# file: nwr_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: NWR -- Niwot Ridge, Colorado -- 40.05 N, 105.58 W, 3523 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 "nwr_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 # CCl4ottoNWRyr CCl4ottoNWRmon CCl4ottoNWRm CCl4ottoNWRsd CCl4ottoNWRn 1995 1 nan nan 0 1995 2 nan nan 0 1995 3 nan nan 0 1995 4 nan nan 0 1995 5 nan nan 0 1995 6 nan nan 0 1995 7 nan nan 0 1995 8 nan nan 0 1995 9 nan nan 0 1995 10 nan nan 0 1995 11 105.190 0.533 1 1995 12 nan nan 0 1996 1 105.220 0.546 1 1996 2 nan nan 0 1996 3 nan nan 0 1996 4 104.559 0.207 4 1996 5 104.504 0.325 3 1996 6 104.735 0.376 2 1996 7 104.921 0.408 5 1996 8 104.212 0.438 2 1996 9 104.298 0.304 2 1996 10 104.372 0.279 3 1996 11 103.725 0.445 3 1996 12 103.398 0.466 3 1997 1 nan nan 0 1997 2 103.535 0.424 2 1997 3 103.570 0.386 1 1997 4 103.430 0.309 2 1997 5 103.970 0.394 1 1997 6 103.345 0.687 5 1997 7 103.544 0.601 2 1997 8 103.225 0.460 3 1997 9 103.429 0.778 3 1997 10 102.782 0.411 3 1997 11 103.320 0.263 3 1997 12 nan nan 0 1998 1 103.330 0.521 1 1998 2 102.824 0.389 2 1998 3 103.360 0.342 1 1998 4 102.750 0.297 1 1998 5 102.252 0.301 2 1998 6 102.774 0.559 2 1998 7 102.956 0.457 3 1998 8 102.405 0.204 3 1998 9 102.523 0.227 4 1998 10 102.050 0.232 1 1998 11 102.291 0.332 2 1998 12 101.906 0.504 4 1999 1 101.190 0.291 1 1999 2 101.460 0.332 2 1999 3 101.507 0.261 3 1999 4 101.646 0.159 2 1999 5 101.438 0.281 4 1999 6 101.304 0.214 4 1999 7 100.992 0.215 3 1999 8 101.287 0.496 3 1999 9 101.209 0.409 3 1999 10 101.403 0.219 3 1999 11 100.671 0.293 4 1999 12 100.550 0.357 1 2000 1 100.745 0.387 4 2000 2 100.295 0.260 3 2000 3 100.139 0.283 2 2000 4 99.968 0.219 2 2000 5 100.219 0.448 3 2000 6 100.379 0.331 3 2000 7 99.801 0.697 3 2000 8 100.442 0.346 2 2000 9 99.740 0.444 4 2000 10 99.680 0.253 2 2000 11 100.015 0.274 3 2000 12 100.357 0.374 4 2001 1 99.827 0.425 4 2001 2 99.680 0.212 3 2001 3 99.317 0.672 2 2001 4 99.861 0.271 3 2001 5 99.923 0.806 2 2001 6 99.347 0.495 2 2001 7 99.711 0.322 3 2001 8 99.655 0.325 3 2001 9 99.364 0.423 3 2001 10 99.526 0.174 3 2001 11 nan nan 0 2001 12 99.257 0.396 2 2002 1 98.974 0.481 2 2002 2 98.544 0.324 2 2002 3 98.956 0.467 4 2002 4 99.270 0.426 1 2002 5 98.369 0.253 3 2002 6 98.528 0.450 3 2002 7 98.172 0.214 3 2002 8 98.070 0.192 2 2002 9 98.487 0.177 2 2002 10 98.600 0.206 1 2002 11 nan nan 0 2002 12 nan nan 0 2003 1 97.630 0.247 1 2003 2 97.750 0.205 1 2003 3 97.816 0.305 3 2003 4 97.103 0.230 2 2003 5 97.543 0.165 4 2003 6 97.650 0.221 1 2003 7 97.017 0.189 3 2003 8 96.530 0.132 1 2003 9 97.023 0.184 3 2003 10 97.096 0.177 2 2003 11 96.840 0.482 3 2003 12 96.617 0.219 2 2004 1 95.860 0.135 1 2004 2 95.410 0.624 1 2004 3 96.364 0.424 2 2004 4 96.312 0.177 3 2004 5 96.412 0.263 2 2004 6 95.850 0.340 1 2004 7 96.013 0.142 3 2004 8 95.990 0.185 1 2004 9 96.100 0.163 3 2004 10 95.896 0.214 4 2004 11 96.056 0.270 2 2004 12 95.859 0.160 4 2005 1 95.812 0.189 3 2005 2 95.614 0.209 2 2005 3 95.680 0.332 2 2005 4 95.044 0.299 3 2005 5 95.232 0.316 3 2005 6 nan nan 0 2005 7 94.961 0.178 4 2005 8 94.936 0.223 4 2005 9 94.860 0.180 1 2005 10 94.480 0.256 1 2005 11 95.058 0.167 4 2005 12 94.625 0.375 2 2006 1 94.839 0.610 3 2006 2 94.337 0.253 4 2006 3 94.308 0.177 2 2006 4 94.103 0.210 4 2006 5 93.865 0.448 3 2006 6 93.968 0.212 3 2006 7 93.791 0.205 5 2006 8 93.558 0.182 2 2006 9 93.589 0.182 3 2006 10 93.568 0.169 