Assessing Numerical Predictions of Fog in the Yellow Sea

Marine fog impacts human health, naval strategy, and biological productivity. Despite its importance, the skill of operational regional and global environmental models in forecasting marine fog and its optical properties remain limited due to our incomplete understanding of the physical processes that drive fog, particularly over its broad range of temporal and spatial scales. As part of the ONR MURI Project “Fog and turbulence interactions in the marine atmosphere” (FATIMA), detailed oceanic and atmospheric observations were collected off the western coast of South Korea in the Yellow Sea in the early summer of 2023. This region is prone to complex air-sea interaction processes at that time of the year, often associated with tidal plumes extending at significant distances from the shore and at times collocated with fog events. In this work, we present validation of numerical predictions computed from a coupled atmosphere-ocean numerical weather prediction model COAMPS for that region against in-situ observations. In particular, we characterize the sensitivity of fog prediction to model errors and demonstrate the need for assimilating as many observations as possible to improve the initial boundary conditions which significantly impact fog forecasts.