The Effect of Radial Velocity Gridding Artifacts on Variationally Retrieved Vertical Velocities
The Effect of Radial Velocity Gridding Artifacts on Variationally Retrieved Vertical Velocities
复制标题
径向速度网格伪影对变分反演垂直速度的影响
DOI：
10.1175/2010jtecha1402.1
复制
发表时间：
2010
影响因子：
2.2
通讯作者：
Kao‐Shen Chung
中科院分区：
文献类型：
--
作者：
S. Collis;A. Protat;Kao‐Shen Chung
摘要本文研究了有序线性插值法产生的伪影的来源及其对变分反演上升气流强度的影响。给出了网格产品中周期性扰动产生的定性推理，并对网格伪影对上升气流提取的影响进行了简单的分析研究。通过将澳大利亚达尔文典型的非收敛流投影到扫描雷达的观察几何上，对网格伪影的影响进行了数值评估。提出了一种对有序线性插值法的简单改进，即混合阶线性插值法，以减少网格伪影。用这两种技术生成的径向速度网格被用来研究虚假上升气流的产生，而简单的有序线性插值法产生了2m S−1量级的错误上升气流。为了研究它对从实际天气事件中反演的垂直速度的影响，雷达衍生器对垂直速度的影响进行了研究。
Abstract This article investigates the source and impact of artifacts produced by ordered linear interpolation techniques on variationally retrieved updraft intensities. Qualitative reasoning for the generation of periodic perturbations in gridded products is presented, and a simple analytical investigation into the impact of gridding artifacts on updraft retrieval is carried out. By projecting a nonconvergent flow typical of Darwin, Australia, onto the viewing geometry of a scanning radar, a numerical assessment of the impact of gridding artifacts is carried out. A simple enhancement to ordered linear interpolation, mixed-order linear interpolation, is proposed to reduce gridding artifacts. Radial velocity grids produced using both techniques are used to investigate the generation of spurious updrafts, with the simple ordered linear interpolation technique producing erroneous updrafts on the order of 2 m s−1. To investigate the impact on vertical velocities retrieved from a real weather event, radar-deri...