Re-evaluation of the lifetimes of the major CFCs and CH3CCl3 using atmospheric trends
Re-evaluation of the lifetimes of the major CFCs and CH3CCl3 using atmospheric trends
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DOI：
10.5194/acp-13-2691-2013
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发表时间：
2013-01-01
影响因子：
6.3
通讯作者：
Fraser, P. J.
中科院分区：
文献类型：
--
作者：
Rigby, M.;Prinn, R. G.;Fraser, P. J.
自《关于消耗臭氧层物质的蒙特利尔议定书》及其修正案生效以来，主要消耗臭氧层物质，特别是CFC-11、-12和-113以及CH3CCl3的增长率显著下降，为全球平流层臭氧的恢复铺平了道路。排放量现在已降至相对较低的水平，因此，这种恢复的速度将在很大程度上取决于这些化合物的大气寿命。第一次消耗臭氧层物质测量始于1970年代初，同时考虑到大气趋势计算出的第一次寿命估计也是如此。我们现在拥有跨越数十年的全球摩尔分数记录，促使我们重新评估寿命。利用1978年至2011年来自高级全球大气气体实验(AGAGE)和美国国家海洋和大气管理局全球监测司(NOAA GMD)的地表测量数据，我们使用多组分逆方法估计了CFC-11、CFC-12、CFC-113和CH3CCl3的寿命。目前在世界气象组织(WMO)最新的臭氧消耗科学评估中建议的CFC-11的稳态寿命为45年，这是我们估计的不确定度下限，使用AGAGE数据时为54(48)(61)年(1-西格玛不确定度)，使用NOAA网络数据时为52(45)(61)年。我们得出的CFC-113的寿命大大高于世界气象组织估计的85年，分别为109(99)(121)(AGAGE)和109(97)(124)(NOAA)。对CFC-12和CH3CCl3稳态寿命的新估计与世界气象组织目前的建议一致，分别为111(95)(132)和112(95)(136)年(分别为CFC-12、AGAGE和NOAA)和5.04(4.92)(5.20)和5.04(4.87)(5.23)年(分别为CH3CCl3、AGAGE和NOAA)。
Since the Montreal Protocol on Substances that Deplete the Ozone Layer and its amendments came into effect, growth rates of the major ozone depleting substances (ODS), particularly CFC-11, -12 and -113 and CH3CCl3, have declined markedly, paving the way for global stratospheric ozone recovery. Emissions have now fallen to relatively low levels, therefore the rate at which this recovery occurs will depend largely on the atmospheric lifetime of these compounds. The first ODS measurements began in the early 1970s along with the first lifetime estimates calculated by considering their atmospheric trends. We now have global mole fraction records spanning multiple decades, prompting this lifetime re-evaluation. Using surface measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the National Oceanic and Atmospheric Administration Global Monitoring Division (NOAA GMD) from 1978 to 2011, we estimated the lifetime of CFC-11, CFC-12, CFC-113 and CH3CCl3 using a multi-species inverse method. A steady-state lifetime of 45 yr for CFC-11, currently recommended in the most recent World Meteorological Organisation (WMO) Scientific Assessments of Ozone Depletion, lies towards the lower uncertainty bound of our estimates, which are 54(48)(61) yr (1-sigma uncertainty) when AGAGE data were used and 52(45)(61) yr when the NOAA net-work data were used. Our derived lifetime for CFC-113 is significantly higher than the WMO estimates of 85 yr, being 109(99)(121) (AGAGE) and 109(97)(124) (NOAA). New estimates of the steady-state lifetimes of CFC-12 and CH3CCl3 are consistent with the current WMO recommendations, being 111(95)(132) and 112(95)(136) yr (CFC-12, AGAGE and NOAA respectively) and 5.04(4.92)(5.20) and 5.04(4.87)(5.23) yr (CH3CCl3, AGAGE and NOAA respectively).