# file: spo_CCl4_MM.dat # # Atmospheric measurements of CCl4 (Carbon Tetrachloride, CT) # # Measurements are from the NOAA/ESRL/GMD/HATS flask program # (http://www.esrl.noaa.gov/gmd/hats/flask/flasks.html). # Instrument ID: Otto # # Location: SPO -- South Pole, Antarctica -- 89.98 S, 24.80 W, 2810 m Elev. # See http://www.esrl.noaa.gov/gmd/dv/site/site_table.html#hats_flask for # more information about flask sampling sites. # # The data reported are from samples collected approximately once per week in # matching, concurrent, flask pairs and later analyzed on a gas chromatograph # with electron capture detection (GC-ECD) located in Boulder, Colorado, USA. # This system uses two standard reference gases for calibration and has been # in operation since very early in 1995. # # CCl4 loss during storage in stainless-steel canisters arises most commonly at # high-latitude and/or high-altitude sites where the air is dry (i.e. ALT, BRW, # MLO, NWR, and SPO -- especially in winter). Extra efforts have been made to # flag samples suspected of suffering from this known artifact, thereby barring # them from inclusion in monthly mean estimates. The user is cautioned, # however, that small biases to the low side may nevertheless remain. # # These data represent monthly mean estimates computed using those data marked # with a 0 in flag column 7 of the companion file named "spo_CCl4_All.dat". With # flask samples collected only weekly on average, monthly sampling statistics # are poor at best. As a result, the error reported is either the standard # deviation of the mean or a floor single-sample precision estimate. # # PIs: Dr. James W. Elkins, Dr. Bradley D. Hall, # Debra J. Mondeel, J. David Nance # # National Oceanic and Atmospheric Administration (NOAA) # Earth System Research Laboratory (ESRL) # 325 Broadway, R/GMD1 # Boulder, CO 80305-3328 # # Email: James.W.Elkins@noaa.gov; Bradley.Hall@noaa.gov # Phone: (303) 497-6224 (303) 497-7011 # # Email: Debra.J.Mondeel@noaa.gov; David.Nance@noaa.gov # Phone: (303) 497-6013 (303) 497-7002 # # Fax: (303) 497-6290 # # Data use policy: # If you use this data in a publication or report, we would appreciate that you # contact the principal investigators (PIs) first and discuss your interests. # The PIs can discuss the quality of the data and any potential problems with # its analysis. Please contact the PIs for more information. The data should # be cited in presentations or publications along the following lines: Carbon Tetrachloride # data from the NOAA/ESRL halocarbons flask program. # # Calibration scale: NOAA 2008 # See http://www.esrl.noaa.gov/gmd/ccl/scales.html for more information about # calibration scales. # # Units: ppt # # Missing value: "nan" # # Data Columns: # yr Year # mon Month # m Monthly mean concentration of CCl4 in ppt # sd