scholarly journals Inclusion of vegetation in the Town Energy Balance model for modelling urban green areas

2012 ◽  
Vol 5 (6) ◽  
pp. 1377-1393 ◽  
Author(s):  
A. Lemonsu ◽  
V. Masson ◽  
L. Shashua-Bar ◽  
E. Erell ◽  
D. Pearlmutter
Keyword(s):  
Energy Balance ◽  
Global Climate ◽  
A Priori ◽  
Urban Canopy ◽  
Bare Soil ◽  
Urban Heat Islands ◽  
Balance Model ◽  
Local Climate ◽  
The Impact ◽  
The Town

Abstract. Cities impact both local climate, through urban heat islands and global climate, because they are an area of heavy greenhouse gas release into the atmosphere due to heating, air conditioning and traffic. Including more vegetation into cities is a planning strategy having possible positive impacts for both concerns. Improving vegetation representation into urban models will allow us to address more accurately these questions. This paper presents an improvement of the Town Energy Balance (TEB) urban canopy model. Vegetation is directly included inside the canyon, allowing shadowing of grass by buildings, better representation of urban canopy form and, a priori, a more accurate simulation of canyon air microclimate. The surface exchanges over vegetation are modelled with the well-known Interaction Soil Biosphere Atmosphere (ISBA) model that is integrated in the TEB's code architecture in order to account for interactions between natural and built-up covers. The design of the code makes possible to plug and use any vegetation scheme. Both versions of TEB are confronted to experimental data issued from a field campaign conducted in Israel in 2007. Two semi-enclosed courtyards arranged with bare soil or watered lawn were instrumented to evaluate the impact of landscaping strategies on microclimatic variables and evapotranspiration. For this case study, the new version of the model with integrated vegetation performs better than if vegetation is treated outside the canyon. Surface temperatures are closer to the observations, especially at night when radiative trapping is important. The integrated vegetation version simulates a more humid air inside the canyon. The microclimatic quantities (i.e., the street-level meteorological variables) are better simulated with this new version. This opens opportunities to study with better accuracy the urban microclimate, down to the micro (or canyon) scale.

scholarly journals Inclusion of vegetation in the Town Energy Balance model for modeling urban green areas

2012 ◽  
Vol 5 (2) ◽  
pp. 1295-1340 ◽  
Author(s):  
A. Lemonsu ◽  
V. Masson ◽  
L. Shashua-Bar ◽  
E. Erell ◽  
D. Pearlmutter
Keyword(s):  
Global Climate ◽  
A Priori ◽  
Urban Canopy ◽  
Bare Soil ◽  
Urban Heat Islands ◽  
Balance Model ◽  
Local Climate ◽  
Heat Islands ◽  
Planning Strategy ◽  
Urban Heat

Abstract. Cities impact both local climate, through urban heat islands, and global climate, because they are an area of heavy greenhouse gas release into the atmosphere due to heating, air conditioning and traffic. Including more vegetation into cities is a planning strategy having possible positive impacts for both concerns. Improving vegetation representation into urban models will allow to address more accurately these questions. This paper presents an improvement of the TEB urban canopy model. Vegetation is directly included inside the canyon, allowing shadowing of grass by buildings, better representation of urban canopy form, and, a priori, a more accurate simulation of canyon air microclimate. The development is performed so that any vegetation model can be used to represent the vegetation part. Here the ISBA model is used. The model results are compared to microclimatic and evaporation measurements performed in small courtyards in a very arid region of Israel. Two experimental landscaping strategies – bare soil or irrigated grass in the courtyard – are observed and simulated. The new version of the model with integrated vegetation performs better than if vegetation is treated outside the canyon. Surface temperatures are closer to the observations, especially at night when radiative trapping is important. The integrated vegetation version simulates a more humid air inside the canyon. The microclimatic quantities are better simulated with this new version. This opens opportunities to study with better accuracy the urban microclimate, down to the micro (or canyon) scale.

