Exploring and visualizing three-dimensional ocean data in the China Digital Ocean Prototype System

INTRODUCTION Oceans, and indeed the entire planet, are changing at faster rates over broader scales than before and in fundamentally new ways. In a very short period of time, the bounty of the oceans has been depleted, and the ocean ecosystems have become seriously disrupted (Wright et al., 2007). The characteristic bounty and global circulation of oceans determine the importance of studying the problems of rising sea levels, the warming of seawater, and the increasing intensity of storms from a global perspective. With the development of ocean observation technologies, a substantial amount of oceanic data and model products are produced by the three-dimensional ocean observation system, a system that is composed of diverse monitoring approaches such as satellite, airplane, ship, high frequency ground wave radar, buoys (moored and drifting), and land-based stations. The study of better technologies that enable the visualization, examination, manipulation, and evaluation of the ocean observation data from a global perspective will allow managers, policy makers and scientists to understand, share, access, and use this data. This paper aims to study the technologies of exploring and visualizing three-dimensional ocean data from the Digital Earth system. Many studies have emerged recently on the application of spatial information technology (especially geographical information systems [GIS]) to the ocean at a regional scale because of this technology’s powerful mapping, geographical analysis and database management abilities. Dao et al. (2005) used GIS to identify appropriate sites for shrimp farming development in the Haiphong province of Vietnam. Chen et al. (2005) researched coastal changes and their environmental impacts in Lingding Bay of the Pearl River Estuary in South China based on a remote sensing and GIS-based integrated analysis. Su et al. (2006a, 2006b) designed the raster-based spatio-temporal hierarchical data model (RSHDM) for the marine information system, which bases itself on the nature of the marine data and overcomes the deficiencies of the current spatio-temporal models that emerge when they are used in the field; these authors also constructed the framework for the functions of the marine geographical information system (MGIS). Tang Yingqi et al. (2006) used ArcView GIS software to manage and develop tools to facilitate the exploration, statistical visualization, and analysis of the sea ice data that are compiled by the National Ice Center (NIC), data that contain abundant information about sea ice geographical coverage and changes during the last 30 years. Yosoon et al. (2009) developed a three-dimensional (3D) GIS extension with the ArcScene 3D GIS software, part of the ArcGIS software package for rock mass classification and fault zone analysis in tunneling. Daniela et al. (2009) presented a new modeling approach that can couple geological and numerical models to simulate groundwater flow and contaminant transport in fractured media through an intermediate mesh generation phase. Igor et al. (2009) developed a new 3D/2D interactive display ABSTRACT