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

2018 ◽  
Author(s):  
Xenia Stavropulos-Laffaille ◽  
Katia Chancibault ◽  
Jean-Marc Brun ◽  
Aude Lemonsu ◽  
Valéry Masson ◽  
...  
Keyword(s):  
Weather Conditions ◽  
Base Flow ◽  
Hydrological Processes ◽  
Balance Model ◽  
Statistical Criterion ◽  
Model Parameters ◽  
Deep Drainage ◽  
Demographic Pressure ◽  
Climate Conditions ◽  
Recent Developments

Abstract. Climate change and demographic pressure are common issues to be considered when conducting urban planning. Local authorities and stakeholders have therefore opted for more nature-based adaptation strategies, which are especially suitable to influence both hydrological and energy processes. Assessing the multiple benefits of such strategies on the urban microclimate thus requires effective numerical tools. This paper presents recent developments of the water budget in the TEB-Veg model (SURFEX v7.3), which allows for a better representation of the hydrological processes of urban subsoil. This new hydrological module has been called TEB-Hydro. The developments studied concern the introduction of subsoil underneath built surfaces, and the processes of: horizontally rebalancing intra-mesh soil moisture, draining soil water via the sewer network, and limiting deep drainage in the aim of achieving a more realistic base flow pattern in the sewer system. A sensitivity analysis is then performed in order to identify the hydrological parameters required for model calibration. The new TEB-Hydro model is evaluated on two small residential catchments in Nantes (France) by comparing simulated sewer discharges to observation findings. In both cases, the model tends to overestimate total sewer discharge and performs better under wet climate conditions, with a KGE statistical criterion greater than 0.80 vs. roughly 0.60 under drier weather conditions. Yet these findings remain encouraging since the same set of model parameters are identified for both catchments, irrespective of meteorological and local physical conditions. This approach opens opportunities to apply the model at the city scale with respect to projections of climate and demographic changes.

scholarly journals Estimates of Uncertainty in Predictions of Global Mean Surface Temperature

2007 ◽  
Vol 20 (5) ◽  
pp. 843-855 ◽  
Author(s):  
J. A. Kettleborough ◽  
B. B. B. Booth ◽  
P. A. Stott ◽  
M. R. Allen
Keyword(s):  
Twentieth Century ◽  
Energy Balance ◽  
Temperature Change ◽  
Radiative Forcing ◽  
Balance Model ◽  
Future Climate Change ◽  
Model Parameters ◽  
Global Mean Temperature ◽  
Mean Temperature ◽  
Global Mean

Abstract A method for estimating uncertainty in future climate change is discussed in detail and applied to predictions of global mean temperature change. The method uses optimal fingerprinting to make estimates of uncertainty in model simulations of twentieth-century warming. These estimates are then projected forward in time using a linear, compact relationship between twentieth-century warming and twenty-first-century warming. This relationship is established from a large ensemble of energy balance models. By varying the energy balance model parameters an estimate is made of the error associated with using the linear relationship in forecasts of twentieth-century global mean temperature. Including this error has very little impact on the forecasts. There is a 50% chance that the global mean temperature change between 1995 and 2035 will be greater than 1.5 K for the Special Report on Emissions Scenarios (SRES) A1FI scenario. Under SRES B2 the same threshold is not exceeded until 2055. These results should be relatively robust to model developments for a given radiative forcing history.

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 Development of a Mass and Energy Balance Model and Its Application for HBI Charged EAFs

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 311
Author(s):  
Niloofar Arzpeyma ◽  
Rutger Gyllenram ◽  
Pär G. Jönsson
Keyword(s):  
Energy Balance ◽  
Slag Composition ◽  
Electricity Consumption ◽  
Electric Arc ◽  
Energy Balance Model ◽  
Balance Model ◽  
Model Parameters ◽  
Metal Oxidation ◽  
Arc Furnaces ◽  
Hot Briquetted Iron

