In the temporal analyses, we observed different be- haviours of earthquakes and tornadoes. While earthquakes show “pure” power-law behaviour, tornadoes generally show power-law behaviour coextensive with characteristic scales. This is especially true when the temporal resolution used for the analysis was high (10 and 60 min bins). In correspon- dence to the typical tornado diurnal distribution that shows a maximum of tornado occurrences on the late afternoon hours (Schaefer and Edwards, 1999), we found the charac- teristic timescale to peak near one day in the return times. An explanation might be that the ingredients that are neces- sary for severe convection (instability, moisture, lift, shear) are more favourably arranged in the afternoon hours (about ingredients-based theory, see e.g. Doswell et al., 1996). We analysed the short time range from about 60 up to 600 min (mesoscale) and the long time range starting with 1 day (syn- optic scale) separately for all tornadoes and for more intense tornadoes with at least F 2 Fujita intensities. In the analysis of the interevent waiting times, the short time range (mesoscale) showed power-law behaviour with almost identical expo- nents of about − 1.6, while the exponents in the synoptic timescale differ: − 1.35 for all tornadoes, − 2.1 for F 2+ tor- nadoes. Additionally, the pdf estimates of all and F 2+ tor- nado interevent waiting times deviate in the very short time range (less than about 60 min, convective scale). Since the probability for having an F 2+ tornado is smaller than that for all tornadoes in this very short time range, it might be a hint that the atmosphere needs slightly more time for re- arranging the necessary conditions for the generation of a successive F 2+ tornado directly after an F 2+ event. The dif- ferent exponents for tornadoes of different intensity ranges in the larger timescale (larger than one day) reflect the fact that stronger tornadoes (F 2+) are rarer compared to the whole
summarizes the GBVTD analysis results for each volume and provides damage- and velocity-based F/EF-Scales for each event. In this table, the radar data volumes are sorted in an increasing overall maximum tangential velocity value order. The Storm Events Database  was used to determine the F/EF ratings for each tornado based on the damage. However, assessing the intensity level of a tornado based on damage surveys is subjective, with various parameters, such as damage markers in the region and quality of structures, contributing to the complexity of the process. As a result, in this work only the velocity range associated with each category of the Enhanced FujitaScale was used to categorize each volume of data. For instance, Goshen County (LaGrange), WY 2009 tornado was rated EF2 based on the damage survey while, volume 1 in this event was rated EF1 based on the maximum tangential velocity retrieved for that volume. Herein the rating of the tornado event was done based on maximum tangential velocity and has been kept consistent through the analysis. Radar volumes categorized as EF0-EF3, based on the maximum tangential velocity extracted by GBVTD, are presented in an increasing EF order in Table 6-1. The translational speed of each tornado as well as the flow
Fujita did occasional detailed post-event analyses for selected tornado cases from the 1950s until his retirement in 1992; he and his graduate students developed a multi- faceted storm survey methodology, using both ground-based and aerial survey methods for assessing the distribution of tornado intensities along a tornado's path (e.g., Forbes and Wakimoto, 1983 ). This effort was limited to no more than a handful of events every year, typically major outbreaks of tornadoes (and other types of storms). Fujita's team gained experience in doing such surveys, although some uncertainty about their ratings was inevitable. The National Severe Storms Laboratory (NSSL) also did occasional scienti ﬁc damage surveys for events within or close to Oklahoma, as part of their tornado-related research. The NWS is not obligated of ﬁcially to use the ﬁndings of surveys done by external agencies, but they certainly have used this information to produce F-scale estimates whenever such surveys have been done and the results made available. At the same time, the NWS was doing fewer of its own detailed scienti ﬁc surveys of major tornado events, presumably because it was expected that Fujita's team (or someone else) would do this for them — such surveys are not free. The main concern for the increasingly infrequent formal NWS post-storm “surveys” has evolved toward assessing the quality of the service provided by the NWS during the event, rather than focusing on the scienti ﬁc and/or engineering issues. Individual NWS of ﬁces are responsible for establishing the intensity rating for every tornado, whether or not an of ﬁcial NWS post-event service assessment is conducted.
Looking at the estimated numbers in Table 1, we see that all countries estimate at least as many tornadoes a year as indicated by their observational records. Russia, again, apparently gives a very conservative estimate, taking into account the large size of the country and the proximity to countries with rather high tornado occurrence, like Estonia (cf. Peterson, 2000). For the countries which give higher estimates, i. e. which believe in some kind of underreporting of tornadic storms, the factor of increase from observations to estimates is usually between 1 and 2. Only Spain expects a factor of 3 between their estimate and current observations.
