摘要：Atmospheric mountain lee waves excited by a strong westerly wind ahead of approaching cold front are shown to have significant effect on GPS positioning. Before the approach of the cold front significant atmospheric gradients caused by the inhomogeneous water vapor are detected at the sites along the east coast of the Izu Peninsula because of a wet atmosphere to the west of these sites. In contrast, the island site 6 km east of the coast detects a strong gradient with the opposite sense. The Geostationary Meteorological Satellite cloud shows rows of the clouds due to mountain lee waves consistent with the GPS measurements. A numerical simulation explains the mountain lee waves. The atmospheric perturbations induce large systematic errors in the estimates of horizontal positions of the sites in the region.
