Filtering 효과를 고려한 중규모 지역기상의 수치해석

Abstract

해안선 근방의 해륙풍장을 해석하기 위한 3차원 중규모 지역기상 수치모델을 이용하여 시간 및 계절의 변화에 따른 흐름장의 변동을 해석하였다. 본모델에서는 지표는 온도를 sine함수에 따라 변화한다고 가정하고 측방향 경계와 수평방향 확산계수대신에 Filter를 사용하였다.

접지층에서의 연직방향 확산계수는 Businger의 모델을 그리고 Eckman층에서는 Mellor와 Yamada의 난류모델을 사용하여 계산하였다. 그 결과 해륙풍장의 특성을 해석하는데 있어서 본 모델은 매우 효과적임을 알 수 있었다.

Numerical experiments have been employed to simulate the land and sea breezes over the coastal region in a three dimensional mesoscale model.

Spcial attention is paid to effect of diurnal and seasional variations and of filtering in horizontal diffusivity and lateral boundary condition which allows lateral propagation of wind disturbance out of the model. In this model, the surface temperature of the land was determined through the surface heat budget consideration with sine function approximation.

The vertical diffusion coefficients of the momentum, heat and specific humidity in surface layer are given by Businger and above surface layer are obtained by level 2 model of the turbulence closure proposed by Mellor and Yamada.

The model is proved to be effective in simulating the structure of the land and sea breezes with various chracteristics.

Numerical experiments have been employed to simulate the land and sea breezes over the coastal region in a three dimensional mesoscale model.

Spcial attention is paid to effect of diurnal and seasional variations and of filtering in horizontal diffusivity and lateral boundary condition which allows lateral propagation of wind disturbance out of the model. In this model, the surface temperature of the land was determined through the surface heat budget consideration with sine function approximation.

The vertical diffusion coefficients of the momentum, heat and specific humidity in surface layer are given by Businger and above surface layer are obtained by level 2 model of the turbulence closure proposed by Mellor and Yamada.

The model is proved to be effective in simulating the structure of the land and sea breezes with various chracteristics.