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NASA NTRS1991

Helium abundances on the moon: Assumptions and estimates

Nuclear energy is a highly desirable source of energy, and He-3 is the most prized of the fusion reactants. As the Wisconsin Group has emphasized, He-3 may be the only true economic ore on the Moon. The lack of a shielding atmosphere on the Moon permits solar-wind alpha particles to impinge upon the lunar regolith and become implanted into the various solid components. In particular, large quantities of helium (5 to 50 ppm) are presented. The measured parameter of I(sub s)/FeO, a direct indicator of maturity and exposure age, can be used as a first approximation to predict the abundances of many solar-wind components in the soils. However, because ilmenite has a much higher retentivity for helium than the other phases, the TiO2 contents of the soils are better indicators of helium contents (Taylor, Space 90). High-Ti mare bassalt regions, such as at the Apollo 17 locale, appear to be the best areas for He mining (15 to 50 ppm He(sub T)), versus 3 to 9 ppm in the Highlands. However, the relationships between I(sub s)/FeO, TiO2 and He-3 contents are complicated - e.g., many of the most He-rich soils are immature to submature. The amount of He-3 in the regolith of the moon is estimated at 220,000 tons in the outer 2 m of the Maria.

Taylor, Lawrence A.↗

NASA NTRS1990

Technology for subsystems of space-based plant growth facilities

Technologies for different subsystems of space-based plant growth facilities are being developed at the Wisconsin Center for Space Automation and Robotics, a NASA Center for the Commercial Development of Space. The technologies include concepts for water and nutrient delivery, for nutrient composition control, and for irradiation. Effort is being concentrated on these subsystems because available technologies cannot be effectively utilized for space applications.

Bula, R. J.↗

NASA NTRS1990

The Astro-1 Observatory mission

This paper describes the NASA's Astro-1 Observatory mission. The three ultraviolet (UV) telescopes and one X-ray telescope that make up this Spacelab mission will observe objects in the solar system, including comets and the outer planets, objects within the Milky Way Galaxy, and high-energy extragalactic objects such as quasi-stellar objects and active galaxies. While briefly discussing the science objectives of the mission, the paper focuses on the history of the mission, the Spacelab hardware assembled by the George C. Marshall Space Flight Center (MSFC) to carry the telescopes into orbit, and the complexities of the systems supporting that payload. Also discussed are the dimensions and capabilities of the Hopkins Ultraviolet Telescope, the Ultraviolet Imaging Telescope, the Wisconsin Ultraviolet Photopolarimeter Experiment, and the Broad Band X-Ray Telescope, all of which will coobserve a number of targets to generate comprehensive data in both the ultraviolet and X-ray ranges of the spectrum. The Astro-1 mission operations are described, and the cooperative functions of other NASA centers are reported.

Jones, Jack↗

NASA NTRS1990

A color gradient in the soft X-ray diffuse background

It is shown that the deviations of the soft X-ray diffuse background B band to C band intensity ratio from a constant value can be described as a simple dipole-like variation across the sky. In terms of the observed Wisconsin B/C band intensity ratio, the mean value is 0.355, the dipole magnitude is 0.106, and the positive dipole axis points toward l = 168.7 deg, b = 11.2 deg, almost in the galactic anticenter direction. This gradient in the spectral hardness can be due to several causes; the simplest is a temperature gradient in the X-ray emitting plasma of the local cavity from about 10 exp 6.2 K toward the galactic center to about 10 exp 5.9 K in the anticenter direction. While the physical origin of such a temperature gradient is uncertain, the alignment of the dipole with the higher temperature (and absorbed) Loop I region may be significant.