scholarly journals An urban trees parameterization for modeling microclimatic variables and thermal comfort conditions at street level with the Town Energy Balance model (TEB-SURFEX v8.0)

2020 ◽  
Vol 13 (2) ◽  
pp. 385-399 ◽  
Author(s):  
Emilie Redon ◽  
Aude Lemonsu ◽  
Valéry Masson
Keyword(s):  
Energy Balance ◽  
Wind Speed ◽  
Air Temperature ◽  
Urban Canopy ◽  
Turbulent Fluxes ◽  
Urban Trees ◽  
Radiation Absorption ◽  
Balance Model ◽  
Climate Index ◽  
The Town

Abstract. The Town Energy Balance (TEB) urban climate model has recently been improved to more realistically address the radiative effects of trees within the urban canopy. These processes necessarily have an impact on the energy balance that needs to be taken into account. This is why a new method for calculating the turbulent fluxes for sensible and latent heat has been implemented. This method remains consistent with the “bigleaf” approach of the Interaction Soil–Biosphere–Atmosphere (ISBA) model, which deals with energy exchanges between vegetation and atmosphere within TEB. Nonetheless, the turbulent fluxes can now be dissociated between ground-based natural covers and the tree stratum above (knowing the vertical leaf density profile), which can modify the vertical profile in air temperature and humidity in the urban canopy. In addition, the aeraulic effect of trees is added, parameterized as a drag term and an energy dissipation term in the evolution equations of momentum and turbulent kinetic energy, respectively. This set of modifications relating to the explicit representation of the tree stratum in TEB is evaluated on an experimental case study. The model results are compared to micrometeorological and surface temperature measurements collected in a semi-open courtyard with trees and bordered by buildings. The new parameterizations improve the modeling of surface temperatures of walls and pavements, thanks to taking into account radiation absorption by trees, and of air temperature. The effect of wind speed being strongly slowed down by trees is also much more realistic. The universal thermal climate index diagnosed in TEB from inside-canyon environmental variables is highly dependent and sensitive to these variations in wind speed and radiation. This demonstrates the importance of properly modeling interactions between buildings and trees in urban environments, especially for climate-sensitive design issues.

Surface energy balance model of transpiration from variable canopy cover and evaporation from residue-covered or bare-soil systems

2009 ◽  
Vol 28 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Luis Octavio Lagos ◽  
Derrel L. Martin ◽  
Shashi B. Verma ◽  
Andrew Suyker ◽  
Suat Irmak
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Canopy Cover ◽  
Bare Soil ◽  
Energy Balance Model ◽  
Balance Model ◽  
Soil Systems

scholarly journals BESTest for Integrated Outdoor-Indoor Energy Balance Modelling

2021 ◽  
Author(s):  
Mohammed Bakkali ◽  
Yasunobu Ashie
Keyword(s):  
Energy Balance ◽  
Three Dimensional ◽  
Building Blocks ◽  
Building Energy ◽  
Energy Simulation ◽  
Balance Model ◽  
Fully Integrated ◽  
Heat Islands ◽  
Urban Heat ◽  
The Impact

In our growing cities, climate change and energy related uncertainties are of great concern. The impact of the Urban Heat Island on comfort, health and the way we use energy still requires further clarification. The outdoor-indoor energy balance model (3D-City Irradiance) presented in this article was developed so as to address these issues. The effects of view factors between urban surfaces on three-dimensional radiation and the effects of fully integrated outdoor-indoor energy balance schemes on heat islands and building indoor thermal loads could be included within different building blocks at a resolution of several metres. The model operated under the ‘stand alone’ mode. It was tested using the Building Energy Simulation Test (BESTest) which demonstrated good levels of agreement for diurnal and seasonal simulations.

scholarly journals Parameterizing the impact of vegetated urban canopies on wind and temperature fields by using a simple nudging method

2021 ◽  
Author(s):  
Ge Cheng ◽  
David Grawe ◽  
K. Heinke Schlünzen
Keyword(s):  
Mesoscale Model ◽  
Three Dimensional ◽  
Urban Canopy ◽  
Temperature Fields ◽  
Simple Method ◽  
Local Climate ◽  
Local Climate Zones ◽  
Urban Canopy Parameterizations ◽  
The Impact ◽  
Nudging Method

