At the end of June the Lorentz Centre/eScience workshop “eWUDAPT:Bringing Science to urban climate mapping and modelling” took place in Leiden in June 2017. Its aim was to combine different expertise (geography, meteorology, data science, observations, etc.) with eScience expertise to provide better understanding of urban environment and improve weather forecasts. Within the context of this workshop, the urban modelling team performed an initial model inter-comparison study focused on interaction between urban and boundary-layer schemes. Based on the initial results we have formed an inter-comparison study that aims to unravel the interactions between urban surface environments and boundary layer dynamics and investigate the sensitivity in the coupling of these two components in different models. The institutes participating in this study will be asked to run a urban canopy model and single-column model of their choice (SCM )for a specific case study over London. As a first step, we will provide the participants with the forcing (geostrophic wind speed, initial profiles, etc.) needed to run their model. In the later stages of the inter-comparison project, the participants will be asked to run the SCM with their choice of schemes, always for the same case study.
Urban areas are characterized by a clearly different meteorology than rural areas. With the refinement of the resolution of numerical weather prediction models, the consideration of the surface energy balance of urban areas require a specific representation to account for radiative trapping, urban vegetation, anthropogenic heat flux, heat storage in the urban fabric. Many urban canopy models of different complexity have been developed in the last decades. Grimmond et al (2010, 2011) compared a myriad of the models on the performance of the surface energy balance, and identified a ranking in the essentials of processes to be represented and parameter space. In that particular study the models were driven by observations taken above the canopy, which is a state of the art method to evaluate land surface models. However, in the real world, these urban canopy schemes are operating in conjunction with boundary-layer schemes that are responsible for transport of heat, moisture and momentum from the surface through the lower atmosphere, as well as with the free atmosphere due to entrainment. This coupling leads to feedbacks and dependencies on the schemes that have so far not been quantified. Here we propose a modelling experiment in which we further evaluate the modelling infrastructure for the urban boundary layer coupled to the urban land surface.
This modelling exercise specifically aims to:
Here you find the SUBLIME case description
The forcing files are provided in .txt format as well as in netcdf format. These together are available in a zipfile that can be downloaded for each stage:
•Evaluate single-column models coupled to the urban surface for the urban environment against field observations at the surface as well and in the PBL.
•Identify key strengths and weaknesses in these model approaches.
•Identify feedbacks and their strengths between urban canopy schemes and boundary-layer scheme.
•Provide a benchmark case study for later use in the community.
In this sense the proposed work build upon earlier experiments in the GABLS (Holtslag et al, 2013) and DICE (Best and Lock, 2016) communities
Phase 0: Offline urban canopy model evaluation
Phase 1: Online (coupled to the boundary layer)urban canopy model evaluation
Graphs of the preliminary results can be found here
In case of questions, please contact:
Gert-Jan Steeneveld (Gert-Jan.Steeneveld@wur.nl)
Grimmond, C.S.B., M. Blackett, M. Best, J. Barlow, J.-J. Baik, S. Belcher, S.I. Bohnenstengel, I. Calmet, F. Chen, A. Dandou , K.Fortuniak, M. Gouvea, R. Hamdi, M. Hendry, H. Kondo, S. Krayenhoff, S.-H. Lee , T. Loridan, A. Martilli, V. Masson, S. Miao, K. Oleson, G. Pigeon, A. Porson, F. Salamanca, L. Shashua-Bar, G.J. Steeneveld, M. Tombrou, J. Voogt, N. Zhang, 2010: The International Urban Energy Balance Models Comparison Project: First results from Phase 1, J. Appl. Meteor. Clim., 49, 1268-1292.
Grimmond, C.S.B, M Blackett, MJ Best, J-J Baik, SE Belcher, J Beringer, SI Bohnenstengel,I Calmet, F Chen, A Coutts, A Dandou, K Fortuniak, ML Gouvea, R Hamdi, M Hendry,
M Kanda, T Kawai, Y Kawamoto, H Kondo, ES Krayenhoff, S-H Lee, T Loridan, A Martilli,V Masson, S Miao, K Oleson, R Ooka, G Pigeon, A Porson, Y-H Ryu, F Salamanca, G.J. Steeneveld, M Tombrou, JA Voogt, D Young, N Zhang, 2010: Initial Results from Phase 2 of the International Urban Energy Balance Comparison Project, Int. J. Climatol.,31,244-272.
Holtslag, A.A.M., G. Svensson, P. Baas, S. Basu, B. Beare, A.C.M. Beljaars, F.C. Bosveld, J. Cuxart, J. Lindvall, G.J. Steeneveld, M. Tjernström, and B.J.H. van de Wiel, 2013: Stable Atmospheric Boundary Layers and Diurnal Cycles – Challenges for Weather and Climate Models, Bull. Amer. Meteorol. Soc.,94, 1691-1706