Snowden, S. L.↗

NASA NTRS1990

The 27-28 October 1986 FIRE IFO cirrus case study - A five lidar overview of cloud structure and evolution

During the case study from the First ISCCP (International Satellite Cloud Climatology Program) Regional Experiment (FIRE) Intensive Field Observation (IFO), one airborne lidar system and four ground-based systems collected linear depolarization, intrinsically calibrated backscatter, and Doppler velocity information. Data presented describe the temporal evolution and spatial distribution of cirrus clouds over an area encompassing southern and central Wisconsin. Cirrus cloud types include dissipating subvisual and thin fibrous cirrus cloud bands, an isolated mesoscale uncinus complex, a large-scale, deep cloud that developed into an organized cirrus structure within the lidar array, and a series of intensifying mesoscale cirrus cloud masses. It is noted that the cirrus frequently developed in the vertical from particle fallstreaks emanating from generating regions at or near cloud tops; however, glaciating supercooled altocumulus clouds contributed to the production of ice mass at the base of the deep cirrus cloud.

Sassen, Kenneth↗

NASA NTRS1990

Cirrus structure and radiative parameters from airborne lidar and spectral radiometer observations - The 28 October 1986 FIRE study

A description is presented of cirrus based on results from a FIRE observation flight in central Wisconsin on October 28, 1986. Cirrus structure and radiative parameters as determined by the ER-2 lidar and imaging spectral radiometers are presented. From the lidar observations a complex structure was shown with differing cloud layers extending over six kilometers of altitude range. Both thin and dense cirrus layers were present and mixed phase clouds were found at lower altitudes. As indicated by the cloud structure, precipitation of crystals from high, but vertically thin, layers produces a significant fraction of the lower cirrus. Multiple layers should be considered as normal for cirrus formations. It is noted that the cloud height is an important factor for satellite cloud retrievals and cloud climatology.

Spinhirne, James D.↗

NASA NTRS1990

The 27-28 October 1986 FIRE IFO cirrus case study - Cloud optical properties determined by High Spectral Resolution Lidar

The High Spectral Resolution Lidar (HSRL) was operated from a roof-top site in Madison, Wisconsin. The transmitter configuration used to acquire the case study data produces about 50 mW of ouput power and achieved eye-safe, direct optical depth, and backscatter cross section measurements with 10 min averaging times. A new continuously pumped, injection seeded, frequency doubled Nd:YAG laser transmitter reduces time-averaging constraints by a factor of about 10, while improving the aerosol-molecular signal separation capabilities and wavelength stability of the instrument. The cirrus cloud backscatter-phase functions have been determined for the October 27-28, 1986 segment of the HSRL FIRE dataset. Features exhibiting backscatter cross sections ranging over four orders of magnitude have been observed within this 33 h period. During this period, cirrus clouds were observed with optical thickness ranging from 0.01 to 1.4. The altitude relationship between cloud top and bottom boundaries and the optical center of the cloud is influenced by the type of formation observed.

Grund, C. J.↗

NASA NTRS1991

Astro - Science in the fast lane

The Space Shuttle mission devoted to astronomy (Astro) is described and data obtained during the nine-day flight are briefly reviewed. The Wisconsin Ultraviolet Photo-Polarimeter Experiment reveals a trough at 2200 A in the spectrum of Alpha Camelopardalis. It is suggested that the 2200-A feature is caused by absorption by graphite-rich interstellar dust. The Broad Band X-ray Telescope made it possible to study the NGC 1399 X-ray spectrum, the spectrum of the BL Lacertae object PKS 2155-304, and a cooling flow in a cluster of galaxies. The Astro mission's search for the missing mass in the form of neutrinos is discussed. Attention is also given to the effect of delays on the Astro activity, and to equipment problems and how they were solved.

Maran, Stephen P.↗

NASA NTRS1992

Extended atmospheres of comets and outer planet-satellite systems

For the hydrogen coma of comet P/Halley, both a Lyman-alpha image and extensive Lyman-alpha scan data obtained by the Pioneer Venus Orbiter Ultraviolet spectrometer as well as H-alpha ground-based spectral observations obtained by the University of Wisconsin Space Physics Group were successfully interpreted and analyzed with our Monte Carlo particle trajectory model. The excellent fit of the model and the Halley data and the water production rate determined near perihelion (9 Feb. 1986) from 13 Dec. 1985 to 13 Jan. 1986 and from 1 Feb. to 7 Mar. 1986 are discussed. Studies for the circumplanetary distribution of atomic hydrogen in the Saturn and Neptune systems were undertaken for escape of H atoms from Titan and Triton, respectively. The discovery of a new mechanism which can dramatically change the normal cylindrically symmetric distribution of hydrogen about the planet is discussed. The implications for the Titan-Saturn and Triton-Neptune are summarized.