<p>Nudging is a simple method that aims to dynamically adjust the model toward the observations by including an additional feedback term in the model governing equation. This method is widely applied in data assimilation due to its simple implementation and reasonable model results. The basic concept of nudging is similar to that of urban canopy parameterization, in which additional terms are usually added in the conservation equations of momentum and energy aiming to simulate the canopy effects. However, few studies have investigated the implementation of nudging methods in urban canopy parameterizations. In this study we developed a multi-layer urban canopy parameterization (UCP) by using a nudging approach to represent the impacts of vegetated urban canopies on temperatures and winds in mesoscale models.</p><p>The difficulty of developing UCP by using a nudging method lies in defining appropriate values for the nudging coefficients and the forcing fields (e.g. indoor temperature fields for temperature nudging). To determine nudging coefficients, we use three major urban canopy morphological parameters: building height, frontal area density and building density. The ranges of these parameters are taken from the values for the Local Climate Zones datasets, in our case for the city of Hamburg. The UCP is employed in the three -dimensional atmospheric mesoscale model METRAS. Results show that this UCP can well simulate wind-blocking effects induced from obstacles as buildings and trees and urban heat island phenomenon for cities. Thus, nudging is an efficient and effective method that can be used for urban canopy parameterizations. However, as well known for nudging, it is not conserving energy. Therefore, we investigated the energy loss by tracking the reduced kinetic energy and internal energy. The UCP and model results will be presented.</p>

Modelling the impact of a Sub-Saharan metropolis (Kampala) on the local climate during specific meteorological conditions of a dry season

2021 ◽  
Author(s):  
Oscar Brousse ◽  
Jonas Van de Walle ◽  
Matthias Demuzere ◽  
Alberto Martilli ◽  
Nicole van Lipzig ◽  
...  
Keyword(s):  
Urban Canopy ◽  
Building Energy ◽  
Dry Season ◽  
Meteorological Conditions ◽  
Sub Saharan Africa ◽  
Wave Radiation ◽  
Local Climate ◽  
Local Climate Zones ◽  
Sub Saharan ◽  
The Impact

<p>In order to build resilient cities in face of climate change in Sub-Saharan Africa, much is to be done to understand the impact of rapid and uncontrolled urbanization on the local climate in the region. Recent efforts by Brousse et al. (2019, 2020) demonstrated that using generic urban parameter information  derived out of Local Climate Zones (LCZ ; Stewart and Oke, 2012) maps created through the World Urban Database and Access Portal Tool framework (Ching et al. 2018) may be used to model the impact of Sub-Saharan African cities on their local climate – using the case of Kampala, the capital city of Uganda. These studies showed that despite the characteristic data scarcity on urban typologies that is present in Sub-Saharan Africa, LCZ could be used as a solution for modelling and studying the urban climates in the region.</p><p>Yet these conclusions were only obtained through the use of the bulk-level urban canopy model TERRA_URB, embedded in the COSMO-CLM regional climate model. We therefore test the applicability of a more complex urban canopy models – the Building Effect Parameterization coupled to the Building Energy Model (BEP-BEM) – over the region. To do so, we focus on short periods with specific meteorological conditions during the dry season spanning from December 2017 to February 2018. These are obtained through a k-means clustering over hourly weather measurements given by the automatic weather station located at the Makerere University, in the city-center of Kampala. Wind direction and speed, 2-meter air temperature, incoming short-wave radiation, precipitation, daily temperature range, 2-meter air relative humidity and near-surface pressure are used to depict 5 weather typologies (ie. clusters) during the dry season. We chose to keep only periods with 5 consecutive days of one weather typology, which results in three 5-day periods of distinct typology. We then run the model for these periods and evaluate its outputs against the state-of-the-art simulation by Brousse et al. (2020) as well as in-situ and satellite observations for certain meteorological variables. After that, we show the effect of the recent urbanization on the local climate for each of those three periods and relate it to the variability in urban heat.</p><p>This study is the first to model a tropical African city at 1 km horizontal resolution using the BEP-BEM model embedded in WRF. The latter could have major implications as more complex urban canopy models coupled to building energy models could shed light on the impact of the built environment on the livability of indoor and outdoor environments in these cities. Furthermore, insights could indeed be gained on the contribution of air conditioning heat fluxes to outdoor temperatures and the energetic consumption needed to keep indoor environments at an optimal temperature. Additionally, by resolving the urban environment in three dimensions, BEP-BEM could help increase our understanding of how specific urban planning and architectural adaptation strategies (like green or cool roofs, roof top solar panel, new building materials, urban greening etc.) may increase the citizens’ thermal comfort and reduce negative health impacts under specific weather conditions.</p>

