Convective aggregation in realistic convective-scale simulations
Convective aggregation in realistic convective-scale simulations
复制标题
真实对流规模模拟中的对流聚集
DOI：
10.1002/2017ms000980
复制
发表时间：
2017
影响因子：
6.8
通讯作者：
Holloway C
中科院分区：
文献类型：
--
作者：
Holloway C
为了研究理想化模型对流自聚集的真实的世界相关性，模拟了热带地区真实的有组织对流的5个15天案例。这些措施包括多个模拟每种情况下，测试对流组织和平均状态的敏感性，相互作用的辐射，相互作用的表面通量，和蒸发的雨。将这些模拟与配置为在理想化辐射对流平衡中运行的相同模型中看到的自聚集进行比较。对柱积分冻结湿静力能的空间方差的预算分析表明，控制运行对辐射的组织有显着的正贡献，对地面通量和输送有显着的负贡献，与理想化运行相似，一旦它们聚集起来。尽管在每种情况下所有实验的横向边界条件相同，但在不同的灵敏度运行之间发现平均柱水蒸气（CWV），CWV分布形状和CWV自相关长度尺度的系统差异，特别是对于那些没有相互作用辐射的实验，表明在理想化和现实模拟中，对这些反馈的敏感性至少有一些相似之处（尽管降水的组织对相互作用辐射的敏感性较低）。这些系统性差异的大小和符号与（1）由于横向边界的平流而导致的均衡和（2）由于缺乏相互作用辐射而导致的解聚之间的粗略平衡一致，这意味着解聚率与具有聚合初始条件和非相互作用辐射的理想化运行中的解聚率相当。这表明，在理想化模拟和真实的世界中，辐射反馈维持聚集对流的方式似乎是相似的。
To investigate the real‐world relevance of idealized‐model convective self‐aggregation, five 15 day cases of real organized convection in the tropics are simulated. These include multiple simulations of each case to test sensitivities of the convective organization and mean states to interactive radiation, interactive surface fluxes, and evaporation of rain. These simulations are compared to self‐aggregation seen in the same model configured to run in idealized radiative‐convective equilibrium. Analysis of the budget of the spatial variance of column‐integrated frozen moist static energy shows that control runs have significant positive contributions to organization from radiation and negative contributions from surface fluxes and transport, similar to idealized runs once they become aggregated. Despite identical lateral boundary conditions for all experiments in each case, systematic differences in mean column water vapor (CWV), CWV distribution shape, and CWV autocorrelation length scale are found between the different sensitivity runs, particularly for those without interactive radiation, showing that there are at least some similarities in sensitivities to these feedbacks in both idealized and realistic simulations (although the organization of precipitation shows less sensitivity to interactive radiation). The magnitudes and signs of these systematic differences are consistent with a rough equilibrium between (1) equalization due to advection from the lateral boundaries and (2) disaggregation due to the absence of interactive radiation, implying disaggregation rates comparable to those in idealized runs with aggregated initial conditions and noninteractive radiation. This points to a plausible similarity in the way that radiation feedbacks maintain aggregated convection in both idealized simulations and the real world.