CEDAR: Mesospheric Gravity Waves Generated by Tropospheric Convection

这项为期三年的工作将调查对流层高度的大范围多单体雷暴中强对流活动产生的重力波对中层的影响。由于其大小，多单体雷暴不能被视为点源，需要推广现有的柱面、孔径型雷暴重力波理论，并考虑所产生的绕射效应。该项目的目的是对二维和三维完全非线性数值模式的中层效应进行系统和集中的研究。推动这一研究计划的悬而未决的科学问题是：(1)在对流层高度由分布式对流源产生的中层柱状重力波的动力学是什么？(2)对流产生的柱状重力波对中层加热率、风廓线和密度扰动有什么影响？为了回答这些问题，PI将开发和应用由对流层高度的分布式对流源向上发射的二维和三维完全非线性的可压缩重力波模式。这些模式将求解一组表示质量、动量和能量守恒的标准方程，并将考虑对流层雷暴的实际对流特性以及环境大气的实际参数(即温度、Brunt-Vaisala频率和风廓线)。

This three year effort will investigate the mesospheric effects of gravity waves generated by strong convection activity in large area multicell thunderstorms at tropospheric altitudes. Due to their large sizes, the multicell thunderstorms cannot be treated as point sources and require generalization of the existing gravity wave theory for cylindrical, aperture type, sources with inclusion of the resultant diffraction effects. The purpose of the project is to undertake a systematic and focused study of mesospheric effects of two and three dimensional fully nonlinear numerical models.The outstanding scientific questions which motivate this research program are (1) What is the dynamics of mesospheric cylindrical gravity waves generated by distributed convective sources at tropospheric altitudes? (2) What are effects of the convectively generated cylindrical gravity waves on mesospheric heating rates, wind profiles, and density perturbations? In order to answer these questions, the PI will develop and apply two and three dimensional, fully non-linear, compressible models of gravity waves launched upward by distributed convective sources at tropospheric altitudes. These models will be solving a standard set of equations expressing conservation of mass, momentum and energy, and will account for realistic convective properties of tropospheric thunderstorms as well as realistic parameters of the ambient atmosphere (i.e., temperature, Brunt-Vaisala frequency, and wind profiles).