# file: mlo_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: MLO -- Mauna Loa, Hawaii -- 19.54 N, 155.58 W, 3397 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 "mlo_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 # CCl4ottoMLOyr CCl4ottoMLOmon CCl4ottoMLOm CCl4ottoMLOsd CCl4ottoMLOn 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 10 105.090 0.348 1 1995 11 105.052 0.288 4 1995 12 104.620 0.383 1 1996 1 104.685 0.361 3 1996 2 105.370 0.679 1 1996 3 104.820 0.427 3 1996 4 105.457 0.466 3 1996 5 104.751 0.356 3 1996 6 105.249 0.847 4 1996 7 105.260 0.340 2 1996 8 105.413 0.434 3 1996 9 105.443 0.393 4 1996 10 104.933 0.595 4 1996 11 105.020 0.724 4 1996 12 103.891 0.652 3 1997 1 103.540 0.536 1 1997 2 104.093 1.117 2 1997 3 104.422 0.551 5 1997 4 104.126 0.246 3 1997 5 104.210 0.565 3 1997 6 104.297 0.569 5 1997 7 103.542 0.311 3 1997 8 103.725 0.263 3 1997 9 103.509 0.743 2 1997 10 103.677 0.317 3 1997 11 103.630 0.406 1 1997 12 103.749 0.356 4 1998 1 103.218 0.323 3 1998 2 103.160 0.348 1 1998 3 103.506 0.891 2 1998 4 103.532 0.519 3 1998 5 103.212 0.646 4 1998 6 103.106 0.315 3 1998 7 103.015 0.213 5 1998 8 103.463 0.591 4 1998 9 102.679 0.282 2 1998 10 102.591 0.467 3 1998 11 102.915 0.351 3 1998 12 102.617 0.589 4 1999 1 102.440 0.214 3 1999 2 102.855 0.501 5 1999 3 103.216 0.302 4 1999 4 102.276 0.383 3 1999 5 102.600 0.947 4 1999 6 102.287 0.766 5 1999 7 101.683 0.381 4 1999 8 101.507 0.295 5 1999 9 102.047 0.368 3 1999 10 101.843 0.585 4 1999 11 101.624 0.269 4 1999 12 101.851 0.694 5 2000 1 101.565 0.376 4 2000 2 101.294 0.406 5 2000 3 100.773 0.250 2 2000 4 100.270 0.839 3 2000 5 100.656 0.284 5 2000 6 100.536 0.574 3 2000 7 100.533 0.728 3 2000 8 101.016 0.831 4 2000 9 100.285 0.218 2 2000 10 100.508 0.795 4 2000 11 100.929 0.475 4 2000 12 100.519 0.435 3 2001 1 100.846 0.600 3 2001 2 100.455 0.151 3 2001 3 100.263 0.249 4 2001 4 100.597 0.260 4 2001 5 99.891 0.453 3 2001 6 100.046 0.577 4 2001 7 100.312 0.693 2 2001 8 99.378 0.362 3 2001 9 99.635 0.570 4 2001 10 100.092 0.737 3 2001 11 99.759 0.260 3 2001 12 99.483 0.735 2 2002 1 99.107 0.256 3 2002 2 99.163 0.325 3 2002 3 99.159 0.194 4 2002 4 98.851 0.237 3 2002 5 98.611 0.152 4 2002 6 98.605 0.459 5 2002 7 98.428 0.278 4 2002 8 98.579 0.524 4 2002 9 98.954 0.486 5 2002 10 98.624 0.513 3 2002 11 98.507 0.650 3 2002 12 98.842 1.419 3 2003 1 97.955 0.200 2 2003 2 97.607 0.467 4 2003 3 97.818 0.197 5 2003 4 97.995 0.235 4 2003 5 97.734 0.255 6 2003 6 97.762 0.282 5 2003 7 97.260 0.527 4 2003 8 96.802 0.761 3 2003 9 97.539 0.547 3 2003 10 97.283 0.207 3 2003 11 96.340 0.237 1 2003 12 96.405 0.248 2 2004 1 97.260 0.235 1 2004 2 96.683 0.537 5 2004 3 96.894 0.488 3 2004 4 96.994 0.187 4 2004 5 96.988 0.417 4 2004 6 96.631 0.510 5 2004 7 96.407 0.191 3 2004 8 96.460 0.216 4 2004 9 96.152 0.270 5 2004 10 96.542 0.739 4 2004 11 96.299 0.275 4 2004 12 96.144 0.244 4 2005 1 95.897 0.202 3 2005 2 95.899 0.359 4 2005 3 95.823 0.267 4 2005 4 95.641 0.222 3 2005 5 95.719 0.260 5 2005 6 95.730 0.351 4 2005 7 95.444 0.225 3 2005 8 95.209 0.282 5 2005 9 95.049 0.229 3 2005 10 95.351 0.152 4 2005 11 95.379 0.484 5 2005 12 94.843 0.417 2 2006 1 94.477 0.307 2 2006 2 94.400 0.224 5 2006 3 94.683 0.389 4 2006 4 94.215 0.435 4 2006 5 94.248 0.253 5 2006 6 93.832 0.675 4 2006 7 93.949 0.169 3 2006 8 93.811 0.244 5 2006 9 93.760 0.414 4 2006 10 93.983 0.259 4 2006 11 93.819 0.396 5 2006 12 93.828 0.489 4 