We are at a crossroads in magnetospheric research, in transition between missions based principally on in situ observations from isolated spacecraft and new missions focused on examining the large-scale magnetosphere via remote sensing or multiple satellite missions. With some exceptions for low-cost missions, single satellites with in situ measurements have gone about as far as they can in providing unique data. The current mission concept of large complements of instruments on any one satellite that provide complete characterizations of the plasma environment is phasing out. With the ISTP missions ending early in the next decade, a new and different type of fleet of simultaneously operating spacecraft will be launched, many of which will be carrying imagers of various types.
The magnetospheric analyst of the future is thus faced with a variety of challenges because the approaches to studying magnetospheric dynamics will be evolving early in the next decade. With these new data sets the analyst will face two fundamental challenges: 1) Can sufficiently quantitative parameters be derived from the data, especially images, which will allow a distinction to be made between various candidate source, loss, and driver mechanisms? and 2) Can the physics of the dynamics be derived from such databases, especially from the fleets of satellites with more limited instrumentation?
The Sixth Huntsville Modeling Workshop, entitled "The New Millennium Magnetosphere: Integrating Imaging, Discrete Observations, and Global Simulations", was held from October 26 - 30, 1998 at Lake Guntersville Lodge in Guntersville, Alabama to address these issues. (Further meeting details can be found at http://science.msfc.nasa.gov/ssl/pad/sppb/workshop/default.htm.) One of the principal accomplishments to emerge from the weeklong workshop was a new definition of imaging, one that includes not only the traditional concept of building pictures by collecting photons, but that also includes detection of energetic neutral atoms (ENA) and the synthesis of large collections of discrete observations (both ground and space based). In short, imaging was defined to be any technique that synthesized information from a large region of space with sufficient resolution to yield results quantitative enough to address current problems in magnetospheric science. This new definition was illustrated with results from current research as well as descriptions of upcoming missions, e.g. IMAGE and TWINS, and proposed future missions.
A second principal accomplishment of the workshop was an elucidation of the challenges noted above. Addressing these challenges will require the use of new techniques and new ways of looking at the magnetosphere, a situation described by one participant as "waiting for Godot". But the community is doing much more than passively waiting for the future. They are actively developing new experimental and theoretical approaches which were discussed throughout the workshop. ENA imaging received much attention, starting with presentation of current images from POLAR/CEPPAD and ASTRID, and continuing with an extended discussion of ENA image inversion techniques. In addition to neutral atom imaging, presentations focused on Radio Plasma Imaging, a new technique that will be flown for the first time on the IMAGE mission. The concept of imaging was further redefined to include synthesis of discrete observations, either from arrays of groundbased instruments, or new fleets of satellites such as those proposed under the Magnetospheric Multiscale and Magnetospheric Constellation missions
The single outstanding feature of the proposed volume is that the monograph articles will explore this new concept of magnetospheric imaging using optical techniques, non-optical techniques, and global modeling. The study of the magnetosphere is defined to include the coupled ionosphere so that groundbased observations and ionospheric modeling are appropriate if they synthesize data from multiple sources or extended regions to yield insight of larger magnetosphere.
Papers will be solicited from the conference attendees, though with some restrictions and omissions noted below. The papers will present original scientific results, with the exception of an opening chapter that will provide a review of magnetospheric observations to date. This opening chapter will provide the context for the chapters which follow.
One chapter will be devoted to theory and modeling as a tool for synthesizing data from multiple sources. This will be followed by two chapters presenting experimental investigations. These investigations will be divided into one chapter devoted to contemporary optical imaging and one devoted to non-optical techniques.
The conference provided a showcase for upcoming and proposed missions and therefore included several talks of a programmatic nature. The proposed monograph will focus on the scientific aspects of imaging as defined above and will not be appropriate for presentation of mission or instrument details outside the context of scientific studies. In addition, each contribution to the monograph will be rigorously peer-reviewed to insure scientific quality, originality of work, relevance to the scientific community, and adherence to the monograph theme. Participation in the conference will not be sufficient reason to be included in the monograph nor will the monograph attempt to include all participants or even all session topics.
We propose to publish a monograph devoted to the collection, assimilation, and synthesis of data from a large region of space with global models with sufficient resolution to yield results quantitative enough to address current problems in magnetospheric science. The final product will be a timely and topical collection of interest to most of the space science and aeronomic community.