Long-lived greenhouse gases in the extra-tropical tropopause region

温带对流层顶地区的长寿命温室气体

• 批准号: 501095243
• 负责人: Dr. Tanja Schuck
• 金额: --
• 依托单位: Institut für Physik der Atmosphäre
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/501095243?language=en
• 关键词: Long; lived; greenhouse; gases; extra

Mixing ratios of the most relevant long-lived greenhouse gases keep increasing in the atmosphere due to ongoing athprogenic emissions. The most dominant greenhouse gases are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). In addition to their relevance as potent gaseous climate forces, these gase exhibit strong gradients across the tropopause and are therefore suited as tracers for atmospheric transport processes. With an atmospheric lifetime of approximately 850 years and continuisly increasin mixing ratios, sulfur hexafluoride (SF6) is frequently used as a tracer of the age of air, an indicator of air mass transport in the stratosphere.The proposed project aims at the harmonization and scientific evaluation of existing measurements from the tropopause region from the IAGOS-CARIBIC observational platform of these four main greenhouse gases and long-lived halogenated trace gases with high global warming potentials. Data cover the period 2005-2020 and as part of the project will be combined with further existing data from measurements onbard the German research aircraft HALO. Data analysis will target trends of greenhouse gas mixing ratios in the upper troposphere, in particular their time lags to ground observations, the variability of long-lived greenhouse gases in the tropopause region, and the identification and source attribution of high mixing ratios encountered in the upper troposphere. The overalll aim is an improved understanding of atmospheric transport processes in and into the tropopause region.In addition, an existing laboratory set-up for detection of halogenated trace gases in air samples based on gas chromatography (GC) coupled with mass spectrometry is to be extended with a small GC unit for detection of SF6 at minimized sample volume consumption. The project plan proposes to investigate options for the non-radioactive detection of SF6 based on pulsed discharge detectors. Such detectors are generally suited for measurements of SF6 but have up to now not been used for measurement of SF6 in the atmosphere. Alternatively, the established detection with an electron capture detector (based on radioactive decay of a Nickel isotope) is foreseen.

由于持续的致病性排放，大气中最相关的长寿命温室气体的混合比率不断增加。最主要的温室气体是二氧化碳（CO2）、甲烷（CH4）和一氧化二氮（N2O）。除了作为强有力的气体气候作用力外，这些气体在对流层顶表现出很强的梯度，因此适合作为大气输送过程的示踪剂。六氟化硫（SF6）的大气寿命约为850年，混合比例不断增加，经常被用作空气年龄的示踪剂，是平流层中气团输送的一个指标。拟议的项目旨在协调和科学评估iagos - caribbean观测平台在对流层顶区域对这四种主要温室气体和具有高全球变暖潜势的长寿命卤化微量气体的现有测量结果。数据涵盖2005-2020年期间，作为项目的一部分，将与德国研究飞机HALO上的进一步现有测量数据相结合。数据分析的目标是对流层上层温室气体混合比的趋势，特别是它们相对于地面观测的时间滞后，对流层顶区域长寿命温室气体的变率，以及对流层上层遇到的高混合比的识别和来源归因。总的目标是增进对对流层顶区域内和进入对流层顶区域的大气输送过程的了解。此外，现有的基于气相色谱（GC）和质谱法检测空气样品中卤化微量气体的实验室装置将扩展为一个小型气相色谱装置，以最小的样本量消耗来检测SF6。项目计划建议研究基于脉冲放电检测器的SF6非放射性检测方案。这种探测器通常适用于SF6的测量，但到目前为止还没有用于测量大气中的SF6。另一种方法是使用电子捕获探测器（基于镍同位素的放射性衰变）进行既定的探测。