## Latest news - **[05.11.2026]** [[Publications#^Tijhuis2026|New paper]] by [[The team#^team-mirjam|Mirjam Tijhuis]] in *Monthly Weather Review*, together with colleagues from DWD, comparing an idealised squall line in the NWP model ICON and our LES code [[MicroHH]]. With an identical case setup, both models simulate the same squall-line structure and circulation, and the mean vertical wind and mass and moisture fluxes agree within 5%. However, ICON produces less surface precipitation and stronger updrafts. The differences come mostly from the advection scheme and the formulation of moist thermodynamics, showing that model physics and numerics matter at least as much as grid spacing. - **[25.09.2026]** [[ODET#^output-Roelofs2026|New paper]] by [[The team#^team-Tristan|Tristan Roelofs]] in *Atmospheric Chemistry and Physics* on fire-induced circulations, using idealised [[MicroHH]] simulations inspired by the Santa Coloma de Queralt fire. Whether a fire-induced circulation develops depends on the ambient wind speed in the direction of the circulation. The circulation strongly reshapes the boundary layer ahead of the fire, first deepening and then thinning it by up to 2 km. This work was done within [[EWED]] and continues in [[ODET]]. - **[25.09.2026]** Our new [[ORCRIST + SUNBEAM|ORCRIST]] project, funded by the NWO Open Technology Programme, has started. Together with the group of Ben van Werkhoven at Leiden University, we will develop fast 3D radiative transfer using GPUs and machine learning to better simulate the interactions between radiation, clouds, and wildfire smoke. We will be recruiting a PhD student soon, so stay tuned! - **[29.04.2026]** In a [[nextGEMS#^output-Heerwaarden2026|new paper]] by multiple team members, we evaluate how well the two km-scale nextGEMS models reproduce Earth's climates with the Köppen-Geiger classification. The major climate categories are captured, but regional biases — driven mainly by precipitation errors — remain, and present-day differences between the two models exceed the 30-year climate change signal in many regions. Observations are from Beck et al. (2023, Sci. Data).  - **[17.04.2026]** [[Publications#^Postema2026|New paper]] by [[The team#^team-Bernard|Bernard Postema]] showing that mesoscale-coupled large-eddy simulations can reproduce the observed wind spectrum from one year down to one minute. Larger mesoscale domains (up to 1024 km) better capture intermediate-scale fluctuations, and both domain size and diffusion formulation strongly shape the simulated wind. - **[21.02.2026]** [[nextGEMS#^output-Veerman2026|New paper]] on the impact of horizontal resolution on surface irradiance over land in km-scale Earth System Models by [[The team#^team-Menno|Menno Veerman]]. Most simulations produce accurate climatologies, but the impact of higher resolution is modest and mostly confined to mountainous areas. Older news can be found in the [[News archive]]. ## About With my [[The team|research group]] I study boundary-layer meteorology and atmospheric convection and the role of radiation and land-atmosphere interactions. - **Research**: Read about our [[Projects overview|projects]] and [[Publications|publications]]. - **Software**: Read about our 3D simulation code [[MicroHH]]. - **Teaching**: Read about [[Introduction to the atmospheric boundary layer|boundary-layer meteorology]]. <div style="padding:56.25% 0 0 0;position:relative;"><iframe src="https://player.vimeo.com/video/764263410?h=beddab2fc1&autoplay=1&loop=1&title=0&byline=0&portrait=0" style="position:absolute;top:0;left:0;width:100%;height:100%;" frameborder="0" allow="autoplay; fullscreen; picture-in-picture" allowfullscreen></iframe></div><script src="https://player.vimeo.com/api/player.js"></script> <div align="center"><i>Simulation of clouds throughout the years. Visualization made for the "Building bridges in cloudy atmospheres" symposium held in October 2022 at Wageningen University.</i></div> <div class="copyright"> Copyright (c) 2024 Chiel van Heerwaarden. All rights reserved. <a href="https://www.flaticon.com/free-icons/cloud" title="cloud icons">Cloud icons created by Freepik - Flaticon</a></div>