Observed Regional Variability of Fog in the Netherlands

The formation of fog is the result of several competing processes. On a large scale, synoptic weather plays a significant role. Locally, its formation is controlled by such factors as land cover (and related surface properties) and topography. The Netherlands proves an excellent location for studies of fog with a strong seasonal cycle and abundant moisture. Yet, even in a small country such as the Netherlands, variations in nocturnal temperature can be large due to heterogeneous land use. With a dense network of high quality observations available throughout the country, the climatology of fog events at different sites is assessed. Some stations (such as the Cabauw site in the centre of the country) are found to experience over twice as many fog events as other stations (e.g., Schiphol Airport). Differences in local fog climatology are shown to not only be the result of local variability in land surface properties, but also non-local and upwind features of the surrounding land surfaces.