********************************************************************** *** Atmospheric CO concentrations (ppbv) derived from flask *** *** samples collected at Cape Ferguson, Australia *** *** Source: L.P. Steele *** *** P.B. Krummel *** *** R.L. Langenfelds *** *** Commonwealth Scientific, *** *** and Industrial Research Organisation, *** *** Aspendale, Victoria, *** *** Australia 3195 *** *** *** *** February 2003 *** *** *** ********************************************************************** Year Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Ann. Ave. 1992 55.58 59.98 61.21 63.88 71.67 74.62 81.98 98.27 100.49 82.45 64.14 1993 55.37 55.4 60.66 61.2 58.29 59.88 71.69 78.1 80.27 88.4 78.28 60.1 67.30 1994 52.86 51.84 53.38 55.83 62.9 71.66 70.18 67.25 79.1 96.01 96.38 76.91 69.53 1995 59.01 58.07 65.05 65.11 61.4 64.26 77.35 88.43 88.12 88.71 86.21 77.47 73.27 1996 69.42 65.57 61.34 60.37 62.21 63.45 64.23 71.4 80.96 81.91 83.87 79.2 70.33 1997 61.18 56.75 73.05 88.19 84.13 74.38 73.66 88.95 116.64 116.18 87.52 65.19 82.15 1998 54.7 51.65 54.47 62.43 65.59 67.85 77.24 82.85 85.41 87.02 77.67 63.55 69.20 1999 55.56 52.28 51.04 58.04 62.63 62.99 75.25 88.56 91 80.86 68.29 61.9 67.37 2000 52.34 44.89 45.02 47.3 53.66 63.56 64.45 70.68 105.93 133.1 107.86 65.25 71.17 2001 53.54 56.35 50.52 49.29 57.5 63.89 77.45 91.87 96.7 107.93 112.74 84.11 75.16 Monthly values, expressed in parts per billion by volume (ppbv), are linked to the gravimetrically derived scale of NOAA/CMDL using a single high-pressure cylinder standard with a CO mole fraction of 196 ppbv. Stability of the CSIRO scale and variations in instrument response are monitored with about 20 high pressure cylinder standards, with lifetimes of 4 to 10 or more years, spanning a CO range of 20 to 400 ppbv. 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. Annual values are the arithmetic means of the 12 monthly values.