Reply to comments on ‘The influence of rotational frontogenesis and its associated shearwise vertical motions on the development of an upper‐level front’
Reply to comments on ‘The influence of rotational frontogenesis and its associated shearwise vertical motions on the development of an upper‐level front’
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回复关于“旋转锋生及其相关的剪切垂直运动对上层锋发展的影响”的评论
DOI：
10.1002/qj.2042
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发表时间：
2013
影响因子：
8.9
通讯作者：
Jonathan E. Martin
中科院分区：
文献类型：
--
作者：
Andrea A. Lang;Jonathan E. Martin
Schultz（2012）提出，我们之前关于沿流地转冷空气平流在上层锋生过程中开始的论点是不完整的。他批评的核心，以及他呼吁加入额外诊断计算的动机，取决于垂直涡度可以相对于等熵旋转等熵的断言。在此响应中，我们推导出∇φ变化率的表达式，该表达式表明涡度相等地旋转∇θ和∇φ，与我们对该效果的原始陈述一致。推导出的表达式也为我们提出先前概念模型的修订提供了动力，强调了变形而不是涡度在∇θ相对于∇φ的微分旋转中的作用，这可能有助于启动沿流地转温度平流。最后，我们提出了一个四年的天气气候学，表明北美中部的上层锋生实际上偏向于以西北气流为特征的环境。版权所有©2012英国皇家气象学会
Schultz (2012) proposes that our previous arguments regarding the initiation of along‐flow geostrophic cold air advection during the upper frontogenesis process are incomplete. The core of his criticism, and the motivation for his call to include additional diagnostic calculations, hinges upon the assertion that the vertical vorticity can rotate isentropes relative to isohypses. In this response we derive an expression for the rate of change of ∇ϕ that demonstrates that vorticity rotates ∇θ and ∇ϕ equally, in accord with our original statement to that effect. The derived expression also provides motivation to propose a revision of our previous conceptual model, highlighting the role of deformation instead of vorticity in the differential rotation of ∇θ relative to ∇ϕ that can contribute to the initiation of along‐flow geostrophic temperature advection. Finally, we present a four‐year synoptic‐climatology suggesting that upper frontogenesis over central North America is, in fact, biased toward environments characterized by northwesterly flow. Copyright © 2012 Royal Meteorological Society