# file: brw_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: BRW -- Barrow, Alaska -- 71.32 N, 156.61 W, 11 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 "brw_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 # CCl4ottoBRWyr CCl4ottoBRWmon CCl4ottoBRWm CCl4ottoBRWsd CCl4ottoBRWn 1996 1 nan nan 0 1996 2 nan nan 0 1996 3 nan nan 0 1996 4 105.247 0.337 2 1996 5 104.994 0.336 5 1996 6 105.473 0.409 3 1996 7 105.023 0.288 3 1996 8 104.803 0.457 3 1996 9 104.335 0.784 2 1996 10 nan nan 0 1996 11 104.819 0.590 3 1996 12 nan nan 0 1997 1 nan nan 0 1997 2 104.249 0.324 3 1997 3 104.041 0.441 2 1997 4 104.420 0.641 1 1997 5 104.539 0.320 5 1997 6 104.276 0.387 4 1997 7 103.916 0.334 3 1997 8 103.727 0.336 5 1997 9 nan nan 0 1997 10 103.057 0.366 2 1997 11 103.310 0.443 2 1997 12 103.940 0.825 1 1998 1 103.370 0.474 1 1998 2 103.748 0.422 2 1998 3 104.120 0.400 1 1998 4 104.116 0.359 2 1998 5 103.537 0.715 4 1998 6 103.168 0.443 2 1998 7 102.860 0.258 5 1998 8 102.489 0.474 2 1998 9 102.453 0.281 2 1998 10 102.653 0.230 2 1998 11 102.368 0.286 2 1998 12 102.606 0.403 2 1999 1 102.081 0.353 2 1999 2 101.990 0.422 1 1999 3 101.901 0.283 2 1999 4 102.096 0.212 3 1999 5 102.025 0.211 4 1999 6 101.780 0.192 2 1999 7 101.513 0.341 4 1999 8 100.999 0.515 4 1999 9 101.017 0.162 3 1999 10 101.020 0.250 5 1999 11 100.721 0.161 2 1999 12 100.481 0.264 3 2000 1 101.141 0.268 3 2000 2 100.640 0.431 2 2000 3 nan nan 0 2000 4 100.570 0.461 1 2000 5 100.201 0.381 3 2000 6 100.603 0.460 4 2000 7 99.760 0.566 2 2000 8 100.209 0.698 3 2000 9 99.889 0.330 4 2000 10 100.075 0.224 3 2000 11 100.238 0.385 4 2000 12 100.666 0.215 3 2001 1 100.254 0.289 3 2001 2 99.487 0.530 2 2001 3 99.744 0.248 2 2001 4 99.890 0.231 1 2001 5 99.581 0.241 3 2001 6 99.710 0.169 5 2001 7 99.385 0.157 4 2001 8 99.157 0.232 3 2001 9 99.042 0.227 4 2001 10 99.052 0.226 2 2001 11 99.180 0.199 4 2001 12 98.740 0.252 1 2002 1 99.030 0.212 1 2002 2 98.930 0.256 1 2002 3 98.945 0.192 4 2002 4 98.277 0.544 2 2002 5 98.504 0.266 4 2002 6 98.538 0.185 3 2002 7 98.306 0.228 3 2002 8 98.422 0.284 2 2002 9 97.726 0.207 2 2002 10 97.893 0.270 3 2002 11 98.007 0.407 3 2002 12 98.060 0.555 1 2003 1 nan nan 0 2003 2 97.743 0.275 3 2003 3 97.316 0.461 3 2003 4 97.490 0.481 2 2003 5 97.394 0.318 7 2003 6 97.341 0.417 2 2003 7 97.175 0.343 3 2003 8 96.929 0.460 5 2003 9 96.611 0.123 4 2003 10 96.362 0.351 3 2003 11 96.613 0.126 2 2003 12 nan nan 0 2004 1 97.020 0.171 1 2004 2 96.274 0.385 3 2004 3 96.320 0.406 1 2004 4 96.664 0.359 4 2004 5 96.530 0.289 1 2004 6 96.331 0.209 4 2004 7 96.085 0.304 4 2004 8 95.772 0.247 4 2004 9 95.744 0.231 3 2004 10 95.605 0.249 4 2004 11 94.944 0.402 3 2004 12 95.816 0.264 2 2005 1 95.793 0.255 3 2005 2 95.502 0.167 3 2005 3 95.172 0.218 3 2005 4 95.174 0.410 3 2005 5 95.326 0.247 4 2005 6 95.226 0.292 5 2005 7 95.068 0.291 4 2005 8 94.768 0.351 3 2005 9 94.577 0.151 5 2005 10 94.511 0.193 4 2005 11 nan nan 0 2005 12 94.190 0.601 1 2006 1 nan nan 0 2006 2 nan nan 0 2006 3 nan nan 0 2006 4 93.833 0.446 2 2006 5 93.975 0.190 4 2006 6 93.997 0.311 3 2006 7 93.648 0.137 4 2006 8 93.425 0.194 4 2006 9 93.316 0.188 4 2006 10 93.141 0.278 4 2006 11 93.888 0.304 2 2006 12 nan nan 0 2007 1 92.780 0.410 1 2007 2 nan nan 0 2007 3 92.806 0.424 2 2007 4 92.389 