The role of orography in a complex area is of great importance, even more so when the study area comprises a coastal region where there is a critical need for topographical information due to the presence of the sea (or, in general, large water masses). The surface boundary condition is generally defined by means of a Digital Elevation Model (DEM), which provides information about terrain heights in the area of interest. Both DEM and computational domains are discrete representations of reality, and need algorithms capable of translating the continuous reality into a discrete model. This study illustrates the care that must be taken when defining the surface boundary condition in order to avoid significant misinterpretation.
Keywords: Boundary Conditions, Coast valley breeze, coastline modeling, Complex orography, Dew point profile, Digital Elevation Model, dispersion patterns, Initial Conditions, mechanical forcing, Mesoscale Models, Nesting, ozone, Planetary boundary layer physics, raob data, Spatial Discretization, thermal gradient, THOES, Time Integration, VOC, wind rose.