Volcanic ash ice-nucleating activity can be enhanced or depressed by ash-gas interaction in the eruption plume
Volcanic ash ice-nucleating activity can be enhanced or depressed by ash-gas interaction in the eruption plume
复制标题
喷发羽流中的火山灰-气体相互作用可以增强或抑制火山灰冰核活动
DOI：
10.1016/j.epsl.2020.116587
复制
发表时间：
2020
影响因子：
5.3
通讯作者：
Maters E
中科院分区：
文献类型：
--
作者：
Maters E
当火山灰浸入过冷水中时，会引发冰成核。这将影响多个过程（例如，在火山灰扩散时，火山灰在喷发羽流和云以及更广泛的大气中起作用（如带电、聚集、沉淀）。以往的研究表明，火山灰的整体性质，反映了源岩浆的化学和相态，可能有助于冰成核活动（INA）的火山灰。然而，它仍然是未探索如何与岩浆气体的热喷发羽流，这不可避免地导致改变灰的表面特性，影响灰INA。在这里，我们证明了火山灰的INA在800和400 °C下暴露于H2O（g）与SO2（g）的混合物中时升高，但在相同温度下暴露于单独的H2O（g）或与HCl（g）的混合物中时显著降低。相反，钾长石和石英的INA减少了所有三个喷发羽处理。在与H2O（g）加热后，所有硅酸盐的INA的减少可能与通过表面脱羟基和/或氧化而损失冰活性位点有关。在HCl（g）或SO2（g）的存在下，金属氯化物或硫酸盐仅在火山灰表面上形成。虽然NaCl和CaCl 2似乎对火山灰INA没有影响，但CaSO 4可能通过表面化学和地形的特定组合来创建冰活性位点。总的来说，我们的研究结果表明，在影响冰成核火山灰的散装矿物和表面蚀变的复杂的相互作用，并强调灰INA的一般敏感性（增强或抑郁症）的火山喷发羽流与岩浆气体的相互作用。
Volcanic ash can trigger ice nucleation when immersed in supercooled water. This will impact several processes (e.g., electrification, aggregation, precipitation) in the eruption plume and cloud and in the wider atmosphere upon ash dispersal. Previous studies show that ash bulk properties, reflecting the chemistry and phase state of the source magma, likely contribute to the ice-nucleating activity (INA) of ash. However, it remains unexplored how interaction with magmatic gases in the hot eruption plume, which inevitably leads to altered ash surface properties, affects the ash INA. Here we demonstrate that the INA of tephra is raised by exposure to H2O(g)mixed with SO2(g)at both 800 and 400 °C, but is substantially reduced by exposure to H2O(g)alone or mixed with HCl(g)at the same temperatures. In contrast, the INA of K-feldspar and quartz is reduced by all three eruption plume processing treatments. The decrease in INA of all silicates after heating with H2O(g)might relate to a loss of ice-active sites by surface dehydroxylation and/or oxidation. In the presence of HCl(g)or SO2(g), respectively, metal chloride or sulphate salts form on the tephra surfaces only. While NaCl and CaCl2seem to have no effect on the tephra INA, CaSO4is inferred to create ice-active sites, potentially through a particular combination of surface chemistry and topography. Overall, our findings suggest a complex interplay of bulk mineralogy and surface alteration in influencing ice nucleation by volcanic ash, and highlight the general sensitivity (enhancement or depression) of ash INA to interaction with magmatic gases in the eruption plume.
登录
查看更多内容
浸入水中的石英的冰核能力及其与钾长石相比的大气重要性
DOI：
10.5194/acp-2019-288
发表时间：
2019
期刊：
--
影响因子：
--
作者：
Harrison A
通讯作者：
Harrison A
重新审视由液滴冷冻实验得出的差速冷冻核光谱：计算方法、应用和置信限
影响因子：
3.8
作者：
G. Vali
通讯作者：
G. Vali
影响因子：
6.3
作者：
Maters, Elena C.;Dingwell, Donald B.;Murray, Benjamin J.
通讯作者：
Murray, Benjamin J.
影响因子：
5.2
作者：
Augustin-Bauditz, S.;Wex, H.;Stratmann, F.
通讯作者：
Stratmann, F.
影响因子：
2.9
作者：
K. Genareau;S. Cloer;K. Primm;M. Tolbert;T. Woods
通讯作者：
T. Woods