Atmospheric Science at IgMin Research | Science Group

Potential Evapotranspiration (PET) is an important variable for monitoring daily agricultural activity as well as meteorological drought. Therefore, it is necessary to investigate the influence of different options of the physical dynamical downscaling and boundary layer schemes on the simulated PET. Using the RegCM4 regional climate model, four simulations were conducted (two for each case) in the period 1997 to 2017. In all simulations, the RegCM4 was configured with 25 km resolution and downscaled by the ERA-Interim reanalysis dataset. To en...sure a reliable estimation of the PET, a calibrated version of the Hargreaves-Samani equation was adopted. A high-resolution product of the ERA5 was used as the observational dataset. Results showed that the simulated PET is insensitive either to the dynamical downscaling or the boundary layer options. Concerning the annual climatological cycle, the RegCM4’s performance varies with month and location. Quantitatively, a root mean square error lies between 1 mm and 1.6 mm day-1, the Nash-Sutcliffe efficiency between 0.2 and 0.6, and the coefficient of determination between 0.5 and 0.75. Additionally, the Linear Scaling (LS) method showed its added value in the evaluation/validation periods. In conclusion, the RegCM4 can be used to develop a regional PET map of Egypt using the LS either in the present climate or under different future scenarios.Read more

When a Maxwellian distribution is assumed for the distribution function in the BGK-type modelled BE, it will give rise to the Euler equations if it is the first-order approximation in the Chapman-Enskog method. Then the second-order equations will yield the N-S equations. Most LBM developed to date are formulated based on the second-order equations. Consequently, the assumption of a flow Mach number M << 1 is inherent in this formulation. This approach creates an unnecessary restriction on the LBM that should be avoided if possible. An al...ternative approach is to formulate a new LBM by considering an equilibrium distribution function where the first-order approximations give rise to the N-S equations. Adopting this approach, a new LBM has been formulated. This new LBM gives reliable results when applied to simulate aeroacoustics, incompressible flows, and compressible flows with and without shocks. Good agreement with measurements and numerical data derived from DAS/DNA calculations is obtained.Read more

The objective of this research paper is to examine and assess the correlation between the economic expansion of European Union member states and the escalating rate of motorization, which subsequently leads to road accidents resulting in significant loss of life and injury. A statistical analysis of economic growth, the rate of motorization, and road incidents in EU member states from 2010 to 2020 constitutes the research methodology. The research paper employs a quantitative approach to analysis and comparison. The research paper demonstrates ...how an increase in the number of motor vehicles in EU member states contributes to road accidents and human mortality. Varying degrees of economic development are associated with disparities between the rate of motorization expansion and the decline in fatalities. Because the rate of increase in motor vehicle usage surpasses the decline in fatalities per motor vehicle at low-income levels. At increased levels of income, the opposite occurs. Practical Implications: This research paper illustrates the importance for road traffic safety authorities to be aware of safety performance indicators and to incorporate them into legislative deliberations in order to bolster the European Union’s “zero victims” objective and provide enhanced protection for motor vehicle accident victims. Originality – This paper examines the correlation between motorization rates and fatalities in various EU member states with varying degrees of economic development over the past few decades.Read more