A Linear Relationship between Vertical Velocity and Condensation Processes in Deep Convection
A Linear Relationship between Vertical Velocity and Condensation Processes in Deep Convection
复制标题
深层对流中垂直速度与凝结过程之间的线性关系
DOI：
10.1175/jas-d-21-0035.1
复制
发表时间：
2022
影响因子：
3.1
通讯作者：
Stephens, Graeme L.
中科院分区：
文献类型：
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作者：
Grant, Leah D.;van den Heever, Susan C.;Haddad, Ziad S.;Bukowski, Jennie;Marinescu, Peter J.;Storer, Rachel L.;Posselt, Derek J.;Stephens, Graeme L.
垂直速度和深层对流中的微物理过程错综复杂地联系在一起，对水和质量的垂直输送、恶劣天气、极端降水和全球环流有着广泛的影响。本研究的目的是探讨垂直速度(w)与深层对流中将水蒸气转化为冷凝水(M)的微物理过程之间关系的函数形式。我们研究了一系列高分辨率模拟，涵盖了一系列热带和中纬度环境，各种对流组织模式，以及不同的模式平台和微物理方案。结果表明，两者之间的关系是线性的，线性拟合的斜率主要是温度的函数，其次是过饱和的函数。除了在冻结和均匀冻结水平附近，线性拟合的ther2一般都在0.6以上。线性拟合作为局部云内温度和环境温度的函数进行了检验。云内温度的结果在整个模拟套件中更加一致，尽管在考虑潜在的观测应用时环境温度更有用。将两者之间的线性关系代入凝析倾向方程，重新排列形成诊断方程。在几个模拟中对诊断方程的性能进行了测试，发现它可以诊断整个云层上半部分的风暴尺度上升气流速度在1 m s−1以内。讨论了线性关系和诊断方程的潜在应用。
Vertical velocities and microphysical processes within deep convection are intricately linked, having wide-ranging impacts on water and mass vertical transport, severe weather, extreme precipitation, and the global circulation. The goal of this research is to investigate the functional form of the relationship between vertical velocity (w) and microphysical processes that convert water vapor into condensed water (M) in deep convection. We examine an ensemble of high-resolution simulations spanning a range of tropical and midlatitude environments, a variety of convective organizational modes, and different model platforms and microphysics schemes. The results demonstrate that the relationship betweenwandMis robustly linear, with the slope of the linear fit being primarily a function of temperature and secondarily a function of supersaturation. TheR2of the linear fit is generally above 0.6 except near the freezing and homogeneous freezing levels. The linear fit is examined both as a function of local in-cloud temperature and environmental temperature. The results for in-cloud temperature are more consistent across the simulation suite, although environmental temperatures are more useful when considering potential observational applications. The linear relationship betweenwandMis substituted into the condensate tendency equation and rearranged to form a diagnostic equation forw. The performance of the diagnostic equation is tested in several simulations, and it is found to diagnose the storm-scale updraft speeds to within 1 m s−1throughout the upper half of the clouds. Potential applications of the linear relationship betweenwandMand the diagnosticwequation are discussed.