ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • GEOPHYSICS  (1.328)
  • 1995-1999
  • 1980-1984  (1.328)
  • 1975-1979
  • 1925-1929
  • 1983  (594)
  • 1981  (734)
Sammlung
Schlagwörter
Erscheinungszeitraum
  • 1995-1999
  • 1980-1984  (1.328)
  • 1975-1979
  • 1925-1929
Jahr
  • 1
    facet.materialart.
    Unbekannt
    The tectonics of anorthosite massifs (1981)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: Anorthosite massifs developed approximately 1.4 to 1.5 billion years ago along an arch which developed parallel to a zone of continental separation as a block which included North America, Europe, and probably Asia separated from a block which included parts of South America, Africa, India, and Australia. Anorthosite massifs also developed at the same time along a belt which runs through the continents which comprise Gondwanaland (South America), Africa, India, Australia, and Antarctica. This was a zone of continental separation which subsequently became a zone of continental collision about 1.2 billion years ago. The northern anorthosite belt also parallels an orogenic belt which was active between 1.8 and 1.7 billion years ago. Heat generated during this mountain building period helped in the formation of the anorthosites.
    Schlagwort(e): GEOPHYSICS
    Materialart: Houston Univ. The 1981 NASA ASEE Summer Fac. Fellowship Program, Vol. 2; 29 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unbekannt
    Low-energy electron flux and its reaction to active experimentation of Spacelab (1981)
    In:  CASI
    Details
    Publikationsdatum: 2006-06-04
    Beschreibung: An instrument capable of observing the natural electron flux in the energy range from 0.1 to 12.0 kiloelectron volts is discussed for use in an experiment intended as a forerunner of a method that will utilize artificially accelerated electrons as tracer particles for electron fields parallel to the magnetic field. Effects that are of importance either as means of detecting the echo beam or as causes of beam perturbations (e.g., spacecraft charging effects and electron background) are to be studied. The use of electron accelerators as a tool to probe magnetospheric processes rather than to modify them is planned.
    Schlagwort(e): GEOPHYSICS
    Materialart: NASA. Marshall Space Flight Center Spacelab Mission 1 Expt. Descriptions; 3 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unbekannt
    Atmospheric emission photometric imaging (1981)
    In:  CASI
    Details
    Publikationsdatum: 2006-06-04
    Beschreibung: A dual-channel video system mounted on a stabilized two-axis gimbal system (mounted on the pallet) with associated optics and data handling electronics described the low light flux observations are required for: (1) investigating ionospheric transport processes by observing Mg+ ions; (2) supporting magnetospheric electron bounce experiments; (3) measuring electron cross sections for selected atmospheric species; (4) detecting small particle contamination; and (5) studying natural auroras.
    Schlagwort(e): GEOPHYSICS
    Materialart: NASA. Marshall Space Flight Center Spacelab Mission 1 Expt. Descriptions; 4 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unbekannt
    DC-magnetic field vector measurement (1981)
    In:  CASI
    Details
    Publikationsdatum: 2006-06-04
    Beschreibung: A magnetometer experiment was designed to determine the local magnetic field by measuring the total of the Earth's magnetic field and that of an unknown spacecraft. The measured field vector components are available to all onboard experiments via the Spacelab command and data management system. The experiment consists of two parts, an electronic box and the magnetic field sensor. The sensor includes three independent measuring flux-gate magnetometers, each measuring one component. The physical background is the nonlinearity of the B-H curve of a ferrite material. Two coils wound around a ferrite rod are necessary. One of them, a tank coil, pumps the ferrite rod at approximately 20 kilohertz. As a consequence of the nonlinearity, many harmonics can be produced. The second coil (i.e., the detection coil) resonates to the first harmonic. If an unknown dc or low-frequency magnetic field exists, the amplitude of the first harmonic is a measure for the unknown magnetic field. The voltages detected by the sensors are to be digitized and transferred to the command and data management system.
