Abstract
The influence of horizontal grid resolution (Δx) and horizontal diffusion on the maximum velocity of the sea breeze circulation is discussed using the results of a two-dimensional numerical model.
The computed maximum updraft (WMAX) of the sea breeze decreases as Δx increases when Δx is larder than a certain value. The maximum velocity, however, approaches a constant as Δx is decreased to values less than the value. Increasing the grid interval is similar to smoothing the peak values of the velocity. The peak values, therefore, are decreased as the grid size is increased. Further, it was found that the WMAX is significantly weakened by horizontal diffusion. The magnitude of WMAX at a given point is not very meaningful, since the value can be altered by changing the grid size and the smoothing method. The area-weighted WMAX appears to be more physically significant in numerically simulated results. Therefore, use should be made of an appropriately fine grid for studying a given phenomena.
