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Simulation of the spreading of volcanic ash particles from the Eyjafjallajökull volcano's eruption at different time instants in the form of "year.month.day.hour:minute" indicated in the panels' label (a-f). 30 × 30 × 30 particles of r = 5 µm and p = 2000 kg m −3 are initiated in a rectangular cuboid of size of 100 km × 100 km × 4 km at 63.63 • N, 19.6 • W, at the altitude of 7 km on 14 April 2010 at 06 UTC. Simulation is initialized with the parameters on the left of Figure A1. Colorbar indicates the altitude of the particles, black color marks deposited particles.
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Large-scale atmospheric pollutant spreading via volcano eruptions and industrial accidents may have serious effects on our life. However, many students and non-experts are generally not aware of the fact that pollutant clouds do not disperse in the atmosphere like dye blobs on clothes. Rather, an initially compact pollutant cloud soon becomes stron...
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... on these data, to get a first impression about the main characteristics of atmospheric pollutant spreading by means of RePLaT-Chaos, Figure 1 shows the simulation of the spreading of a single, initially compact ash cloud of height of 4 km injected into the atmosphere due to the eruption of the Eyjafjallajökull on 14 April 2010 at 06:00 UTC. The ash cloud in the simulation consisted of 2.7 × 10 4 particles with r = 5 µm and p = 2000 kg m −3 . ...
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... ash cloud in the simulation consisted of 2.7 × 10 4 particles with r = 5 µm and p = 2000 kg m −3 . Figure 1 illustrates that within a few days the ash cloud travels over Scandinavia and reaches Eastern Europe due to being transported by the northwesterly winds of a high pressure system located south of Iceland at the beginning and then moving towards Scandinavia. Figure 1 demonstrates well that the spreading of volcanic ash clouds (and any atmospheric pollutants) differs from the dispersion of dye droplets on clothes. ...
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... 1 illustrates that within a few days the ash cloud travels over Scandinavia and reaches Eastern Europe due to being transported by the northwesterly winds of a high pressure system located south of Iceland at the beginning and then moving towards Scandinavia. Figure 1 demonstrates well that the spreading of volcanic ash clouds (and any atmospheric pollutants) differs from the dispersion of dye droplets on clothes. The latter is of a slowly growing circular shape, while Figure 1 shows that an important feature of atmospheric pollutant spreading is the rapid distortion of an initially small and compact cloud into an increasingly stretched, filament-like shape, extending to a region of some thousands of kilometers within a few days. ...
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... 1 demonstrates well that the spreading of volcanic ash clouds (and any atmospheric pollutants) differs from the dispersion of dye droplets on clothes. The latter is of a slowly growing circular shape, while Figure 1 shows that an important feature of atmospheric pollutant spreading is the rapid distortion of an initially small and compact cloud into an increasingly stretched, filament-like shape, extending to a region of some thousands of kilometers within a few days. As mentioned in the Introduction, the observed rapid stretching of pollutant clouds is a consequence of the chaotic nature of the spreading. ...
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... the beginning (see Figure 1a), the top of the ash cloud reaches the altitude of 9 km (cyan color). However, due to the impact of gravity, the particles descend in the atmosphere more or less continuously (but not uniformly), and after two days they reach the altitude of about 4-6 km (green color, Figure 1c). ...
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... the beginning (see Figure 1a), the top of the ash cloud reaches the altitude of 9 km (cyan color). However, due to the impact of gravity, the particles descend in the atmosphere more or less continuously (but not uniformly), and after two days they reach the altitude of about 4-6 km (green color, Figure 1c). Within three days, the altitude of the ash cloud in an extended region decreases even below 2-3 km (yellow color, Figure 1d). ...
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... due to the impact of gravity, the particles descend in the atmosphere more or less continuously (but not uniformly), and after two days they reach the altitude of about 4-6 km (green color, Figure 1c). Within three days, the altitude of the ash cloud in an extended region decreases even below 2-3 km (yellow color, Figure 1d). After 10 days a large number of particles are found to be deposited on the ground (black color, Figure 1f) across Siberia. ...
