Transport timescales and halogen budget in the Arctic polar Vortex and the UTLS during HALO-ASCCI

ASCCI项目是北半球极地的Halo任务，在冬末到初春研究北极最低平流层和对流层上层的臭氧。ASCCI运动的科学背景在同一申请人(Andreas Engel)和Björn-Martin Sinnhuber(Kit Karlsruhe)的运动协调提案中进行了描述。在这里，我们特别侧重于与法兰克福大学拟议的与ASCCI运动有关的工作有关的方面。法兰克福大学使用具有电子捕获(GC-ECD)和质谱分析(GC-MS)检测的现场气相色谱仪。该仪器能够使用电子碰撞(EI)和负化学电离(NCI)以及平均年龄示踪剂SF6来测量广泛的卤代烃。我们侧重于与卤代烃、其大气分布、大气中总的卤素负荷、平流层中的有效氯和溴以及空气平均年龄有关的方面，特别是将在ASCCI期间调查的极地冬季条件。我们将在本报告中提出的主要研究问题是：-与2015/2016年冬季相比，大气氯预算发生了怎样的变化，当时进行了上一次北极极地光晕冬季行动。--与2015/2016年冬季相比，大气溴的预算变化如何--使用一种新的和改进的方法确定平均年龄时，平流层下层的典型输送时间(平均空气年龄)是多少？-氯和溴的预算以及平均年龄与南半球的分布相比如何，特别是如果数据是在涡旋相对坐标系中计算的话？

The project ASCCI is a HALO mission in the Northern Hemisphere polar late winter to early spring to study ozone in the Arctic lowermost stratosphere and upper troposphere. The scientific background of the ASCCI campaign is described in the campaign co-ordination proposal by the same applicant (Andreas Engel) and Björn-Martin Sinnhuber (KIT Karlsruhe). Here we focus specifically on aspects related to the work proposed at University Frankfurt in relation to the ASCCI campaign. University Frankfurt operates an in-situ gas chromatograph with electron capture (GC-ECD) and with mass spectrometric (GC-MS) detection. The instrument is capable of measuring a wide suite of halocarbons, using both Electron Impact (EI) and Negative Chemical Ionization (NCI), and also the mean age tracer SF6. We focus on aspects related to halocarbons, their atmospheric distribution, on total halogen loading of the atmosphere, available chlorine and bromine in the stratosphere and on aspects of mean age of air, specifically for the polar winter conditions to be investigated during ASCCI. The main research question we will adress within this proosal are: - how has the atmospheric chlorine budget chenged in comparison to the winter 2015/2016 when the last Arctic polar winter campaign with HALO was performed. - how has the atmospheric bromine budget chenged in comparison to the winter 2015/2016 when the last Arctic polar winter campaign with HALO was performed - what are typical transport times (mean age of air) in the lower stratosphere using a new and improved method to determine mean age? - How do chlroine and bromine budgets and also mean age compare to the Southern Hemisphere distributions, in particular if data are comared in a vortex-relative coordinate system?