    Schlagwort(e): GEOPHYSICS
    Materialart: NASA. Marshall Space Flight Center Spacelab Mission 1 Expt. Descriptions; 2 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unbekannt
    Investigation on Atmospheric H and D through the measurement of their Lyman-alpha emissions (1981)
    In:  CASI
    Details
    Publikationsdatum: 2006-06-04
    Beschreibung: Study of sources of Lyman-alpha emission in the atmosphere, in the interplanetary medium, and perhaps in the galactic medium is planned. Sources of Lyman-alpha emission are described and a schematic of the instrument presented.
    Schlagwort(e): GEOPHYSICS
    Materialart: NASA Marshall Space Flight Center Spacelab Mission 1 Expt. Descriptions; 3 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unbekannt
    Space experiments with particle accelerators (1981)
    In:  CASI
    Details
    Publikationsdatum: 2006-06-04
    Beschreibung: The purpose of space experiments with particle accelerators (SEPAC) is to carry out active and interactive experiments on and in the Earth's ionosphere and magnetosphere. It is also intended to make an initial performance test for an overall program of Spacelab/SEPAC experiments. The instruments to be used are an electron beam accelerator, magnetoplasma dynamic arcjet, and associated diagnostic equipment. The accelerators are installed on the pallet, with monitoring and diagnostic observations being made by the gas plume release, beam-monitor TV, and particle-wave measuring instruments also mounted on the pallet. Command and display systems are installed in the module. Three major classes of investigations to be performed are vehicle charge neutralization, beam plasma physics, and beam atmosphere interactions. The first two are mainly onboard plasma physics experiments to measure the effect of phenomena in the vicinity of Spacelab. The last one is concerned with atmospheric modification and is supported by other Spacelab 1 investigations as well as by ground-based, remote sensing observations.
    Schlagwort(e): GEOPHYSICS
    Materialart: NASA. Marshall Space Flight Center Spacelab Mission 1 Expt. Descriptions; 4 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unbekannt
    Ozone and aircraft operations (1981)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: The cabin ozone problem is discussed. Cabin ozone in terms of health effects, the characteristics of ozone encounters by aircraft, a brief history of studies to define the problem, corrective actions taken, and possible future courses of action are examined. It is suggested that such actions include avoiding high ozone concentrations by applying ozone forecasting in flight planning procedures.
    Schlagwort(e): GEOPHYSICS
    Materialart: NASA. Marshall Space Flight Center Proc.: 5th Ann. Workshop on Meteorol. and Environ. Inputs to Aviation Systems; p 40-44
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unbekannt
    Comparisons of global ozone trends inferred from the BUV experiment on Nimbus 4 and the ground-based network (1981)
    In:  CASI
    Details
    Publikationsdatum: 2006-03-27
    Beschreibung: Preliminary comparisons between global ozone burdens derived from the backscattered ultraviolet (BUV) experiment on Nimbus 4 and those inferred from an analysis of ground-based network data seem to indicate significant differences in the inter-annual variability of ozone. Some of the observed differences may be due to improper weighting of the ground-based network data, slowly changing planetary wave structure over the fixed station, of small inter-annual changes in meridional transport parameters. There is also some evidence which indicates that the polar stratosphere at high latitudes may represent an important ozone storage resevoir which tends to compensate for large scale changes observed in the regions outside of the polar stratosphere. Possible consequences of this are that the global trends derived from ground based ozone measurements may not be valid and furthermore that the current satellite techniques by themselves may be sufficient. An ozone monitoring system which includes observations from satellites, ground-based stations, balloons and rockets may be necessary.
    Schlagwort(e): GEOPHYSICS
    Materialart: Goddard Lab. for Atmospheric Sci., Collected Reprints, 1978 - 1979, Vol. 1; p 279
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unbekannt
    Measurement of trace levels of chlorine in the stratosphere (1981)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: Mathematical models of stratospheric ozone have predicted a reduction in the total ozone due to chlorofluoromethanes released into the atmosphere. Analytical procedures for the collection of air in the stratosphere and for analysis of these air samples for trace levels of chlorine, regardless of the state of chemical composition were developed. Calibration experiments are conducted in order to validate all methods and procedures. Results of neutron activation analysis calibration procedures using standard chlorine gases are included.