Standard deviation of the mean (or single-sample precision value) # n Number of samples # CCl4ottoSPOyr CCl4ottoSPOmon CCl4ottoSPOm CCl4ottoSPOsd CCl4ottoSPOn 1998 1 nan nan 0 1998 2 nan nan 0 1998 3 nan nan 0 1998 4 nan nan 0 1998 5 nan nan 0 1998 6 nan nan 0 1998 7 nan nan 0 1998 8 nan nan 0 1998 9 nan nan 0 1998 10 nan nan 0 1998 11 nan nan 0 1998 12 100.650 0.260 1 1999 1 nan nan 0 1999 2 nan nan 0 1999 3 nan nan 0 1999 4 nan nan 0 1999 5 nan nan 0 1999 6 nan nan 0 1999 7 nan nan 0 1999 8 nan nan 0 1999 9 nan nan 0 1999 10 nan nan 0 1999 11 nan nan 0 1999 12 nan nan 0 2000 1 nan nan 0 2000 2 nan nan 0 2000 3 nan nan 0 2000 4 nan nan 0 2000 5 nan nan 0 2000 6 nan nan 0 2000 7 nan nan 0 2000 8 nan nan 0 2000 9 nan nan 0 2000 10 nan nan 0 2000 11 98.170 0.268 1 2000 12 98.000 0.304 1 2001 1 nan nan 0 2001 2 nan nan 0 2001 3 nan nan 0 2001 4 nan nan 0 2001 5 nan nan 0 2001 6 nan nan 0 2001 7 nan nan 0 2001 8 nan nan 0 2001 9 nan nan 0 2001 10 nan nan 0 2001 11 96.824 0.295 2 2001 12 96.484 0.332 2 2002 1 97.267 0.361 2 2002 2 96.820 0.778 1 2002 3 97.220 0.202 1 2002 4 96.540 0.516 1 2002 5 nan nan 0 2002 6 96.660 0.539 1 2002 7 nan nan 0 2002 8 96.110 0.301 1 2002 9 95.700 0.232 1 2002 10 96.370 0.224 1 2002 11 95.450 0.232 1 2002 12 95.713 0.226 2 2003 1 95.390 0.203 1 2003 2 95.530 0.211 1 2003 3 95.420 0.195 1 2003 4 nan nan 0 2003 5 94.950 0.244 1 2003 6 95.310 0.395 1 2003 7 94.650 0.358 1 2003 8 94.890 0.374 1 2003 9 nan nan 0 2003 10 nan nan 0 2003 11 94.417 0.615 2 2003 12 94.879 0.212 2 2004 1 94.271 0.186 2 2004 2 94.621 0.375 2 2004 3 94.210 0.206 1 2004 4 nan nan 0 2004 5 94.470 0.249 1 2004 6 94.360 0.218 1 2004 7 nan nan 0 2004 8 94.050 0.240 1 2004 9 94.130 0.218 1 2004 10 94.350 0.208 1 2004 11 93.940 0.405 1 2004 12 93.696 0.453 2 2005 1 93.780 0.243 1 2005 2 nan nan 0 2005 3 93.290 0.377 1 2005 4 93.180 0.327 1 2005 5 93.160 0.401 1 2005 6 92.690 0.605 1 2005 7 93.220 0.201 1 2005 8 nan nan 0 2005 9 92.730 0.137 1 2005 10 93.480 0.180 1 2005 11 92.720 0.142 1 2005 12 92.476 0.533 4 2006 1 92.455 0.146 4 2006 2 92.430 0.213 1 2006 3 92.160 0.372 1 2006 4 91.850 0.449 1 2006 5 91.870 0.344 1 2006 6 91.230 0.613 1 2006 7 91.960 0.279 1 2006 8 91.840 0.309 1 2006 9 91.614 0.242 2 2006 10 91.649 0.435 3 2006 11 91.610 0.208 1 2006 12 91.899 0.148 2 2007 1 91.837 0.325 2 2007 2 91.483 0.353 2 2007 3 91.540 0.341 1 2007 4 91.060 0.226 1 2007 5 91.410 0.227 1 2007 6 90.748 0.676 4 2007 7 90.930 0.369 1 2007 8 90.536 0.587 2 2007 9 nan nan 0 2007 10 90.476 0.205 2 2007 11 90.705 0.243 2 2007 12 90.113 0.184 3 2008 1 90.138 0.229 3 2008 2 89.987 0.969 2 2008 3 89.880 0.292 1 2008 4 89.920 0.252 1 2008 5 89.370 0.247 1 2008 6 89.569 0.353 3 2008 7 89.250 0.228 1 2008 8 89.402 0.263 2 2008 9 89.030 0.177 1 2008 10 88.911 0.220 3 2008 11 88.872 0.312 3 2008 12 88.773 