A Study of Traffic Emissions Based on Floating Car Data for Urban Scale Air Quality Applications

Urban air quality in cities is strongly influenced by road traffic emissions. Micro-scale models have often been used to evaluate the pollutant concentrations at the scale of the order of meters for estimating citizen exposure. Nonetheless, retrieving emissions information with the required spatial and temporal details is still not an easy task. In this work, we use our modelling system PMSS (Parallel Micro Swift Spray) with an emission dataset based on Floating Car Data (FCD), containing hourly data for a large number of road links within a 1 × 1 km2 domain in the city of Rome for the month of May 2013. The procedures to obtain both the emission database and the PMSS simulations are hosted on CRESCO (Computational Centre for Research on Complex Systems)/ENEAGRID HPC facilities managed by ENEA. The possibility of using such detailed emissions, coupled with HPC performance, represents a desirable goal for microscale modeling that can allow such modeling systems to be employed in quasi-real time and nowcasting applications. We compute NOx concentrations obtained by: (i) emissions coming from prescribed hourly modulations of three types of roads, based on vehicle flux data in the FCD dataset, and (ii) emissions from the FCD dataset integrated into our modelling chain. The results of the simulations are then compared to concentrations measured at an urban traffic station.

Friction coefficient of solid lubricating coating as a function of contact pressure: experimental results and microscale modeling

The paper presents experimental analysis of relation between friction coefficient and contact pressure of $$\hbox {MoS}_2$$ MoS 2 film deposited on $$\hbox {Ti}_6\hbox {Al}_4\hbox {V}$$ Ti 6 Al 4 V substrate in contact with sapphire ball during reciprocating sliding motion. It is shown that the value of friction coefficient decreases with increasing contact pressure. A microscale modeling approach is next developed to mimic the experimental observations. Representative volume element is defined based on the actual topography of outer surface of $$\hbox {MoS}_2$$ MoS 2 film. Assuming thermo-elastic material properties, the calculations on the asperity level are performed in two steps. Firstly, the mechanical contact between two surfaces is calculated. As a result, the relation between the global load and micro-stress distribution is obtained. Secondly, for a given stress load, thermal analysis is performed providing temperature fluctuation within simplified conical asperity. By assuming relation between friction coefficient and temperature on the microscale, it is possible to obtain macroscopic friction coefficient as a function of contact pressure. In the end, model results are compared with experimental data. The novel aspects of presented approach lie in the selection of three main factors on a micro-level defining macroscopic friction. They are actual surface topography, microscopic temperature and microscopic friction-temperature relation.

Synthesis of Flow and Thermal Transport in Porous Media as Applied to Biological Applications

The biological systems are tied to the molecular transport across the living tissues which in turn highly depend on kinetic and thermal energy exchanges. For various applications ranging from artery modeling to very sensitive tissue modeling such as the brain, porous media modeling accurately predicts the biological behavior. This article elaborately addresses the fundamentals of porous media and provides a comprehensive synthesis of the theory development from the primary methods available in the literature to the modern mathematical formulations. Specifically, this manuscript concentrates on two remarkable biological applications including (1) blood flow interactions with the porous tissue and (2) hydrodynamic impacts of particle-particle interactions in the microscale modeling that requires Lagrangian frame.

Observational and Modeling Analysis of Land-Atmosphere Interactions over Adjacent Irrigated and Rainfed Cropland During the GRAINEX Field Campaign.

<p>Continued scientific study has revealed that land use and land cover change play a key role in climate and that the application of irrigation is an important biogeophysical contributor to climate modification across spatial scales. The Great Plains Irrigation Experiment (GRAINEX) was conducted in the spring and summer of 2018 to investigate Land-Atmosphere interactions just prior to and through the growing season across adjacent, but distinctly unique, soil moisture regimes (contrasting irrigated and rainfed fields). GRAINEX was uniquely designed for the development and analysis of an extensive observational dataset for comprehensive process studies of Land-Atmosphere interactions, by focusing on irrigated and rainfed croplands in a ~100 x 100 km domain in southeastern Nebraska. Observation platforms included multiple NCAR EOL Integrated Surface Flux Systems and Integrated Sounding Systems, NCAR CSWR Doppler Radar on Wheels, 1200 radiosonde balloon launches from 5 sites, the NASA GREX airborne L-Band radiometer, and 75 University of Alabama-Huntsville Environmental Monitoring Economic Monitoring Sensor Hubs<strong> </strong>(EMESH mesonet stations). The presentation will provide an overview of the field campaign, the dataset collected, and investigate the contrast of L-A intractions across an irrigation gradient through observations and mesoscale/microscale modeling on timescales ranging from the diurnal to the seasonal. Attention will be given to how variations in the land surface state, as a function of irrigation fraction, impacts near-surface meteorology and atmospheric boundary layer evolution at local and regional scales.</p>

Mesoscale, Microscale, and Numerical Models: Limitations and Future Evolution

Numerical models have been instrumental in analyzing the wind field of non-synoptic wind storms as it is very difficult to obtain a complete data set from observations alone. Depending on the application, one must decide between mesoscale modeling, microscale modeling, or a combination of the two. Mesoscale modeling considers the full extent of the physics involved in the atmosphere but is limited in the spatiotemporal resolution that can be achieved. On the other hand, microscale modeling can produce a high-fidelity simulation of the wind field, but often lacks in the extent of the physics and physical mechanisms that are simulated. Applications and limitations of these modeling techniques are discussed, as well as the future direction of mesoscale and microscale modeling of non-synoptic wind storms.

GIS Data as a Valuable Source of Information for Increasing Resolution of the WRF Model for Warsaw

The Weather Research and Forecasting (WRF) model is commonly associated with meteorological data, but its algorithms may also use geographical data. The objective of this paper is to evaluate the impact of the high resolution CORINE Land Cover (CLC) data and the SRTM topography on the estimation accuracy of the weather model parameters in the WRF microscale simulations (200 × 200 m) for Warsaw. In the presented studies, the authors propose their own method of attaching the CLC data to the WRF microscale modeling for the CLC border areas, where first calculational domains reach beyond areas of CLC coverage. As a part of the research, the adaptation of the proposed method was examined by the assessment of the WRF microscale modeling simulations for Warsaw. The modified IGBP MODIS land use/land cover (LULC) and USGS GMTED2010 terrain elevation geographical data (30 arc seconds) was applied for the WRF simulations as default. As higher resolution geographical data (100 m), the LULC from CORINE Land Cover (CLC) 2018 data, and the SRTM topography were adopted. In this study the forecasts of air temperature and relative humidity at 2 m, and wind (speed and direction) at 10 m above ground level obtained using the WRF model for particular simulations were evaluated against measurements made at the Warsaw airports: Chopin (EPWA) and Babice (EPBC). The research has indicated that for microscale calculation fields there are noticeable changes in the meteorological parameter values when the CLC and the SRTM data are integrated into the WRF model, which in most cases yielded more accurate values of temperature and relative humidity at 2 m. This has also proved the correctness of the proposed methodology of the CLC data adoption. The improvement in the forecasted meteorological parameters is different for the particular locations and depends on the degree of the LULC and topography data change after higher resolution data adoption.