Although the release of conditional symmetric instability (CSI) by slantwise convection is recognized as an important baroclinic process, the basic dynamics of these circulations and their representation in numerical models remain inadequately understood. To address this issue, a series of 2D idealized experiments of pure slantwise convection are performed in an initially statically stable environment using the non‐hydrostatic Weather Research and Forecasting model, with the horizontal grid lengths varying between 1 and 40 km. The results show that the larger‐scale feedbacks of the slantwise convection converge numerically when a cross‐band grid length (∆y) of 5 km is reached. The differences between the non‐converged and converged results tie closely to the release of a shallow layer of conditional instability that inevitably accompanies the early development of the slantwise circulation due to differential advection of saturation equivalent potential temperature ( ${\theta }_{\mathrm{e}}^{*}$). The resolved small‐scale upright convection embedded within the slantwise band can energize the horizontal acceleration of the slantwise band at mid‐to‐upper levels by transporting low geostrophic momentum upward that results in localized inertial instability. The convective cell also enhances the large‐scale CSI neutralization by advecting high ${\theta }_{\mathrm{e}}^{*}$ downward with strong downdraughts that orient more vertically than coarser‐gridded runs. Moreover, ∆y ≤ 5 km also better resolves the horizontal pressure gradients for cross‐band motions. This work suggests that global/climate numerical weather prediction models may not adequately resolve important characteristics of slantwise convection. As most cumulus schemes target only upright convection, the inclusion of parametrized slantwise convection may improve their performance.

中文翻译：

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在理想框架下倾斜对流动力学对网格间距建模的敏感性

尽管通过斜向对流释放条件对称不稳定性（CSI）被认为是重要的斜压过程，但对这些环流的基本动力学及其在数值模型中的表示仍然缺乏足够的了解。为了解决这个问题，使用非静水天气研究和预报模型在初始静态稳定的环境中进行了一系列纯斜向对流的2D理想化实验，水平网格长度在1至40 km之间变化。结果表明，当跨带网格长度为（y）时，斜向对流的较大规模反馈在数值上收敛。）达到5公里。非收敛和收敛结果之间的差异与条件不稳定浅层的释放紧密相关，由于饱和等效电位温度的对流差异，不可避免地伴随着倾斜环流的早期发展而释放出条件不稳定的浅层。${\theta }_{\mathrm{Ë}}^{*}$）。嵌入在倾斜带内的已分解的小规模直立对流可以通过向上输送低的地转运动动量来激发倾斜带在中上水平的水平加速度，从而导致局部惯性不稳定性。对流单元还可以通过对流单元的高平移来增强大规模CSI中和作用。${\theta }_{\mathrm{Ë}}^{*}$向下的气流强于较粗糙的滑道更垂直的方向。此外，Δ ÿ  ≤  5公里也更好解决跨带的运动水平压力梯度。这项工作表明，全球/气候数值天气预报模型可能无法充分解决倾斜对流的重要特征。由于大多数积云方案仅以直立对流为目标，因此包含参数化的斜向对流可能会改善其性能。