RAPID: Preserving a Unique Archive for Long-Term Solar Variability Studies

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This is a short-term (one-year) effort to preserve and digitize a set of hand-drawn charts going back more than 40 years of solar features identified from Hydrogen-alpha images of the Sun. They were defined in 1964 as a means to identify and track major magnetic structures on the surface of the Sun and their evolution. This was before modern measurements of solar magnetism were routinely available. They were produced consistently and continually through 2010 and have formed the basis for important discoveries about solar magnetic field and surface evolution. However, this valuable resource is now in imminent danger of being lost because the scientist in charge and his two assistants, who were trained by him and worked with him on the maps, have retired. They are the only people with intimate knowledge of the technique behind the charts. Furthermore, while much of the original data set has been saved in their homes, is has not otherwise been preserved in copies or in digital form. Nor is it protected from loss through flooding, fire, etc. The main purpose of this RAPID award is to ensure that the entire set of charts is organized, scanned and digitally processed using a consistent, machine-readable format, thus creating a readily accessible dataset that can be utilized scientifically for years to come. The two assistants will carry out the majority of the effort, in collaboration with solar physics scientist and experts in the scanning, digital processing and data archiving of scientific data. The final digitized, searchable maps will be archived at NOAA's National Geophysical Data Center. This set of synoptic maps constitutes a unique and significant observational resource on the evolution of large-scale solar features over the course of four solar cycles. Once digitized, they can be used to measure the proportions of the solar surface exhibiting specific phenomena, and the locations of these features as a function of latitude and longitude (as defined by pixel location). The data can then be used to evaluate the proportions and their changes over time. This will provide extremely useful information that can be used to test theories and models for predicting the Sun's activity as a whole over a single cycle or over numerous cycles. It will also be useful for a wealth of other studies concerning specific features at the Sun, such as filaments, coronal holes or plage regions, as well as their variations over time in terms of quantity, location or movement.