    Schlagwort(e): GEOPHYSICS
    Materialart: Houston Univ. The 1981 NASA ASEE Summer Fac. Fellowship Program, Vol. 2; 15 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unbekannt
    GRM - Observing the terrestrial gravity and magnetic fields in the 1990's (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: NASA is proposing to launch a new geopotential fields exploration system called the Geopotential Research Mission (GRM). Two spacecraft will be placed in a circular polar orbit at 160 km altitude. Distances between these satellites will vary from 100 to 600 km. Both scalar and vector magnetic fields will be measured by magnetometers mounted on a boom positioned in the forward direction on the lead satellite. Gravity data will be computed from the measured change in distance between the two spacecraft. This quantity, called the range-rate, will be determined from the varying frequency (Doppler shift) between transmitter and receiver on each satellite. Expected accuracies (at the one-sigma level) are: gravity field, 1.0 milliGal, 5 cm geoid height; magnetics, scalar field 2 nT, vector to 20 arcsec, both resolved to less than 100 km. With these more accurate and higher resolution data, it will be possible to investigate the earth's structure from the crust (with the shorter wavelength gravity and magnetic anomalies) through the mantle (from the intermediate wavelength gravity field) and into the core (using the longer wavelength gravity and magnetic fields).
    Schlagwort(e): GEOPHYSICS
    Materialart: EOS (ISSN 0096-3941); 64; 609-611
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 11
    facet.materialart.
    Unbekannt
    Measurements of stratospheric SO2 after the EL Chichon eruptions (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Samples of stratospheric trace gases were obtained on eight flights of NASA high-altitude aircraft from April 16 through December 13, 1982. The sampling occurred at altitudes from 15 to 22 km, latitudes from 23 to 52 deg N, and longitudes from 108 to 130 deg W. The cryogenically concentrated samples were analyzed by gas chromatography for SO2, a primary precursor of the gas-to-particle conversion process. The measured mixing ratio of SO2 varied between 8 and 132 pptv. Evidence from aerosol measurements indicates that a few of our early samples may have been collected in the fringes of the volcanic cloud from El Chichon. Samples obtained on some later flights may have been from the eruption cloud but were taken at times when most of the volcanically injected SO2 should have been converted to H2SO4.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters (ISSN 0094-8276); 10; 1045-104
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 12
    facet.materialart.
    Unbekannt
    Effect of the eruption of El Chichon stratospheric aerosol size and composition (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Dominant effects of the El Chichon eruption on stratospheric aerosols at 19.8 to 20.7 km are: (1) vapor depositional growth of the small-aerosol (background) mode; (2) development of a large-particle mode by sedimentation from the highest altitudes in the cloud; (3) a change in the large-particle mode from sulfate-coated silicates to sulfate aerosols, some with silicate cores; (4) a 100-fold increase in sulfate mass in the large particle mode. Terminal velocities of large silicate particles, maximum r = 2.3 micron, sampled 1 month after eruption, and calibrated with the aid of lidar data, indicate initial injection to 26 to 27 km. Smaller velocities of sulfate aerosols, median r = 0.5 micron, are compatible with major growth in 2 to 3 months at 27 to 28 km. Aerosol settling accounts for the descent of the main lidar return to 26.5 km in August and to 20 to 21 km in December.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters (ISSN 0094-8276); 10; 1021-102
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 13
    facet.materialart.
    Unbekannt
    Possible effects of the El Chichon volcanic cloud on the radiation budget of the northern tropics (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A series of calculations with a one-dimensional, time-marching, radiative-convective model are performed to assess the impact of the El Chichon volcanic cloud on the radiation budget of the northern tropics during the 6-month period following the injection of volcanic material into the stratosphere. Extensive measurement of the cloud obtained from airborne, spacecraft, and ground platforms were used to define the model parameters and to test the predictions of the model. The El Chichon cloud is predicted to have caused an increase in planetary albedo of 10 percent, a decrease in total solar radiation of 2-3 percent at the ground on cloudless days, and an increase in temperature of 3.5 K at the 24-km (30-mb) level. These predictions are compatible with relevant observations, within their respective error bars.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters (ISSN 0094-8276); 10; 1057-106
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 14
    facet.materialart.