scholarly journals Improvements to the hydrological processes of the Town Energy Balance model (TEB-Veg, SURFEX v7.3) for urban modelling and impact assessment

2018 ◽  
Vol 11 (10) ◽  
pp. 4175-4194 ◽  
Author(s):  
Xenia Stavropulos-Laffaille ◽  
Katia Chancibault ◽  
Jean-Marc Brun ◽  
Aude Lemonsu ◽  
Valéry Masson ◽  
...  
Keyword(s):  
Energy Balance ◽  
High Performance ◽  
Hydrological Processes ◽  
Balance Model ◽  
Statistical Criterion ◽  
Model Parameters ◽  
Water Drainage ◽  
Deep Drainage ◽  
Complete Representation ◽  
The Town

Abstract. Climate change and demographic pressures are affecting both the urban water balance and microclimate, thus amplifying urban flooding and the urban heat island phenomena. These issues need to be addressed when engaging in urban planning activities. Local authorities and stakeholders have therefore opted for more nature-based adaptation strategies, which are especially suitable in influencing hydrological and energy processes. Assessing the multiple benefits of such strategies on the urban microclimate requires high-performance numerical tools. This paper presents recent developments dedicated to the water budget in the Town Energy Balance for vegetated surfaces (TEB-Veg) model (surface externalisée; SURFEX v7.3), thus providing a more complete representation of the hydrological processes taking place in the urban subsoil. This new hydrological module is called TEB-Hydro. Its inherent features include the introduction of subsoil beneath built surfaces, the horizontal rebalancing of intra-mesh soil moisture, soil water drainage via the sewer network and the limitation of deep drainage. A sensitivity analysis is then performed in order to identify the hydrological parameters required for model calibration. This new TEB-Hydro model is evaluated on two small residential catchments in Nantes (France), over two distinct periods, by comparing simulated sewer discharge with observed findings. In both cases, the model tends to overestimate total sewer discharge and performs better under wet weather conditions, with a Kling–Gupta efficiency (KGE) statistical criterion greater than 0.80 vs. approximately 0.60 under drier conditions. These results are encouraging since the same set of model parameters is identified for both catchments, irrespective of meteorological and local physical conditions. This approach offers opportunities to apply the TEB-Hydro model at the city scale alongside projections of climate and demographic changes.

scholarly journals Evaluation of the Town Energy Balance Model in Cold and Snowy Conditions during the Montreal Urban Snow Experiment 2005

2010 ◽  
Vol 49 (3) ◽  
pp. 346-362 ◽  
Author(s):  
A. Lemonsu ◽  
S. Bélair ◽  
J. Mailhot ◽  
S. Leroyer
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Transition Period ◽  
Sensible Heat Flux ◽  
Heat Fluxes ◽  
Surface Radiation ◽  
Anthropogenic Heat ◽  
Balance Model ◽  
Spatial And Temporal Variability ◽  
The Town

