The Climate-fit.City service (https://www.climate-fit.city) provides the best available scientifi... more The Climate-fit.City service (https://www.climate-fit.city) provides the best available scientific urban climate data and information for public and private end users operating in cities. Within the Climate-fit.City H2020 project, the benefits of urban climate information for end user communities was demonstrated, considering services in diverse domains (Climate and Health, Building Energy, Emergency Planning, Urban Planning, Active Mobility, Tourism and Cultural Heritage) to improve decision-making and to help end users to better address the consequences of climate change at the local scale. The socio-economic impact assessment performed in the Climate-fit.City project has demonstrated that, in all the cases, there are actual and potential added values in terms of public service effectiveness, economic impacts, policy innovation and social impacts. Further impact was also revealed in terms of raising awareness by end users, policymakers and the general public about climate change. ...
[1] The objective of this paper is to present the validation over Greenland of a thermodynamic sn... more [1] The objective of this paper is to present the validation over Greenland of a thermodynamic snow-ice model that was complemented with the snow metamorphism and albedo parameterizations of the Centre d’Etudes de la Neige (Grenoble, France) in order to make the surface albedo variable and interactive. Special attention is given to the surface albedo since it is the most important parameter in energy exchanges with the atmosphere for snow and ice melt. The development of an integrated (snow, ice, and water) albedo model takes into account the different surface types observed on an ice sheet, and the snow albedo is calculated from the simulated surface snow grains. The validation for a polar site has been done at ETH Camp (West Greenland, 1155 m above sea level) during the 1990 and 1991 summer seasons. Although both ablation seasons differed greatly (in 1990 it showed a negative mass balance while in 1991 it ended with a positive mass balance), a single model configuration was able to provide good results for both 1990 and 1991. These simulations show that the snow metamorphism laws included enable an accurate simulation of the surface albedo and henceforth of the surface mass balance for a polar site, provided that the snow model is correctly forced at its surface level and that meltwater retention, percolation, and drainage are well represented in the snow model. The model results are also compared with two other modeling approaches, and differences between the three snow models are detailed. INDEX TERMS: 1827 Hydrology:
The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow re... more The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow regional climate model with a 25 km horizontal resolution. The simulated snow water content allows a direct comparison with the satellite derived melt signal. The model is forced with 6-hourly ERA-40 reanalysis at its boundaries. An evaluation of the simulated precipitation and a comparison of the modeled melt zone and the surface albedo with remote sensing observations are presented. Both the distribution and quantity of the simulated precipitation agree with observations from coastal weather stations, estimates from other models and the ERA-40 reanalysis. There are overestimations along the steep eastern coast which are most likely due to the "topographic barrier effect". The simulated extent and time evolution of the wet snow zone compare generally well with satellite derived data, except during rainfall events on the ice sheet and because of a bias in the passive microwave re...
The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow re... more The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow regional climate model with a 25 km horizontal resolution. The simulated snow water content allows a direct compar ison with the satellite derived melt signal. The model is forced with 6-hourly ERA-40 re analysis at its boundaries. An evaluation of the simulated precipitation and a com parison of the modelled melt zone and the surface albedo with remote sensing observations are presented. Both the distribution and quantity of the simulated precipitation agree with observations from coastal weather stations, estimates from other models and the ERA-4 0 reanalysis. There are overestimations along the steep eastern coast which are most likely due to the "topographic barrier effect". The simulated extent and time evolution of the wet snow zone compare generally well with satellite derived data, except during rainfall even ts on the ice sheet and because of a bias in the passive microw...
During the last 15 years, the official assessment maps in Flanders have improved from a map consi... more During the last 15 years, the official assessment maps in Flanders have improved from a map consisting of only measured data points to a high resolution assessment which covers the complete area and takes into account several types of sources and street canyons. In order to improve this level of detail, multiple steps were taken. First of all, a land use regression model was introduced at an hourly scale at 4 × 4 km2 resolution. Secondly, a Gaussian model was added for both point and line sources, correcting for emission double counting. Finally, a street canyon model was added to the chain, leading to improved resolution in these street canyons. In this work, we will discuss the problems encountered in these years such as how to account for double counting of emissions, how to correct the locations of the simplified road network and how to determine when street canyon calculations must be performed and how we solved them.