    Unbekannt
    A revised thermospheric model based on mass spectrometer and incoherent scatter data - MSIS-83 (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: It is noted that the model presented here extends the previous description of neutral parameters to the base of the thermosphere in a continuous manner while maintaining the basic structure of the MSIS model at higher altitudes. As the altitude decreases, the composition approaches lower atmosphere values, whereas yearly, and to a lesser extent daily, variations in temperature and density are in reasonable agreement with earlier results for the lower thermosphere. An alternate description is given of magnetic storm variations on the basis of the three hour ap indices and an 8- to 10-hour exponential decay in thermospheric density and temperature response after a heating event. Additional coefficients are included for the time independent and magnetic activity terms, among them a longitudinally dependent seasonal magnetic activity effect. The description of molecular oxygen derives from mass spectrometer and EUV absorption measurements rather than ion chemistry.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 10170-10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 15
    facet.materialart.
    Unbekannt
    Response of the mobile VLBI design to error sources (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The response of Mobile VLBI design to error sources is addressed. The sensitivity of the hydrogen maser to variations in ambient temperature is discussed, with an example of drifts in the frequency system causing excursions in the time-delay observable exceeding + or - 200 cm. It is shown that baselines determined only from S-band data can contain errors in excess of 30 cm during periods of high ionospheric activity. The effect of the troposphere on baseline solutions is examined by comparing calibrations from the Water Vapor Radiometer (WVR) to those from a surface model. The apparent ability of the WVR to track relatively short-period fluctuations in water vapor is noted. Finally, consideration is given to the effects of source structure and the technique of monitoring closure of the time-delay observable around a closed figure of baselines.
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 16
    facet.materialart.
    Unbekannt
    Stratospheric condensation nuclei and possible solar influences (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Balloon-borne measurements of condensation nuclei and H2SO4 molecules in large negative ion clusters have been made in the stratosphere at around 30 km altitude. The nuclei observed were in the 0.01-0.1 micron diameter range. Consideration was given to sunspot activity as a triggering event for ionization of upper atmospheric H2SO4 species and subsequent formation of the nuclei. A numerical model was defined for a steady state between the H2SO4 association and ion recombination in order to determine a critical nucleation rate. It is concluded that condensation nuclei are produced in ion nucleation in an H2SO4 supersaturated polar cloud chamber, with the process being initiated by solar flare particle ionization.
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 17
    facet.materialart.
    Unbekannt
    A study of solar activity-ozone relationship from Nimbus-4 BUV data (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The total O3 and the O3 mixing ratio at various pressure levels in the stratosphere measured from the Nimbus-4 BUV experiment over a 7-yr period (1970 to 1977) comprises a comprehensive data base available to study the possible effects of solar variability on stratospheric O3. It is shown that with the decrease in solar activity from 1970 to 1976, the globally averaged O3 inferred from Nimbus-4 data decreases from about 10 to 12 percent in the upper stratosphere to about 1 to 3 percent in the lower stratosphere. The systematic decrease in O3 seems to be correlated with the conventional indices of solar activity; however, it is difficult to account for the observed changes at various pressure levels with the current understanding of the photochemical models and the solar UV flux variations over a solar cycle.
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 18
    facet.materialart.
    Unbekannt
    Delta function excitation of waves in the earth's ionosphere (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Excitation of the earth's ionosphere by delta function current sheets is considered, and the temporal and spatial evolution of wave packets is analyzed for a two-component collisional F2 layer. Approximations of an inverse Fourier-Laplace transform via saddle point methods provide plots of typical wave packets. These illustrate cold plasma wave theory and may be used as a diagnostic tool since it is possible to relate specific features, e.g., the frequency of a modulation envelope, to plasma parameters such as the electron cyclotron frequency. It is also possible to deduce the propagation path length and orientation of a remote radio beacon.
    Schlagwort(e): GEOPHYSICS
    Materialart: Radio Science (ISSN 0048-6604); 18; 1337-135
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 19
    facet.materialart.
