The Interactive Earth Science Data Visualization Gallery (vizGal)

Many scientific institutions are running sophisticated Earth system models as part of the global effort to understand and predict the state of the Earth's climate. These institutions have invested heavily in the development of their model codes and the computing infrastructure necessary to run the complex coupled climate studies. Increasingly, the climate modeling community believes that the behavior of a particular model is best understood when it is possible to compare it to the behavior of other related models. The Live Access Server (LAS) is a well-established Web-application software system for display and analysis of geo-science data sets. The LAS group has long been active in the development of tools to facilitate easy, Web-based model inter-comparison and other visualization of earth science data. The LAS software, which can be downloaded and installed by anyone, gives data providers an easy way to establish services for their on-line data holdings so their users can make plots, create and download sub-sets in a variety of formats, and compare and analyze data.

As part of our work funded through the Earth System Grid Center for Enabling Technologies (ESG-CET) project, we have developed a suite of flexible web-based data access and scientific visualization tools that facilitate direct model-to-model comparisons and visualizations. These new tools break down many of the traditional barriers that have inhibited model inter-comparisons such as the vast size of the datasets; physically distributed files; differing and sometimes challenging coordinate systems; and the subtle metadata that explains the differences between model configurations. This paper will focus on one of the premier tools in the LAS suite for inter-comparison called the Interactive Earth Science Data Visualization Gallery, known as vizGal.

The vizGal takes advantage of the remote data sub-setting capabilities of OPeNDAP and server-side analysis available via F-TDS to move only the minimum data necessary to create the product. Additionally, the LAS system uses a sophisticated cache system to reuse plots and computations whenever possible. The vizGal user interface, which offers a level of interactivity that rivals desktop applications, was built using the Google Web Toolkit (GWT). The paper will explore how we overcame the challenge of building highly interactive software in a Web environment and of visualizing and performing analysis on large remote data collections.