<p&amp... more <p>Biodiversity is increasingly under pressure from climate change, which affects the habitat suitability for species as well as the efficiency of ecosystem services. Management of these issues, for instance through ecosystem restoration or species dispersal measures, is often hindered by a lack of appropriate information about (future) climate conditions.  To address this, an operational Sectoral Information System (SIS) for the Biodiversity sector (SIS Biodiversity) is designed within the Copernicus programme Climate Change Service (C3S). This new SIS provides tailored bio-climatic indicators and applications, and delivers novel evidence regarding impacts of past, present and future climate. As such, it provides support to decision making challenges that are currently facing unmet climate data needs.<br> <br>The new climate service for SIS Biodiversity will be demonstrated, including the outline, workflow and outcomes of the use cases. The service is built upon the Copernicus Data Store platform (CDS; ), and takes into account (1) the barriers in ongoing bio-climate assessments and (2) the user requirements of diverse stakeholders (e.g. researcher institutes, local NGO’s, the International Union for Conservation of Nature and Natural Resources (IUCN),…). These have been collected during workshops and bilateral meetings in 2019. A common barrier is the lack of reliable and high-resolution information about states and dynamics of the soil, sea, ice and air for the past and the future climate. Therefore, the service provides relevant bio-climatic indicators on the basis of a wealth of available variables from the latest ERA5 reanalysis datasets and the CMIP5 global climate projections available in CDS. In order to provide information at high resolution and minimize inconsistencies between observed and modelled variables, different downscaling and bias-correction techniques are applied. A common requirement is a universal and flexible interface to the bio-climatic indicators in an easy-to-use and coherent platform that is applicable for different fauna and flora species of interest. Therefore, different applications have been developed within CDS for generating bio-climate suitability envelopes from the high-resolution indicators and to evaluate climate suitability and impacts for the species under present and future climate. Finally, the service is currently tested and refined on the basis of specific use cases. Special attention is given to their transferability to other global and topical studies, hence maximizing external user uptake throughout existing research and policy networks.</p>
ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences
Risk situation can be mitigated by prevention measures, early warning tools and adequate monitori... more Risk situation can be mitigated by prevention measures, early warning tools and adequate monitoring of past experiences where Earth Observation and geospatial analysis have an adding value. This paper discusses the potential use of Earth Observation data and especially Land Cover / Land Use map in addressing within the three aspects of the risk assessment: danger, exposure and vulnerability. Evidences of the harmful effects of air pollution or heat waves are widely admitted and should increase in the context of global warming. Moreover, urban areas are generally warmer than rural surroundings, the so-called urban heat island. Combined with in-situ measurements, this paper presents models of city or local climate (air pollution and urban heat island), with a resolution of less than one kilometer, developed by integrating several sources of information including Earth Observation data and in particular Land Cover / Land Use. This assessment of the danger is then be related to a map of...
Journal of Geophysical Research Atmospheres, Apr 27, 2003
The objective of this paper is to present the validation over Greenland of a thermodynamic snow-i... more The objective of this paper is to present the validation over Greenland of a thermodynamic snow-ice model that was complemented with the snow metamorphism and albedo parameterizations of the Centre d'Etudes de la Neige (Grenoble, France) in order to make the surface albedo variable and interactive. Special attention is given to the surface albedo since it is the most important parameter in energy exchanges with the atmosphere for snow and ice melt. The development of an integrated (snow, ice, and water) albedo model takes into account the different surface types observed on an ice sheet, and the snow albedo is calculated from the simulated surface snow grains. The validation for a polar site has been done at ETH Camp (West Greenland, 1155 m above sea level) during the 1990 and 1991 summer seasons. Although both ablation seasons differed greatly (in 1990 it showed a negative mass balance while in 1991 it ended with a positive mass balance), a single model configuration was able to provide good results for both 1990 and 1991. These simulations show that the snow metamorphism laws included enable an accurate simulation of the surface albedo and henceforth of the surface mass balance for a polar site, provided that the snow model is correctly forced at its surface level and that meltwater retention, percolation, and drainage are well represented in the snow model. The model results are also compared with two other modeling approaches, and differences between the three snow models are detailed.