0.171 3 2009 1 88.808 0.289 2 2009 2 88.580 0.785 2 2009 3 89.040 0.256 1 2009 4 88.459 0.375 2 2009 5 nan nan 0 2009 6 88.389 0.228 2 2009 7 88.320 0.229 1 2009 8 88.480 0.173 1 2009 9 88.600 0.314 1 2009 10 87.780 0.272 2 2009 11 88.129 0.228 2 2009 12 88.298 0.393 3 2010 1 88.016 0.438 2 2010 2 87.794 0.247 2 2010 3 nan nan 0 2010 4 87.318 0.877 2 2010 5 87.500 0.246 1 2010 6 86.910 0.603 1 2010 7 87.130 0.250 1 2010 8 86.780 0.249 1 2010 9 86.700 0.228 1 2010 10 86.755 0.275 3 2010 11 86.377 0.714 2 2010 12 86.486 0.413 4 2011 1 86.781 0.215 2 2011 2 86.189 0.286 2 2011 3 85.770 0.207 3 2011 4 85.620 0.380 1 2011 5 nan nan 0 2011 6 nan nan 0 2011 7 nan nan 0 2011 8 85.241 0.318 2 2011 9 nan nan 0 2011 10 84.860 0.377 1 2011 11 85.270 0.912 2 2011 12 85.072 0.139 2 2012 1 85.268 0.197 4 2012 2 85.161 0.201 3 2012 3 85.080 0.438 1 2012 4 85.109 0.870 2 2012 5 84.930 0.171 1 2012 6 84.855 0.622 2 2012 7 84.720 0.139 1 2012 8 83.888 0.518 3 2012 9 83.570 0.432 1 2012 10 83.760 0.584 1 2012 11 84.319 0.195 2 2012 12 84.186 0.551 2 2013 1 nan nan 0 2013 2 83.890 0.751 1 2013 3 83.710 0.472 1 2013 4 83.275 0.254 2 2013 5 83.600 0.229 1 2013 6 83.042 0.256 2 2013 7 82.630 1.573 1 2013 8 83.488 0.412 2 2013 9 83.580 0.273 1 2013 10 83.291 0.169 2 2013 11 83.029 0.316 3 2013 12 83.255 0.235 3 2014 1 83.230 0.375 1 2014 2 82.945 0.444 2 2014 3 82.400 0.353 1 2014 4 82.020 0.325 1 2014 5 nan nan 0 2014 6 81.885 0.267 3 2014 7 81.246 0.348 2 2014 8 81.973 0.172 2 2014 9 81.514 0.501 2 2014 10 81.761 0.410 2 2014 11 81.270 0.273 1 2014 12 81.921 0.714 2 2015 1 81.170 0.775 1 2015 2 81.368 0.287 2 2015 3 81.400 0.365 1 2015 4 81.500 0.783 1 2015 5 nan nan 0 2015 6 81.028 0.252 2 2015 7 nan nan 0 2015 8 80.406 0.322 3 2015 9 79.980 0.439 1 2015 10 80.427 0.785 2 2015 11 nan nan 0 2015 12 80.629 0.395 2 2016 1 nan nan 0 2016 2 80.179 0.297 4 2016 3 79.980 0.316 1 2016 4 79.263 0.375 2 2016 5 79.590 0.297 1 2016 6 79.466 0.400 2 2016 7 79.410 0.670 1 2016 8 79.592 0.336 2 2016 9 79.640 0.459 1 2016 10 79.290 0.342 2 2016 11 79.496 0.315 2 2016 12 79.068 0.361 3 2017 1 nan nan 0 2017 2 78.891 0.253 4 2017 3 78.490 0.198 1 2017 4 78.215 0.301 2 2017 5 78.210 0.192 1 2017 6 78.080 0.416 1 2017 7 78.140 0.616 1 2017 8 77.787 0.519 3 2017 9 78.369 0.236 2 2017 10 78.169 0.262 2 2017 11 78.330 0.217 1 2017 12 78.526 0.269 2 2018 1 78.206 0.391 3 2018 2 78.200 0.272 5 2018 3 78.186 0.437 2 2018 4 77.636 0.629 2 2018 5 77.660 1.053 1 2018 6 77.940 0.446 4 2018 7 78.470 0.886 1 2018 8 78.105 0.984 2 2018 9 77.072 0.735 2 2018 10 76.993 0.715 3 2018 11 76.939 0.740 2 2018 12 77.961 0.375 4 2019 1 77.970 0.461 1 2019 2 77.800 0.223 1 2019 3 nan nan 0 2019 4 nan nan 0 2019 5 nan nan 0 2019 6 nan nan 0 2019 7 nan nan 0 2019 8 nan nan 0 2019 9 nan nan 0 2019 10 nan nan 0 2019 11 nan nan 0 2019 12 nan nan 0