# file: sum_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: SUM -- Summit, Greenland -- 72.58 N, 38.48 W, 3217.54 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 "sum_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 # CCl4ottoSUMyr CCl4ottoSUMmon CCl4ottoSUMm CCl4ottoSUMsd CCl4ottoSUMn 2004 1 nan nan 0 2004 2 nan nan 0 2004 3 nan nan 0 2004 4 nan nan 0 2004 5 nan nan 0 2004 6 95.942 0.233 2 2004 7 95.658 0.137 2 2004 8 95.600 0.200 1 2004 9 nan nan 0 2004 10 95.350 0.340 1 2004 11 95.544 0.188 3 2004 12 95.432 0.107 2 2005 1 95.454 0.199 2 2005 2 95.285 0.212 2 2005 3 95.266 0.292 2 2005 4 95.377 0.241 2 2005 5 95.354 0.245 2 2005 6 95.146 0.110 2 2005 7 nan nan 0 2005 8 94.653 0.168 4 2005 9 nan nan 0 2005 10 94.220 0.234 1 2005 11 94.547 0.207 2 2005 12 94.090 0.249 1 2006 1 94.338 0.176 2 2006 2 94.312 0.183 2 2006 3 93.590 0.943 1 2006 4 94.023 0.262 2 2006 5 94.148 0.227 4 2006 6 93.592 0.199 3 2006 7 nan nan 0 2006 8 93.319 0.197 2 2006 9 93.710 0.232 1 2006 10 93.480 0.253 2 2006 11 93.710 0.208 1 2006 12 93.549 0.262 2 2007 1 93.564 0.453 2 2007 2 92.838 0.373 2 2007 3 93.019 0.243 2 2007 4 92.410 0.759 1 2007 5 93.355 0.403 2 2007 6 92.803 0.319 2 2007 7 92.779 0.323 3 2007 8 92.545 0.450 4 2007 9 92.171 0.223 5 2007 10 91.990 0.332 2 2007 11 91.900 0.274 2 2007 12 91.820 0.186 2 2008 1 91.770 0.237 2 2008 2 91.605 0.213 2 2008 3 91.319 0.232 2 2008 4 90.918 0.283 2 2008 5 90.975 0.206 2 2008 6 90.840 0.226 6 2008 7 90.897 0.201 4 2008 8 90.656 0.217 4 2008 9 90.313 0.276 2 2008 10 90.260 0.318 2 2008 11 90.315 0.205 2 2008 12 90.212 0.246 2 2009 1 89.997 0.207 2 2009 2 90.030 0.209 1 2009 3 89.668 0.273 2 2009 4 89.560 0.233 1 2009 5 89.710 0.275 1 2009 6 89.831 0.215 2 2009 7 89.502 0.182 5 2009 8 89.678 0.199 5 2009 9 89.713 0.213 3 2009 10 89.737 0.185 2 2009 11 89.864 0.171 2 2009 12 89.570 0.262 2 2010 1 89.103 0.134 2 2010 2 89.388 0.245 2 2010 3 89.270 0.172 2 2010 4 89.300 0.172 2 2010 5 88.990 0.230 2 2010 6 88.707 0.184 2 2010 7 88.517 0.158 3 2010 8 87.788 0.201 3 2010 9 87.909 0.247 4 2010 10 87.750 0.214 2 2010 11 87.701 0.184 2 2010 12 87.817 0.226 2 2011 1 87.624 0.164 2 2011 2 87.419 0.188 2 2011 3 87.478 0.304 2 2011 4 87.348 0.196 2 2011 5 87.485 0.177 2 2011 6 87.355 0.144 2 2011 7 87.127 0.173 3 2011 8 86.842 0.222 3 2011 9 86.515 0.238 3 2011 10 86.680 0.235 1 2011 11 86.770 0.277 1 2011 12 86.792 0.481 2 2012 1 86.341 0.220 2 2012 2 86.250 0.438 1 2012 3 85.975 0.307 2 2012 4 86.142 0.219 2 2012 5 86.480 0.179 2 2012 6 85.857 0.353 2 2012 7 86.076 0.192 5 2012 8 nan nan 0 2012 9 85.100 0.381 2 2012 10 85.182 0.317 2 2012 11 85.419 0.201 2 2012 12 85.456 0.212 2 2013 1 85.050 0.287 1 2013 2 84.910 0.764 1 2013 3 84.928 0.146 2 2013 4 85.000 0.132 2 2013 5 84.720 0.207 2 2013 6 nan nan 0 2013 7 84.473 2.646 2 2013 8 84.612 0.209 2 2013 9 84.511 0.308 4 2013 10 84.655 0.295 2 2013 11 84.650 0.324 2 2013 12 84.700 0.248 3 2014 1 84.585 0.256 2 2014 2 84.138 0.224 2 2014 3 84.369 0.180 2 2014 4 84.075 0.456 2 2014 5 84.360 0.278 2 2014 6 83.640 0.186 1 2014 7 83.516 0.193 5 2014 8 83.447 0.202 3 2014 9 83.293 0.185 4 2014 10 83.493 0.392 2 2014 11 83.435 0.340 2 2014 12 83.050 0.309 2 2015 1 82.990 0.322 2 2015 2 82.952 0.359 2 2015 3 82.740 0.393 2 2015 4 82.625 0.579 2 2015 5 82.709 0.291 2 2015 6 nan nan 0 2015 7 82.354 0.260 2 2015 8 82.107 0.432 5 2015 9 81.727 0.467 4 2015 10 81.863 0.295 2 2015 11 81.935 0.322 2 2015 12 82.100 0.470 1 2016 1 81.665 0.458 2 2016 2 81.412 0.413 2 2016 3 81.390 0.488 1 2016 4 81.080 0.515 1 2016 5 nan nan 0 2016 6 80.974 0.665 2 2016 7 81.028 0.368 2 2016 8 80.953 0.341 5 2016 9 81.052 0.370 3 2016 10 80.830 0.295 2 2016 11 81.400 0.416 1 2016 12 81.100 0.428 2 2017 1 80.901 0.372 2 2017 2 80.462 0.364 2 2017 3 80.402 0.282 2 2017 4 80.749 0.311 2 2017 5 80.388 0.283 2 2017 6 80.260 0.402 1 2017 7 80.830 0.231 3 2017 8 80.060 0.339 5 2017 9 79.879 0.236 4 2017 10 80.047 0.467 2 2017 11 80.060 0.338 1 2017 12 79.605 0.194 2 2018 1 79.689 0.184 2 2018 2 79.610 0.253 1 2018 3 79.279 0.302 2 2018 4 79.190 0.325 2 2018 5 79.230 0.289 1 2018 6 nan nan 0 2018 7 79.132 0.206 3 2018 8 79.574 0.433 5 2018 9 79.630 0.263 4 2018 10 79.630 0.426 1 2018 11 79.870 0.221 1 2018 12 79.686 0.304 2 2019 1 79.681 0.297 2 2019 2 79.370 0.249 2 2019 3 79.178 0.260 2 2019 4 79.370 0.363 2 2019 5 79.209 0.262 2 2019 6 78.999 0.239 3 2019 7 79.260 0.549 1 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