Influence of input climatic data on simulations of annual energy needs of a building: energyplus and WRF modeling for a case study in Rome (Italy)

The simulation of the energy consumptions in an hourly regime is necessary in order to perform calculations on residential buildings of particular relevance for volume or for architectural features. In such cases, the simplified methodology provided by the regulations may be inadequate, and the use of software like EnergyPlus is needed. To obtain reliable results, usually, significant time is spent on the meticulous insertion of the geometrical inputs of the building, together with the properties of the envelope materials and systems. Less attention is paid to the climate database. The databases available on the EnergyPlus website refer to airports located in rural areas near major cities. If the building to be simulated is located in a metropolitan area, it may be affected by the local heat island, and the database used as input to the software should take this phenomenon into account. To this end, it is useful to use a meteorological model such as the Weather Research and Forecasting (WRF) model to construct an appropriate input climate file. A case study based on a building located in the city center of Rome (Italy) shows that, if the climatic forcing linked to the heat island is not considered, the estimated consumption due to the cooling is underestimated by 35–50%. In particular, the analysis and the seasonal comparison between the energy needs of the building simulated by EnergyPlus, with the climatic inputs related to two airports in the rural area of Rome and with the inputs provided by the WRF model related to the center of Rome, show discrepancies of about (i) WRF vs. Fiumicino (FCO): Δ = −3.48% for heating, Δ = 49.25% for cooling; (ii) WRF vs. Ciampino (CIA): Δ = −7.38% for heating, Δ = +35.52% for cooling

Characterization of nitrogen dioxide variability using ground-based and satellite remote sensing and in situ measurements in the Tiber valley (Lazio, Italy)

The spatial-temporal distributions of nitrogen dioxide (NO2) in a rural area of Tiber valley were evaluated over one year (March 2022-February 2023) using remote sensing and in situ measurements. Surface concentration monitoring was conducted using a Pandora-2s spectrometer and a chemiluminescence analyzer operated at the Liberti Observatory (CNR-IIA). In spring, when the growing season and the agricultural activities increase, NO2 peaks were detectable by the Pandora but not by the in situ analyzer. The tropospheric Pandora and TROPOMI VCD products showed similar temporal patterns as those of the analyzer at the Observatory. High TROPOMI VCD levels in spring were detected at the Observatory and at six sites selected as representative of rural, residential, and industrial environments. WRF simulations found that high pollution events, observed by the Pandora and analyzer, occurred in calm wind conditions, favouring the accumulation of NO2 locally emitted. The complementary dataset provided by remote sensing and in situ techniques efficiently captured the spatial-temporal NO2 variability in a rural site exposed to low emission sources, thus supporting future decisional policies and actions

Impact of Highly Reflective Materials on Meteorology, PM10 and Ozone in Urban Areas: A Modeling Study with WRF-CHIMERE at High Resolution over Milan (Italy)

The Urban Heat Island (UHI) is a well-known phenomenon concerning an increasing percentage of the world’s population due to the growth rates of metropolitan areas. Given the health and economic implications of UHIs, several mitigation techniques are being evaluated and tested. In this study, we consider the use of highly reflective materials for urban surfaces, and we carried out numerical experiments using the Weather Research and Forecasting model coupled with the CHIMERE model in order to investigate the effects of these materials on the meteorology and air quality in the urban area of Milan (Italy). Results show that an increase in albedo from 0.2 to 0.7 for urban roofs, walls and streets leads to a decrease in UHI intensity by up to 2–3 °C and of the planetary boundary layer (PBL) height of about 500 m. However, the difference of PM10 and ozone between urban and surrounding areas increases by a factor of about 2, attributable to the reduction of PBL height and wind speed and to the increased reflected solar radiation that may enhance photochemical production during the daytime. Therefore, if anthropogenic emissions are held at the same levels, the potential benefit to the UHI in terms of thermal discomfort may have negative repercussions on air quality

Laboratory simulations of an urban heat island in a stratified atmospheric boundary layer

In the atmospheric boundary layer (ABL), under high pressure conditions and negligible geostrophic winds, problems associated with pollution are the most critical. In this situation, the urban heat island plays a major role in the close-to-the-ground atmospheric dynamics and in dispersion processes at scales in the order of tens of meters (small scales). This article presents water tank laboratory simulations of an urban heat island in a stably stratified ABL, neglecting geostrophic winds and the effects of Coriolis force. The phenomenon is studied in the framework of a similarity theory developed for a nocturnal and low-aspect ratio urban heat island extended to the diurnal case. Image analysis techniques appear suitable to fully describe the phenomenon. The high resolution data provides a detailed fluid dynamic characterization of the urban heat island circulation. Present laboratory results, normalized by similarity theory scaling parameters, compare well with literature data

Numerical study of the daytime planetary boundary layer over an idealized urban area. Influence of surface properties, anthropogenic heat flux, and geostrophic wind intensity

Large-eddy simulations of an idealized diurnal urban heat island are performed using the Weather Research and Forecasting Model. The surface energy balance over an inhomogeneous terrain is solved considering the anthropogenic heat contribution and the differences of thermal and mechanical properties between urban and rural surfaces. Several cases are simulated together with a reference case, considering different values of the control parameters: albedo, thermal inertia, roughness length, anthropogenic heat emission, and geostrophic wind intensity. Spatial distributions of second-moment statistics, including the turbulent kinetic energy (TKE) budget, are analyzed to characterize the structure of the planetary boundary layer (PBL). The effect of each control parameter value on the turbulent properties of the PBL is investigated with respect to the reference case. For all of the analyzed cases, the primary source of TKE is the buoyancy in the lower half of the PBL, the shear in the upper half, and the turbulent transport term at the top. The vertical advection of TKE is significant in the upper half of the PBL. The control parameters significantly influence the shape of the profiles of the transport and shear terms in the TKE budget. Bulk properties of the PBL via proper scaling are compared with literature data. A log-linear relationship between the aspect ratio of the heat island and the Froude number is confirmed. For the first time, the effect of relevant surface control parameters and the geostrophic wind intensity on the bulk and turbulent properties of the PBL is systematically investigated at high resolution

