******************************************************************* *** Atmospheric CO2 concentrations (ppmv) derived from flask *** *** air samples collected at Alert, NWT, Canada *** *** *** *** Source: C.D. Keeling *** *** T.P. Whorf, and the Carbon Dioxide Research Group *** *** Scripps Institution of Oceanography (SIO) *** *** University of California *** *** La Jolla, California USA 92093-0444 *** *** *** *** May 2005 *** *** *** ******************************************************************* Year Jan. Feb. Mar. Apr. May Jun. July Aug. Sept. Oct. Nov. Dec. Annual Annual-Fitted 1985 -99.99 -99.99 -99.99 -99.99 352.62 348.19 343.36 -99.99 338.63 342.77 347.10 349.44 -99.99 -99.99 1986 351.12 351.66 352.84 353.11 353.71 351.80 347.00 340.55 339.40 344.28 348.70 349.50 348.64 348.47 1987 351.61 352.26 354.04 353.72 354.68 352.95 348.36 341.18 340.53 346.20 349.41 352.67 349.80 349.94 1988 354.19 355.56 356.29 357.30 357.00 356.29 348.54 344.18 -99.99 349.58 354.89 357.54 (352.98) 352.71 1989 356.38 358.94 360.14 359.59 359.61 357.76 351.63 345.79 346.22 349.89 354.78 358.32 354.92 355.05 1990 359.35 360.18 360.84 360.66 360.27 357.76 351.33 346.28 347.13 350.85 355.82 358.49 355.75 355.86 1991 360.53 362.12 361.00 361.93 361.52 359.93 354.19 347.61 348.71 352.99 357.61 359.97 357.34 357.30 1992 362.16 362.22 363.80 362.65 363.19 361.65 353.95 347.02 347.85 352.23 356.87 361.08 357.89 357.91 1993 361.90 361.94 362.77 363.52 -99.99 360.97 354.18 348.13 348.46 353.40 357.01 360.34 (357.97) 358.15 1994 363.05 364.18 364.87 364.47 364.32 362.13 356.72 350.88 350.69 356.06 360.09 363.27 360.06 359.84 1995 363.49 364.94 366.72 366.33 365.75 364.32 358.59 352.06 353.45 357.27 362.34 365.65 361.74 361.83 1996 366.93 366.71 367.63 368.15 369.14 367.33 361.53 356.11 354.51 360.12 363.85 365.52 363.96 363.77 1997 367.72 369.08 368.17 368.83 369.49 367.57 360.79 355.16 356.01 360.71 364.77 367.81 364.67 364.73 1998 369.40 370.12 370.88 370.53 371.56 369.28 364.50 357.46 360.54 364.04 368.74 371.58 367.39 367.27 1999 372.60 373.85 373.75 374.10 374.50 372.04 364.81 359.11 359.65 364.94 369.82 372.62 369.31 369.34 2000 373.23 375.13 374.83 375.42 376.18 374.01 366.54 360.78 361.77 367.51 370.58 373.37 370.78 370.78 2001 375.49 375.94 376.42 377.48 377.67 374.78 367.38 361.67 363.39 367.74 373.18 374.41 372.13 372.11 2002 376.68 377.42 378.27 378.73 379.01 375.95 370.78 364.07 365.36 370.25 374.04 377.99 374.04 374.11 2003 379.03 379.36 380.90 381.39 382.38 381.02 373.78 367.97 368.55 372.28 377.75 379.99 377.03 377.01 2004 382.44 382.36 381.58 383.21 383.58 382.59 374.58 368.69 368.55 373.39 378.49 381.62 378.42 378.60 Monthly values are expressed in parts per million (ppm) and reported in the 2003A SIO manometric mole fraction scale. The monthly values have been adjusted to the 15th of each month. Missing values are denoted by -99.99. The "annual" average is the arithmetic mean of the twelve monthly values. In years with one or two missing monthly values, annual values were calculated by substituting a fit value (4-harmonics with gain factor and spline) for that month and then averaging the twelve monthly values.