Changes to the turbulent kinematics of a volcanic plume inferred from lightning data
Changes to the turbulent kinematics of a volcanic plume inferred from lightning data
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DOI：
10.1002/2015gl064199
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发表时间：
2015-05-28
影响因子：
5.2
通讯作者：
Bruning, Eric C.
中科院分区：
文献类型：
--
作者：
Behnke, Sonja A.;Bruning, Eric C.
2009年雷杜特火山喷发产生了一系列爆炸性事件，其中最大的一次产生了类似雷暴的火山闪电。闪电能谱是从喷发期间收集的闪电测绘数据计算出来的。将这些光谱与羽流发展的每个阶段预期的湍流特征进行了比较。早期出现的小闪光长度尺度与气体推力和初始对流阶段有关。随着爆炸事件的进展，闪光长度、刻度和闪光能量的增加与羽流体积的增加有关。具有大范围闪光长度(0.2-10公里)的光谱和小闪光长度尺度(1公里)的光谱峰值与来自气体推力、对流和伞状/火山灰云区的光谱叠加有关。在气体推力强迫结束并向漂移灰云过渡的10min左右，观测到了一个约5/3的幂定律斜率，这可能反映了漂移灰云的消散状态。
The 2009 Redoubt Volcano eruption produced a series of explosive events, the largest of which produced episodes of volcanic lightning similar to thunderstorms. Flash energy spectra were calculated from lightning mapping data collected during the eruption. The spectra were compared to the turbulence characteristics expected from each stage of plume development. Small flash length scales present at early times were associated with the gas thrust and initial convective stages. Increases in flash length scales and flash energy as the explosive events progressed were associated with an increase in volume of the plume. Spectra with a large range in flash length scales (0.2-10km) and a spectral peak at small flash length scales (< 1km) were associated with a superposition of spectra from gas thrust, convective, and umbrella/ash cloud regions. An approximate 5/3 power law slope was observed on the order of 10min after gas thrust forcing had ended and the transition to a drifting ash cloud was underway, which may reflect the dissipating state of the drifting ash cloud.