Postdoc Directory

Gert-Jan Duine

Research Associate
College and Graduate School of Arts & Sciences
Department
Environmental Science
Mentor/Advisor
Stephan de Wekker
Degrees

PhD University of Toulouse, France

MSc Meteorology & Air Quality, Wageningen University, the Netherlands

BSc Soil, Water & Atmosphere, Wageningen University, the Netherlands

Although I come from a flat country, my main focus is on atmospheric processes over mountainous and hilly terrains. Being educated at the Meteorology & Air Quality Group in Wageningen, the Netherlands, most of my academic research is focused on atmospheric boundary-layer processes. The boundary layer is that layer of the atmosphere which reacts on processes occurring close or at the Earth's surface. As it is influenced by for example surface heating from the Sun and nighttime surface cooling, it shows a strong diurnal cycle. 

My PhD-research was on down-valley winds developing in nocturnal stable boundary layers, and focused on a prealpine area in southeastern France. It was a collaboration between the Laboratoire de Modelisation des Transferts dans l'Environnement, CEA Cadarache and the Laboratoire d'Aerologie, University of Toulouse. For impact calculations and operational forecasting related to dispersion, it was needed to characterize the down-valley winds in two joint valleys of different scales. To characterize these, the KASCADE field experiment was conducted in the winter of 2012/2013. The WRF numerical model was set up for the region and simulated to investigate the flows in a spatial extent. Full text of the thesis is available at: https://tel.archives-ouvertes.fr/tel-01263986/  The KASCADE data is free of use for any research purpose concerning boundary-layer processes over complex terrain.

Also for my postdoc I focus on boundary layer processes, but now on daily convective boundary layers. Together with Prof. De Wekker, we will look at the spatio-temporal variability of convective boundary layer (CBL) depths over complex (mountainous) terrains in global transport models. These models are typically run on coarse grid spacing.  For a correct estimation of carbon fluxes, which is strongly dependent on CBL depth, the simulation of CBLs is a crucial parameter. There is a large uncertainty in the representation of CBLs in the global models, and how these biases translate to uncertainties in the CO2 concentrations near the surface. We will firstly evaluate the performance of coarse global models in their simulation of PBL depths, we hope to improve the representation of CBLs, and then we should be able to assess the improvement of CO2-budgets in such models. We try to achive these goals by using a combination of high-resolution numerical models and existing observational studies.