Climate Dynamics Observational Theoretical and Computational Research on the Climate System, Jan 9, 2006
Measurements from ETH-Camp and JAR1 AWS (West Greenland) as well as coupled atmosphere-snow regio... more Measurements from ETH-Camp and JAR1 AWS (West Greenland) as well as coupled atmosphere-snow regional climate simulations have highlighted flaws in the cross-polarized gradient ratio (XPGR) technique used to identify melt from passive microwave satellite data. It was found that dense clouds (causing notably rainfall) on the ice sheet severely perturb the XPGR melt signal. Therefore, the original XPGR melt detection algorithm has been adapted to better incorporate atmospheric variability over the ice sheet and an updated melt trend for the 1988 2003 period has been calculated. Compared to the original algorithm, the melt zone area increase is eight times higher (from 0.2 to 1.7% year-1). The increase is higher with the improved XPGR technique because rainfall also increased during this period. It is correlated to higher atmospheric temperatures. Finally, the model shows that the total ice sheet runoff is directly proportional to the melt extent surface detected by satellites. These results are important for the understanding of the effect of Greenland melting on the stability of the thermohaline circulation.
The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow re... more The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow regional climate model with a 25 km horizontal resolution. The simulated snow water content allows a direct comparison with the satellite derived melt signal. The model is forced with 6-hourly ERA-40 reanalysis at its boundaries. An evaluation of the simulated precipitation and a comparison of the modeled melt zone and the surface albedo with remote sensing observations are presented. Both the distribution and quantity of the simulated precipitation agree with observations from coastal weather stations, estimates from other models and the ERA-40 reanalysis. There are overestimations along the steep eastern coast which are most likely due to the "topographic barrier effect". The simulated extent and time evolution of the wet snow zone compare generally well with satellite derived data, except during rainfall events on the ice sheet and because of a bias in the passive microwave re...
In this work, we have investigated the effect of modified land use patterns on urban air quality ... more In this work, we have investigated the effect of modified land use patterns on urban air quality inside the city as well as in the vicinity of the urban region under consideration (Antwerp, Belgium). Only changes in the meteorological fields have been taken into account, i.e. no variations in emission fields have been implemented. The level of greening and the kind of greening (pastures, crops, woods) has been changed in order to obtain multiple distinct patterns. The defined greening scenario's have been analyzed using the Eulerian air quality model AURORA in which the atmospheric fields needed for the dispersion calculations are provided by the non-hydrostatic atmospheric meso-scale model ARPS. Inside the ARPS model, the representation of the soil-vegetation processes was upgraded to better represent urban areas. The final results indicate relatively small changes in the resulting ozone fields although that differences between two realistic extremes in greening scenario's ...
... CLEMENS MENSINK*, LEO DE NOCKER, KOEN DE RIDDER VITO - Flemish Institute for Technological Re... more ... CLEMENS MENSINK*, LEO DE NOCKER, KOEN DE RIDDER VITO - Flemish Institute for Technological Research, Boeretang 200, B-2400 Mol ... Mild respiratory effects in asthmatics Chronic respiratory illness Restricted activity days (RAD's) Congestive heart failure in elderly ...
The ESA-funded SEVESEO project aims at developing a decision-making tool that integrates environm... more The ESA-funded SEVESEO project aims at developing a decision-making tool that integrates environmental parameters derived from satellite imagery with pollutant transport models in order to support the risk management at Seveso-II industries. The development of the SEVESEO Information System (SEVESEO IS) implies the integration of contaminant transport models that aim at determining the environmental impact of a Seveso type accident, by modeling transport of pollutants around the site. By integrating this information with local geographic information an operational GIS tool will be provided. This GIS tool will be able to support decision making during technological accidents, to assess the impact of the accident on the local environment and to indicate the areas at risk.
