The ACRIM data in the context of stellar variability

The Active Cavity Radiometer Irradiance Monitor (ACRIM) total-irradiance data from the Solar Maximum Mission have given a first comprehensive view of solar variability in the stellar sense. Five types of solar variability have been identified thus far. These have small amplitudes, less than a few tenths of one percent, and are at levels generally not yet detectable on other stars. The possible stellar analogs are interesting physically, and in particular may help us to understand solar behavior on longer time scales. The ACRIM data is described from the stellar point of view. The present state of stellar time-series photometry is discussed

Scientific tradeoffs in pinhole/occulter facility accommodation

The Pinhole/Occulter Facility (P/OF) consists of state-of-the-art instruments for the study of particle acceleration in the solar corona, and uses a large structure to obtain very high angular resolution. P/OF has been studied in the past as an attached payload for the Space Shuttle, and has been the subject of study by a NASA Science Working Group (P/OFSWG). Appendix A lists various technical studies and reports carried out under the auspices of P/OFSWG and the Program Development Office of NASA Marshall Space Flight Center. Under the rationalization of NASA flight opportunities following the Challenger disaster, and the beginning of the Space Station Freedom program, the sortie-mode deployment of P/OF seemed less efficient and desirable. Thus, NASA decided to reconsider P/OF for deployment on the Space Station Freedom. The technical studies for this deployment continue at the present and will evolve as our knowledge of Space Station architecture and capabilities increase. MSFC contracted with Teledyne Brown Engineering for these technical studies

Ion energy storage for post-flare loops

Low-energy non-thermal protons may have long lifetimes in coronal loops with low density and high temperature. If energy were stored in such protons in the initial phases of a solar flare, it could be released slowly during the later phases. Within the present observational limits for post-flare loops, this mechanism should be considered in addition to a field-line reconnection theory of the Kopp and Pneuman type. The thin-target gamma ray emission from the trapped protons is below present limits, but more sensitive observations can test the hypothesis

Characterization of total flare energy

It is concluded that the estimates of total energy in the prime flares lie well below the Active Cavity Radiometer Irradiance Monitor upper limits. This is consistent with our knowledge of the energy distribution in solar flares. Insufficient data exist for us to be very firm about this conclusion, however, and major energetic components could exist undetected, especially in the EUV-XUV and optical bands. In addition, the radiant energy cannot quantitatively be compared at this time with non-radiant terms because of even larger uncertainties in the latter

Solar analysis of solar-constant monitoring package (SMM)

The activity cavity radiometer irradiance monitor is supplying the first high precision data on solar total irradiance at the Earth. Thee classes of variability were discovered: large variations of amplitudes up to 0.2%; small high frequency variations in the form of a continuum in the periodogram, extending up to the Nyquist frequency; and sharp spikes at frequencies corresponding to the individual p modes already known from radial velocity measurements. The observed variations (up to 0.3%, on time scales of several days) were identified with sunspot darkness. The data analysis is expected to give information about the solar interior, as well as about the solar input to the terrestrial climate

Solar coronal non-thermal processes (Solar Maximum Mission)

The Solar Maximum Mission was used to study solar coronal phenomena in hard X-radiation, since its instrument complement included the first solar hard X-ray telescope. Phenomena related to those discovered from OSO-5 and OSO-7 observations were emphasized

Information Rich 3D Computer Modeling of Urban Environments

We are living in an increasingly information rich society. Geographical Information Systems now allow us to precisely tag information to specific features, objects and locations. The Internet is enabling much of this information to be accessed by a whole spectrum of users. At CASA we are attempting to push this technology towards a three-dimensional GIS, that works across the Internet and can represent significant chunks of a large city. We believe that the range of possible uses for such technology is diverse, although we feel that urban planning is an area that can benefit greatly. An opportunity to push this “planning technology” arose when CASA won a tender from Hackney Council to develop a dynamic website for community participation in the process of regenerating the Woodberry Down Estate. This is a run down part of northeast London that is undergoing a major redevelopment. CASA has developed a system that not only informs the local residents about the redevelopment process but it also enables them to use dynamic visualisations of the “before and after effects” of different plans, and then to discuss and vote on the variety of options