Smyth, William H.↗

NASA NTRS1992

Wind Profiles Derived from Volume Imaging Lidar Data: Enhancements to the Algorithm and Comparisons with Insitu Observations

This paper presents wind measurements made with the University of Wisconsin Volume Imaging Lidar (VIL) during Aug. 1989 as part of the First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment (FIFE). Enhancements to the algorithm are described. Comparisons of these results to aircraft, balloon, and surface based wind measurements are presented. Observations of the spatial variance of aerosol backscatter are also compared to measurements of the convective boundary layer depth. Measurements are based on two-dimensional cross correlations between horizontal image planes showing the spatial distribution of aerosol scattering observed by the lidar at intervals of approximately 3 minutes. Each image plane covers an area of 500-1000 sq km and the winds calculated represent area averages.

Piironen, A. K.↗

NASA NTRS1991

First ultraviolet spectropolarimetry of hot supergiants

UV spectropolarimetric observations of the early-type supergiant stars P Cygni and Kappa Cassiopeiae obtained with the Wisconsin UV Photo-Polarimeter Experiment (WUPPE) are presented. Contrary to model predictions, the intrinsic polarization of P Cyg remains constant in the Balmer continuum except for a broad dip between 2600 and 3000 A. This decrease in polarization is discussed in terms of possible Fe line blanketing effects. The intrinsic position angle is essentially constant in the UV except for a rotation across the feature between 2600 and 3000 A. The intrinsic polarization of Kappa Cas is small; most of the observed polarization is interstellar in nature. The Serkowski curve extrapolated into the UV is found to fall consistently below the observed polarization. A slight rotation in position angle from optical to UV wavelengths is noted. Very good agreement is found between the mean continuum polarization obtained by WUPPE and the broadband UV polarization measurement obtained by Gehrels (1968).

Taylor, M.↗

NASA NTRS1992

The first spectropolarimetric study of the wavelength dependence of interstellar polarization in the ultraviolet

The first UV spectropolarimetry along six lines of sight with significant interstellar polarization is reported. The observations were obtained with the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) during the Astro-1 mission. HD 37903, HD 62542 and HD 99264 show a wavelength dependence which follows the Serkowski relation extrapolated into the UV. HD 25443 and Alpha Cam have UV polarization well in excess of the Serkowski extrapolation. HD 197770 clearly shows a polarization bump which closely matches the 2175 A extinction feature. This bump polarization can be fitted by small aligned graphite disks. The differences along various lines of sight might be the result of differences in the environments which affect the size and alignment of the grains.

Clayton, Geoffrey C.↗

NASA NTRS1990

Moisture and heat budgets of a cirrus cloud from aircraft measurements during fire - October 31 case study

Increasing knowledge of cirrus cloud properties can contribute to general circulation model development and ultimately to a better understanding of climate. The objective of this study is to gain better understanding of cirrus cloud characteristics. Observations from different sensors during the FIRE experiment which took place in Wisconsin over Oshkosh (Starr, 1987), together with pertinent calculations, will be used to understand the dynamic, microphysical, and radiative characteristics of these clouds.

Gultepe, I.↗

NASA NTRS1992

Cloud-property retrieval using merged HIRS and AVHRR data

A technique is developed that uses a multispectral, multiresolution method to improve the overall retrieval of mid- to high-level cloud properties by combining HIRS sounding channel data with higher spatial resolution AVHRR radiometric data collocated with the HIRS footprint. Cirrus cloud radiative and physical properties are determined using satellite data, surface-based measurements provided by rawinsondes and lidar, and aircraft-based lidar data collected during the First International Satellite Cloud Climatology Program Regional Experiment in Wisconsin during the months of October and November 1986. HIRS cloud-height retrievals are compared to ground-based lidar and aircraft lidar when possible. Retrieved cloud heights are found to have close agreement with lidar for thin cloud, but are higher than lidar for optically thick cloud. The results of the reflectance-emittance relationships derived are compared to theoretical scattering model results for both water-droplet spheres and randomly oriented hexagonal ice crystals. It is found that the assumption of 10-micron water droplets is inadequate to describe the reflectance-emittance relationship for the ice clouds seen here. Use of this assumption would lead to lower cloud heights using the ISCCP approach. The theoretical results show that use of hexagonal ice crystal phase functions could lead to much improved results for cloud retrieval algorithms using a bispectral approach.

