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Mudanjiang, China

Zhao Y.,Chinese Institute of Crustal Dynamics | Zhao Y.,China Earthquake Administration | Liang Y.,Mudanjiang Seismic Station | Ma B.,Mudanjiang Seismic Station | And 2 more authors.
Acta Petrologica Sinica | Year: 2014

The eruption of Iceland's Eyjafjallajökull volcano in April-May 2010 resulted in an unprecedented disruption to Europe's airline industry as well as a huge economic loss. Such serious impact reminds us with vital importance to monitor ash cloud efficiently. Volcanic ash cloud is a mixture of volcanic debris and gases, with the former mainly composed of rocks, minerals and volcanic glass pieces all measuring less than 2mm in diameter, and the latter including major gases such as water vapor, CO2, SO2, H2S, CH4, CO, HCL, HF, HBr, and NOx etc. Using the FY-3A/VIRR data with China's own independent intellectual property rights, this paper attempts to identify volcanic ash cloud by adopting Split Window Temperature Difference method (SWTD), RGB nature color method and Mid-Infrared data etc. on the dates with typical wind direction changes in different phases of the Eyjafjallajökull volcanic eruption. Then, this paper makes a comparative study on the identification results with reference to the volcanic ash monitoring reports of Iceland and the research results of predecessors. The study suggests that in the preliminary stage of volcanic eruption high concentration of water vapor in volcanic ash cloud will compensate the reverse absorption and prevent the identification of volcanic ash cloud with SWTD method. Whereas Mid-Infrared data is more effective in identifying thermal volcanic ash cloud in the early volcanic eruption thanks to its sensitivity to high temperature objects to free from the influence of water vapor. In the mid and late eruption, three methods all perform well with high density of ash cloud. Satellite images clearly show the location and the drift direction of the ash cloud, which are also corresponding to the meteorological conditions. Hence, the identification methods prove to be correct. The research results indicate that FY-3A/VIRR data with our own independent intellectual property rights is capable of monitoring the ash cloud. How to define the boundary of the volcanic ash cloud more clearly and calculate the density of the volcanic ash cloud more accurately will be the focus of the further research.

Zhao Y.,China Earthquake Administration | Ma B.,Mudanjiang Seismic Station | Liang Y.,Mudanjiang Seismic Station | Li T.,Mudanjiang Seismic Station | Zhang M.,Shanghai University
Journal of Natural Disasters | Year: 2015

Volcanic ash clouds can pose a threat to air transport safety directly, so it is necessary to predict the trajectories of volcanic ash clouds. Depending on the data of numerical weather forecast, attracting structures method and PUFF model both can do it. By using the principle of the two methods, this paper applies the precise atmospheric trajectory parameter data of United States from 1958 to 1997 to calculate the attracting structures of wind field, simplifies calculation process and frees from dependance on numerical weather forecast data. It realizes the prediction of volcanic ash cloud drift path. And a comparison with attracting structures method was carried out. Results show that it is feasible to track the volcanic ash cloud with the calculation method of wind field.

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