A reassessment of the soil sink for atmospheric carbon tetrachloride based upon static flux chamber measurements

作者：Happell James D^*; Mendoza Yudania; Goodwin Kelly

来源：Journal of Atmospheric Chemistry, 2014, 71(2): 113-123.

DOI：10.1007/s10874-014-9285-x

• CCl4
• Sink
• Soil uptake
• Flux chamber
• Atmospheric budget

Static flux chamber measurements of CCl4 uptake by soils in boreal, subtropical and tropical forests have been used to reassess the sink strength for this ozone depleting chemical. Happell and Roche (Geophys. Res. Lett. 30(2), 1088-1091, 2003) used flux estimates from soil concentration gradients to calculate a partial CCl4 atmospheric lifetime (tau(soil)) of 90 years. More recently, it is has been assumed that a better estimate of tau(soil) is 195 years (Montzka et al. 2011). In the work here, the rate of CCl4 uptake was calculated from 453 flux chamber measurements using an exponential fit to the chamber CCl4 concentration change with time. This analysis indicated that the flux rate estimate in Happell and Roche (Geophys. Res. Lett. 30(2) 1088-1091, 2003) was overestimated by 2.75, yielding a new estimate of tau(soil) for CCl4 of 245 years. Significant correlations of CCl4 uptake to temperature, soil moisture, or time of year were not observed. This work provides additional evidence that CCl4 uptake by soils is a common process and needs to be considered when developing an atmospheric budget for this compound.

• 出版日期2014-6