    Unbekannt
    Normal mode study of the earth's rigid body motions (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: In this paper it is shown that the earth's rigid body (rb) motions can be represented by an analytical set of eigensolutions to the equation of motion for elastic-gravitational free oscillations. Thus each degree of freedom in the rb motion is associated with a rb normal mode. Cases of both nonrotating and rotating earth models are studied, and it is shown that the rb modes do incorporate neatly into the earth's system of normal modes of free oscillation. The excitation formula for the rb modes are also obtained, based on normal mode theory. Physical implications of the results are summarized and the fundamental differences between rb modes and seismic modes are emphasized. In particular, it is ascertained that the Chandler wobble, being one of the rb modes belonging to the rotating earth, can be studied using the established theory of normal modes.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 9437-944
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 20
    facet.materialart.
    Unbekannt
    A mechanism for plasma waves at the harmonics of the plasma frequency in the electron foreshock boundary (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A bump-on-tail unstable reduced velocity distribution, constructed from data obtained at the upstream boundary of the electron foreshock by the GSFC electron spectrometer experiment on the ISEE-1 satellite, is used as the initial plasma state for a numerical integration of the 1D-Vlasov-Maxwell system of equations. The integration is carried through the growth of the instability, beyond its saturation, and well into the stabilized plasma regime. A power spectrum computed for the electric field of the stabilized plasma is dominated by a narrow peak at the Bohm-Gross frequency of the unstable field mode but also contains significant power at the harmonics of the Bohm-Gross frequency. The harmonic power is in sharp peaks which are split into closely spaced doublets. The fundamental peak at the Bohm-Gross frequency is split into a closely spaced triplet. The mechanism for excitation of the second harmonic is shown to be second order wave-wave coupling. Previously announced in STAR as N83-17315
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 9081-909
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 21
    facet.materialart.
    Unbekannt
    Medium scale disturbances in total ozone during Southern Hemisphere summer (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Distinct medium scale disturbances in Southern Hemisphere total ozone were observed by the Nimbus 7 Total Ozone Mapping Spectrometer during the 1979 FGGE observing period. These disturbances are shown to be a result of advection by the zonal harmonic wave five which is centered near the tropopause (Salby, 1982). The contribution to the total ozone field by vertical advection due to this wave is shown to be nearly equal to that due to horizontal advection.
    Schlagwort(e): GEOPHYSICS
    Materialart: American Meteorological Society, Bulletin (ISSN 0003-0007); 64; 1358-136
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 22
    facet.materialart.
    Unbekannt
    Isotopic evidence from the eastern Canadian shield for geochemical discontinuity in the Proterozoic mantle (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The Nd and Sr isotopic compositions presently reported for anorthosites and related rocks from the Grenville and Nain Provinces of the eastern Canadian shield indicate that the massifs were delivered from at least two distinct mantle source regions which were established before 1650 Myr ago. These regions were episodically involved in magmatism over about 500 Myr. One reservoir was isotopically similar to the depleted, modern midocean ridge basalt source. The other reservoir was chondritic-to-moderately-enriched, and is most easily identified in the Nain Province, but may have occurred scattered throughout Superior Province, as well.
    Schlagwort(e): GEOPHYSICS
    Materialart: Nature (ISSN 0028-0836); 306; 679
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 23
    facet.materialart.
    Unbekannt
    Distribution, abundance and carbon isotopic composition of gaseous hydrocarbons in Big Soda Lake, Nevada - An alkaline, meromictic lake (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The study of the distribution and isotopic composition of low molecular weight hydrocarbon gases at the Big Soda Lake, Nevada, has shown that while neither ethylene nor propylene were found in the lake, ethane, propane, isobutane and n-butane concentrations all increased with water column depth. It is concluded that methane has a biogenic origin in both the sediments and the anoxic water column, and that C2-C4 alkanes have biogenic origins in the monimolimnion water and shallow sediments. The changes observed in delta C-13/CH4/ and CH4/(C2H6 + C3H8) with depth in the water column and sedimeents are probably due to bacterial processes, which may include anaerobic methane oxidation and different rates of methanogenesis, and C2-to-C4 alkane production by microorganisms.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geochimica et Cosmochimica Acta (ISSN 0016-7037); 47; 2107-211
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 24
    facet.materialart.
