Spurious production of cloud-edge supersaturations by Eulerian models
Spurious production of cloud-edge supersaturations by Eulerian models
复制标题
欧拉模型产生的云边缘过饱和度的虚假产生
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
G. Feingold
中科院分区：
文献类型：
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作者：
B. Stevens;R. Walko;W. Cotton;G. Feingold
摘要在云底以外的云边缘产生异常的过饱和，这对试图代表欧拉网格上液滴光谱演变的建模者来说是一个棘手的挑战。虽然这个问题最显着地表现为模型，明确地预测过饱和度场，它也存在于模型中的批量冷凝计划，其中冷凝发生隐式。虽然这个问题已经讨论了截断误差与有限差分近似平流的背景下，这说明更一般地表明，云边缘过饱和问题是一个基本问题，与普遍存在的假设，即强迫液滴光谱很好地代表了平均热力学场。在某些方面，这种假设相当于无法表示网格内的部分云量。虽然众所周知的后果，这个问题是低估的TEM…
Abstract The production of anomalous supersaturations at cloud edges other than cloud base has presented a vexing challenge for modelers attempting to represent the evolution of a droplet spectrum across an Eulerian grid. Although the problem manifests itself most dramatically for models that explicitly predict on the supersaturation field, it is also present in models with bulk condensation schemes in which condensation happens implicitly. Although the problem has been discussed in the context of truncation errors associated with finite difference approximations to advection, this note demonstrates more generally that the cloud-edge supersaturation problem is a fundamental problem associated with the ubiquitous assumption that the forcings on the droplet spectra are well represented by the mean thermodynamic fields. In certain respects, this assumption is equivalent to failing to represent fractional cloudiness within a grid. Although well-known consequences of this problem are the underprediction of tem...