********************************************************************** *** Measurements of CH4 mixing ratio and D/H and *** *** 13C/12C isotope ratios in atmospheric samples *** *** from Niwot Ridge, Colorado, U.S.A. *** *** *** *** Dec. 29, 1994 to Apr. 27, 2001 *** *** *** *** Source: S.C. Tyler *** *** Department of Earth System Science *** *** University of California *** *** Irvine, CA 92697 *** *** *** *** May 2003 *** *** *** ********************************************************************** Each mixing ratio data point represents the result of one sample measurement made with a precision of 5 ppb. Each d13C-CH4 data point represents the result of one sample measurement made with an overall precision of 0.05 per mil. Error in dD-CH4 measurement is 1 standard deviation from the mean of multiple samples. Date Time CH4 d13CH4 dD-CH4 dD-CH4 wind wind wind (local conc. spd. spd. dir. time) (ppb) (per (per s.d. (mph) (km/hr) (degrees) mil) mil) (1s) 12/29/1994 11:00AM 1764.9 -47.06 NM NM 4 6.4 225 1/26/1995 11:00AM 1753.8 -47.24 NM NM 3 4.8 315 2/16/1995 11:30AM 1769.4 -47.17 NM NM 3 4.8 157 4/14/1995 11:20 1789.0 -47.15 NM NM NM NM NM 5/4/1995 11:30 1793.1 -47.16 NM NM 2 3.2 280 5/11/1995 11:45 1786.4 -47.12 NM NM 13 20.9 292 6/16/1995 11:40 1738.5 -47.29 NM NM 5 8.0 157 6/29/1995 11:15 1818.9 -47.42 NM NM NM NM NM 7/14/1995 11:30 1755.9 -47.02 NM NM 3 4.8 135 8/3/1995 11:00 1741.5 -47.27 NM NM 3 4.8 292 8/25/1995 11:55 1730.3 -47.23 NM NM NM NM NM 9/7/1995 11:30 1763.0 -47.41 NM NM 0 0.0 45 9/22/1995 10:45 1759.8 -47.49 NM NM 8 12.9 180 10/5/1995 12:20 1769.8 -47.45 NM NM 3 4.8 292 11/1/1995 11:00 1784.6 -47.38 NM NM 3 4.8 270 11/17/1995 12:00 1769.0 -47.52 NM NM 15 24.1 270 12/1/1995 11:40 1761.4 -47.06 NM NM 25 40.2 292 12/22/1995 11:30 1815.5 -47.17 NM NM NM NM NM 2/2/1996 13:00 1796.3 -47.49 NM NM 3 4.8 202 2/8/1996 11:45 1739.4 -47.40 NM NM 6 9.7 292 3/15/1996 10:45 1778.3 -47.38 NM NM 1 1.6 225 4/5/1996 12:00 1769.2 -47.36 NM NM 2 3.2 135 4/12/1996 11:00 1780.2 -47.38 NM NM 3 4.8 225 5/3/1996 12:00 1741.1 -47.22 NM NM 5 8.0 225 6/14/1996 10:45 1754.6 -47.22 NM NM 8 12.9 315 7/22/1996 11:35 1792.8 -47.44 NM NM 2 3.2 360 9/12/1996 11:30 1818.5 -47.38 NM NM 2 3.2 120 9/27/1996 11:45 1814.1 -47.58 NM NM 1 1.6 225 10/11/1996 11:55 1763.6 -47.39 NM NM 6 9.7 315 11/15/1996 11:15 1828.3 -47.44 NM NM 3 4.8 135 12/12/1996 11:00 1773.0 -47.34 NM NM 4 6.4 150 1/9/1997 10:45 1794.6 -47.30 NM NM 16 25.7 300 1/17/1997 10:45 1789.7 -47.25 NM NM 16 25.7 270 2/6/1997 14:00 1839.9 -47.32 NM NM 3 4.8 45 2/21/1997 10:40 1806.6 -47.28 NM NM 7 11.3 270 4/3/1997 12:30 1791.3 -47.16 NM NM 3 4.8 360 5/1/1997 11:45 1788.0 -47.05 NM NM 13 20.9 270 5/14/1997 10:30 1761.1 -47.12 NM NM 6 9.7 315 5/22/1997 11:30 1762.3 -47.19 NM NM 0 0.0 0 7/11/1997 11:30 NM -47.10 NM NM 3 4.8 300 7/25/1997 12:42 NM -47.15 NM NM 2 3.2 135 