Thermal radiance observations of an active lava flow during the June 1984 eruption of Mount Etna
Thermal radiance observations of an active lava flow during the June 1984 eruption of Mount Etna
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1984 年 6 月埃特纳火山喷发期间活跃熔岩流的热辐射观测
DOI：
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
M. Abrams
中科院分区：
文献类型：
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作者：
D. Pieri;L. Glaze;M. Abrams
根据陆地卫星专题制图仪采集的数据，分析了1984年6月20日从意大利西西里埃特纳火山东南部火山口观测到的活跃熔岩流的热收支。专题制图仪的图像是为数不多的空间和光谱分辨率足够的卫星数据集之一，可以对活跃熔岩流的热辐射分布和强度进行校准测量。使用来自两个反射红外通道的辐射数据，我们可以估计活动流最热部分的温度和面积，这些部分对应于流表面的热（>500 °C）裂缝或区域。使用这种技术，我们估计只有10%-20%的总辐射热功率输出是由热区或裂缝发出的，它们占观察到的表面积的不到1%。通常，似乎只有在热裂缝或热区域构成大于流的表面积的约1%的情况下，来自这些特征的损失才会显著降低内部流温度。使用我们的辐射观测作为边界条件的多组分热模型的流动内部温度，我们推断，该流的部分进行分析，边界层和流动厚度的影响占主导地位的辐射区控制抑郁症的核心温度。
The thermal budget of an active lava flow observed on 20 June 1984 from the Southeast crater of Mount Etna, Sicily, Italy, was analyzed from data taken by the Landsat Thematic Mapper. The Thematic Mapper images constitute one of the few satellite data sets of sufficient spatial and spectral resolution to allow calibrated measurements on the distribution and intensity of thermal radiation from active lava flows. Using radiance data from two reflective infrared channels, we can estimate the temperature and areas of the hottest parts of the active flow, which correspond to hot (>500 °C) fractures or zones at the flow surface. Using this technique, we estimate that only 10%-20% of the total radiated thermal power output is emitted by hot zones or fractures, which constitute less than 1% of the observed surface area. Generally, it seems that only where hot fractures or zones constitute greater than about 1% of the surface area of the flow will losses from such features significantly reduce internal flow temperatures. Using our radiance observations as boundary conditions for a multicomponent thermal model of flow interior temperature, we infer that, for the parts of this flow subject to analysis, the boundary layer and flow thickness effects dominate over radiant zones in controlling the depression of core temperature.