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

这项研究的总体目的是更好地了解与地貌异质性对大气的影响有关的物理过程，并通过发展分析理论，促进在更大尺度模式上对这些影响的参数化。首席调查员将侧重于：进一步发展在以前的支持下形成的分析理论；调查平坦地貌中持续的中尺度流动和由地貌变化产生的波动的作用；评估这些大气流动对对流层结构，特别是稳定性和风廓线的影响。这项研究的需要源于对以前完成的野外实验数据和相关数值结果的分析，这些结果表明，自由大气中的信号可能与中尺度波和中尺度垂直输送有关。这意味着，在非均匀的平坦地貌上产生的中尺度气流，当这些气流持续几天时，会影响对流层的稳定性和风廓线。首席调查员将在晴朗和微风的情况下量化中尺度对自由大气的影响。此外，当环境风和稳定性剖面有利于波的传播时，研究人员将确定这些扰动渗透到自由大气的深度。首席研究人员将研究中尺度波能如何影响对流层环境，以及相关的动量会聚和沉积。成功完成这项研究最终可能导致数值模式中更好的参数化和这些模式更好的天气预报。

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.