Satellite Observations of Halogen-Containing Molecules

高层大气中的臭氧消耗主要是由氯氟烃(CFCs)等氯化分子的人为释放造成的。这种对臭氧层的破坏增加了到达地面的有害紫外线辐射量。作为《蒙特利尔议定书》的结果，寿命较长的氟氯化碳正在被含有氢(氢氯氟碳化合物)和不含氯的分子(氢氟碳化合物)的寿命较短的物种所取代。预计《蒙特利尔议定书》的成功将在本世纪中叶结束对臭氧的破坏。为了核实遵守情况并监测进展情况，需要测量这些物种的浓度作为时间、地点和海拔的函数。臭氧破坏发生在高层大气中，因此需要对那里的氯和氟预算进行测量。我们建议用大气化学实验傅里叶变换光谱仪(ACE-FTS)测量全球主要含氟和含氯气体(包括有机源气体和无机产物气体)的分布。从2004年到现在，ACE卫星一直在提供高质量的数据，因此可以根据海拔和纬度得出趋势。含有有机氟和氯的物种是强有力的温室气体。事实上，这组气体仅次于二氧化碳和甲烷，是气候变化的第三大驱动因素。《蒙特利尔议定书》的成功带来了无意中的气候惠益，尽管替代品氢氟碳化物的迅速增加令人担忧。我们建议确定其中许多物种的寿命延长，我们的全球分布将导致对全球变暖潜力和辐射作用力的更好估计，从而量化它们在导致气候变化方面的有效性。气候变化和高层大气中的臭氧消耗是大气科学中最重要的两个问题。我们的建议将为世界气象组织2014年臭氧消耗科学评估和政府间气候变化专门委员会正在进行的2013/2014年度第五次评估报告作出重要贡献。

Ozone depletion in the upper atmosphere is caused mainly by the anthropogenic release of chlorinated molecules such as chlorofluorocarbons (CFCs). This damage to the ozone layer increases the amount of deleterious ultraviolet radiation that reaches the ground. As a result of the Montreal Protocol long-lived CFCs are being replaced by shorter-lived species that contain hydrogen (hydrochlorofluorocarbons, HCFCs) and molecules without chlorine (hydrofluorocarbons, HFCs). It is anticipated that the success of the Montreal Protocol will end ozone destruction by the middle of this century. In order to verify compliance and monitor progress, the concentrations of these species need to be measured as function of time, location and altitude. Ozone destruction takes place in the upper atmosphere so measurements of chlorine and fluorine budgets are needed there. We propose to measure the global distributions of the main fluorine- and chlorine-containing gases (both organic source gases and inorganic product gases) with the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). The ACE satellite has been providing high quality data from 2004 to the present so trends can be derived as a function of altitude and latitude. Organic fluorine- and chlorine-containing species are powerful greenhouse gases. In fact, after carbon dioxide and methane, this group of gases are the third most important drivers of climate change. The success of the Montreal Protocol has lead to an inadvertent climate benefit, although the rapid increase in replacement HFCs is cause for concern. We propose to determine improved lifetimes for many of these species, and our global distributions will lead to improved estimates of global warming potentials and radiative forcings that quantify their effectiveness in causing climate change.Climate change and ozone depletion in the upper atmosphere are two of the most important problems in atmospheric science. Our proposal will make important contributions to the World Meteorological Organization's 2014 Scientific Assessment of Ozone Depletion and the Fifth Assessment Report of the Intergovernmental Panel on Climate Change that is now under way for 2013/2014.