Understanding seasonality and trends of transport pathways and composition in the upper troposphere lower stratosphere (UTLS) region

了解对流层上层平流层下层 (UTLS) 区域运输路径和成分的季节性和趋势

• 批准号: 200687776
• 负责人: Professor Dr. Felix Plöger
• 金额: --
• 依托单位: Arbeitsgruppe Atmosphärenphysik
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/200687776?language=en
• 关键词: Understanding; seasonality; trends; transport; pathways

Seasonality and trends in transport pathways affect the trace gas composition of the upper troposphere lower stratosphere (UTLS) which, in turn, impacts radiative forcing and climate change. Currently, transport in the UTLS and its link to a changing climate is a rapidly expanding field in atmospheric science. This proposal for a research fellowship at the National Center for Atmospheric Research (NCAR/ACD) at Boulder/USA aims at developing novel diagnostic tools for an improved understanding of transport pathways in the UTLS, with particular focus on seasonality and trends and the impact on trace gas composition. Using the chemistry transport model CLaMS and the climate model WACCM, a new diagnostic tool for calculating the age spectrum of stratospheric air, the probability distribution of transport time scales of air parcels originating at the tropical tropopause, will be developed, based on various decaying tracers. Considering the age spectrum is a major step forward going beyond current research where mainly the mean age is considered. The method will be validated against age spectra from pulse experiments and against trajectory transit time distributions. The new age spectrum diagnostic will be applied to the CLaMS and WACCM models as a tool for model transport evaluation. The combination of the different age spectrum diagnostics and trajectory statistics will provide new deep insight into the relative strength and the seasonality of different pathways between the tropical and the extratropical lower stratosphere and long-term circulation trends. Hence, the proposed work will be an important step towards an improved understanding of our changing climate system.

输送路径的季节性和趋势影响对流层上部和平流层下部的痕量气体组成，这反过来又影响辐射强迫和气候变化。目前，UTLS中的传输及其与气候变化的联系是大气科学中一个迅速扩展的领域。这项在美国博尔德国家大气研究中心（NCAR/ACD）的研究奖学金提案旨在开发新的诊断工具，以提高对UTLS传输路径的理解，特别关注季节性和趋势以及对痕量气体成分的影响。将利用化学输送模式CLaMS和气候模式WACCM这一计算平流层空气年龄谱的新诊断工具，根据各种衰减示踪剂，开发起源于热带对流层顶的气包输送时间尺度的概率分布。考虑年龄谱是超越目前主要考虑平均年龄的研究的一个重大步骤。该方法将验证对年龄谱脉冲实验和对轨迹渡越时间分布。新的年龄谱诊断将应用于CLaMS和WACCM模式作为模式传输评估的工具。不同的年龄谱诊断和轨迹统计相结合，将提供新的深入了解热带和热带外低平流层和长期环流趋势之间的不同路径的相对强度和季节性。因此，拟议的工作将是朝着更好地了解我们不断变化的气候系统迈出的重要一步。