# file: thd_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: THD -- Trinidad Head, California -- 41.05 N, 124.15 W, 107 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 "thd_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 # CCl4ottoTHDyr CCl4ottoTHDmon CCl4ottoTHDm CCl4ottoTHDsd CCl4ottoTHDn 2002 1 nan nan 0 2002 2 nan nan 0 2002 3 99.256 0.225 3 2002 4 98.850 0.535 6 2002 5 98.515 0.216 8 2002 6 98.692 0.144 4 2002 7 98.616 0.547 5 2002 8 97.946 0.173 4 2002 9 98.521 0.263 4 2002 10 98.296 0.192 4 2002 11 98.430 0.174 1 2002 12 nan nan 0 2003 1 97.815 0.143 3 2003 2 97.622 0.154 4 2003 3 97.632 0.209 4 2003 4 97.594 0.120 4 2003 5 97.515 0.230 6 2003 6 97.362 0.193 6 2003 7 97.104 0.212 4 2003 8 96.908 0.285 4 2003 9 96.910 0.263 4 2003 10 96.976 0.233 5 2003 11 96.889 0.464 4 2003 12 96.879 0.141 4 2004 1 96.838 0.243 4 2004 2 96.511 0.126 4 2004 3 96.580 0.171 5 2004 4 96.424 0.158 4 2004 5 96.604 0.192 4 2004 6 96.429 0.190 5 2004 7 96.125 0.182 4 2004 8 96.382 0.202 3 2004 9 95.968 0.274 5 2004 10 95.961 0.190 4 2004 11 95.254 0.288 2 2004 12 95.849 0.183 5 2005 1 95.823 0.119 3 2005 2 95.655 0.189 4 2005 3 95.702 0.175 3 2005 4 95.510 0.166 4 2005 5 95.669 0.148 5 2005 6 95.329 0.201 4 2005 7 95.305 0.399 4 2005 8 94.751 0.295 5 2005 9 94.706 0.191 4 2005 10 94.777 0.371 4 2005 11 94.900 0.219 1 2005 12 95.509 0.340 2 2006 1 94.623 0.177 2 2006 2 94.683 0.295 3 2006 3 94.687 0.276 2 2006 4 94.359 0.239 4 2006 5 94.003 0.307 5 2006 6 94.136 0.167 4 2006 7 93.954 0.262 4 2006 8 93.618 0.177 5 2006 9 93.365 0.151 3 2006 10 93.636 0.238 4 2006 11 93.575 0.167 5 2006 12 93.790 0.187 3 2007 1 93.445 0.296 3 2007 2 93.248 0.270 4 2007 3 93.197 0.248 4 2007 4 93.369 0.195 3 2007 5 92.769 0.166 3 2007 6 93.252 0.220 4 2007 7 93.019 0.226 3 2007 8 93.023 0.255 3 2007 9 92.659 0.218 3 2007 10 92.388 0.229 4 2007 11 92.249 0.270 3 2007 12 92.098 0.227 3 2008 1 92.090 0.213 3 2008 2 92.036 0.194 4 2008 3 91.787 0.203 2 2008 4 91.671 0.225 4 2008 5 91.929 0.225 4 2008 6 91.535 0.213 5 2008 7 91.080 0.268 4 2008 8 91.035 0.249 4 2008 9 90.879 0.227 4 2008 10 90.701 0.217 4 2008 11 90.796 0.243 5 2008 12 90.834 0.270 4 2009 1 90.328 0.376 4 2009 2 90.040 0.224 5 2009 3 90.192 0.211 3 2009 4 89.926 0.192 4 2009 5 89.859 0.278 2 2009 6 89.994 0.225 4 2009 7 89.645 0.236 4 2009 8 89.731 0.171 5 2009 9 89.795 0.345 3 2009 10 90.039 0.285 3 2009 11 89.744 0.266 3 2009 12 89.781 0.213 4 2010 1 89.687 0.214 2 2010 2 89.491 0.235 3 2010 3 89.427 0.210 3 2010 