Evolving infrasound detections from Bogoslof volcano, Alaska: insights from atmospheric propagation modeling
Evolving infrasound detections from Bogoslof volcano, Alaska: insights from atmospheric propagation modeling
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阿拉斯加博戈斯洛夫火山不断变化的次声探测：大气传播模型的见解
DOI：
10.1007/s00445-020-1360-3
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发表时间：
2020
影响因子：
3.5
通讯作者：
M. Haney
中科院分区：
文献类型：
--
作者：
H. Schwaiger;J. Lyons;A. Iezzi;D. Fee;M. Haney
博戈斯洛夫火山是阿拉斯加阿留申弧的弧后火山，于2016年12月中旬开始喷发序列，于2017年8月下旬结束，有70个单独的喷发事件。由于岛上没有当地的地震或次声观测站，阿拉斯加火山观测站依靠遥远的地球物理网络和遥感技术来评估火山爆发期间的活动。AVO拥有六个次声阵列来监测阿留申岛弧沿着的活动：阿达克、四山岛、奥克莫克、阿库坦、沙角和迪灵厄姆。在次声阵列上探测火山喷发受当地以及中尺度气象条件的影响，这些条件在短期和长期尺度上变化很大。距离博戈斯洛夫（Okmok）最近的阵列的次声探测，潜伏期约为3分钟，在监测喷发期间的活动方面发挥了至关重要的作用。尽管Okmok阵列相对接近Bogoslof（60公里），但次声探测并不均匀，只有大约三分之二的事件被成功探测到。位于迪灵厄姆（816公里）的最远的阵列探测到了大约一半的爆炸事件，所有其他阵列探测到的爆炸事件不到一半。我们比较观察次声传播模型预测，使用正常模式和抛物方程正演模型，解释在整个AVO次声网络的70个爆炸事件的检测变化。前向模型利用新创建的、公开可用的AVO-G2 S大气重建，使用低层大气的数值天气预报数据，加上高层大气风速和温度的经验模型。我们发现，在有利的传播条件下，Bogoslof事件的长距离检测（> 100公里）在很大程度上与季节性变化一致，而区域检测（< 100公里）与传播模型不太一致。了解数值模型的输出与过去的观测结果相比，将有助于它们在AVO和其他观测站的未来业务设置中的使用。
Bogoslof volcano, a back-arc volcano in Alaska’s Aleutian arc, began an eruptive sequence in mid-December 2016 that ended in late August 2017, with 70 individual eruptive episodes. Because there were no local seismic or infrasound stations on the island, the Alaska Volcano Observatory (AVO) relied on distant geophysical networks and remote sensing techniques to assess activity during the eruption. AVO maintains six infrasound arrays to monitor activity along the Aleutian arc: Adak, the Island of Four Mountains, Okmok, Akutan, Sand Point, and Dillingham. Eruption detection at infrasound arrays is subject to local as well as mesoscale meteorological conditions that vary greatly over both short and long timescales. Infrasound detections from the array nearest to Bogoslof (Okmok), with a latency of about 3 min, played a crucial role in monitoring activity during the eruption. Despite the relative proximity of the Okmok array to Bogoslof (60 km), infrasound detections were not uniformly observed with only about two-thirds of the events successfully detected. The farthest array at Dillingham (816 km) detected approximately half of the explosive events, with all other arrays detecting less than half of the events. We compare observations with infrasound propagation model predictions, using both normal mode and parabolic equation forward models, to interpret the variation in detections of the 70 explosive events across the AVO infrasound network. The forward models utilize the newly created, publicly available AVO-G2S atmospheric reconstruction using numerical weather predictions data for the lower atmosphere, coupled with upper atmosphere empirical models of wind speeds and temperature. We find that long-range detections (> 100 km) of Bogoslof events are largely aligned with seasonal variability in favorable propagation conditions, while regional detections (< 100 km) are less consistent with propagation modeling. Understanding the output of numerical models in comparison to past observations will facilitate their use in future operational settings for AVO and other observatories.
2016 年至 2017 年阿拉斯加博戈斯洛夫火山喷发期间，充冰是否产生了火山闪电？
影响因子：
3.5
作者：
Van Eaton, Alexa R.;Schneider, David J.;Smith, Cassandra M.;Haney, Matthew M.;Lyons, John J.;Said, Ryan;Fee, David;Holzworth, Robert H.;Mastin, Larry G.
通讯作者：
Mastin, Larry G.