Diurnal Coastal Wind Cycles Near the Critical Latitude

During 2005-2006, a network of boundary-layer wind profilers was in place in southeast Texas in support of air pollution studies. The profiler data set is analyzed for evidence of regular diurnal wind variations excited by the land-sea contrast. Periodic oscillations are found, but with maximum amplitude 100-200 km from the coast, 300-400 m above ground level, and several m/s in strength. Other oscillations associated with the Great Plains low-level jet are detected, as well as variations at higher altitude that are as yet unexplained. The coastal oscillations and their spatial and temporal structure will be discussed in the context of linear sea breeze theory and low-level jet formation.