28 330.57 331.91 330.00 1974 332.93 333.40 333.92 334.87 335.13 333.41 329.69 326.47 327.10 329.99 332.20 333.44 331.88 1975 334.36 334.71 335.14 336.00 336.16 334.34 330.51 327.21 327.80 330.71 332.93 334.19 332.84 1976 335.13 335.50 335.98 336.85 337.00 335.13 331.27 328.00 328.67 331.64 333.92 335.25 333.70 1977 336.28 336.76 337.31 338.33 338.64 336.93 333.17 329.93 330.66 333.73 336.08 337.44 335.44 1978 338.44 338.87 339.36 340.29 340.50 338.67 334.78 331.44 332.12 335.18 337.55 338.94 337.18 1979 339.99 340.48 341.04 342.05 342.33 340.54 336.65 333.28 333.95 337.00 339.32 340.63 338.94 1980 341.58 341.96 342.43 343.33 343.48 341.53 337.52 334.12 334.81 337.89 340.24 341.59 340.04 1981 342.60 343.03 343.53 344.49 344.70 342.79 338.75 335.25 335.88 338.97 341.31 342.64 341.16 1982 343.61 344.00 344.46 345.38 345.55 343.60 339.50 335.97 336.63 339.78 342.22 343.64 342.03 1983 344.73 345.24 345.84 346.92 347.25 345.44 341.46 338.04 338.82 342.09 344.60 346.06 343.87 1984 347.15 347.63 348.20 349.20 349.39 347.40 343.24 339.70 340.41 343.58 345.99 347.36 345.77 1985 348.37 348.77 349.27 350.24 350.45 348.48 344.28 340.66 341.33 344.56 347.04 348.46 346.83 1986 349.52 349.96 350.48 351.47 351.68 349.68 345.44 341.78 342.47 345.73 348.24 349.68 348.01 1987 350.78 351.27 351.85 352.93 353.25 351.35 347.19 343.63 344.45 347.87 350.52 352.09 349.77 1988 353.30 353.89 354.57 355.73 356.05 354.09 349.86 346.26 347.04 350.36 352.87 354.28 352.36 1989 355.31 355.71 356.19 357.16 357.34 355.25 350.88 347.12 347.83 351.19 353.77 355.25 353.58 1990 356.36 356.83 357.37 358.41 358.64 356.59 352.22 348.45 349.20 352.61 355.24 356.75 354.89 1991 357.89 358.38 358.95 360.02 360.26 358.18 353.74 349.90 350.59 353.95 356.49 357.90 356.35 1992 358.92 359.28 359.75 360.69 360.79 358.54 353.97 350.09 350.80 354.18 356.75 358.21 356.83 1993 359.30 359.74 360.28 361.33 361.56 359.44 354.94 351.06 351.82 355.32 358.02 359.59 357.70 1994 360.77 361.30 361.92 363.05 363.34 361.25 356.75 352.87 353.64 357.18 359.89 361.45 359.45 1995 362.62 363.13 363.73 364.86 365.15 363.06 358.53 354.64 355.45 359.04 361.80 363.39 361.28 1996 364.57 365.08 365.70 366.80 367.02 364.79 360.15 356.21 356.98 360.51 363.19 364.69 362.97 1997 365.81 366.26 366.80 367.87 368.10 365.90 361.25 357.26 358.07 361.74 364.58 366.26 364.16 1998 367.56 368.20 368.93 370.22 370.66 368.64 364.14 360.27 361.20 364.96 367.85 369.50 366.84 1999 370.72 371.22 371.80 372.88 373.08 370.79 365.98 361.82 362.53 366.13 368.88 370.43 368.86 2000 371.59 372.06 372.65 373.75 373.95 371.64 366.85 362.79 363.64 367.35 370.18 371.81 369.86 2001 373.03 373.55 374.16 375.29 375.55 373.27 368.44 364.28 365.08 368.82 371.69 373.35 371.38 2002 374.60 375.15 375.79 376.99 377.32 375.12 370.36 366.28 367.20 371.07 374.08 375.84 373.32 2003 377.19 377.83 378.54 379.81 380.17 377.95 373.14 368.99 369.86 373.70 376.65 378.33 376.01 2004 379.59 380.11 380.75 381.91 382.13 379.75 374.80 370.61 371.48 375.30 378.23 379.92 377.88 2005 381.20 381.77 382.45 383.70 384.05 381.80 376.93 372.76 373.70 377.67 380.75 382.56 379.95 2006 383.95 384.60 385.32 386.61 386.97 384.70 379.76 375.50 376.36 380.27 383.27 384.98 382.69 2007 386.25 386.79 387.43 388.63 388.91 386.55 381.51 377.17 378.01 381.92 384.91 386.61 384.56 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.