Sulfuryl fluoride in the global atmosphere

Abstract

The first calibrated high‐frequency, high‐precision, in situ atmospheric and archived air measurements of the fumigant sulfuryl fluoride (SO2F2) have been made as part of the Advanced Global Atmospheric Gas Experiment (AGAGE) program. The global tropospheric background concentration of SO2F2 has increased by 5 ± 1% per year from ∼0.3 ppt (parts per trillion, dry air mol fraction) in 1978 to ∼1.35 ppt in May 2007 in the Southern Hemisphere, and from ∼1.08 ppt in 1999 to ∼1.53 ppt in May 2007 in the Northern Hemisphere. The SO2F2 interhemispheric concentration ratio was 1.13 ± 0.02 from 1999 to 2007. Two‐dimensional 12‐box model inversions yield global total and global oceanic uptake atmospheric lifetimes of 36 ± 11 and 40 ± 13 years, respectively, with hydrolysis in the ocean being the dominant sink, in good agreement with 35 ± 14 years from a simple oceanic uptake calculation using transfer velocity and solubility. Modeled SO2F2 emissions rose from ∼0.6 Gg/a in 1978 to ∼1.9 Gg/a in 2007, but estimated industrial production exceeds these modeled emissions by an average of ∼50%. This discrepancy cannot be explained with a hypothetical land sink in the model, suggesting that only ∼2/3 of the manufactured SO2F2 is actually emitted into the atmosphere and that ∼1/3 may be destroyed during fumigation. With mean SO2F2 tropospheric mixing ratios of ∼1.4 ppt, its radiative forcing is small and it is probably an insignificant sulfur source to the stratosphere. However, with a high global warming potential similar to CFC‐11, and likely increases in its future use, continued atmospheric monitoring of SO2F2 is warranted.

Reactive and nonreactive quenching of O(1D) by the potent greenhouse gases SO2F2, NF3, and SF5CF3

“…Mühle et al (2) recently proposed an efficient removal pathway for SO 2 F 2 via ocean uptake and hydrolysis, which they believe limits its atmospheric lifetime to 36 AE 11 years, implying a GWP of 4780 (100-year time horizon). If the rate of oceanic uptake is evaluated properly, then Oð 1 DÞ reaction would be only a minor loss pathway for SO 2 F 2 in the atmosphere.…”

“…Deactivation of O( 1 D) by SF 5 CF 3 is slow enough (k 3 < 2.0 × 10 −13 cm 3 molecule −1 s −1 at 298 K) that reaction with O( 1 D) is unimportant as an atmospheric removal mechanism for SF 5 CF 3 . The kinetics of O( 1 D) reactions with SO 2 (k 4 ) and CS 2 (k 5 ) have also been investigated at 298 K. We find that k 4 ¼ (2.2 AE 0.3) × 10 −10 and k 5 ¼ (4.6 AE 0.6) × 10 −10 cm 3 molecule −1 s −1 ; branching ratios for reactive quenching are 0.76 AE 0.12 and 0.94 AE 0.06 for the SO 2 and CS 2 reactions, respectively. All uncertainties reported above are estimates of accuracy (2σ) and rate coefficients k i (T) (i ¼ 1; 2) calculated from the above Arrhenius expressions have estimated accuracies of AE15% (2σ).…”

“…The fumigant SO 2 F 2 is widely used as a replacement for the ozone-depleting compound CH 3 Br. The tropospheric background mixing ratio of SO 2 F 2 is found to be 1.53 parts per trillion (ppt) in the Northern Hemisphere and 1.35 ppt in the Southern hemisphere and is increasing by 5 AE 1 percent per year (2). NF 3 is primarily used in the electronics industry as a plasma etchant and equipment cleaning gas (3).…”

Mass transfer and reaction kinetics of sulfuryl fluoride absorption with aqueous sodium hydroxide solutions

“…SO 2 F 2 is a strong greenhouse gas with global warming potential of 4780 (relative to CO 2 for the 100 year time horizon), and the concentration of SO 2 F 2 in the global atmosphere has been increasing 5% each year since 1978 (Papadimitriou et al, 2008;Mühle et al, 2009). In addition, SO 2 F 2 gas was marked as an inhalation hazardous material, and long term exposure can cause damage to a human's central nervous system and inhalation system, etc.…”

Effects of diatomaceous earth on the mortality and progeny production of Rhyzopertha dominica (Coleoptera: Bostrychidae

“…Methyl bromide, for example, has been banned by Montreal Protocol worldwide due to its ozone depleting properties, while many pests have already developed phosphine-resistant strains due to improper fumigations (Zettler & Arthur 2000). Additionally, sulphuryl fluoride is now being considered as a gas to the greenhouse effect and global warming (Mühle et al 2009). Moreover, few residual insecticides are currently registered for use in grain storage; however, they are also subject to health, environmental, and pest resistance considerations (Subramanyam & Hagstrum 1995).…”