Transport in the Stratosphere at Low Latitudes and the Quasi-Biennial Oscillation

低纬度平流层的传输和准两年一次的振荡

• 批准号: 9634394
• 负责人: Donal O'Sullivan
• 金额: $ 22.99万
• 依托单位: NorthWest Research Associates, Incorporated
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 1998-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9634394&HistoricalAwards=false
• 关键词: Transport; Stratosphere; Low; Latitudes; Quasi

9634394 O'Sullivan Transport from the tropics to the extratropics in the stratosphere occurs mainly by isentropic advection and stirring into the active surf zone of the winter hemisphere midlatitudes. The transport couples two regions of differing constituent concentrations: the (upwelling) tropical region and the (mostly downwelling) extratropics. Besides varying seasonally, such transport is affected by the quasi-biennial oscillation (QBO). The principal objective of this research is to investigate the manner in which the QBO affects transport by (a) its mean meridional circulations, (b) its modulation of Rossby wave propagation and breaking at the low latitudes, (c) its modulation of the extratropical Rossby wave activity and surf zone mixing, and consequently (d) its modulation of the global Brewer-Dobson residual circulation strength during the winter season. The study will rely primarily on numerical simulations with a three-dimensional model of the middle atmosphere and a tracer transport model. The results will be compared with other simulations and satellite observations of the middle atmosphere. This work will also provide estimates of stratospheric transport rates form the tropics to the extratropics for each season and for different phases of the QBO as a function of height. Dr. O'Sullivan is a young scientist who has established an excellent reputation in the middle atmosphere research community. His work is contributes not only to better understanding of stratospheric dynamics, but also provides critical information on processes that affect the photochemical processes of the region as well. ***

9634394 O‘Sullivan从热带到平流层温带外的输送主要通过等熵平流和搅动进入冬半球中纬度的活动海浪带进行。这种输送耦合了两个成分浓度不同的地区：(上升的)热带地区和(主要是下降的)温带外地区。这种输送除了受季节变化影响外，还受准两年振荡(QBO)的影响。这项研究的主要目的是研究QBO影响输送的方式：(A)它的平均经向环流，(B)它对低纬Rossby波传播和破裂的调制，(C)它对温带Rossby波活动和海浪带混合的调制，以及(D)它对冬季全球Brewer-Dobson剩余环流强度的调制。这项研究将主要依靠中层大气三维模型和示踪剂输送模型的数值模拟。结果将与其他模拟和卫星观测的中层大气进行比较。这项工作还将提供每个季节从热带到温带外的平流层传输速率的估计，以及QBO的不同阶段随高度的变化。奥沙利文博士是一位年轻的科学家，在中层大气研究界建立了良好的声誉。他的工作不仅有助于更好地了解平流层动力学，而且还提供了关于影响该区域光化学过程的过程的关键信息。***