********************************************************************** *** Atmospheric CH4 concentrations (ppbv) derived from flask *** *** samples collected at Mawson, Antarctica *** *** Source: L.P. Steele *** *** P.B. Krummel *** *** R.L. Langenfelds *** *** Commonwealth Scientific, *** *** and Industrial Research Organisation, *** *** Aspendale, Victoria, *** *** Australia 3195 *** *** *** *** January 2003 *** *** *** ********************************************************************** Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann Ave 1984 1565.72 1572.34 1580.07 1586.76 1587.72 1585.64 1582.31 1577.51 1985 1569.71 1563.8 1563.97 1570.76 1580.27 1587.21 1593.11 1598.32 1600.7 1601.24 1598.33 1591.64 1584.92 1986 1585.57 1581.66 1581.46 1584.95 1590.61 1598.11 1606.47 1611.74 1612.58 1612.64 1609.85 1602.33 1598.16 1987 1594.86 1591.97 1593.6 1598.83 1604.71 1610.67 1618.41 1623.33 1625.09 1627.46 1624.92 1616.62 1610.87 1988 1609.65 1604.76 1604.01 1607.95 1613.24 1620.41 1627.49 1632.95 1635.27 1635.03 1634.39 1628 1621.10 1989 1619.19 1615.65 1615.21 1619.92 1628.15 1635.79 1642.58 1646.56 1650.76 1651.33 1644.81 1637.44 1633.95 1990 1631.39 1627.2 1625.75 1629.92 1637.54 1644.37 1650.89 1655.64 1657.09 1655.77 1651.39 1645.57 1642.71 1991 1639.71 1634.47 1633.77 1639.06 1645.63 1652.84 1661.37 1666.54 1668 1670.46 1669.68 1664.24 1653.81 1992 1657.77 1652.87 1653.11 1657.26 1662.92 1669.91 1676.37 1680.01 1680.79 1679.3 1675.44 1666.99 1667.73 1993 1656.86 1652.52 1653.24 1657.24 1663.32 1670.01 1675.24 1678.78 1680.98 1680.87 1676.32 1668.48 1667.82 1994 1661.33 1655.38 1653.58 1658.26 1665.67 1672.58 1679.22 1684.23 1687.06 1688.28 1684.63 1677.38 1672.30 1995 1671.29 1666.29 1665.22 1668.41 1672.54 1679.25 1686.05 1690.38 1692.41 1692.38 1689.02 1681.67 1679.58 1996 1672.9 1666.92 1666.48 1669.62 1674.71 1681.81 1688.76 1692.51 1694.03 1694.16 1689.88 1682.72 1681.21 1997 1675.35 1669.87 1670.61 1676.2 1682.91 1690.2 1696.47 1700.53 1701.68 1701.12 1697.52 1690.13 1687.72 1998 1683.4 1679.08 1677.1 1679.5 1686.3 1694.66 1701.9 1707.83 1711.29 1712.44 1708.68 1700.02 1695.18 1999 1693.57 1689.35 1687.71 1691.85 1698.73 1705.67 1712.93 1718.66 1720.2 1719.35 1714.95 1706.89 1704.99 2000 1699.76 1693.54 1690.11 1694.46 1701.01 1707.88 1715.68 1719.7 1721.15 1720.13 1714.89 1706.61 1707.08 2001 1697.89 1691.98 1690.38 1694.28 1701.99 1708.35 1713.89 1718.92 1720.51 1719.2 1714.29 1707.11 1706.57 Monthly values are expressed in parts per billion by volume (ppbv) and reported in the CSIRO94 CH4 Scale [Steele, et al., 1996, pp. 107-110, in: Baseline Atmospheric Program (Australia) 1994-95, edited by R.J.Francey, A.L. Dick, and N. Derek]. 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.