The Climate-fit.City service (https://www.climate-fit.city) provides the best available scientifi... more The Climate-fit.City service (https://www.climate-fit.city) provides the best available scientific urban climate data and information for public and private end users operating in cities. Within the Climate-fit.City H2020 project, the benefits of urban climate information for end user communities was demonstrated, considering services in diverse domains (Climate and Health, Building Energy, Emergency Planning, Urban Planning, Active Mobility, Tourism and Cultural Heritage) to improve decision-making and to help end users to better address the consequences of climate change at the local scale. The socio-economic impact assessment performed in the Climate-fit.City project has demonstrated that, in all the cases, there are actual and potential added values in terms of public service effectiveness, economic impacts, policy innovation and social impacts. Further impact was also revealed in terms of raising awareness by end users, policymakers and the general public about climate change. ...
[1] The objective of this paper is to present the validation over Greenland of a thermodynamic sn... more [1] The objective of this paper is to present the validation over Greenland of a thermodynamic snow-ice model that was complemented with the snow metamorphism and albedo parameterizations of the Centre d’Etudes de la Neige (Grenoble, France) in order to make the surface albedo variable and interactive. Special attention is given to the surface albedo since it is the most important parameter in energy exchanges with the atmosphere for snow and ice melt. The development of an integrated (snow, ice, and water) albedo model takes into account the different surface types observed on an ice sheet, and the snow albedo is calculated from the simulated surface snow grains. The validation for a polar site has been done at ETH Camp (West Greenland, 1155 m above sea level) during the 1990 and 1991 summer seasons. Although both ablation seasons differed greatly (in 1990 it showed a negative mass balance while in 1991 it ended with a positive mass balance), a single model configuration was able to provide good results for both 1990 and 1991. These simulations show that the snow metamorphism laws included enable an accurate simulation of the surface albedo and henceforth of the surface mass balance for a polar site, provided that the snow model is correctly forced at its surface level and that meltwater retention, percolation, and drainage are well represented in the snow model. The model results are also compared with two other modeling approaches, and differences between the three snow models are detailed. INDEX TERMS: 1827 Hydrology:
The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow re... more The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow regional climate model with a 25 km horizontal resolution. The simulated snow water content allows a direct comparison with the satellite derived melt signal. The model is forced with 6-hourly ERA-40 reanalysis at its boundaries. An evaluation of the simulated precipitation and a comparison of the modeled melt zone and the surface albedo with remote sensing observations are presented. Both the distribution and quantity of the simulated precipitation agree with observations from coastal weather stations, estimates from other models and the ERA-40 reanalysis. There are overestimations along the steep eastern coast which are most likely due to the "topographic barrier effect". The simulated extent and time evolution of the wet snow zone compare generally well with satellite derived data, except during rainfall events on the ice sheet and because of a bias in the passive microwave re...
The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow re... more The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow regional climate model with a 25 km horizontal resolution. The simulated snow water content allows a direct compar ison with the satellite derived melt signal. The model is forced with 6-hourly ERA-40 re analysis at its boundaries. An evaluation of the simulated precipitation and a com parison of the modelled melt zone and the surface albedo with remote sensing observations are presented. Both the distribution and quantity of the simulated precipitation agree with observations from coastal weather stations, estimates from other models and the ERA-4 0 reanalysis. There are overestimations along the steep eastern coast which are most likely due to the "topographic barrier effect". The simulated extent and time evolution of the wet snow zone compare generally well with satellite derived data, except during rainfall even ts on the ice sheet and because of a bias in the passive microw...
During the last 15 years, the official assessment maps in Flanders have improved from a map consi... more During the last 15 years, the official assessment maps in Flanders have improved from a map consisting of only measured data points to a high resolution assessment which covers the complete area and takes into account several types of sources and street canyons. In order to improve this level of detail, multiple steps were taken. First of all, a land use regression model was introduced at an hourly scale at 4 × 4 km2 resolution. Secondly, a Gaussian model was added for both point and line sources, correcting for emission double counting. Finally, a street canyon model was added to the chain, leading to improved resolution in these street canyons. In this work, we will discuss the problems encountered in these years such as how to account for double counting of emissions, how to correct the locations of the simplified road network and how to determine when street canyon calculations must be performed and how we solved them.