In the current analysis, we pose a simple, but fundamental, question: do the physiological effects of solar radiation scale directly with the intensity of irradiance? That is, are changes in the intensity of the radiative heat input to the animal’s outer surface matched proportionately by changes in the intensity of its physiological responses to such heat input? We address this question by measuring the changes in metabolic heat production in response to exposure to simulated solar radiation in a small mammal, the Siberian hamster (Phodopus sungorus). Endotherms exposed to air temperatures below thermal neutrality reduce their metabolic heat production when exposed to solar radiation as a source of additional heat input. The intensity of this depression in thermostatic heat production has been used as a measure of the physiologically significant rate of solar heat gain to the animal (e.g. Walsberg and Wolf,
Not all the coping mechanisms that participants observed were positive. One participant noticed signs of increased alcohol consumption when seeing the liquor area cleaned out at a local store. Another Participant noticed more people going to the casinos that were now open in the area. Perhaps the most negative coping method surrounded suicide. Most participants were shocked to find out how many people had taken their own lives. Shortly after the tornado participant one asked a friend who worked in mental health if she had seen an increase in suicide and she responded “we have 13 so far”. This participant was so moved by this information that he changed and focused his writing on mental health. In addition, a concerted effort was made throughout the Joplin school system to address the development of risky behaviors including suicide. Participant eleven indicated that efforts to support the students were broad based and that more than 1,500 of the 7,700 students received counseling. He thought as many as 600 were still receiving help and let out a sigh of relief because the Joplin schools had not lost any child to suicide.
To examine the cyclonic tornado (2.C-1) more closely, a vertical cross-section (Figure 18) was analyzed along the east-west coordinate through the center of the cyclonic tornado (Figure 16). A peak northward velocity component of over 60 m/s occurs on the tornado’s eastern side, and a southward component of over 30m/s occurs on the western side. The stronger magnitude of wind speed on the eastern side of the tornado circulation in Figure 18 is mostly due to the translation of the tornado. A tangential component of about 45 m/s can be determined by removing the translation speed from the velocity field. The diameter of vortex core is 500m (four grid points) at low-levels and increases in diameter with altitude. If the numerical simulation had assumed a finer grid resolution, the velocities likely would have been stronger and would have extended closer to the ground. The largest pressure deficit occurred at lower elevations (Figure 16B) in response to the stronger tangential velocities. Vertical pressure gradients within the tornado acted to accelerate its vertical motion, resulting in the strong annular updraft. Adverse vertical pressure gradients within the tornado core caused a flow reversal (i.e., downward motion with the vortex core). The primary dynamics of the simulated tornado were similar to what has been discussed in previous studies utilizing high- resolution axisymmetric numerical models (e.g., Proctor; 12,13 Lewellen and Lewellen 71 ).
The Computational Fluid Dynamics software, Fluent 6.3 was used for the current three-dimensional numerical simulation of laboratory scaletornado-like vortices. Unsteady Reynolds Averaged Navier-Stokes (RANS) equations were solved on structured grids and a quasi-steady state solution was reached. The simulations were performed for swirl ratios S = 0.1, 0.2, 0.28, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, and 2.0. An initial grid with boundary layer at the base and Hex/Wedge mesh elements with around 150,000 cells was developed using the commercial software ‘Gambit’. Subsequent grid adaptations were performed using the ‘Velocity-Gradient-adaptation’, ‘Region-adaptation’ and ‘Wall-Y+-adaptation’ features in Fluent (Fluent 2006). Since the study was focused on the surface-layer wind profiles, the grid adaptations were also focused near the base surface. Following grid convergence criterion of less than 2% variation in maximum velocity near the base, a maximum of around 1,000,000 cells were used in the simulations. Based on the previous results obtained by Hangan and Kim (2008) the Reynolds Stress Model (RSM) was used for modeling turbulence. The basic equations defining this model are presented in Appendix A. The segregated implicit solver, SIMPLEC pressure velocity coupling and second order discretization for pressure, momentum, turbulent kinetic energy and specific dissipation rate were used.
Before concluding this episode, we note two items of particular historical importance. First, in the course of systematically elaborating models of city entrails, the important work of Ogawa and Fujita (1980) and Fujita and Ogawa (1982) was conceived. The models allowed not just consumers but also firms to be mobile, subject to a spatial externality. These papers were about 20 years ahead of their time. Second, and also in the course of this line of research, the foundations of Episode 2: The New Economic Geography were developed. This can be seen most clearly in section 3 of Fujita (1986), a precursor of Fujita (1991) as well as the work of Abdel-Rahman and Fujita (1990, 1993). Here the famous Starrett Spatial Impossibility Theorem is used to motivate why standard, classical general equilibrium models cannot generate cities endogenously, and proposals for modifying them are made. One notable passage is quoted here (p. 124): “We could generate many interesting problems by appropriately fusing di ff erent models in the above three categories, A, B and C. It would be wise, however, to thoroughly study each pure category first.”
