Tracer measurements with HAGAR-V during PHILEAS to investigate the impact of the Asian monsoon on the extratropical UTLS

在该项目的框架内，我们建议i）在2023年夏天的HALO PHILEAS使命期间使用新型HAGAR-V仪器对一套示踪剂进行原位测量，ii）对所获得的HAGAR-V示踪剂数据进行分析，以实现该使命的科学目标。HAGAR-V结合了NATIONAL分析仪的快速CO2测量，一种测量长寿命示踪剂的双通道GC/ECD系统（SF6和F12每45秒一次; Halon-1211、F11和F113，每90秒一次），以及双通道GC/MS系统，每90秒一次，（C2 H2，iso-C5 H12，n-C5 H12），短寿命的氯代烃（CH 2Cl 2，CHCl 3，C2Cl 4），以及其它长寿命的卤代烃（CCl 4，CHCl 3，HFC-125，HFC-134 a，HFC-32）。因此，HAGAR-V涵盖了大多数主要的氯源气体以及最重要的氯化VSLS。这些物种在中纬度对流层顶的局部寿命范围从几天到多年不等，这将被用于沿着与CO2的季节变化结合气象数据和CLaMS模拟，以限制传输的时间尺度和优势传输路径从亚洲季风反气旋（AMA）到热带外UTLS。CH 2Cl 2和CHCl 3在AMA内部得到强烈增强，将与长寿命示踪剂一起用于研究从AMA脱落的涡旋的结构和混合，以获得来自AMA和其他区域的空气来源的分数，并评估从AMA输出的空气对北方最低平流层组成的影响。此外，NMHC的测量将允许检测新鲜污染和生物质燃烧的影响，从而有助于气溶胶前体物的调查。

In the frame of this project we propose i) in situ measurements of a suite of tracers with the novel HAGAR-V instrument during the HALO PHILEAS mission in the summer of 2023 and ii) analysis of the obtained HAGAR-V tracer data toward the scientific goals of that mission. HAGAR-V combines a fast CO2 measurement by NDIR analyzer, a 2-channel GC/ECD-system measuring long-lived tracers (SF6 and F12 every 45 s; Halon-1211, F11 and F113 every 90 s) and a 2-channel GC/MS system targeting a suite of further tracer species every 90 s, including NMHC (C2H2, iso-&n-C5H12), short-lived chlorocarbons (CH2Cl2, CHCl3, C2Cl4), and further long-lived halocarbons (CCl4, CHCl3, HFC-125, HFC-134a, HFC-32). HAGAR-V thus covers most major chlorine source gases as well as the most important chlorinated VSLS. Local lifetimes of these species at the midlatitude tropopause range from several days to many years, which will be used along with the seasonal variation of CO2 in combination with meteorological data and CLaMS simulations to constrain transport time scales and dominant transport paths from the Asian Monsoon anticyclone (AMA) into the extratropical UTLS. The species CH2Cl2 and CHCl3 are strongly enhanced inside the AMA and will be used together with long-lived tracers to study the structure and mixing of eddies shed from the AMA, to derive fractions of air origin from the AMA and other regions, and to assess the impact of air export from the AMA on the composition of the northern lowermost stratosphere. Further, the measurements of NMHC will allow to detect influence of fresh pollution and biomass burning and thus contribute to the investigation of aerosol precursors.