<p&amp... more <p>Biodiversity is increasingly under pressure from climate change, which affects the habitat suitability for species as well as the efficiency of ecosystem services. Management of these issues, for instance through ecosystem restoration or species dispersal measures, is often hindered by a lack of appropriate information about (future) climate conditions.  To address this, an operational Sectoral Information System (SIS) for the Biodiversity sector (SIS Biodiversity) is designed within the Copernicus programme Climate Change Service (C3S). This new SIS provides tailored bio-climatic indicators and applications, and delivers novel evidence regarding impacts of past, present and future climate. As such, it provides support to decision making challenges that are currently facing unmet climate data needs.<br> <br>The new climate service for SIS Biodiversity will be demonstrated, including the outline, workflow and outcomes of the use cases. The service is built upon the Copernicus Data Store platform (CDS; ), and takes into account (1) the barriers in ongoing bio-climate assessments and (2) the user requirements of diverse stakeholders (e.g. researcher institutes, local NGO’s, the International Union for Conservation of Nature and Natural Resources (IUCN),…). These have been collected during workshops and bilateral meetings in 2019. A common barrier is the lack of reliable and high-resolution information about states and dynamics of the soil, sea, ice and air for the past and the future climate. Therefore, the service provides relevant bio-climatic indicators on the basis of a wealth of available variables from the latest ERA5 reanalysis datasets and the CMIP5 global climate projections available in CDS. In order to provide information at high resolution and minimize inconsistencies between observed and modelled variables, different downscaling and bias-correction techniques are applied. A common requirement is a universal and flexible interface to the bio-climatic indicators in an easy-to-use and coherent platform that is applicable for different fauna and flora species of interest. Therefore, different applications have been developed within CDS for generating bio-climate suitability envelopes from the high-resolution indicators and to evaluate climate suitability and impacts for the species under present and future climate. Finally, the service is currently tested and refined on the basis of specific use cases. Special attention is given to their transferability to other global and topical studies, hence maximizing external user uptake throughout existing research and policy networks.</p>
ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences
Risk situation can be mitigated by prevention measures, early warning tools and adequate monitori... more Risk situation can be mitigated by prevention measures, early warning tools and adequate monitoring of past experiences where Earth Observation and geospatial analysis have an adding value. This paper discusses the potential use of Earth Observation data and especially Land Cover / Land Use map in addressing within the three aspects of the risk assessment: danger, exposure and vulnerability. Evidences of the harmful effects of air pollution or heat waves are widely admitted and should increase in the context of global warming. Moreover, urban areas are generally warmer than rural surroundings, the so-called urban heat island. Combined with in-situ measurements, this paper presents models of city or local climate (air pollution and urban heat island), with a resolution of less than one kilometer, developed by integrating several sources of information including Earth Observation data and in particular Land Cover / Land Use. This assessment of the danger is then be related to a map of...
Journal of Geophysical Research Atmospheres, Apr 27, 2003
The objective of this paper is to present the validation over Greenland of a thermodynamic snow-i... more The objective of this paper is to present the validation over Greenland of a thermodynamic snow-ice model that was complemented with the snow metamorphism and albedo parameterizations of the Centre d'Etudes de la Neige (Grenoble, France) in order to make the surface albedo variable and interactive. Special attention is given to the surface albedo since it is the most important parameter in energy exchanges with the atmosphere for snow and ice melt. The development of an integrated (snow, ice, and water) albedo model takes into account the different surface types observed on an ice sheet, and the snow albedo is calculated from the simulated surface snow grains. The validation for a polar site has been done at ETH Camp (West Greenland, 1155 m above sea level) during the 1990 and 1991 summer seasons. Although both ablation seasons differed greatly (in 1990 it showed a negative mass balance while in 1991 it ended with a positive mass balance), a single model configuration was able to provide good results for both 1990 and 1991. These simulations show that the snow metamorphism laws included enable an accurate simulation of the surface albedo and henceforth of the surface mass balance for a polar site, provided that the snow model is correctly forced at its surface level and that meltwater retention, percolation, and drainage are well represented in the snow model. The model results are also compared with two other modeling approaches, and differences between the three snow models are detailed.
