James R. Thieman

Jovian dual-sinusoidal HOM lane features observed by Galileo

A well defined sinusoidal-shaped “band” of reduced emission intensity exists within Jovian HOM from 500 kHz to 3 MHz at all Jovian longitudes as observed by the Galileo spacecraft. A less prominent sinusoidal-shaped band feature exists in the same frequency range but is 180° out of phase with the more prominent feature. We used a multiple Jovian rotation spectrogram technique to fully display both bands and found that these sinusoidal-shaped features are the source of the “lanes” previously studied in Voyager and Ulysses data. Our extension of the simple straight-line ray model by Gurnett et al. [1998] provides a qualitative explanation for the observed features. We found that the two sinusoidal bands show an asymmetry about the longitude of the northern tip of the magnetic dipole (202° CML). Enhancements of emission can be seen along the edges of the bands which may be interpreted as caustic surfaces.

SPASE 2.0: a standard data model for space physics

SPASE—for Space Physics Archive Search and Extract—is a group with a charter to promote collaboration and sharing of data for the Space Plasma Physics community. A major activity is the definition of the SPASE Data Model which defines the metadata necessary to describe resources in the broader heliophysics data environment. The SPASE Data Model is primarily a controlled vocabulary with hierarchical relationships and with the ability to form associations between described resources. It is the result of many years of effort by an international collaboration (see http://www.spase-group.org) to unify and improve on existing Space and Solar Physics data models. The genesis of the SPASE group can be traced to 1998 when a small group of individuals saw a need for a data model. Today SPASE has a large international participation from many of the major space research organizations. The design of the data model is based on a set of principles derived from evaluation of the existing heliophysics data environment. The development guidelines for the data model are consistent with ISO-2788 (expanded in ANSI/NISO Z39.19) and the administration for the data model is comparable to that described in the ISO standards ISO-11179 and ISO-20943. Since the release of version 1.0 of the data model in 2005, the model has undergone a series of evolutions. SPASE released version 2.0 of its data model in April 2009. This version presents a significant change from the previous release. It includes the capability to describe a wider range of data products and to describe expert annotations which can be associated with a resource. Additional improvements include an enhanced capability to describe resource associations and a more unified approach to describing data products. Version 2.0 of the SPASE Data Model provides a solid foundation for continued integration of worldwide research activities and the open sharing of data.

Virtual observatories for space and solar physics research

As soon as the first data became available online over the Internet, it was obvious that different sites holding related datasets should appear to the end user as a single data system, even if the data itself is stored at multiple locations. To achieve this objective in the context of continuing parallel development of multiple data centres, in 2003 several actors in the realm of space plasmas created the international consortium Space Physics Archive Search and Extract (SPASE). Since 2005 US participation in SPASE has been supported by NASA, and early in 2006 NASA funded five new Virtual Observatories to cater for different aspects of solar system plasma science. This paper outlines the current status of the SPASE effort, the opportunities it offers, its specificities with respect to other parts of the astronomical virtual observatory, and the possibilities it offers for space weather.

SPASE and the Heliophysics Virtual Observatories

The Space Physics Archive Search and Extract (SPASE) project has developed an information model for interoperable access and retrieval of data within the Heliophysics (also known as space and solar physics) science community. The diversity of science data archives within this community has led to the establishment of many virtual observatories to coordinate the data pathways within Heliophysics subdisciplines, such as magnetospheres, waves, radiation belts, etc. The SPASE information model provides a semantic layer and common language for data descriptions so that searches might be made across the whole of the heliophysics data environment, especially through the virtual observatories.

SPASE: The Connection along Solar and Space Physics Data Centers

The Space Physics Archive Search and Extract (SPASE) project is an international collaboration among Heliophysics (solar and space physics) groups concerned with data acquisition and archiving. The SPASE group has simplified the search for data through the development of the SPASE Data model as a common method to describe data sets in the archives. The data model is an XML-based schema and is now in operational use. The use is expanding, but there are still other groups who could benefit from adopting SPASE. We discuss the present state of SPASE usage and how we foresee development in the future.

Large Database Access and Usage in the Earth and Space Sciences through Computer Networks

The development of the worldwide computer network has fostered the creation of and access to many data information systems and databases. These offer the capability for users to identify, access, use, and intercompare data from remote locations. It is not always easy to find the best sources of information for a particular problem. Directories for this purpose have existed for some time, and new methods are being developed for network information location, especially for systems such as the World-Wide Web and other network tools. It is still important, however, that there be consistency and standard approaches to the information content for effective information retrieval.