East Asia and Western Pacific METEOROLOGY AND CLIMATE

365
A THREE-DIMENSIONAL MODEL OF THE CHINA SEAS AND
ASPECTS OF TYPHOON SURGE PREDICTIONS
S. K. Liu 1 , P. Wu 2 ,T. Y. Wu 3 , and S. T.Wang 3
ABSTRACT
This paper describes the numerical modeling work of the China Seas.
The area covered by the model is shown in Fig. 1. Within the large model
which has a I/I by 1/1 degree grid network, there are two levels of
submodels nested within the modeling domain. The regional submodels have
spatial resolutions between 1/8 degree and 1/24 degree. These submodels
obtain their open boundary conditions from the China Sea model.
majority of these regional models are three-dimensional, baroclinic, and have
five layers. For several coastal and esturaine systems, there are
two-dimensional models with variable grid network. Their open boundary
points are connected to the regional models.
The primary purpose of the modeling work is for ocean engineering and
coastal planing.
The
One recent application of the model is to predict coastal
storm surge due to typhoon and astronomical tides. Due to the nonlinear
dynamics associated with the coastal currents, the abnormal water level due
to the com bined action of typhoon and tides cannot be computed separate ly.
This is particularly true in coastal areas with strong tidal currents and
overtides induced by bottom dissipation or geometry.
The paper also discusses several operational aspects associated with the
forecast and areas for improvements.
1 RAND Corp. USA, and Consultant, Science & Tech. Advisory Group.
2 Science and Technology Advisory Group, the Executive Yuan.
3 Central Weather Bureau.