Supplemental information for flask data provided from the Global Monitoring Division of the National Oceanic and Atmospheric Administrationís Global Monitoring Laboratory (NOAA/GML) as a result of analysis on gas chromatography with mass spectrometry instrumentation.

Measurements of halocarbons and other trace gases from flasks by gas chromatography with mass spectrometry detection.

Principal Investigators:

Data Usage

Follow this link for the GML/HATS data use policy.

Key to NOAA GCMS Flask Data Files:

Other notes:

Data are reported in this file only if the flask pairs had no statistically discernable difference at the 90-95% confidence level; if the standard deviation of the individual flasks within a pair is larger than the instrument precision determined by replicate injections, those results are not included here. Some additional culling of data is also based on relative magnitudes of flask differences within a pair.

Results for HFC-365mfc were published in Montzka et al. (2015) referenced to an incorrect calibration scale. Results referenced to the correct scale now appear in the posted file that includes measurement and derived emissions provided in that paper (JPhysChem2014 paper) and in web data files from NOAA HATS.

Compound listing:

Data available on GML/HATS website

Global surface mixing ratios, total tropospheric chlorine, bromine and fluorine

Known data issues:

We strive to provide the highest quality data possible for all periods. However, NOAA flask data obtained by the GCMS for some compounds analyzed during the 2008.5-2009.5 period are subject to some small biases owing to instrumental issues during that period. Data obtained for CH3CCl3 during that time period, for example, should not be used for deriving hydroxyl radical concentrations.

Furthermore, flask data for HCFC-142b shows some anomalously low values in recent years and specific seasons that are not yet flagged. Work is ongoing to discern the cause and apply the appropriate flags, but as of 2015, this is not yet completed.

For more information, see the articles in which initial portions of these data are published: