1. General Model Information

Name: Korea-East-Yellow Seas Model Ver. 1.0

Acronym: KEY


Main medium: aquatic
Main subject: hydrology
Organization level: ecosystem
Type of model: partial differential equations
Main application:
Keywords: hydrodynamics, korea, sea

Contact:

Moon-Sik Suk
Physical Oceanography Division
Korea Ocean Research & Development Institute
Ansan POB 29, 425-600, Seoul Korea
and
Lakshmi Kantha
University of Colorado
Boulder, CO 80303 U.S.A.

Home page: key.kordi.re.kr (in preparation)

Author(s):

Abstract:

  The purpose of this study is for operational task to examine the spatio-temporal distribution of the concentrations of pollutants incoming to the sea. Model results are to be served as a given environmental dynamical oceanographic condition, and the information of the circulation and dispersion environments. This kind of experiment should be realistic as much as possible with the actual state-of-the-art. Thus a more improved three-dimensional model with real-time forcing is required to correspond to the need of high-resolution information near the source of pollutants. Local approach for a limited region has an intrinsic limitation since sea-water movements are not confined only to the inner sea, e.g., near bay or estuaries but open to any place of the outer sea. Therefore, it should be noticed that ocean circulation must be computed by a basin-scale model. Meso-scale phenomena in the ocean are not only fundamental to predict the ocean circulation but also need to be resolved from the ocean management point of view. Any limited regional approach can be carried out simply by extracting the objective domain from the [K E Y] grid system (Suk et al 1996), and the results are to be easily compared with those obtained from different model domain. In this study, a newly-improved circulation model for the East Sea (EC) is presented, which is a three-dimensional, data assimilating and eddy-resolving model corresponding to the need of high-resolution information about the sea.
  A unified grid system that covers the entire seas around Korea is constructed. This grid system is named as [K E Y] and K, E, and Y stand for the Korea Sea (entire domain), the East Sea and the Yellow Sea, respectively. Combining one of the three letters above with the letter representing its main purpose, e.g., T for tide and C for circulation, 6 kinds can be produced such as KT, KC, ET, EC, YT, and YC models. The model domain of the East Sea (EC) extracted from the [K E Y] grid system is shown in Fig. 2 (Suk et al 1996).

  Existing data including weekly MCSST(JPL/NASA) images clearly show the existence of the polar front across the basin in the East Sea. Initiation, growth and dissolution of the warm- and cold-core rings are also evident. We focus on the process how the East Sea responds to external forcings as well as on the predictability and limitations thereof.

  The equations of motion in the model are the same as those of Blumberg and Mellor (1987) except for the mixed-layer scheme, which is replaced by that of Kantha and Clayton (1993). Monthly sea-surface winds (Hellerman and Rosenstein 1983, Na et al. 1988), temperatures and salinities (JODC 1975) are used as mean states. The initial fields of temperature and salinity are filled with those in January from the historical data (JODC 1975, Levitus 1982). A constant influx through the Korea Strait is given by 2 Sv since recent observations have demonstrated that there is only a small amount of the annual fluctuation in volume transport. As surface forcings weekly surface temperatures (MCSST) are used throughout 1990-1996. SSH derived using 4-year mean sea level from altimetry data compiled by CCAR for 1993-1996 is applied through data assimilation scheme.

  We run the EC model for 3 year with mean states, then for 1990-1992 with only weekly MCSST forcing, and for 1993-1996 additionally with SSH data assimilation. Since the sea-surface elevation of model output is an important benchmark for the oceanographic condition which reveals the circulation in total, it is worthwhile to examine the characteristic features of the sea-surface elevation in the East Sea. And we examine our model results by comparing with in-situ observation such as ARGOS drifters.

  The annual variation of the sea-surface elevation has been well reproduced with mean states. Two branches are clearly shown; one is the East Korea Warm Current (EKWC) flowing northwards along the Korean coasts, and the other the nearshore branch along the Japanese coasts. The model simulates the real circulation of the East Sea in a reasonable manner such that the separation latitude of the EKWC from the Korean coasts may have the annual variability and the oceanic conditions are ready to repeat the previous annual cycle in a year.

  There is a cyclonic gyre as a whole over the Japan basin, which results in the Liman Current flowing southwards along the Syberian coasts. The fluctuation of the polar front crossing the middle of the basin causes the flow pattern to change throughout the whole basin. In addition, it is clearly noticed that the warm rings appear to the south of the polar front over the Ulleung and the Yamato basins all the year round.

  The detailed record and the description of any oceanic accidents such as oil spill and/or red-tide events may contribute a lot to the model experiments. For it is impossible to carry out field experiments with real pollutants to improve the model capability for the oceanic prediction.
Source of the abstract: KEY-Homepage


II. Technical Information

II.1 Executables:

Operating System(s):

II.2 Source-code:

Programming Language(s):

II.3 Manuals:



II.4 Data:



III. Mathematical Information


III.1 Mathematics


III.2 Quantities


III.2.1 Input

III.2.2 Output


IV. References



V. Further information in the World-Wide-Web

KEY-Homepage

VI. Additional remarks


Last review of this document by:
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:45 CEST 2002

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