On the association between high outdoor thermo-hygrometric comfort index and severe ground-level ozone. A first investigation

According to the European Environment Agency, the year 2015 was the warmest on record to that point, with a series of heat waves from May to September resulted in high levels of tropospheric ozone. The implications of such a year on the human well-being and health are therefore of multiple nature and can be quantified referring to the exceedances of the corresponding thresholds. This work focused on the analysis of the May–September period of 2015 in the city of Milan (Italy) in terms of Mediterranean Outdoor Comfort Index (MOCI) and ozone concentrations, recorded by monitoring stations and modeled through the Weather Research and Forecasting model. Main findings show that thermo-hygrometric stress events (periods of at least six consecutive days characterized by daily maximum values of the MOCI higher than 0.5) are characterized by daily ozone higher than the guideline level of the World Health Organization (equal to 100 μgm−3). This means that thermo-hygrometric stress conditions are added up to poor air quality conditions, with severe risks for human health. Moreover, a daily MOCI-daily ozone correlation coefficient equal to 0.6 was found for the whole period. The degree of correspondence between ozone events (defined according to the European Air Quality Directive) and MOCI events was also investigated pointing out that 86% and 95% of days during ozone events are correctly predicted by events of recorded and modeled MOCI respectively, with a corresponding false alarm rate of 3% and 9%

NUTRITIONAL EVALUATION OF FRESH AND DRIED GOJI BERRIES CULTIVATED IN ITALY

The nutritional profile of fresh and dried goji berries cultivated in Italy was investigated. The obtained data confirm goji berries as a source of nutritional and healthy components, such as vitamin E, minerals and fibre. Taking into account the Recommended Daily Allowance (RDA) for minerals and vitamins established by the Commission of the European Communities, Goji berries provide significant amounts of dietary fibre and zeaxanthin and can be declared on the label as a potential source of vitamins E and C. Moreover, dried goji berries can be declared as a source of K, P, Cu, Fe Mn, Zn

High resolution numerical and experimental modeling of the Urban Heat Island circulation

The three-dimensional non-hydrostatic meteorological model WRF (Weather Research and Forecast) is used in Large-Eddy Simulation (LES) mode to reproduce the coherent structures associated to the Urban Heat Island (UHI) circulation. Horizontal resolution of 50 m and a vertically stretched grid with a finer resolution close to the surface is employed in the numerical model in order to compute the mean variables and the turbulence statistics. Experiments are conducted in a thermally controlled test section filled with distilled water. The velocity field is determined through image analysis techniques. Temperatures are measures by means of thermocouples arrays. Different UHI intensities and background initial stratifications are investigated with both the numerical code and the experimental apparatus and results compared with literature data. The turbulent structures of the UHI circulation are correctly reproduced by the LES model while the standard deviations are underestimated in the laboratory experiments

Numerical and experimental simulations of local winds

Local circulation dynamics have a strong impact on the climate evolution as they contribute to the redistribution of energy and scalars from the regional to the global scale. Mesoscale phenomena are driven by surface heat, momentum and moisture fluxes; the intensity and distribution of these forcings can be significantly modified by the urbanization. The present work describes numerical and experimental investigations of the flow over an urban area. The circulation arises from the temperature difference between the city and the suburbs, called the Urban Heat Island (UHI) phenomenon. The three-dimensional non-hydrostatic meteorological model WRF has been used to perform Large Eddy Simulations of the UHI flow and its evolution during the complete day-night cycle. The domain is assumed to be planar in the cross-flow direction and periodic lateral boundary conditions are imposed. The laboratory experiments are conducted in a thermally controlled water tank to simulate an initially stably stratified environment and an electric heater solidal with the bottom of the tank mimics the urban site. Image analysis techniques have been used to reconstruct the velocity fields, while temperatures are acquired by multiple thermocouple arrays. The high resolution of both the numerical and laboratory experiments allows a detailed characterization of both mean and turbulent properties of the UHI circulation. Present numerical and laboratory results, normalized by similarity theory scaling parameters, compare well with literature data. © Springer Science+Business Media B.V. 2012

Outdoor thermal perception and comfort conditions in the Köppen-Geiger climate category BSk. One-year field survey and measurement campaign in Konya, Turkey

This study presents an analysis of the thermo-hygrometric conditions in the city of Konya (Turkey). A one-year transversal field survey was carried out in the Selçuk University campus and 2295 valid questionnaires were collected. In each questionnaire, randomly selected interviewees provided personal information and judged their perception and thermal preference according to the ASHRAE 7-point and McIntyre scales, respectively. For each interviewee, a value of the Physiological Equivalent Temperature (PET) was calculated based on the values of operational variables obtained from the questionnaires and the environmental variables measured during the survey. This allowed to calculate the seasonal preferred and neutral PETs and the annual PET comfort range. Also, the scale of the PET thermal perception was determined for the Konya population and, more generally, for the inhabitants of the BSk Köppen-Geiger climate zone. Statistical analyzes carried out in terms of Variance Inflationary Factor, multicollinearity assessment and Best Subsets Analysis led to the identification of the Turkish Outdoor Comfort Index, an empirical index able to predict the average value of the thermal perception of a large group of individuals living in the aforementioned climate zone. Moreover, the equations of the Predicted Percentage of Dissatisfied (PPD) were obtained for each season