Lagrangian Studies of Stratospheric Transport Barriers

平流层传输障碍的拉格朗日研究

• 批准号: 9714384
• 负责人: Janusz Eluszkiewicz
• 金额: $ 16.9万
• 依托单位: Atmospheric and Environmental Research Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-11-15 至 1999-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9714384&HistoricalAwards=false
• 关键词: Lagrangian; Studies; Stratospheric; Transport; Barriers

9714384 Eluszkiewicz The principal investigator seeks to understand the physical processes responsible for transport of trace species in the stratosphere across internal barriers such as the tropopause and the boundary between the tropics and extratropics. The transport rates across these boundaries are important in determining the budgets of key constituent gases, including stratospheric water vapor and lower stratospheric and tropospheric ozone, and play a crucial role in the assessment of the chemical and climatic impact of trace gases emitted to the atmosphere, for example by supersonic and subsonic aircraft. Despite its recognized importance, progress in understanding this transport has been impeded by the fact that the relevant spatial scales are often smaller than can be resolved by spacecraft observations or computed using Eulerian advection schemes. Under this project the PI will simulate the global effects of both large and small scale transport using a specially developed Lagrangian trajectory package incorporated into the Geophysical Fluid Dynamics Laboratory SKYHI general circulation model (GCM). The Lagrangian technique will be used to explore the following: ( The difference in the trace gas distributions computed using Eulerian and Lagrangian approaches and the impact of these differences on the mean age of stratospheric air as computed in a GCM ( The nature of stratosphere-troposphere exchange in the extratropics and the seasonal patterns as revealed by the mass fluxes across the tropopause simulated in the model. Insights gained from this research will be useful in the general development of trajectory techniques for other GCMs and/or assimilation models. In particular, this research will study the sensitivity to the choice of vertical coordinate and to the sampling frequency of the wind data used in the trajectory calculations, including the option of performing the calculations on-line, i.e., on each integration time step of the wind-generating model. These studies will thus contribute to a better understanding of the Lagrangian approach both as a three-dimensional high-resolution advection scheme and as a visualization tool.

小行星9714384 首席研究员试图了解平流层中痕量物种穿越对流层顶和热带与热带外边界等内部障碍的物理过程。跨越这些边界的迁移率对于确定平流层水蒸气和平流层下层及对流层臭氧等主要成分气体的收支十分重要，并且在评估超音速和亚音速飞机等向大气层排放的微量气体的化学和气候影响方面发挥着关键作用。尽管其重要性得到公认，但由于相关的空间尺度往往小于航天器观测或欧拉平流方案计算所能分辨的尺度，因此对这种输运的理解进展受阻。 在这个项目下，PI将使用一个专门开发的拉格朗日轨迹包，结合到地球物理流体动力学实验室SKYHI大气环流模型（GCM）中，模拟大规模和小规模运输的全球影响。拉格朗日技术将用于探索以下内容： （使用欧拉和拉格朗日方法计算的痕量气体分布的差异以及这些差异对大气环流模式中计算的平流层空气平均年龄的影响（模式中模拟的对流层顶质量通量所揭示的热带外平流层-对流层交换的性质和季节模式。 从这项研究中获得的见解将是有用的轨迹技术的其他GCM和/或同化模式的一般发展。特别是，这项研究将研究对垂直坐标选择和轨迹计算中使用的风数据采样频率的敏感性，包括在线执行计算的选项，即，在风力发电模型的每个积分时间步长上。 因此，这些研究将有助于更好地了解拉格朗日方法作为一个三维高分辨率平流计划和可视化工具。