4 89.586 0.240 4 2010 5 89.510 0.195 4 2010 6 89.167 0.235 4 2010 7 88.830 0.211 5 2010 8 88.997 0.189 3 2010 9 88.855 0.172 3 2010 10 88.922 0.352 5 2010 11 88.355 0.193 2 2010 12 88.672 0.175 4 2011 1 88.609 0.191 3 2011 2 88.263 0.223 4 2011 3 88.442 0.189 4 2011 4 88.242 0.367 4 2011 5 87.936 0.253 4 2011 6 87.999 0.193 3 2011 7 87.620 0.293 5 2011 8 87.339 0.192 4 2011 9 87.119 0.127 5 2011 10 87.200 0.211 4 2011 11 87.263 0.146 3 2011 12 87.171 0.198 5 2012 1 87.273 0.307 3 2012 2 86.676 0.170 4 2012 3 86.730 0.178 2 2012 4 86.684 0.175 4 2012 5 86.564 0.274 4 2012 6 86.965 0.204 5 2012 7 86.475 0.303 3 2012 8 86.473 0.353 3 2012 9 86.093 0.136 4 2012 10 86.442 0.357 4 2012 11 86.465 0.162 4 2012 12 86.309 0.541 3 2013 1 85.950 0.322 1 2013 2 86.015 0.324 3 2013 3 85.925 0.248 5 2013 4 85.771 0.280 4 2013 5 85.478 0.293 4 2013 6 85.946 0.207 4 2013 7 85.208 0.297 3 2013 8 85.199 0.353 2 2013 9 nan nan 0 2013 10 nan nan 0 2013 11 84.810 0.182 2 2013 12 84.567 0.281 5 2014 1 84.790 0.317 1 2014 2 85.030 0.217 4 2014 3 nan nan 0 2014 4 nan nan 0 2014 5 nan nan 0 2014 6 nan nan 0 2014 7 84.433 0.319 3 2014 8 84.305 0.275 5 2014 9 83.930 0.397 4 2014 10 84.311 0.174 4 2014 11 84.370 0.279 2 2014 12 nan nan 0 2015 1 83.760 0.253 3 2015 2 83.502 0.233 5 2015 3 83.410 0.515 3 2015 4 83.126 0.394 3 2015 5 83.145 0.322 4 2015 6 83.055 0.170 4 2015 7 83.341 0.302 4 2015 8 83.049 0.233 5 2015 9 82.967 0.195 4 2015 10 83.327 0.251 4 2015 11 82.886 0.166 5 2015 12 82.847 0.346 4 2016 1 82.278 0.495 3 2016 2 82.297 0.403 3 2016 3 82.688 0.472 3 2016 4 82.338 0.274 5 2016 5 82.449 0.483 3 2016 6 82.547 0.482 3 2016 7 82.219 0.409 3 2016 8 81.701 0.261 2 2016 9 82.091 0.603 3 2016 10 81.918 0.247 2 2016 11 82.038 0.220 4 2016 12 82.225 0.345 3 2017 1 82.545 0.526 4 2017 2 82.055 0.444 3 2017 3 81.913 0.308 5 2017 4 82.258 0.460 4 2017 5 81.678 0.882 4 2017 6 81.910 0.789 5 2017 7 81.678 0.980 3 2017 8 80.963 0.348 4 2017 9 81.067 0.712 5 2017 10 81.340 0.502 4 2017 11 81.615 0.625 3 2017 12 80.709 0.752 4 2018 1 80.985 0.506 3 2018 2 80.874 0.398 3 2018 3 79.876 0.343 5 2018 4 80.215 0.910 3 2018 5 80.106 0.530 5 2018 6 80.588 0.665 3 2018 7 nan nan 0 2018 8 79.311 0.389 2 2018 9 79.269 0.638 4 2018 10 79.685 0.541 4 2018 11 80.319 0.347 3 2018 12 79.955 0.674 5 2019 1 79.616 0.689 3 2019 2 79.327 0.346 4 2019 3 80.071 0.532 3 2019 4 79.355 0.191 4 2019 5 79.705 0.531 5 2019 6 79.513 0.674 4 2019 7 79.041 0.397 3 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