A static mass and energy balance model combined with a MgO saturation slag model is developed for electric arc furnaces. The model parameters including distribution ratios and dust factors are calibrated for a specific furnace using experimental data. Afterward, the model is applied to study the effect of charging different amounts of hot briquetted iron (HBI) on energy consumption, charged slag former amount, and slag composition. The following results were obtained per each 1% increase of HBI additions: (i) a 0.16 Nm3/t decrease in the amount of injected oxygen for metal oxidation, (ii) a 1.29 kWh/t increase in the electricity consumption, and (iii) a 34 kg increase in the amount of the slag.

scholarly journals Transient Climate Response in a Two-Layer Energy-Balance Model. Part I: Analytical Solution and Parameter Calibration Using CMIP5 AOGCM Experiments

2013 ◽  
Vol 26 (6) ◽  
pp. 1841-1857 ◽  
Author(s):  
O. Geoffroy ◽  
D. Saint-Martin ◽  
D. J. L. Olivié ◽  
A. Voldoire ◽  
G. Bellon ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Energy Balance ◽  
Analytical Solution ◽  
Deep Ocean ◽  
Energy Balance Model ◽  
Balance Model ◽  
Model Parameters ◽  
Climate Change Scenarios ◽  
Ocean Heat Uptake ◽  
Transient Climate Response

Abstract This is the first part of a series of two articles analyzing the global thermal properties of atmosphere–ocean coupled general circulation models (AOGCMs) within the framework of a two-layer energy-balance model (EBM). In this part, the general analytical solution of the system is given and two idealized climate change scenarios, one with a step forcing and one with a linear forcing, are discussed. These solutions give a didactic description of the contributions from the equilibrium response and of the fast and slow transient responses during a climate transition. Based on these analytical solutions, a simple and physically based procedure to calibrate the two-layer model parameters using an AOGCM step-forcing experiment is introduced. Using this procedure, the global thermal properties of 16 AOGCMs participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5) are determined. It is shown that, for a given AOGCM, the EBM tuned with only the abrupt 4×CO2 experiment is able to reproduce with a very good accuracy the temperature evolution in both a step-forcing and a linear-forcing experiment. The role of the upper-ocean and deep-ocean heat uptakes in the fast and slow responses is also discussed. One of the main weaknesses of the simple EBM discussed in this part is its ability to represent the evolution of the top-of-the-atmosphere radiative imbalance in the transient regime. This issue is addressed in Part II by taking into account the efficacy factor of deep-ocean heat uptake.

scholarly journals Assessing the transferability and robustness of an enhanced temperature-index glacier-melt model

2009 ◽  
Vol 55 (190) ◽  
pp. 258-274 ◽  
Author(s):  
Marco Carenzo ◽  
Francesca Pellicciotti ◽  
Stefan Rimkus ◽  
Paolo Burlando
Keyword(s):  
Energy Balance ◽  
Meteorological Conditions ◽  
Shortwave Radiation ◽  
Balance Model ◽  
Model Parameters ◽  
Radiation Factor ◽  
Temperature Index ◽  
Clear Sky ◽  
Few Data ◽  
Parameter Values

AbstractWe investigate the transferability of an enhanced temperature-index melt model that was developed and tested on Haut Glacier d’Arolla, Switzerland, in the 2001 season. The model’s empirical parameters (temperature factor, TF, and shortwave radiation factor, SRF) are recalibrated for: (1) other locations on Haut Glacier d’Arolla; (2) subperiods of distinct meteorological conditions; (3) different years on Haut Glacier d’Arolla; and (4) other glaciers in different years. The model parameters are optimized against simulations of an energy-balance model validated against ablation observations. Results are compared with those obtained with the original parameters. The model works very well when applied to other sites, seasons and glaciers, with the exception of overcast conditions. Differences are due to underestimation of high melt rates. The parameter values are associated with the prevailing energy-balance conditions, showing that high SRF are obtained on clear-sky days, whereas higher TF are typical of locations where glacier winds prevail and turbulent fluxes are high. We also provide a range of parameters clearly associated with the site’s location and its meteorological characteristics that could help to assign parameter values to sites where few data are available.

