The EMS Young Scientist Award 2013 was awarded to Gert-Jan Steeneveld, Wageningen University, The Netherlands, for the publication Steeneveld, G. J., S. Koopmans, B. G. Heusinkveld, L. W. A. van Hove, and A. A. M. Holtslag, 2011: Quantifying urban heat island effects and human comfort for cities of variable size and urban morphology in the Netherlands, J. Geophys. Res., 116, D20129, https://doi.org/10.1029/2011JD015988.
Gert-Jan received his PhD in 2007 on a thesis entitled “Understanding and Prediction of Atmospheric Stable Boundary Layers over Land”. The nocturnal stable boundary layer is a challenge to forecast and to understand, due to the multiple processes that play a role, especially for conditions with low wind speeds. The thesis research has been strongly inspired by the analysis and modelling of a series of nights with contrasting wind regimes during the CASES-99 field campaign. The results show that single column models can satisfactorily forecast the nighttime boundary layer provided that the large scale meteorological forcing conditions and land surface states are well prescribed. For calm conditions atmospheric turbulence dies out, and processes as radiation divergence and coupling with the land surface take over the in a natural way. Subsequently, the found insights were implemented in the MM5 mesoscale model. Also in the thesis research a new formulation for depth of the stable boundary layer, a critical parameter in air quality forecasting was developed.
As a postdoc Gert-Jan extended his focused to fog research. In the context of the Casimir-Ziegler visitor’s grant he worked at the Meteorologiches Institute of the Rheinische Friedrich-Wilhelms Universiteit in Bonn (Germany). The fog research is concentrated on large eddy simulation of fog events, and understanding the character of the turbulence in fog layers, and comparing the large eddy simulation results to outcome of weather forecast models.
Since 2009, he is also involved in two HYDRALAB water tank experiments in the statified flume of CNRM/GAME/Meteo-France in Toulouse (France). These experiments aim to shed a better light on turbulence and wave propagation in stratified conditions over flat terrain and hilly terrain, and to eventually use this knowledge to improve meteorological forecasting of the stable boundary layer.
Later on, urban meteorology became an additional research interest. As a first step, he participated in the evaluation of land surface models for the urban environment (organised by King’s college/Sue Grimmond). In addition, a study was performed on the quantification of the urban heat island effects in the Netherlands, that had received so far only small research attention. Innovatively crowdsourced meteorological data from hobby meteorologists were used (e.g. via wunderground.com). The study shows that even in a mild Cfb climate as in the Netherlands, the urban heat island effect and adverse human thermal comfort occur frequently. These data also indicated that green vegetation is a robust tool to limit the urban heat island effects.
The currently running E-Science project “Summer in the city” aims to develop a forecasting system to predict highly detailed meteorological forecast within cities. This requires a big data challenge in terms of mesoscale modeling and observations. Two Dutch cities have been equipped with tens of weather stations in order to verify the weather forecast for the urban environment.
Moreover Gert-Jan is currently a board member of Dutch Association for the Advancement of Meteorology (NVBM), and associate editor of the Quarterly Journal of the Royal Meteorological Society, and convenor of the EMS Annual meeting session ASI3 on “Formulation, validation and parameterization of small-scale processes in atmospheric modelling”.