Tropospheric Impact of Waves and Flows Generated by Landscape Heterogeneity: A Theoretical Investigation

本研究的总体目标是更好地理解与景观异质性对大气影响相关的物理过程，并通过发展一种分析理论，对这些影响在更大尺度模型上的参数化作出贡献。首席研究员将重点关注：在先前支持下发展的分析理论的进一步发展；研究平坦景观中由景观变异性产生的持续中尺度流和波的作用；这些大气流动对对流层结构，特别是稳定性和风廓线的评价。本研究的需要源于对先前完成的现场实验数据和相关数值结果的分析，这些结果表明，自由大气中的特征可能与中尺度波和中尺度垂直输送有关。这意味着，在非均匀平坦地形上产生的中尺度气流，当这些气流持续数天时，可以影响对流层的稳定性和风廓线。首席研究员将量化在晴朗的日子里，微风条件下自由大气的中尺度印记。此外，当环境风和稳定性剖面有利于传播波时，研究人员将确定这些扰动在自由大气中渗透的深度。首席研究员将研究对流层环境如何受到中尺度波能的影响，以及相关的动量汇聚和沉积。这项研究的成功完成将最终导致数值模式中更好的参数化，并从这些模式中获得更好的天气预报。

The general aim of this research is to better understand the physical processes associated with the influence of landscape heterogeneity on the atmosphere, and, through the development of an analytic theory, to contribute to the parameterization of these effects on larger-scale models. The Principal Investigators will focus on: the further development of an analytic theory developed under previous support; investigating the role of persistent mesoscale flows and waves generated by landscape variability in flat landscapes; the evaluation of these atmospheric flows on tropospheric structures, specifically stability and wind profiles. The need for this study is motivated from the analysis of data from previously completed field experiments and related numerical results, which have shown that signatures in the free atmosphere may be related to mesoscale waves and mesoscale vertical transport. The implication is that mesoscale flow, which is generated over heterogeneous flat landscapes, can influence the tropospheric stability and wind profile, when these flows persist for a few days.The Principal Investigators will quantify the mesoscale imprint on the free atmosphere during clear days with light wind conditions. In addition, when the environmental wind and stability profiles are favorable to propagating waves, the researchers will determine how deeply these perturbations penetrate into the free atmosphere. The Principal Investigators will study how the tropospheric environment is influenced by mesoscale wave energy, and associated momentum convergence and deposition.Successful completion of this research could eventually lead to better parameterizations in numerical models and better weather forecasts from these models.