Southern Hemispheric halogen budgets, mean age distributions, age spectra and interhemispheric difference using GhOST-MS observations during SOUTHTRAC

这项建议的主要目的是在SOUTHTRAC活动期间对卤代烃和SF6进行观测。SF6是一种示踪剂，可用于计算平均通过时间(平均年龄)。测量将使用Halo上的原位气相色谱仪Ghost-MS进行，该仪器已在之前的Halo任务中成功部署。这些测量将被用来调查以下两个工作包，这两个工作包都将由一名博士生解决：主要问题：WP1：南半球的平均年龄和年龄谱？上海理工大学的平均年龄分布是怎样的？它与北半球的分布是否不同，由此可以得出关于平流层-对流层交换的哪些结论？通过对短寿命物质的观测得出的渡越时间分布是什么样子？这些年龄谱与模拟的年龄谱相比如何？是否存在半球间的差异？WP2：南半球的氯和溴收支短命物质在两个半球之间的分布有何不同？这些分布与使用不同排放情景的模型计算结果吻合程度如何？南半球UTLS的氯和溴的卤素预算是多少？它与北半球相比怎么样？这可能会对臭氧消耗产生哪些影响？

TThe main purpose of this proposal is to perform observations of halogenated hydrocarbons and SF6 during the SOUTHTRAC campaign. SF6 is a tracer which can be used to derive mean transit times (mean age). The measurements will be performed with the in-situ gas chromatograph GHOST-MS on board HALO, which has been successfully deployed during previous HALO missions. The measurements will be used to investigate the following two work packages, which will both be addressed by a PhD student: main questions: WP1: mean age and age spectra of the Southern Hemisphere? What is the distribution of mean age in the SH UTLS? Is it different from the Northern Hemisphere distribution and which conclusions on stratosphere-troposphere-exchange can be drawn from this?What do transit time distributions derived from the observation of short-lived substances look like? How do these age spectra compare to modelled age spectra? Is there an interhemispheric difference?WP2: chlorine and bromine budget of the Southern HemisphereHow does the distribution of short lived substances differ between the two hemispheres? How well do the distributions agree with model calculations using different emission scenarios? What is the halogen budget of the Southern Hemisphere UTLS for both chlorine and bromine? How does it compare to the Northern Hemisphere? Which implications can this have for ozone depletion?