026.doc
Accuracy Assessment of Ocean Tide Models in the China Seas
Nanhua YU, Cheng HUANG, Center for Atrogeodynamics Research, Shanghai
Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China.
nhyu@center.shao.ac.cn, Phone: 86-21-64386191 ext. 396. FAX: 86-21-64384618.
Abstract. The first comprehensive ocean tide model is developed in 1980 by E. Schwiderski, the
availability of the TOPEX/POSEIDON spaceborne radar altimeter observations has allowed
development of more than 10 improved barotropic tide models during 1994-1996, and the same
number of further improved models by 2000. The TOPEX/POSEIDON global barotropic ocean tide
models developed during 1994-1996 have been assessed as with accuracy of 2-3 cm rms in the deep
ocean, a spatial resolution on the order of 50 km, and with significantly degraded accuracy near
coastal regions (Shum et al., 1997; Desai et al.,1997). The next generations of ocean tide models are
now available taking advantage of more than 6 years of TOPEX/POSEIDON (T/P) altimeter data and
more sophisticated hydrodynamical modeling and associated assimilation techniques. We have
conducted a study to assess the prediction capability of six current ocean tide models, with a focus on
the coastal regions, including Yellow Sea and China Seas. Results indicated that there is noticeable
improvement of the current models over the 1996 models both in the deep ocean and in the coastal
oceans, although the coastal ocean tidal errors are still significant. Independent data used for accuracy
assessment include pelagic tidal constants, and radar altimeter sea level measurements from T/P,
Geosat and ERS-1. The primary purpose of tide model studies is to choose a model for corrections of
altimeter data to study coastal circulations in China Seas, which is one of the focused research areas
for the APSG (Asian-Pacific Space Geodesy) project.
Oral presentation
Oceanography