********************************************************************** *** Carbon dioxide (CO2) mixing ratio, d13C-CO2, and d18O-CO2 *** *** at Niwot Ridge, Colorado, USA *** *** *** *** *** *** Feb. 2, 1996 to Nov. 5, 1999 *** *** *** *** Source: S.C. Tyler *** *** Department of Earth System Science *** *** University of California *** *** Irvine, CA 92697 *** *** *** *** *** *** January 2004 *** *** *** ********************************************************************** Each mixing ratio data point represents the result of one sample measurement made with a precision of 3 ppm. Each d13C-CO2 data point represents the result of one sample measurement made with an overall precision of 0.05 per mil. Each d18O-CO2 data point represents the result of one sample measurement made with an overall precision of 0.20 per mil. Date Local CO2 d13CO2 d18O-CO2 wind wind wind Time conc. (per (per spd. spd. dir. (ppm) mil) mil) (mph) (km/hr) (degrees) 2/2/1996 13:00 365.21 -7.77 -0.85 3 4.8 202 2/8/1996 11:45 359.98 -7.61 -0.39 6 9.7 292 3/15/1996 10:45 363.75 -7.81 -1.38 1 1.6 225 4/5/1996 12:00 359.13 -7.58 -1.39 2 3.2 135 4/12/1996 11:00 361.00 -7.57 -0.98 3 4.8 225 5/3/1996 12:00 358.65 -7.51 -1.10 5 8.0 225 6/14/1996 10:45 362.38 -7.71 -1.53 8 12.9 315 7/22/1996 11:35 355.72 -7.56 -3.47 2 3.2 360 9/12/1996 11:30 352.68 -7.44 -1.58 2 3.2 120 9/27/1996 11:45 356.74 -7.62 -3.31 1 1.6 225 10/11/1996 11:55 359.35 -7.55 -0.58 6 9.7 315 11/15/1996 11:15 370.13 -7.87 -0.86 3 4.8 135 12/12/1996 11:00 364.39 -7.75 -0.81 4 6.4 150 1/9/1997 10:45 368.40 -8.01 -1.31 16 25.7 300 1/17/1997 10:45 366.87 -7.91 -0.67 16 25.7 270 2/6/1997 14:00 344.87 -8.33 -1.54 3 4.8 45 2/21/1997 10:40 359.65 -8.00 -1.10 7 11.3 270 4/3/1997 12:30 387.41 -8.03 -0.38 3 4.8 360 5/1/1997 11:45 360.62 -8.04 -1.20 13 20.9 270 5/14/1997 10:30 354.48 -7.69 0.20 6 9.7 315 5/22/1997 11:30 354.31 -7.63 -0.56 0 0.0 0 7/11/1997 11:30 NM -7.41 -0.15 3 4.8 300 7/25/1997 12:42 NM -7.37 -0.42 2 3.2 135 8/21/1997 10:45 356.71 -7.43 NM 18 29.0 270 9/11/1997 12:15 365.96 -7.39 -0.15 4 6.4 135 10/10/1997 11:00 354.35 -7.46 -0.42 6 9.7 270 10/23/1997 11:20 354.87 -7.64 -1.84 11 17.7 225 11/20/1997 11:13 354.91 -7.94 -2.28 7 11.3 240 12/5/1997 12:00 359.29 -7.97 -2.74 19 30.6 315 12/18/1997 11:00 355.01 -7.80 -1.99 5 8.0 300 1/8/1998 11:10 359.51 -8.36 -2.80 15 24.1 315 2/6/1998 10:40 358.44 -8.07 -0.12 12 19.3 315 2/26/1998 10:45 363.41 -8.23 -3.04 25 40.2 270 4/2/1998 10:35 360.45 -8.22 -2.78 10 16.1 60 5/15/1998 10:15 365.75 -8.29 -2.39 10 16.1 300 5/29/1998 10:40 359.26 -7.75 -0.87 2 3.2 120 6/4/1998 10:15 357.75 -7.83 -2.08 2 3.2 135 6/26/1998 11:30 353.98 -7.62 -2.19 8 12.9 240 8/7/1998 10:00 353.18 -7.54 -0.75 1 1.6 60 8/28/1998 10:45 351.71 -7.53 0.03 1 1.6 270 9/25/1998 10:45 351.21 -7.55 0.12 6 9.7 270 10/15/1998 10:45 351.79 -7.61 -0.65 5 8.0 300 11/29/1998 10:45 358.92 -7.82 -1.38 3 4.8 315 12/3/1998 10:45 356.18 -7.78 -1.08 4 6.4 135 12/17/1998 11:30 355.48 -7.76 -0.74 20 32.2 315 1/15/1999 10:45 358.42 -7.95 -1.19 25 40 270 2/26/1999 10:40 364.83 -8.07 -1.13 10 16 240 4/2/1999 10:50 366.63 -8.22 -1.75 2 3.2 135 4/22/1999 11:40 365.81 -8.26 -1.80 2 3.2 135 5/6/1999 10:45 366.46 -8.13 -0.99 13 20.8 270 5/21/1999 11:10 362.86 -7.87 0.13 2 3.2 225 6/3/1999 10:35 374.59 -7.80 0.25 3 4.8 315 6/18/1999 10:30 366.86 -7.74 -0.06 13 20.8 270 7/1/1999 10:40 354.62 -7.65 -0.77 6 9.6 270 7/29/1999 10:45 363.43 -7.63 -1.30 7 11.2 270 9/3/1999 10:45 369.84 -7.49 -0.99 6 9.6 235 9/16/1999 10:35 365.98 -7.23 -0.63 3 4.8 45 10/15/1999 10:50 363.88 -7.62 -0.49 6 9.6 135 11/5/1999 10:15 367.51 -7.75 -1.60 9 14.4 240 NM -- not measured Mixing ratio values three for dates in 1997 are not plotted because they are more than 2 s.d. from the mean of all values. These dates are 2/6/97, 4/3/97, and 9/11/97.