2007 1 93.393 0.353 3 2007 2 93.577 0.263 4 2007 3 93.364 0.284 4 2007 4 93.027 0.272 4 2007 5 93.070 0.215 4 2007 6 93.325 0.256 4 2007 7 93.103 0.322 4 2007 8 92.986 0.233 5 2007 9 93.157 0.300 4 2007 10 92.739 0.470 3 2007 11 92.857 0.382 5 2007 12 92.400 0.325 3 2008 1 92.543 0.271 3 2008 2 92.062 0.239 5 2008 3 91.928 0.178 4 2008 4 91.447 0.337 4 2008 5 92.140 0.385 4 2008 6 91.838 0.355 4 2008 7 91.315 0.221 5 2008 8 91.097 0.474 3 2008 9 90.986 0.195 4 2008 10 91.064 0.323 5 2008 11 90.649 0.222 4 2008 12 90.537 0.264 4 2009 1 90.787 0.347 4 2009 2 90.371 0.281 4 2009 3 90.391 0.328 3 2009 4 90.223 0.196 5 2009 5 90.213 0.227 4 2009 6 90.007 0.335 3 2009 7 89.982 0.199 5 2009 8 89.863 0.176 2 2009 9 90.373 0.220 5 2009 10 90.198 0.199 4 2009 11 90.268 0.147 4 2009 12 90.081 0.297 3 2010 1 89.915 0.417 4 2010 2 90.341 0.430 3 2010 3 89.643 0.463 4 2010 4 90.042 0.250 3 2010 5 89.851 0.334 5 2010 6 89.172 0.238 2 2010 7 89.434 0.394 4 2010 8 89.569 0.234 5 2010 9 89.452 0.341 4 2010 10 89.480 0.196 3 2010 11 89.237 0.356 4 2010 12 88.788 0.418 4 2011 1 89.020 0.149 4 2011 2 88.752 0.293 4 2011 3 88.735 0.400 4 2011 4 88.661 0.251 3 2011 5 87.967 0.624 5 2011 6 87.861 0.427 4 2011 7 88.201 0.221 4 2011 8 87.967 0.323 5 2011 9 87.837 0.435 4 2011 10 87.706 0.212 4 2011 11 88.002 0.312 5 2011 12 87.405 0.229 4 2012 1 87.309 0.550 4 2012 2 86.960 0.594 2 2012 3 87.216 0.187 4 2012 4 87.213 0.258 5 2012 5 86.920 0.297 3 2012 6 87.246 0.195 4 2012 7 87.161 0.210 4 2012 8 86.641 0.211 4 2012 9 87.257 0.256 3 2012 10 86.911 0.470 5 2012 11 86.798 0.691 4 2012 12 85.978 0.503 4 2013 1 85.992 0.246 4 2013 2 86.604 0.344 4 2013 3 86.049 0.518 3 2013 4 86.053 0.327 5 2013 5 86.094 0.398 4 2013 6 85.897 0.352 3 2013 7 85.377 0.390 3 2013 8 86.011 0.408 3 2013 9 85.670 1.710 1 2013 10 85.572 2.040 2 2013 11 85.530 0.217 1 2013 12 85.224 0.209 4 2014 1 85.382 0.464 3 2014 2 85.318 0.356 4 2014 3 nan nan 0 2014 4 nan nan 0 2014 5 nan nan 0 2014 6 85.160 0.267 1 2014 7 84.542 0.487 4 2014 8 84.882 0.248 4 2014 9 84.597 0.485 5 2014 10 84.666 0.559 4 2014 11 85.058 0.251 3 2014 12 84.373 0.567 5 2015 1 84.212 0.628 4 2015 2 84.047 0.271 3 2015 3 83.936 0.594 4 2015 4 83.753 0.383 3 2015 5 83.577 0.327 3 2015 6 83.701 0.699 5 2015 7 83.610 0.608 3 2015 8 83.388 0.259 3 2015 9 83.613 0.222 5 2015 10 83.593 0.431 4 2015 11 83.550 0.269 2 2015 12 83.337 0.317 4 2016 1 83.013 0.270 3 2016 2 82.560 0.262 1 2016 3 83.210 1.156 2 2016 4 82.181 0.506 4 2016 5 82.665 0.337 5 2016 6 82.852 0.495 2 2016 7 82.540 0.690 1 2016 8 83.030 0.602 4 2016 9 82.960 0.356 1 2016 10 82.108 0.234 3 2016 11 82.390 0.294 3 2016 12 82.490 0.566 1 2017 1 82.867 0.566 2 2017 2 82.522 0.576 5 2017 3 82.130 0.487 4 2017 4 82.148 0.377 2 2017 5 82.447 0.592 3 2017 6 81.514 0.624 3 2017 7 81.461 0.713 5 2017 8 81.622 0.585 4 2017 9 81.748 0.696 3 2017 10 81.631 0.225 4 2017 11 81.348 0.884 3 2017 12 80.772 0.865 4 2018 1 81.156 0.809 5 2018 2 80.759 0.403 4 2018 3 80.579 0.480 3 2018 4 81.305 1.289 4 2018 5 80.431 1.223 2 2018 6 79.507 0.361 2 2018 7 nan nan 0 2018 8 79.930 0.707 2 2018 9 79.378 0.351 6 2018 10 79.962 0.624 8 2018 11 80.612 0.745 8 2018 12 80.583 0.683 3 2019 1 79.869 0.678 5 2019 2 79.649 0.503 3 2019 3 80.961 0.398 3 2019 4 80.020 0.560 5 2019 5 80.125 0.876 3 2019 6 79.962 0.702 4 2019 7 79.479 0.311 4 2019 8 79.713 0.600 4 2019 9 nan nan 0 2019 10 nan nan 0 2019 11 nan nan 0 2019 12 nan nan 0