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... three days, the altitude of the ash cloud in an extended region decreases even below 2-3 km (yellow color, Figure 1d). After 10 days a large number of particles are found to be deposited on the ground (black color, Figure 1f) across Siberia. The deposition distribution shows another important characteristic, typical of chaotic phenomena, namely that it is inhomogeneous with filamentary structure, with denser and sparser regions. ...
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... deposition distribution shows another important characteristic, typical of chaotic phenomena, namely that it is inhomogeneous with filamentary structure, with denser and sparser regions. Additionally, it can be also seen that particles do not fall out from the atmosphere at almost the same time as a coherent patch but rather some parts of the ash cloud are deposited by the 7th day after the eruption already (Figure 1e), while several particles are still in the middle of the troposphere, at an altitude of about 5 km (green) even after 10 days (Figure 1f). As it is introduced in Section 1, this kind of deposition dynamics is characteristic to transiently chaotic phenomena. ...
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... deposition distribution shows another important characteristic, typical of chaotic phenomena, namely that it is inhomogeneous with filamentary structure, with denser and sparser regions. Additionally, it can be also seen that particles do not fall out from the atmosphere at almost the same time as a coherent patch but rather some parts of the ash cloud are deposited by the 7th day after the eruption already (Figure 1e), while several particles are still in the middle of the troposphere, at an altitude of about 5 km (green) even after 10 days (Figure 1f). As it is introduced in Section 1, this kind of deposition dynamics is characteristic to transiently chaotic phenomena. ...
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... the atmospheric spreading of a larger number of particles with r = 7 µm for a longer time period, it turns out that a ratio of 10 −5 -10 −6 of the particles is able to survive more than two months in the atmosphere, as well as that the initial location of the long-and short-living particles folds into each other in thin filaments in a fractal structure in extended regions [55]. Figure 3c demonstrates that the inhomogeneity and irregularity in the pattern of the deposited particles in Figure 1f is not the consequence of the initially small extension of the volcanic ash cloud studied in Section 4.1. The filamentary deposition pattern with denser and sparser regions, typical for transient chaos, can also be seen even for particles initially distributed completely uniformly over the whole globe. ...
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... user chooses either the New simulation-set parameters or the New simulation-read parameters menu item, in both cases the simulation parameters should be given at first (left panel of the screen in Figures A1 and A2). These parameters are the following: For topological entropy (length) calculation, the box is worth checking and 1 should be given for the reflection coefficient. ...
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... there is no wrong or empty text field, a pop-up window indicates that the Simulation setup is generated. Then the disabled right panel (the parameter settings of the pollutant cloud ( Figure A1) or the data for reading particles of a pollutant cloud ( Figure A2)) becomes enabled. ...
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... case of choosing the New simulation-set parameters option ( Figure A1) the user should set the following parameters of the particles which will fill a rectangular cuboid: Diameter (mean-std.dev.): the diameter of the particles is log-normally distributed with the user given mean and standard deviation [µm] (format: non-negative real). As mentioned in Section 3.1, the diameter 0 µm corresponds to gas particles which are advected by the instantaneous velocity of the atmospheric flow at each time instant (their terminal velocity in Equation (6) is 0). ...
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... a pop-up window indicates that the pollutant cloud is generated (Number of particles: <particle number>.). Then the disabled bottom right panel (for setting the display properties of the simulation and starting the simulation calculation ( Figure A1)) becomes enabled. ...
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... the bottom right panel ( Figure A1 and Figure A2) the user should check whether if she/he wants to watch the spreading of the pollutant cloud during the simulation calculation (Display during calculation?) and if yes, how many particles of the pollutant cloud should be drawn (Number of particles to display, format: integer). ...
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... for tracking the calculation of the simulation with displaying the particle positions. The simulation and the pollutant cloud are initialized with the parameters in Figure A1. The colorbar indicates the altitude of the particles. ...
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... saved simulation and the time dependence of the length of a pollutant cloud. The simulation is initialized with the simulation parameters on the left of Figure A1 but with top and bottom reflection coefficients of 1 and inserting new particles if the distance of two particles is greater than 100 km. The pollutant cloud is initialized as a meridional line segment of 400 km at 47 • N, 19 • E and at the altitude of 5500 m. ...
