By: Thirza van Laar, Tobias Marke
Date: 22.06.-23.06.2017
Locations: Institute for Geophysics and Meteorology - Cologne, RWTH Aachen
In the framework of the IRTG invited speaker program we were glad to invite Jordi Vila for a visit in Cologne and in Aachen during the TR32 General Meeting. Jordi is professor of Meteorology and Air Quality at Wageningen University in the Netherlands.
At the Institute of Marine and Atmospheric Research in Utrecht, Jordi did his PhD on the role of atmospheric turbulence on chemical reactions from 1989 to 1992. He then started to work with mesoscale models like WRF. Since 1999 Jordi works in the Meteorology and Air Quality section at Wageningen University, also as a lecturer for Bachelor, Master and PhD students.
His work focuses on Large-Eddy Simulations (LES) of boundary layer processes including clouds, mesoscale phenomena and the interactions between the land surface and the atmosphere. The scientific approach is to bridge different fields (chemistry, atmospheric dynamics, biology) to study these processes on different scales, based on simple conceptual models to complex LES and mesoscale models, which are also validated by field observations.
The main findings include that the the impact of cloud optical thickness changes the partition between direct and diffuse radiation and influences the surface energy budget. This is causing differences in evapotranspiration and sensible heat fluxes, which is the main driver of turbulent thermals, transporting heat and moisture and hence influencing cloud formation. These coupled processes are resolved by LES, but need parameterizations in climate models.
The talk in Cologne was dealing with evapotranspiration and cloud variability on regional subgrid scales, with special emphasis on the coupling of clouds and surface properties. During the GM in Aachen, Jordi gave an interactive lecture using the Chemistry Land Surface Soil Slab model CLASS, that he developed together with colleagues. This conceptual model can be used to investigate and understand interaction processes in a well-mixed boundary layer by changing different parameters within a computational fast and easy to use graphical interface.
Furthermore, we could benefit from this two day visit to discuss future steps of our PhD studies, in terms of how to describe cloud fields and surface properties using model simulations.