Effects of External Parameters on the Flow Field in the Coastal Region—A Linear Model

Abstract

The land and sea breeze (LSB) and steady conviction (SC), superimposed on the geostrophic wind U, were analyzed by a linear model, the SC being driven by the diurnal-mean land-sea temperature difference and causing seasonal changes in the climate in the coastal region. An extension of Walsh's model (1974) was made to include SC and the effect of the Prandtl number (Pr). The influences of U, as well as the Coriolis force f/w, mean atmospheric stratification Grr (a form of Grashof number) and Pr on the LSB and SC were investigated. The LSB and SC are similar in their effects on the flow pattern, the wind speed and spatial dimensions being almost the same as at middle and higher latitudes when U = 0. The vertical dimension, the horizontal dimension and the wind speed are proportional to Gr0rPr¼, Gr0.387rPr0. and Gr?½rPr??, respectively. The f/w effect is very small except for the dimensions of SC. The wind speeds of the LSB and SC created by a unit temperature difference between land and sea, as well as the structure and development of the sea breeze opposing U, were also investigated.