Climate Dynamics Observational Theoretical and Computational Research on the Climate System, Jan 9, 2006
Measurements from ETH-Camp and JAR1 AWS (West Greenland) as well as coupled atmosphere-snow regio... more Measurements from ETH-Camp and JAR1 AWS (West Greenland) as well as coupled atmosphere-snow regional climate simulations have highlighted flaws in the cross-polarized gradient ratio (XPGR) technique used to identify melt from passive microwave satellite data. It was found that dense clouds (causing notably rainfall) on the ice sheet severely perturb the XPGR melt signal. Therefore, the original XPGR melt detection algorithm has been adapted to better incorporate atmospheric variability over the ice sheet and an updated melt trend for the 1988 2003 period has been calculated. Compared to the original algorithm, the melt zone area increase is eight times higher (from 0.2 to 1.7% year-1). The increase is higher with the improved XPGR technique because rainfall also increased during this period. It is correlated to higher atmospheric temperatures. Finally, the model shows that the total ice sheet runoff is directly proportional to the melt extent surface detected by satellites. These results are important for the understanding of the effect of Greenland melting on the stability of the thermohaline circulation.
The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow re... more The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow regional climate model with a 25 km horizontal resolution. The simulated snow water content allows a direct comparison with the satellite derived melt signal. The model is forced with 6-hourly ERA-40 reanalysis at its boundaries. An evaluation of the simulated precipitation and a comparison of the modeled melt zone and the surface albedo with remote sensing observations are presented. Both the distribution and quantity of the simulated precipitation agree with observations from coastal weather stations, estimates from other models and the ERA-40 reanalysis. There are overestimations along the steep eastern coast which are most likely due to the "topographic barrier effect". The simulated extent and time evolution of the wet snow zone compare generally well with satellite derived data, except during rainfall events on the ice sheet and because of a bias in the passive microwave re...
In this work, we have investigated the effect of modified land use patterns on urban air quality ... more In this work, we have investigated the effect of modified land use patterns on urban air quality inside the city as well as in the vicinity of the urban region under consideration (Antwerp, Belgium). Only changes in the meteorological fields have been taken into account, i.e. no variations in emission fields have been implemented. The level of greening and the kind of greening (pastures, crops, woods) has been changed in order to obtain multiple distinct patterns. The defined greening scenario's have been analyzed using the Eulerian air quality model AURORA in which the atmospheric fields needed for the dispersion calculations are provided by the non-hydrostatic atmospheric meso-scale model ARPS. Inside the ARPS model, the representation of the soil-vegetation processes was upgraded to better represent urban areas. The final results indicate relatively small changes in the resulting ozone fields although that differences between two realistic extremes in greening scenario's ...
... CLEMENS MENSINK*, LEO DE NOCKER, KOEN DE RIDDER VITO - Flemish Institute for Technological Re... more ... CLEMENS MENSINK*, LEO DE NOCKER, KOEN DE RIDDER VITO - Flemish Institute for Technological Research, Boeretang 200, B-2400 Mol ... Mild respiratory effects in asthmatics Chronic respiratory illness Restricted activity days (RAD's) Congestive heart failure in elderly ...
The ESA-funded SEVESEO project aims at developing a decision-making tool that integrates environm... more The ESA-funded SEVESEO project aims at developing a decision-making tool that integrates environmental parameters derived from satellite imagery with pollutant transport models in order to support the risk management at Seveso-II industries. The development of the SEVESEO Information System (SEVESEO IS) implies the integration of contaminant transport models that aim at determining the environmental impact of a Seveso type accident, by modeling transport of pollutants around the site. By integrating this information with local geographic information an operational GIS tool will be provided. This GIS tool will be able to support decision making during technological accidents, to assess the impact of the accident on the local environment and to indicate the areas at risk.
Uploads
Papers by Filip Lefebre