4 2006 11 93.615 0.252 4 2006 12 93.560 0.208 3 2007 1 93.445 0.220 2 2007 2 93.046 0.261 3 2007 3 92.450 0.613 1 2007 4 92.891 0.187 3 2007 5 93.071 0.185 4 2007 6 92.735 0.198 2 2007 7 92.973 0.278 3 2007 8 92.832 0.244 2 2007 9 92.925 0.313 2 2007 10 92.280 0.214 2 2007 11 92.576 0.361 2 2007 12 91.859 0.735 2 2008 1 91.775 0.308 3 2008 2 91.900 0.317 3 2008 3 92.350 0.257 1 2008 4 91.114 0.308 2 2008 5 92.090 0.333 1 2008 6 91.347 0.195 5 2008 7 91.068 0.163 2 2008 8 91.127 0.410 2 2008 9 90.710 0.195 4 2008 10 90.943 0.345 4 2008 11 91.009 0.306 4 2008 12 90.406 0.196 5 2009 1 90.104 0.178 2 2009 2 90.098 0.245 3 2009 3 89.589 0.263 2 2009 4 89.915 0.262 2 2009 5 89.504 0.290 2 2009 6 89.718 0.307 3 2009 7 89.594 0.249 4 2009 8 89.584 0.174 4 2009 9 89.870 0.172 4 2009 10 89.942 0.506 3 2009 11 89.643 0.220 4 2009 12 89.725 0.253 2 2010 1 89.520 0.310 3 2010 2 89.463 0.361 2 2010 3 89.363 0.174 3 2010 4 89.174 0.172 4 2010 5 89.283 0.219 2 2010 6 88.855 0.268 2 2010 7 88.734 0.241 3 2010 8 88.956 0.241 3 2010 9 88.901 0.182 4 2010 10 88.455 0.225 2 2010 11 88.287 0.245 3 2010 12 88.301 0.370 3 2011 1 88.032 0.278 4 2011 2 88.347 0.474 3 2011 3 88.167 0.287 3 2011 4 87.570 0.223 3 2011 5 87.501 0.310 2 2011 6 87.209 0.371 3 2011 7 87.365 0.196 2 2011 8 87.203 0.182 3 2011 9 87.612 0.395 3 2011 10 87.196 0.298 4 2011 11 87.208 0.417 4 2011 12 87.152 0.799 2 2012 1 87.000 0.415 1 2012 2 86.549 0.163 3 2012 3 nan nan 0 2012 4 86.014 0.375 2 2012 5 86.529 0.271 3 2012 6 86.290 0.156 1 2012 7 86.076 0.231 3 2012 8 86.138 0.276 3 2012 9 86.300 0.337 1 2012 10 86.299 0.354 3 2012 11 86.183 0.217 2 2012 12 85.751 0.636 2 2013 1 85.863 0.365 3 2013 2 nan nan 0 2013 3 85.195 0.355 2 2013 4 85.310 0.286 1 2013 5 85.414 0.361 2 2013 6 nan nan 0 2013 7 85.425 0.269 3 2013 8 85.570 1.529 1 2013 9 85.137 0.788 2 2013 10 84.450 3.767 1 2013 11 84.400 0.311 1 2013 12 84.250 1.013 2 2014 1 84.830 0.208 1 2014 2 84.286 0.564 3 2014 3 84.710 0.500 1 2014 4 84.590 1.273 1 2014 5 84.621 0.504 3 2014 6 84.610 0.264 3 2014 7 83.649 0.446 3 2014 8 83.956 0.342 3 2014 9 84.076 0.166 5 2014 10 83.996 0.436 3 2014 11 82.960 0.864 1 2014 12 83.906 0.261 5 2015 1 83.279 0.295 3 2015 2 nan nan 0 2015 3 83.196 0.195 2 2015 4 83.680 0.376 1 2015 5 83.090 0.258 1 2015 6 82.957 0.351 5 2015 7 82.850 0.305 4 2015 8 82.910 0.220 1 2015 9 82.869 0.252 4 2015 10 82.833 0.312 2 2015 11 81.898 0.219 2 2015 12 82.380 0.594 2 2016 1 82.611 0.269 2 2016 2 nan nan 0 2016 3 82.028 0.327 3 2016 4 81.892 0.866 2 2016 5 81.928 0.422 2 2016 6 81.743 0.374 4 2016 7 81.730 0.471 1 2016 8 81.435 0.388 2 2016 9 81.541 0.498 4 2016 10 81.312 0.339 2 2016 11 81.357 0.304 3 2016 12 81.713 0.326 2 2017 1 80.490 0.615 1 2017 2 81.300 0.352 1 2017 3 81.370 0.506 1 2017 4 81.640 0.383 1 2017 5 81.106 0.342 3 2017 6 81.063 0.354 2 2017 7 80.520 0.257 1 2017 8 80.600 0.704 3 2017 9 80.230 0.767 3 2017 10 80.090 0.353 2 2017 11 80.281 0.350 3 2017 12 79.974 0.301 3 2018 1 80.164 0.464 4 2018 2 79.410 0.400 1 2018 3 nan nan 0 2018 4 79.370 0.371 1 2018 5 79.511 0.425 2 2018 6 79.802 0.382 2 2018 7 nan nan 0 2018 8 78.713 0.622 2 2018 9 78.347 0.255 2 2018 10 79.137 0.573 2 2018 11 78.878 0.581 2 2018 12 78.421 0.737 3 2019 1 nan nan 0 2019 2 77.990 0.412 1 2019 3 79.100 1.073 1 2019 4 78.908 0.820 2 2019 5 79.098 0.377 3 2019 6 78.706 0.578 2 2019 7 78.677 0.362 5 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