Boundary-Layer Atmospheric Processes in Mountainous Terrain: Results from MATERHORN-X

The study of atmospheric boundary-layer processes in complex terrain continues to be an active area of research considering its profound implications on numericalweather prediction (NWP). The improvement of current predictions at small scale and in complex environments is emerging as a result of increasing demands from society, particularly regarding the many applications involving mountain weather. Among them is the increase of urban settlements in the world in complex terrain, and a large fraction of world population depends on a daily basis on good weather predictions at increased spatial resolution. The effective implementation of mitigation measures for reducing urban air pollution, prediction or management of extremes of urban heat island as well as defining the triggers for local climate rely upon the ability of models to predict flow that is often generated or modified by complex terrain. In addition, intensive weather phenomena near mountains are a safety hazard to aircraft and unmanned aerial vehicles, but they are often missed in predictions, either because of the inadequacy of resolution or the lack of the correct dynamics in the model. Improving mountain weather forecasts is the goal of the interdisciplinary Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) program (2011–2016), as discussed by Fernando and Pardyjak (2013) and Fernando et al. (2015).