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Alexander, B, Vollmer MK, Jackson T, Weiss RF, Thiemens MH.  2001.  Stratospheric CO2 isotopic anomalies and SF6 and CFC tracer concentrations in the Arctic polar vortex. Geophysical Research Letters. 28:4103-4106.   10.1029/2001gl013692   AbstractWebsite

Isotopic measurements (delta O-17 and delta O-18) Of CO2 along with concentration measurements of SF6, CC1(3)F (CFC-11), CC1(2)F(2) (CFC-12) and CC1(2)FCC1F(2) (CFC-113) in stratospheric samples collected within the Arctic polar vortex are reported. These are the first simultaneous measurements of the concentration of fluorinated compounds and the complete oxygen isotopic composition Of CO2 in the middle atmosphere. A mass-independent anomaly in the oxygen isotopic composition Of CO2 is observed that arises from isotopic exchange with stratospheric O(D-1) derived from O-3 photolysis. The data exhibit a strong anti-correlation between the Delta O-17 (the degree of the mass-independent anomaly) and molecular tracer concentrations. The potential ability of tl-ris isotopic proxy to trace mesospheric and stratospheric transport is discussed.

Arnold, T, Ivy DJ, Harth CM, Vollmer MK, Muhle J, Salameh PK, Steele LP, Krummel PB, Wang RHJ, Young D, Lunder CR, Hermansen O, Rhee TS, Kim J, Reimann S, O'Doherty S, Fraser PJ, Simmonds PG, Prinn RG, Weiss RF.  2014.  HFC-43-10mee atmospheric abundances and global emission estimates. Geophysical Research Letters. 41:2228-2235.   10.1002/2013gl059143   AbstractWebsite

We report in situ atmospheric measurements of hydrofluorocarbon HFC-43-10mee (C5H2F10; 1,1,1,2,2,3,4,5,5,5-decafluoropentane) from seven observatories at various latitudes, together with measurements of archived air samples and recent Antarctic flask air samples. The global mean tropospheric abundance was 0.210.05ppt (parts per trillion, dry air mole fraction) in 2012, rising from 0.040.03ppt in 2000. We combine the measurements with a model and an inverse method to estimate rising global emissionsfrom 0.430.34Ggyr(-1) in 2000 to 1.130.31Ggyr(-1) in 2012 (similar to 1.9TgCO(2)-eqyr(-1) based on a 100year global warming potential of 1660). HFC-43-10meea cleaning solvent used in the electronics industryis currently a minor contributor to global radiative forcing relative to total HFCs; however, our calculated emissions highlight a significant difference from the available reported figures and projected estimates.

Arnold, T, Manning AJ, Kim J, Li SL, Webster H, Thomson D, Muhle J, Weiss RF, Park S, O'Doherty S.  2018.  Inverse modelling of CF4 and NF3 emissions in East Asia. Atmospheric Chemistry and Physics. 18:13305-13320.   10.5194/acp-18-13305-2018   AbstractWebsite

Decadal trends in the atmospheric abundances of carbon tetrafluoride (CF4) and nitrogen trifluoride (NF3) have been well characterised and have provided a time series of global total emissions. Information on locations of emissions contributing to the global total, however, is currently poor. We use a unique set of measurements between 2008 and 2015 from the Gosan station, Jeju Island, South Korea (part of the Advanced Global Atmospheric Gases Experiment network), together with an atmospheric transport model, to make spatially disaggregated emission estimates of these gases in East Asia. Due to the poor availability of good prior information for this study, our emission estimates are largely influenced by the atmospheric measurements. Notably, we are able to highlight emission hotspots of NF3 and CF4 in South Korea due to the measurement location. We calculate emissions of CF4 to be quite constant between the years 2008 and 2015 for both China and South Korea, with 2015 emissions calculated at 4.3 +/- 2.7 and 0.36 +/- 0.11 Gg yr(-1), respectively. Emission estimates of NF3 from South Korea could be made with relatively small uncertainty at 0.6 +/- 0.07 Gg yr(-1) in 2015, which equates to similar to 1.6% of the country's CO2 emissions. We also apply our method to calculate emissions of CHF3 (HFC-23) between 2008 and 2012, for which our results find good agreement with other studies and which helps support our choice in methodology for CF4 and NF3.

Arnold, T, Muhle J, Salameh PK, Harth CM, Ivy DJ, Weiss RF.  2012.  Automated measurement of nitrogen trifluoride in ambient air. Analytical Chemistry. 84:4798-4804.   10.1021/ac300373e   AbstractWebsite

We present an analytical method for the in situ measurement of atmospheric nitrogen trifluoride (NF3), an anthropogenic gas with a 100-year global warming potential of over 16 000. This potent greenhouse gas has a rising atmospheric abundance due to its emission from a growing number of manufacturing processes and an expanding end-use market. Here we present a modified version of the "Medusa" preconcentration gas chromatography/mass spectrometry (GC/MS) system of Miller, B. R.; Weiss, R. F.; Salameh, P. K.; Tanhua, T.; Greally, B. R; Male, J.; Simmonds, P. G. Anal. Chem. 2008, 80 (5), 1536-1545. By altering the techniques of gas separation and chromatography after initial preconcentration, we are now able to make atmospheric measurements of NF3 with relative precision <2% (1 sigma) for current background clean air samples. Importantly, this method augments the currently operational Medusa system, so that the quality of data for species already being measured is not compromised and NF3 is measured from the same preconcentrated sample. We present the first in situ measurements of NF3 from La Jolla, California made 11 times daily, illustrating how global deployment of this technique within the AGAGE (Advanced Global Atmospheric Gases Experiment) network could facilitate estimation of global and regional NF3 emissions over the coming years.

Arnold, T, Harth CM, Mühle J, Manning AJ, Salameh PK, Kim J, Ivy DJ, Steele PL, Petrenko VV, Severinghaus JP, Baggenstos D, Weiss RF.  2013.  Nitrogen trifluoride global emissions estimated from updated atmospheric measurements. Proceedings of the National Academy of Sciences.   10.1073/pnas.1212346110   AbstractWebsite

Nitrogen trifluoride (NF3) has potential to make a growing contribution to the Earth’s radiative budget; however, our understanding of its atmospheric burden and emission rates has been limited. Based on a revision of our previous calibration and using an expanded set of atmospheric measurements together with an atmospheric model and inverse method, we estimate that the global emissions of NF3 in 2011 were 1.18 ± 0.21 Gg⋅y−1, or ∼20 Tg CO2-eq⋅y−1 (carbon dioxide equivalent emissions based on a 100-y global warming potential of 16,600 for NF3). The 2011 global mean tropospheric dry air mole fraction was 0.86 ± 0.04 parts per trillion, resulting from an average emissions growth rate of 0.09 Gg⋅y−2 over the prior decade. In terms of CO2 equivalents, current NF3 emissions represent between 17% and 36% of the emissions of other long-lived fluorinated compounds from electronics manufacture. We also estimate that the emissions benefit of using NF3 over hexafluoroethane (C2F6) in electronics manufacture is significant—emissions of between 53 and 220 Tg CO2-eq⋅y−1 were avoided during 2011. Despite these savings, total NF3 emissions, currently ∼10% of production, are still significantly larger than expected assuming global implementation of ideal industrial practices. As such, there is a continuing need for improvements in NF3 emissions reduction strategies to keep pace with its increasing use and to slow its rising contribution to anthropogenic climate forcing.