scholarly journals Numerical Simulation of Volcanic Ash Plume Dispersal from Kuchinoerabujima on 29 May 2015

2016 ◽  
Vol 37 (2) ◽  
pp. 79-90 ◽  
Author(s):  
Hiroshi L. TANAKA ◽  
Masato IGUCHI
Keyword(s):  
Numerical Simulation ◽  
Volcanic Ash ◽  
Plume Dispersal ◽  
Ash Plume

Numerical Simulations of Volcanic Ash Plume Dispersal from Kelud Volcano in Indonesia on February 13, 2014

2016 ◽  
Vol 11 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Hiroshi L. Tanaka ◽  
◽  
Masato Iguchi ◽  
Setsuya Nakada ◽  
◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Model Simulation ◽  
Ground Deformation ◽  
Dispersion Model ◽  
Danger Zone ◽  
2014 Eruption ◽  
Southern Half ◽  
Ash Dispersion ◽  
Plume Dispersal ◽  
Ash Plume

In order to evaluate airborne ash densities, a real-time volcanic ash dispersion model, PUFF, is applied to the February 13, 2014 eruption of Kelud volcano in Indonesia. The emission rate of the ash mass from the vent is estimated based on the empirical formulae tested at Sakurajima volcano using ground deformation and seismic monitoring data.According to the result of the PUFF model simulation, the circular shape of the anvil ash cloud 17 km in height extends during the first two hours over a radius of 200 km from the volcano. The core region within 50 km of the volcano shows an airborne ash density of 1000 mg/m3. Three hours after the initial eruption, the area with 100 mg/m$^bm 3$ extends 300 km to the west, covering Yogyakarta Airport. Due to low-level winds, Surabaya Airport to the northeast also becomes part of the area with 100 mg/m3. The result of the ash plume dispersal 7 hours into the eruption indicates that the entire island of Java is in the danger zone for commercial airliners, as ash exceeds 10 mg/m3. Although satellite images show that the ash plume is located only in the southern half of western Java, the simulation results quantitatively indicate much wider extents of the aircraft danger zone.

scholarly journals Airborne observations of the Eyjafjalla volcano ash cloud over Europe during air space closure in April and May 2010

2011 ◽  
Vol 11 (5) ◽  
pp. 2245-2279 ◽  
Author(s):  
U. Schumann ◽  
B. Weinzierl ◽  
O. Reitebuch ◽  
H. Schlager ◽  
A. Minikin ◽  
...  
Keyword(s):  
Mass Concentration ◽  
Volcanic Ash ◽  
Particle Density ◽  
Airborne Lidar ◽  
Particle Sedimentation ◽  
Space Closure ◽  
Ash Plume ◽  
Ground Based Lidar ◽  
Ash Cloud ◽  
Mass Concentrations

Abstract. Airborne lidar and in-situ measurements of aerosols and trace gases were performed in volcanic ash plumes over Europe between Southern Germany and Iceland with the Falcon aircraft during the eruption period of the Eyjafjalla volcano between 19 April and 18 May 2010. Flight planning and measurement analyses were supported by a refined Meteosat ash product and trajectory model analysis. The volcanic ash plume was observed with lidar directly over the volcano and up to a distance of 2700 km downwind, and up to 120 h plume ages. Aged ash layers were between a few 100 m to 3 km deep, occurred between 1 and 7 km altitude, and were typically 100 to 300 km wide. Particles collected by impactors had diameters up to 20 μm diameter, with size and age dependent composition. Ash mass concentrations were derived from optical particle spectrometers for a particle density of 2.6 g cm−3 and various values of the refractive index (RI, real part: 1.59; 3 values for the imaginary part: 0, 0.004 and 0.008). The mass concentrations, effective diameters and related optical properties were compared with ground-based lidar observations. Theoretical considerations of particle sedimentation constrain the particle diameters to those obtained for the lower RI values. The ash mass concentration results have an uncertainty of a factor of two. The maximum ash mass concentration encountered during the 17 flights with 34 ash plume penetrations was below 1 mg m−3. The Falcon flew in ash clouds up to about 0.8 mg m−3 for a few minutes and in an ash cloud with approximately 0.2 mg m−3 mean-concentration for about one hour without engine damage. The ash plumes were rather dry and correlated with considerable CO and SO2 increases and O3 decreases. To first order, ash concentration and SO2 mixing ratio in the plumes decreased by a factor of two within less than a day. In fresh plumes, the SO2 and CO concentration increases were correlated with the ash mass concentration. The ash plumes were often visible slantwise as faint dark layers, even for concentrations below 0.1 mg m−3. The large abundance of volatile Aitken mode particles suggests previous nucleation of sulfuric acid droplets. The effective diameters range between 0.2 and 3 μm with considerable surface and volume contributions from the Aitken and coarse mode aerosol, respectively. The distal ash mass flux on 2 May was of the order of 500 (240–1600) kg s−1. The volcano induced about 10 (2.5–50) Tg of distal ash mass and about 3 (0.6–23) Tg of SO2 during the whole eruption period. The results of the Falcon flights were used to support the responsible agencies in their decisions concerning air traffic in the presence of volcanic ash.