Abstract Using the Montreal Urban Snow Experiment (MUSE) 2005 database, surface radiation and energy exchanges are simulated in offline mode with the Town Energy Balance (TEB) and the Interactions between Soil, Biosphere, and Atmosphere (ISBA) parameterizations over a heavily populated residential area of Montreal, Quebec, Canada, during the winter–spring transition period (from March to April 2005). The comparison of simulations with flux measurements indicates that the system performs well when roads and alleys are snow covered. In contrast, the storage heat flux is largely underestimated in favor of the sensible heat flux at the end of the period when snow is melted. An evaluation and an improvement of TEB’s snow parameterization have also been conducted by using snow property measurements taken during intensive observational periods. Snow density, depth, and albedo are correctly simulated by TEB for alleys where snow cover is relatively homogeneous. Results are not as good for the evolution of snow on roads, which is more challenging because of spatial and temporal variability related to human activity. An analysis of the residual term of the energy budget—including contributions of snowmelt, heat storage, and anthropogenic heat—is performed by using modeling results and observations. It is found that snowmelt and anthropogenic heat fluxes are reasonably well represented by TEB–ISBA, whereas storage heat flux is underestimated.

scholarly journals Comparison of the Impact of Global Climate Changes and Urbanization on Summertime Future Climate in the Tokyo Metropolitan Area

2012 ◽  
Vol 51 (8) ◽  
pp. 1441-1454 ◽  
Author(s):  
Sachiho A. Adachi ◽  
Fujio Kimura ◽  
Hiroyuki Kusaka ◽  
Tomoshige Inoue ◽  
Hiroaki Ueda
Keyword(s):  
Climate Change ◽  
Metropolitan Area ◽  
Global Climate Change ◽  
Temperature Increase ◽  
Climate Changes ◽  
Global Climate ◽  
Local Climate ◽  
Tokyo Metropolitan Area ◽  
Global Climate Changes ◽  
The Impact

AbstractIn this study, the impact of global climate change and anticipated urbanization over the next 70 years is estimated with regard to the summertime local climate in the Tokyo metropolitan area (TMA), whose population is already near its peak now. First, five climate projections for the 2070s calculated with the aid of general circulation models (GCMs) are used for dynamical downscaling experiments to evaluate the impact of global climate changes using a regional climate model. Second, the sensitivity of future urbanization until the 2070s is examined assuming a simple developing urban scenario for the TMA. These two sensitivity analyses indicate that the increase in the surface air temperature from the 1990s to the 2070s is about 2.0°C as a result of global climate changes under the A1B scenario in the Intergovernmental Panel on Climate Change’s Special Report on Emissions Scenarios (SRES) and about 0.5°C as a result of urbanization. Considering the current urban heat island intensity (UHII) of 1.0°C, the possible UHII in the future reaches an average of 1.5°C in the TMA. This means that the mitigation of the UHII should be one of the ways to adapt to a local temperature increase caused by changes in the future global climate. In addition, the estimation of temperature increase due to global climate change has an uncertainty of about 2.0°C depending on the GCM projection, suggesting that the local climate should be projected on the basis of multiple GCM projections.

scholarly journals Utilization of Climate Files Predicting Future Weather in Dynamic Building Performance Simulation – A review

2021 ◽  
Vol 2069 (1) ◽  
pp. 012070
Author(s):  
C N Nielsen ◽  
J Kolarik
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Dynamical Downscaling ◽  
Global Climate ◽  
Global Climate Models ◽  
Weather Data ◽  
Building Performance ◽  
Comprehensive Overview ◽  
Local Climate ◽  
The Impact

Abstract As the climate is changing and buildings are designed with a life expectancy of 50+ years, it is sensible to take climate change into account during the design phase. Data representing future weather are needed so that building performance simulations can predict the impact of climate change. Currently, this usually requires one year of weather data with a temporal resolution of one hour, which represents local climate conditions. However, both the temporal and spatial resolution of global climate models is generally too coarse. Two general approaches to increase the resolution of climate models - statistical and dynamical downscaling have been developed. They exist in many variants and modifications. The present paper aims to provide a comprehensive overview of future weather application as well as critical insights in the model and method selection. The results indicate a general trend to select the simplest methods, which often involves a compromise on selecting climate models.

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