Actors of the main activity in large complex centres during the 23 solar cycle maximum

During the maximum of Solar Cycle 23, large active regions had a long life, spanning several solar rotations, and produced large numbers of X-class flares and CMEs, some of them associated to magnetic clouds (MCs). This is the case for the Halloween active regions in 2003. The most geoeffective MC of the cycle (Dst = −457) had its source during the disk passage of one of these active regions (NOAA 10501) on 18 November 2003. Such an activity was presumably due to continuous emerging magnetic flux that was observed during this passage. Moreover, the region exhibited a complex topology with multiple domains of different magnetic helicities. The complexity was observed to reach such unprecedented levels that a detailed multi-wavelength analysis is necessary to precisely identify the solar sources of CMEs and MCs. Magnetic clouds are identified using in situ measurements and interplanetary scintillation (IPS) data. Results from these two different sets of data are also compared.     

Autonomous Landing Guidance Systems

All weather tactical aircraft recovery and high sortie generation rates from forward, possibly battle damaged landing areas will reqire autonomous landing guidance systems which are independent of ground-based cooperative aids. A recently completed study has examined the operational requirements and assessed current and near term technology for an answer to this need. The Landing Systems Requirements/Synthesis Study has defined the Pilot/vehicle Interface and imaging sensor suite required, based on the concept of augmenting pilot forward vision with sensor imagery and guidance symbology on a HUD during low visibility landings. Image processing technology was also assessed for potential enhancement of the information presented to the pilot. This paper summarizes the final report of the Study, which is in publication.     

Relative contributions of terrestrial and solar wind ions in the plasma sheet

A major uncertainty concerning the origins of plasma sheet ions is due to the fact that terrestrial H⁺ can have similar fluxes and energies as H⁺ from the solar wind. The situation is especially ambiguous during magnetically quiet conditions (AE < 60γ) when H⁺ typically contributes more than 90% of the plasma sheet ion population. In this study we examine that problem using a large data set obtained by the ISEE-1 Plasma Composition Experiment. The data suggest that one component of the H⁺ increases in energy with increasing activity, roughly in proportion to $\text{1}\text{4}$ the energy of the He⁺⁺, whereas the other H⁺ component has about the same energy at all activity levels, as do the O⁺ and the He⁺. If we can assume that the H⁺ of solar wind origin on the average has about the same energy-per-nucleon as the He⁺⁺, which is presumably almost entirely from the solar wind, then the data imply that as much as 20–30% of the H⁺ can be of terrestrial origin even during quiet conditions.     

Thermospheric model calculations based on turbulence data

Thermospheric model calculations are presented which explain the seasonal compositional changes of helium and argon by the combined effect of seasonal-latitudinal variations of turbulence and global seasonal winds. The observational base of the model calculations is given by empirical data of upper thermospheric densities and by estimates of the turbopause height derived from composition measurements and incoherent scatter temperatures in the lower thermosphere. The results are compared with observations of the seasonal variability of atomic oxygen in the turbopause region.     

Equatorial cloud properties on Venus from pioneer orbiter infrared observations

Infrared observations of Venus from the Pioneer Orbiter have been used to study the limb darkening properties of the cloud tops at wavelengths and spatial resolutions not previously attained. The preliminary results show evidence for an extensive haze feature over the equatorial morning terminator and for small amounts of a far-infrared absorber concentrated near local noon, also near the equator. The evidence for these features is reviewed and their possible origins briefly discussed.     

Absorbers seen near the Venus cloud tops from pioneer Venus

Spin-scan images from the Pioneer Venus Orbiter UV Spectrometer and the Cloud Photopolarimeter provide a set of planetary contrast measurements in the wavelength range 1990A to 3650A and phase angles from 33°–130°. The planet is darkest at the point where the UVS line of sight penetrates perpendicular to the cloud tops: thus the absorbing material responsible must be deep in the atmosphere. Sulfur dioxide absorption can explain the amount of contrast seen between 2000A and 3200A. At the longer wavelengths, the persistence of contrast requires another absorber which is deeper in the atmosphere and strongly associated with the location of the SO₂. Part of the observed contrast is due to the high-lying haze discovered from Pioneer Venus polarimetry. The correlation between planetary contrast and polarization does not support large scale clearing or major vertical motions of the cloud tops as the sole cause of the observed contrast. However, a scheme in which absorbers subject to photochemical destruction are mixed upward into the cloud top region provides a consistent explanation for the origin of these markings.     

The Berkeley parasitic SETI program

Parasitic programs for the Search for Extraterrestrial Intelligence (SETI), carried out concurrently with conventional radio astronomical observing programs, can be an attractive and cost-effective means of exploring the large multidimensional search space intrinsic to this effort. We describe a microprocessor-based automated SETI acquisition system which searches for and records spectra of narrowband signals in the IF band of an observatory receiver. Data taken with this system over 35 days at the Hat Creek Radio Observatory at 1612 MHz are discussed. Out of approximately 10⁵ spectra processed during this period, 4000 were identified by the system as containing narrowband signals and were recorded. Subsequent analysis indicates that over 3900 of these are due to local RF contamination. The remainder are undergoing further investigation.     

The university of wyoming's small scientific balloon program

Over 500 small scientific balloons have been launched by the University of Wyoming's Atmospheric physics Group from 26 locations over the globe in a study of stratospheric aerosol physics and chemistry which began in 1971. These flights have led to a basic understanding of the evolution of sulfurous gases, injected into the stratosphere by major volcanic eruptions, into sulfuric acid aerosol droplets. The recent use of new, thin film balloon technology, to reduce cost and simplify launch techniques, has been a major advantage to the program.     

Three Years of Progress in Integrated Diagnostics

In 1983 the NSIA sponsored the first Integrated Diagnostics National Conference. The major finding from this Conference was the lack of integration of those technologies which are part of the diagnostic process. Since that time, much has been done to implement the concept of integrated diagnostics. The NSIA has produced a baseline report on the implementation of the concept. This was followed by a series of Service programs aimed at implementation. The Office of the Secretary of Defense considers solutions to the diagnostic problem to be one of its major R&D goals. This paper discusses the progress made during the last three years on the implementation of integrated diagnostics. The paper also discusses the author's ideas on where the program is going.     

Factors Relating to the Application of Radioisotopes to Circulatory Support Systems

Radioisotope power supplies for heart assist devices and total replacements are being developed. In a radioisotopically powered artificial heart, heat from the decay of radioisotopes would be converted to fluid power to operate a blood pump. Radioisotope power sources offer the advantages of being completely implantable and having a relatively long life. Initial efforts have been directed toward developing conceptual designs of radioisotope heat engines, evaluating candidate radioisotopes fuel forms, and studying the radiation doses to be expected from the various fuel forms. Conceptual design studies indicate that a power supply capable of meeting the specifications of a circulatory support system can be developed. The most promising fuel is plutonium-238. Radiation does not appear to be a problem.