Figure 8 shows the estimated class-averaged representative volume loss potential and run-up values for the Catalan coast. As expected, the higher the intensity of the storm, the larger the eroded volume will be. Thus, mean eroded volume val- ues range from about 10 m 3 /m/storm to 100 m 3 /m/storm for classes I and V, respectively, in reflective beaches and from 7 m 3 /m/storm to 25 m 3 /m/storm for dissipative ones. This means that the increase in the magnitude of the erosion po- tential due to the increase of storm category mainly affects reflective beaches. It has to be considered that these amounts represent the erosion capacity of the storm and that they will verify only if such volume is available at a given coastal stretch. In other words, they characterize the contribution of the forcing (storm) to the considered hazard (erosion).
Though this approach cannot be used in the case of the long narrow econ- omy of Fujita and Krugman (1995), the advances in numerical methods over the last two decades made it possible to conduct systematic simulations for a high dimensional space of endogenous variables under symmetry as well as certain asymmetries of location space. Most notably, as demonstrated by Ikeda, Murota, an Tatsuhito Kono, and Takayama (2014); Ikeda, Murota, and Takayama (2014); Ikeda, Murota, Akamatsu, and Takayama (2016), it is now possible to formally predict the bifurcation path of stable equilibria in many-region models by utilizing a combination of group-theoretic and computational bifurcation theory (see, e.g., Ikeda, Akamatsu, and Kono, 2012). Furthermore, an advance in numerical optimization methods, the merit func- tion approach of Fukushima (1992), adopts projection dynamics (instead of the standard replicator dynamics) as the migration mechanism. This advance made it possible to conduct a large scale Monte Carlo simulation for highly disaggregated models (with respect to both geography and industry), e.g., under the industrial structure estimated by Broda and Weinstein (2006) above. An initial such attempt is Akamatsu, Mori, and Takayama (2016). Thus, although once almost dismissed, Masa’s initial aspirations for con- struction and application of the NEG framework are now being succeeded by the next generation of models and researchers.
The core of Tornado Server is very small. Without libraries it can be as small as about 800Kb. The files are organised into directories based on their functionality, for example all the core server files are in /bin, JDBC driver jar files are in /jdbc, server configuration files are in /config, temporary files in /temp, etc. Each directory has a readme.txt file in it to describe its use. Once you have the installed directory structure it can be copied easily between machines using a simple file copy. The server code is small and non-resource consuming, so it is easy to run a Tornado Server instance on your personal workstation without suffering any performance degradation.
The paper is organized as follows. Some preliminaries and main results are introduced in Sect. 2, such as the local well-posedness of the problem (1.1), (1.2) and some auxiliary lemmas to be used later, as well as the blow-up theorems of Fujita type. The main results are proved in Sect. 3.
This paper is arranged as follows. Some preliminaries are introduced in Section , in- cluding the local existence theorem, the comparison principle, and a property of solutions from propagation of disturbances. The Fujita type theorems are established in Section . Finally in Section , the critical case will be concerned.
This paper concerns the asymptotic behavior of the solution to a class of coupled semilinear parabolic systems with gradient terms. The Fujita-type blow-up theorems are established and the critical Fujita curve is determined not only by the behavior of the coeﬃcients of the gradient term and the source terms at inﬁnity, but also by the spacial dimension.
Based on the demonstrations, have the students work together to list all the words they can think of to describe the movement of a tornado. (These may include—”spinning,” “twirling,” “speeding,” “rushing,” “blowing,” “twisting,” “running” and “skipping.”) Have them draw the funnel-shaped cloud of a tornado on a large sheet of construction paper and write the descriptive words in the winds around the tornado.
understanding the impacts of natural disaster-induced maternal stress concomitant with hurricane or tornado disasters, on pregnancy outcomes; and help enlighten and enable disaster preparedness efforts to meet the needs of maternal and neonatal populations. The findings of this investigation could also validate previous research on the impacts of hurricanes on poor birth outcomes, and add scholarship on the influence of tornado disasters on pregnancy outcomes. Discoveries from this investigation could perhaps help improve approaches to evaluating and measuring the effects of maternal stress on adverse pregnancy outcomes, such as infant mortality; and create an aperture for future research on the impact of exposure to maternal stress on the neonate in-utero, and across the life course. Correspondingly, the conclusion of this study may possibly make important contributions to public health and medical practitioners and policymakers. As a result of this investigation, public health and medical practitioners, and policymakers could be afforded insights to help inform their decision-making and advance the concept and implementation of funding and programs for maternal and infant health disaster preparedness, facilitating an improved readiness posture for vulnerable maternal and neonatal populations and their communities, to prepare for and respond to future hurricane and tornado natural disasters.