Analyses of three-dimensional weather radar data from volcanic eruption clouds
Analyses of three-dimensional weather radar data from volcanic eruption clouds
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DOI：
10.1016/j.jvolgeores.2021.107178
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发表时间：
2021-02-20
影响因子：
2.9
通讯作者：
Iguchi, Masato
中科院分区：
文献类型：
--
作者：
Maki, Masayuki;Kim, Yura;Iguchi, Masato
本文论证了天气雷达资料的三维分析和可视化在喷发柱内部结构及其三维落灰分布研究中的优势。3D数据是使用一台运行中的X波段偏振雷达收集的，该雷达位于日本樱岛昭和喷口附近11公里处。选择了三个喷发案例进行分析，以研究环境风条件对喷发柱内部结构和1000米高度水平落灰分布的影响：2013年6月13日平静风下3677米高的喷发(案例1)，2013年10月7日3982米高的喷发(案例2)和2013年8月18日中风下4520米高的喷发(案例3)。开发了三维天气雷达数据分析工具(ANT3D)程序包，用于构造来自喷发柱的3D恒定高度平面位置指示器(3D CAPP1)数据。3DCAPI数据的定量落灰分析表明，1级喷发、2级喷发和3级喷发的总落灰量分别为6.24x10(7)、9.99x10(7)和6.71x10(7)kg，总落灰面积分别为29.7万、151.3和107.7千米(2)。结果表明，在1000m高度，落灰量最大的区域取决于环境条件。1级喷发的累积落灰分布区域局限于喷口周围，而2级喷发由于多次喷发，灰尘分布向下风方向拉长，形成多个灰尘浓度极大值。3级喷发的累积落灰分布也向下风方向拉长，但在樱岛内陆发现了比2级喷发大的单一最大浓度。使用表面绘制、体绘制、鸟瞰和横断面分析等技术将3D CAPPI数据可视化。3D可视化显示，在所有三个案例中，垂直大小分类和聚集都发生在喷发柱的浮力驱动区域。这一研究结果将有助于理解火山喷发的柱状动力学和水平落灰运移。(C)2021年爱思唯尔B.V.保留所有权利。
This paper demonstrates the advantages of three-dimensional (3D) analysis and visualization of weather radar data for studies on the inner structure of eruption columns and their 3D ash-fall distributions. The 3D data were collected using an operational X-band polarimetric radar located similar to 11 km from the Showa vent of Sakurajima, Japan. Three eruption cases were chosen for the analysis to study the effect of environmental wind conditions on the inner structure of an eruption column and horizontal ash-fall distributions at 1000 m height: a 3677-m-high eruption on 13 June 2013 under calm winds (Case 1), a 3982-m-high eruption on 7 October 2013 under strong winds (Case 2), and a 4520-m-high eruption on 18 August 2013 under moderate winds (Case 3). The Analytical Tools for Three-dimensional Weather Radar Data (ANT3D) package was developed and used for the construction of 3D constant altitude plan position indicator (3D CAPP1) data from eruption columns. The quantitative ash-fall analyses of 3D CAPPI data revealed that the total ash-fall amounts of the Case 1, Case 2, and Case 3 eruptions were 6.24 x 10(7), 9.99 x 10(7), and 6.71 x 10(7) kg, respectively, and the total ash-fall areas at the 1000-m height were 29.7, 151.3, and 107.7 km(2), respectively. It was shown that the area of the maximum ash-fall amount at the 1000-m height depends on the environmental conditions. The accumulated ash-fall distribution area was limited to over and around the vent in the Case 1 eruption, whereas the ash distribution pattern was elongated to the downwind direction and multiple ash concentration maxima were formed in the Case 2 eruption probably due to the multiple eruptions. The accumulated ash-fall distribution was also elongated to the down wind direction in the Case 3 eruption but a single maximum concentration which was larger than that in the Case 2 eruption was found inland of Sakurajima. The 3D CAPPI data were visualized using techniques such as surface rendering, volume rendering, bird's eye viewing, and cross-sectional analysis. The 3D visualizations suggest that vertical size-sorting and aggregation occurred in the buoyancy-driven regions of the eruption columns in all three cases. The results of this study will contribute to the understanding of volcanic eruption column dynamics and horizontal ash-fall transportation. (C) 2021 Elsevier B.V. All rights reserved.