8/21/1997 10:45 1727.1 -47.22 NM NM 18 29.0 270 9/11/1997 12:15 1754.8 -47.23 NM NM 4 6.4 135 10/10/1997 11:00 1761.5 -47.37 NM NM 6 9.7 270 10/23/1997 11:20 1781.1 -47.28 NM NM 11 17.7 225 11/20/1997 11:13 1791.2 -47.40 NM NM 7 11.3 240 12/5/1997 12:00 1800.5 -47.31 NM NM 19 30.6 315 12/18/1997 11:00 1774.1 -47.22 NM NM 5 8.0 300 1/8/1998 11:10 1795.9 -47.28 NM NM 15 24.1 315 2/6/1998 10:40 1794.4 -47.18 NM NM 12 19.3 315 2/26/1998 10:45 1812.9 -47.29 NM NM 25 40.2 270 4/2/1998 10:35 1840.1 -47.18 NM NM 10 16.1 60 5/15/1998 10:15 1805.8 -47.11 NM NM 10 16.1 300 6/4/1998 10:15 1785.4 -47.07 NM NM 2 3.2 135 6/26/1998 11:30 1774.9 -47.11 NM NM 8 12.9 240 8/7/1998 10:00 1740.5 -47.07 NM NM 1 1.6 60 8/28/1998 10:45 1760.4 -47.12 -91.7 0.1 1 1.6 270 9/25/1998 10:45 1742.7 -47.15 -90.3 1.9 6 9.7 270 10/15/1998 10:45 1777.0 -47.21 -94.2 0.5 5 8.0 300 11/29/1998 10:45 1807.6 -47.20 -95.3 1.9 3 4.8 315 12/3/1998 10:45 1786.7 -47.20 -94.5 1.9 4 6.4 135 12/17/1998 11:30 1769.8 -47.23 -91.9 0.3 20 32.2 315 1/15/1999 10:45 1816.5 -47.20 -95.9 1.1 25 40 270 2/26/1999 10:40 1789.6 -47.24 -94.5 0.8 10 16 240 4/2/1999 10:50 1845.3 -47.13 -99.2 1.3 2 3.2 135 4/22/1999 11:40 1836.6 -47.20 -98.5 1.2 2 3.2 135 5/6/1999 10:45 1805.6 -47.12 -99.8 2.4 13 20.8 270 5/21/1999 11:10 1782.6 -47.03 -93.0 1.6 2 3.2 225 6/3/1999 10:35 1781.1 -46.94 -92.6 0.6 3 4.8 315 6/18/1999 10:30 1783.7 -47.02 -93.2 0.5 13 20.8 270 7/1/1999 10:40 1767.1 -47.07 -91.0 1.0 6 9.6 270 7/29/1999 10:45 1774.0 -47.03 -89.0 0.3 7 11.2 270 9/3/1999 10:45 1761.1 -47.10 -90.1 0.8 6 9.6 235 9/16/1999 10:35 1788.3 -47.27 -94.3 0.6 3 4.8 45 10/15/1999 10:50 1793.8 -47.22 -93.2 1.1 6 9.6 135 11/5/1999 10:15 1799.0 -47.26 NM NM 9 14.4 240 11/19/1999 11:30 1807.3 -47.29 NM NM 11 17.6 270 1/7/2000 11:00 1801.9 -47.26 -94.7 0.0 3 4.8 45 1/20/2000 10:45 1770.4 -47.05 -94.1 1.5 8 12.8 270 2/3/2000 10:45 1812.9 -47.23 -95.8 0.1 8 12.8 270 2/25/2000 11:00 1814.8 -47.21 -94.1 2.2 20 32 270 3/23/2000 11:15 1804.1 -47.07 -94.2 1.2 3 4.8 315 4/14/2000 10:45 1769.7 -47.03 -88.7 1.7 7 11.2 270 4/30/2000 10:45 1778.4 -47.05 -89.4 2.6 4 6.4 315 5/26/2000 11:05 1774.1 -47.10 -89.0 1.5 10 16 270 6/9/2000 11:20 1766.9 -47.00 -89.1 1.9 5 8 300 7/14/2000 11:25 1763.0 -47.05 -89.4 0.4 2 3.2 30 8/3/2000 10:40 1766.8 -46.95 -90.6 1.1 2 3.2 90 8/24/2000 11:00 1789.1 -47.07 -89.2 1.1 6 9.6 270 9/8/2000 10:45 1759.7 NM -88.8 0.8 5 8 135 9/21/2000 11:10 1910.1 NM NM NM 2 3.2 45 10/13/2000 10:45 1802.1 NM -94.4 1.2 8 12.8 315 11/9/2000 10:40 1799.5 NM -94.7 1.7 10 16 225 12/8/2000 10:45 1779.6 NM -93.8 1.3 6 9.6 270 1/12/2001 11:00 1782.1 NM -91.3 2.1 6 9.6 240 1/26/2001 10:15 1816.3 NM -93.8 0.0 5 8 270 2/12/2001 10:45 1806.4 NM -94.2 1.1 5 8 135 3/9/2001 10:50 1806.8 NM -90.6 1.3 10 16 270 3/22/2001 10:45 1775.9 NM -88.7 2.1 4.5 7.2 270 4/27/2001 10:30 1805.3 NM -90.3 0.7 3 4.8 270 NM -- not measured