Baum, Bryan A.↗

NASA NTRS1992

The first linear polarization spectra of Wolf-Rayet stars in the ultraviolet - EZ Canis Majoris and Theta Muscae

During the 1990 December Astro-1 Space Shuttle mission, spectropolarimetry was conducted in the wavelength region from 1400 to 3200 A of the Wolf-Rayet stars EZ CMa (WN5) and Theta Mus (WC6 + O9.5I) with the Wisconsin Ultraviolet Photo-Polarimeter Experiment. The UV polarization of EZ CMa displays features which correspond to emission lines. This indicates a large, about 0.8 percent, intrinsic UV-continuum polarization, and provides further evidence that the wind of EZ CMa is highly distorted. The polarization of Theta Mus does not change across emission lines, or the strong interstellar 2200 A feature. The polarization decreases smoothly to shorter wavelengths, at constant position angle. The combined UV-optical polarization spectrum of Theta Mus can be described well with interstellar polarization following a Serkowski law.

Schulte-Ladbeck, R. E.↗

NASA NTRS1991

Experimental investigations of He II flows at high Reynolds number

Fluid dynamics studies of He II at high Reynolds number (Re(d) greater than 10 exp 6) reveal characteristics which are best interpreted in terms of classical scaling relationships. In particular, the smooth tube friction factor is seen to correlate with the Von Karman-Nikuradse formulation. Also, the performance of a centrifugal pump is unchanged whether being used with He I or He II. These effects are expected to result provided the He II possesses a viscous sublayer and that the drag is determined by laminar flow within this layer. On the other hand, heat transfer in He II is substantially different from that of He I because of the unique internal convection mechanism present in this quantum fluid. These experiments are performed in the University of Wisconsin liquid helium flow facility which has unique capabilities of He II temperature, pressure and flow.

Van Sciver, Steve W.↗

NASA NTRS1992

Data management in NOAA

NOAA has 11 terabytes of digital data stored on 240,000 computer tapes. There are an additional 100 terabytes (TB) of geostationary satellite data stored in digital form on specially configured SONY U-Matic video tapes at the University of Wisconsin. There are over 90,000,000 non-digital form records in manuscript, film, printed, and chart form which are not easily accessible. The three NOAA Data Centers service 6,000 requests per year and publish 5,000 bulletins which are distributed to 40,000 subscribers. Seventeen CD-ROM's have been produced. Thirty thousand computer tapes containing polar satellite data are being copied to 12 inch WORM optical disks for research applications. The present annual data accumulation rate of 10 TB will grow to 30 TB in 1994 and to 100 TB by the year 2000. The present storage and distribution technologies with their attendant support systems will be overwhelmed by these increases if not improved. Increased user sophistication coupled with more precise measurement technologies will demand better quality control mechanisms, especially for those data maintained in an indefinite archive. There is optimism that the future will offer improved media technologies to accommodate the volumes of data. With the advanced technologies, storage and performance monitoring tools will be pivotal to the successful long-term management of data and information.

Callicott, William M.↗

NASA NTRS1990

Epidemiologic research in Antarctica

A study of epidemiology of respiratory viruses that was begun in the early 1960's is described. Locations selected for the study included a Wisconsin University housing village, a second grade school population, individual volunteers who associated socially, married couples, and the winter-over population at McMurdo Bay and at Scott Base in the Antarctic. It was concluded that most rhinovirus transmission is through aerosolized particles. Air filtration and careful nasal sanitation with virucidal tissues are determined to be effective in blocking rhinovirus transmission and should be useful in both isolated space colonies and in ordinary earth-bound populations.

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