Topographical effects on the coastal atmospheric surface layer

Land-Air-sea interaction can significantly affect the coastal atmospheric surface layer (CASL) and consequently, the local atmosphere. Despite its importance, our knowledge of coastal air-sea interaction is limited, and weather prediction models frequently generate erroneous predictions for coastal conditions due to a lack of an appropriate parameterization. Land topology, significantly varying thermal conditions across land and water, and oceanic processes such as ocean waves, wave breaking, and currents can all add to the complexity of a coastal atmospheric boundary layer, making its study difficult. In this study, we used LES to investigate the effect of topography on the CASL. The land topology is captured via the immersed-boundary method. We ran simulations for various locations along the Monterey Bay in California. The terrain in the test cases ranges from almost flat terrain with a maximum elevation of about 15m near the Moss landing state beach to mountain topography on the Monterey Bay peninsula with a maximum elevation of about 140m. Different thermal stratifications of the onshore flow are considered. The LES results show that topography can have a substantial impact on the CASL. The outcomes of this study will contribute to a better understanding of land-air-sea interaction in coastal regions.