scholarly journals Seasonal Adaptation of the Thermal-Based Two-Source Energy Balance Model for Estimating Evapotranspiration in a Semiarid Tree-Grass Ecosystem

2020 ◽  
Vol 12 (6) ◽  
pp. 904 ◽  
Author(s):  
Vicente Burchard-Levine ◽  
Héctor Nieto ◽  
David Riaño ◽  
Mirco Migliavacca ◽  
Tarek S. El-Madany ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Energy Balance ◽  
Structural Characteristics ◽  
Sensitivity Analyses ◽  
Balance Model ◽  
Model Parameters ◽  
Error Statistics ◽  
Seasonal Adaptation ◽  
Simple Strategy ◽  
Wide Range

The thermal-based two-source energy balance (TSEB) model has accurately simulated energy fluxes in a wide range of landscapes with both remote and proximal sensing data. However, tree-grass ecosystems (TGE) have notably complex heterogeneous vegetation mixtures and dynamic phenological characteristics presenting clear challenges to earth observation and modeling methods. Particularly, the TSEB modeling structure assumes a single vegetation source, making it difficult to represent the multiple vegetation layers present in TGEs (i.e., trees and grasses) which have different phenological and structural characteristics. This study evaluates the implementation of TSEB in a TGE located in central Spain and proposes a new strategy to consider the spatial and temporal complexities observed. This was based on sensitivity analyses (SA) conducted on both primary remote sensing inputs (local SA) and model parameters (global SA). The model was subsequently modified considering phenological dynamics in semi-arid TGEs and assuming a dominant vegetation structure and cover (i.e., either grassland or broadleaved trees) for different seasons (TSEB-2S). The adaptation was compared against the default model and evaluated against eddy covariance (EC) flux measurements and lysimeters over the experimental site. TSEB-2S vastly improved over the default TSEB performance decreasing the mean bias and root-mean-square-deviation (RMSD) of latent heat (LE) from 40 and 82 W m−2 to −4 and 59 W m−2, respectively during 2015. TSEB-2S was further validated for two other EC towers and for different years (2015, 2016 and 2017) obtaining similar error statistics with RMSD of LE ranging between 57 and 63 W m−2. The results presented here demonstrate a relatively simple strategy to improve water and energy flux monitoring over a complex and vulnerable landscape, which are often poorly represented through remote sensing models.

scholarly journals Optimal Estimation of Stochastic Energy Balance Model Parameters

2020 ◽  
Vol 33 (18) ◽  
pp. 7909-7926 ◽  
Author(s):  
Donald P. Cummins ◽  
David B. Stephenson ◽  
Peter A. Stott
Keyword(s):  
Maximum Likelihood ◽  
Energy Balance ◽  
Surface Temperature ◽  
General Circulation ◽  
General Circulation Models ◽  
Information Criteria ◽  
Likelihood Method ◽  
Balance Model ◽  
Space Representation ◽  
Model Parameters

AbstractThis study has developed a rigorous and efficient maximum likelihood method for estimating the parameters in stochastic energy balance models (with any k > 0 number of boxes) given time series of surface temperature and top-of-the-atmosphere net downward radiative flux. The method works by finding a state-space representation of the linear dynamic system and evaluating the likelihood recursively via the Kalman filter. Confidence intervals for estimated parameters are straightforward to construct in the maximum likelihood framework, and information criteria may be used to choose an optimal number of boxes for parsimonious k-box emulation of atmosphere–ocean general circulation models (AOGCMs). In addition to estimating model parameters the method enables hidden state estimation for the unobservable boxes corresponding to the deep ocean, and also enables noise filtering for observations of surface temperature. The feasibility, reliability, and performance of the proposed method are demonstrated in a simulation study. To obtain a set of optimal k-box emulators, models are fitted to the 4 × CO2 step responses of 16 AOGCMs in CMIP5. It is found that for all 16 AOGCMs three boxes are required for optimal k-box emulation. The number of boxes k is found to influence, sometimes strongly, the impulse responses of the fitted models.

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