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... saved simulation and the time dependence of the ratio of non-escaped particles. The simulation is initialized with the simulation parameters on the left of Figure A1 but with an end date of "2010.04.30.06:00:00" and with calculating the ratio of non-escaped particles. The pollutant cloud is initialized as 250 × 250 × 1 particles at 0 • N, 0 • E and at the altitude of 5500 m with an extension of 4 × 10 4 km × 2 × 10 4 km × 0 m (i.e., covering the entire globe uniformly). ...
Citations
... A whole new opportunity to teach chaos has emerged with the appearance of a program named RePLaT-Chaos [12] developed for high school students by a colleague [13], [14]. This program can be used to monitor the spreading of volcanic ash in the atmosphere (Figure 8.) utilizing observation-based wind fields. ...
Besides being an active field of research, chaotic phenomena are also encountered in our everyday life, thus it’s worth discussing them also in formal education in public schools. This paper presents the authors’ experiences in teaching chaos on secondary level. A teaching module that encompasses mechanics lab experiments and numerical simulations of typical chaotic systems have been implemented and evaluated. The module offers a number of multimedia applications whose availability in teacher education is also discussed.
... It also includes easy-to-understand explanations on the properties of atmospheric spreading and chaos. The application is based on the previously developed RePLaT (Real Particle Lagrangian Trajectory) model [13] and has the same computational background as the "full" version called RePLaT-Chaos [14]. The latter version of the application differs from RePLaT-Chaos-edu being designed for advanced experts (e.g. for university students) and allows every simulation parameters of the spreading, generally not necessarily known by secondary school students, to be set up by the user. ...
... In this way even the smallest features resolved by the meteorological fields are taken into account [17]. A more detailed discussion of the equations of the motion can be found in [13][14]. ...
The continental- and global-scale spreading of pollutants emitted from volcano eruptions or industrial accidents is an everyday issue in our life. Nevertheless, students are generally not aware of the fact that pollutant clouds do not spread in the atmosphere like dye blobs on clothes, rather an initially small and compact pollutant cloud becomes soon strongly stretched, while becoming filamentary and folded. This paper introduces an application called Replat-Chaos-edu by means of which students can investigate the characteristics of the atmospheric dispersion of volcanic ash clouds and other pollutants in an interactive way. The simulations utilize meteorological data and follow the time evolution of pollutant clouds consisting of a large number of individual particles. Replat-Chaos-edu is also a suitable tool for studying the so-called chaotic features of the advection. The software was tested at the Berzsenyi Dániel Grammar School and the Szent István Grammar School (Budapest, Hungary) in the framework of Physics classes and during a project week, respectively.
... Another side branch is related to the spreading of volcanic ash in the atmosphere (see figure 8). A freely accessible program [13,14] can be downloaded on the student's computer. The simulation is based on meteorological wind data measured in a certain period over the Globe, and generates the path of a large number of small, spherical particles of the typical density of volcanic ash in this wind field. ...
Chaotic phenomena are not part of standard curricula, although this subject offers several interesting aspects which can help students better understand basic features of science. A central observation is that even simple physical systems, if chaotic, are unpredictable, just like the weather. We present the principles applied when developing a freely available short interactive material and outline the material itself. By the means of this material students can become acquainted with the elements of chaos science and also learn that the regular motions taught in physics lessons are the exceptions rather than the rule since a slight modification of the set-up (e.g. letting the suspension point of a pendulum move periodically) converts the motion to chaotic. The material can be used in both classroom and online teaching.
... This inter-comparison model suggested that these deviations may be owing to a need for further improvements both in the emission inventories and additional formation pathways in chemical transport models, while meteorological conditions also require improvement to simulate elevated atmospheric pollutants. Itahashi et al. [6] presented the possible pathways to solve the subject of model underestimation of SO 4 2− during winter found in J-STREAM. A winter haze period in December 2016 was examined by involving aqueous-oxidations and gas-phase oxidation by three stabilized Criegee intermediates into the CMAQ model. ...
The Atmosphere Special Issue entitled “Air Pollution Modeling: Local, Regional, and Global-Scale Applications” comprises nine original papers [...]
