CDAW LWS 2002

Solar Energetic Particles (SEPs) are a critical element of space weather. The study of the SEP phenomenon is relevant to all five NASA Strategic Enterprises (Aerospace Technology, Biological and Physical Research, Earth Science, Human Exploration and Development of Space, and Space Science). SEPs are closely related to coronal mass ejections (CMEs) and flares. While CMEs originating from close to the disk center are geoeffective from the geomagnetic point of view, SEPs can reach Earth from a much broader range of solar longitudes. Understanding the acceleration and propagation of SEPs is a great scientific challenge. The vast array of space and ground-based instruments that became available over the past few years provides an excellent opportunity to take a closer look at the SEP phenomenon and its relation to CMEs, flares and interplanetary shocks in the inner heliosphere. The available data sets can be collectively utilized to address a number of SEP-related issues:

What are the primary characteristics that make a CME or flare produce SEPs?
Are electron accelerators also proton accelerators?
How do shocks weaken as they move out from the Sun and how does the shock history affect SEP intensities and spectra at the shock peak?
How do the spectral shape and its time dependence for various SEP species vary with source and interplanetary parameters, CMEs. and shocks?
What is the energy dependence of the streaming limit and how does it depend upon plasma parameters of the region through which the particles propagate?
Can we distinguish between the effects of temperature and density of the source plasma from the energy dependence of the Fe charge state?
Can we use the variations element abundance ratios to determine Q/A (charge-to-mass ratio) and the transport properties?
What is the compositional variation of solar particle events and can the compositional variation be predicted?
How do the injected and accelerated abundances vary with time? How do colliding CMEs or shocks alter the abundances? The spectra? Are there any features in the SEPs that coincide with the times of CME collisions?
Are there features associated with the spotty behavior of type II bursts in the electrons at 1 AU? What about the ion intensities or abundances?
How well can we characterize and predict SEPs and their impact on near-Earth space and the atmosphere?
What is the relationship between SEPs and the energetic particles in the magnetosphere?
How is SEP access to the inner magnetosphere determined during the transient phase?
How are SEPs trapped and subsequently lost in the inner magnetosphere?
What correlations are there between definable SEP parameters and corresponding effects on the atomosphere, geospace, technological systems?

We propose a new Coordinated Data Analysis Workshop (CDAW) to bring together scientists of Living With a Star (LWS) disciplines to interact and establish long-term collaborations. The focal point of the CDAW will be the set of all major SEP events of cycle 23 (until the end of 2001). The number of participants will be restricted to a maximum of 60. Our intent is to attract a set of participants who can contribute data, data products, models, and analysis tools to achieve the scientific goals of the CDAW. This would involve assembling and pre-processing the data sets well ahead of the CDAW and a lot of effort has to go in much before the workshop. The data from the CDAW and the results produced during the CDAW will be made available on line after the workshop to the broader scientific and space weather community for continued research.

Working groups will be formed to address specific questions and the findings will be summarized at the end of the workshop. Arrangements will be made to publish the initial results as letter papers and a conference will follow after allowing enough time to complete collaborative work started at the CDAW.

If you have any questions or comments, please contact Nat Gopalswamy, Barbara Thompson or any member of the organizing committee.

March 2002
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