0.204 3 2007 5 93.030 0.343 1 2007 6 93.245 0.242 3 2007 7 93.091 0.370 2 2007 8 93.090 0.271 2 2007 9 92.383 0.495 4 2007 10 91.711 0.304 2 2007 11 91.878 0.460 2 2007 12 92.080 0.484 1 2008 1 nan nan 0 2008 2 91.533 0.305 2 2008 3 nan nan 0 2008 4 92.230 0.210 1 2008 5 91.829 0.238 5 2008 6 91.701 0.281 4 2008 7 91.195 0.261 4 2008 8 91.001 0.410 2 2008 9 90.584 0.214 2 2008 10 90.647 0.177 3 2008 11 90.255 0.242 2 2008 12 89.819 0.180 4 2009 1 90.040 0.366 1 2009 2 89.845 0.299 3 2009 3 89.893 0.189 2 2009 4 89.790 0.273 2 2009 5 89.823 0.245 4 2009 6 89.683 0.213 4 2009 7 89.648 0.240 4 2009 8 89.648 0.149 4 2009 9 89.507 0.157 4 2009 10 89.799 0.168 2 2009 11 89.725 0.417 2 2009 12 89.399 0.319 3 2010 1 89.512 0.396 2 2010 2 89.604 0.204 2 2010 3 88.757 0.233 4 2010 4 89.365 0.220 5 2010 5 89.396 0.226 4 2010 6 89.100 0.226 3 2010 7 88.854 0.171 5 2010 8 88.884 0.217 4 2010 9 88.435 0.217 3 2010 10 88.348 0.115 3 2010 11 88.248 0.200 4 2010 12 88.573 0.221 3 2011 1 88.220 0.334 1 2011 2 88.171 0.198 3 2011 3 88.201 0.491 4 2011 4 87.327 0.188 2 2011 5 87.650 0.269 2 2011 6 87.561 0.191 4 2011 7 87.543 0.212 5 2011 8 87.240 0.193 3 2011 9 87.116 0.160 3 2011 10 86.866 0.196 4 2011 11 87.054 0.248 2 2011 12 87.202 0.195 2 2012 1 nan nan 0 2012 2 86.349 0.449 3 2012 3 nan nan 0 2012 4 86.748 0.228 2 2012 5 86.837 0.160 5 2012 6 86.804 0.179 4 2012 7 86.503 0.183 3 2012 8 86.196 0.207 5 2012 9 86.350 0.234 4 2012 10 86.126 0.279 4 2012 11 86.180 0.202 5 2012 12 86.370 0.385 1 2013 1 nan nan 0 2013 2 nan nan 0 2013 3 86.416 0.287 2 2013 4 85.924 0.240 2 2013 5 85.831 0.238 3 2013 6 85.698 0.207 3 2013 7 85.460 0.233 5 2013 8 85.656 1.062 2 2013 9 nan nan 0 2013 10 nan nan 0 2013 11 nan nan 0 2013 12 nan nan 0 2014 1 nan nan 0 2014 2 84.860 0.273 1 2014 3 84.853 0.336 3 2014 4 85.210 0.288 1 2014 5 nan nan 0 2014 6 84.524 0.523 2 2014 7 84.347 0.198 4 2014 8 84.237 0.531 3 2014 9 83.909 0.270 4 2014 10 84.095 0.305 4 2014 11 84.436 0.572 3 2014 12 84.070 0.276 3 2015 1 83.990 0.368 1 2015 2 84.250 0.226 1 2015 3 nan nan 0 2015 4 nan nan 0 2015 5 83.430 0.241 2 2015 6 83.402 0.210 5 2015 7 83.060 0.207 4 2015 8 83.054 0.308 3 2015 9 82.753 0.184 4 2015 10 82.868 0.193 4 2015 11 82.787 0.220 2 2015 12 nan nan 0 2016 1 82.627 0.467 2 2016 2 82.580 0.472 1 2016 3 nan nan 0 2016 4 81.894 0.366 2 2016 5 82.031 0.453 3 2016 6 82.366 0.385 4 2016 7 82.431 0.372 2 2016 8 82.175 0.347 4 2016 9 82.068 0.236 2 2016 10 81.751 0.467 2 2016 11 81.425 0.273 2 2016 12 82.126 0.555 2 2017 1 81.460 0.171 1 2017 2 80.790 0.535 1 2017 3 81.701 0.237 3 2017 4 81.364 0.420 4 2017 5 81.229 0.300 4 2017 6 81.188 0.877 2 2017 7 80.970 0.325 4 2017 8 81.101 0.567 4 2017 9 80.621 0.353 3 2017 10 81.088 0.360 4 2017 11 81.175 0.738 5 2017 12 80.680 0.632 4 2018 1 81.149 0.472 4 2018 2 80.040 0.187 1 2018 3 79.500 0.383 1 2018 4 80.556 0.484 4 2018 5 80.088 0.485 4 2018 6 79.562 0.242 2 2018 7 nan nan 0 2018 8 nan nan 0 2018 9 79.414 0.694 3 2018 10 79.206 0.688 5 2018 11 80.147 0.262 3 2018 12 79.648 1.041 2 2019 1 79.660 0.289 1 2019 2 79.590 0.559 2 2019 3 79.751 0.369 3 2019 4 78.625 0.416 4 2019 5 79.575 0.274 5 2019 6 79.444 0.337 4 2019 7 79.163 0.649 5 2019 8 79.080 0.219 1 2019 9 nan nan 0 2019 10 nan nan 0 2019 11 nan nan 0 2019 12 nan nan 0