scholarly journals Ash plume top height estimate using AATSR

2014 ◽  
Vol 7 (4) ◽  
pp. 3863-3913
Author(s):  
T. H. Virtanen ◽  
P. Kolmonen ◽  
E. Rodríguez ◽  
L. Sogacheva ◽  
A.-M. Sundström ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Quality Parameters ◽  
Height Estimate ◽  
Brightness Temperatures ◽  
In Situ Data ◽  
Estimate Method ◽  
Ash Plume ◽  
Along Track

Abstract. An algorithm is presented for estimation of volcanic ash plume top height using the stereo view of the Advanced Along Track Scanning Radiometer (AATSR) aboard ENVISAT. The algorithm is based on matching the top of atmosphere (TOA) reflectances and brightness temperatures of the nadir and 55° forward views, and using the resulting parallax to obtain the height estimate. Various retrieval parameters are discussed in detail, several quality parameters are introduced, and post-processing methods for screening out unreliable data have been developed. The method is compared against other satellite observations and in-situ data. The proposed algorithm is designed to be fully automatic, and can be implemented into operational retrieval algorithms. Combined with automated ash detection using the brightness temperature difference between the 11 μm and 12 μm channels, the algorithm allows simultaneous retrieval of horizontal and vertical dispersion of volcanic ash efficiently. A case study on the eruption of the Icelandic volcano Eyjafjallajökull in 2010 is presented. The height estimate method results are validated against available satellite and ground based data.

scholarly journals Ash plume top height estimation using AATSR

2014 ◽  
Vol 7 (8) ◽  
pp. 2437-2456 ◽  
Author(s):  
T. H. Virtanen ◽  
P. Kolmonen ◽  
E. Rodríguez ◽  
L. Sogacheva ◽  
A.-M. Sundström ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Quality Parameters ◽  
Brightness Temperatures ◽  
In Situ Data ◽  
Vertical Dispersion ◽  
Fully Automatic ◽  
Ash Plume ◽  
Along Track

Abstract. An algorithm is presented for the estimation of volcanic ash plume top height using the stereo view of the Advanced Along Track Scanning Radiometer (AATSR) aboard Envisat. The algorithm is based on matching top of the atmosphere (TOA) reflectances and brightness temperatures of the nadir and 55° forward views, and using the resulting parallax to obtain the height estimate. Various retrieval parameters are discussed in detail, several quality parameters are introduced, and post-processing methods for screening out unreliable data have been developed. The method is compared to other satellite observations and in situ data. The proposed algorithm is designed to be fully automatic and can be implemented in operational retrieval algorithms. Combined with automated ash detection using the brightness temperature difference between the 11 and 12 μm channels, the algorithm allows efficient simultaneous retrieval of the horizontal and vertical dispersion of volcanic ash. A case study on the eruption of the Icelandic volcano Eyjafjallajökull in 2010 is presented.

scholarly journals Design and Preliminary Testing of the Volcanic Ash Plume Receiver Network

2019 ◽  
Vol 36 (3) ◽  
pp. 353-367
Author(s):  
Nicholas Rainville ◽  
Scott Palo ◽  
Kristine M. Larson ◽  
Mario Mattia
Keyword(s):  
Volcanic Ash ◽  
Detection Method ◽  
Low Cost ◽  
Signal Strength ◽  
Distributed Sensor ◽  
Additional Processing ◽  
Signal Path ◽  
Ash Plume ◽  
Processing Steps

AbstractThe presence of volcanic ash in the signal path between a GPS satellite and a ground-based receiver strongly correlates with a decrease in GPS signal strength. This effect has been seen in data collected from GPS sites located near active volcanoes; however, the sparse placement of existing GPS sites limits the applicability of this technique as an ash plume detection method to relatively few well-instrumented volcanoes. This deficiency has motivated the development of a low-cost distributed sensor system based on navigation-grade GPS receivers, which can take advantage of attenuated GPS signals to increase the quality and availability of real-time ash plume observations during an eruption. This GPS-based system has been designed specifically to meet remote sensing needs while operating autonomously in difficult conditions and minimizing on-site infrastructure requirements. Prototypes of this system have undergone long-term testing and the data collected from this testing have been used to develop the additional processing steps necessary to account for the different behavior of navigation grade GPS equipment compared to the geodetic equipment used at existing GPS sites.

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