Improving the Understanding of Halocarbon Lifetimes and Emissions

本研究使用建模工具来提高对各种卤代烃在大气中的排放和寿命的了解，这些卤代烃包括氯氟烃（CFCs）、氢氯氟烃（hcfc）、氢氟碳化合物（hfc）和全氟化化合物，如六氟化硫（SF-6）和环脲己糖（CF-6）。包括氟氯烃和氟氯烃在内的卤碳化合物的排放加剧了全球气候变化和臭氧损失，而氢氟碳化物和全氟化气体的排放加剧了气候变化。这项研究的结果将与今后国际上对臭氧、气候和化学的评估有关。该项目的三个组成部分包括：(1)使用先前开发并应用于CFC-11、-12和-13的概率贝叶斯模型，改进对扩大范围内卤碳气体的库、排放、寿命及其各自不确定性的研究；(2)在最近关于海洋对氟氯化碳-11的寿命的重大影响的模拟工作的基础上，努力审查海洋及其随时间变化对一系列卤代碳气体的寿命、排放和区域大气浓度的潜在影响；(3)利用全球大气模式研究大气寿命、平流层-对流层交换和对流层卤化碳浓度的年际变化。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This research uses modeling tools to improve the understanding of the emissions and lifetimes in the atmosphere of a broad range of halocarbons, including chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and fully fluorinated compounds such as sulfur hexafluoride (SF-6) and cycloinulohexaose (CF-6). Emissions of halocarbons, including CFCs and HCFCs, contribute to both global climate change and ozone loss, while those of the HFCs and perfluorinated gases contribute to climate change. The results of this research will be relevant to future international assessments of ozone, climate, and chemistry.The three components of this project include: (1) Improved studies of the banks, emissions, lifetimes, and their respective uncertainties for an expanded range of halocarbon gases, using a probabilistic Bayesian model developed and applied previously for CFC-11, -12 and -13; (2) Efforts to examine the potential influence of the ocean and its variability over time on lifetimes, emissions, and regional atmospheric concentrations for a range of halocarbon gases, building on recent modelling work of the significant effects of the ocean on the lifetime of CFC-11; and (3) Research on the interannual dynamical variations in the atmospheric lifetimes, stratospheric-tropospheric exchange, and tropospheric concentrations of halocarbons using a global atmospheric model.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.