    Unbekannt
    Autoregressive harmonic analysis of the earth's polar motion using homogeneous International Latitude Service data (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The homogeneous set of 80-year-long (1900-1979) International Latitude Service (ILS) polar motion data is analyzed using the autoregressive method (Chao and Gilbert, 1980), which resolves and produces estimates for the complex frequency (or frequency and Q) and complex amplitude (or amplitude and phase) of each harmonic component in the data. The ILS data support the multiple-component hypothesis of the Chandler wobble. It is found that the Chandler wobble can be adequately modeled as a linear combination of four (coherent) harmonic components, each of which represents a steady, nearly circular, prograde motion. The four-component Chandler wobble model 'explains' the apparent phase reversal during 1920-1940 and the pre-1950 empirical period-amplitude relation. The annual wobble is shown to be rather stationary over the years both in amplitude and in phase, and no evidence is found to support the large variations reported by earlier investigations. The Markowitz wobble is found to be marginally retrograde and appears to have a complicated behavior which cannot be resolved because of the shortness of the data set.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 10299-10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 25
    facet.materialart.
    Unbekannt
    Comparison of Yamato and Victoria Land polymict eucrites - A view from mineralogical and isotopic studies (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: New interior samples of four Yamato polymict eucrites (Y74159, Y74450, Y75011, and Y75015) have been studied by electron microprobe, transmission electron microscope, and X-ray diffraction techniques, and compared with several samples of the Victoria Land polymict eucrites. These same samples have been analysed using Rb-Sr and Nd-Sm isotopic systematics. Several grains of inverted pigeonite, with blebby augite similar to those in Binda and Moama, have been identified in all four Yamato eucrites. Coarse-grained meso-stasis-rich subophitic basalts, which contain Mg-rich pigeonite (with Fe-rich olivine veinlets) zoned outward to a subcalcic ferroaugite rims, have also been found. These unique clasts were not found in ALH76005, 77302, 78040, 7858, and 78165 and EET eucrites. The tight grouping of Rb/Sr and Sm/Nd ratos, and similar modal compositions of the Yamato group indicate that they are most likely to be pieces from a single fall, and distinct from the ALH and EET groups. However, the Yamato, Allan Hills, and Elephant Moraine groups may sample a few distinct magmas or similar but different source regions on the same parent body.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research, Supplement (ISSN 0148-0227); 88; B245-B25
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 26
    facet.materialart.
    Unbekannt
    SERIES - Satellite Emission Range Inferred Earth Surveying (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The Satellite Emission Range Inferred Earth Surveying (SERIES) concept is based on the utilization of NAVSTAR Global Positioning System (GPS) radio transmissions without any satellite modifications and in a totally passive mode. The SERIES stations are equipped with lightweight 1.5 m diameter dish antennas mounted on trailers. A series baseline measurement accuracy demonstration is considered, taking into account a 100 meter baseline estimation from approximately one hour of differential Doppler data. It is planned to conduct the next phase of experiments on a 150 m baseline. Attention is given to details regarding future baseline measurement accuracy demonstrations, aspects of ionospheric calibration in connection with subdecimeter baseline accuracy requirements of geodesy, and advantages related to the use of the differential Doppler or pseudoranging mode.
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 27
    facet.materialart.
    Unbekannt
    Calculated stormtime variations in plasmaspheric thermal ion composition (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Model calculations describing stormtime variations in the earth's dayside plasmasphere are used to examine variations in ion composition. The model storm is initiated by high-latitude thermospheric heating that generates meridional winds that carry neutral species, momentum, and energy equatorward. The thermosphere acts on the plasmasphere through collisional transfer of momentum and through chemical reactions between neutral species and ions. Over latitudes near the region of thermospheric heating, the thermosphere-plasmasphere coupling processes cause enhancement in the density of oxygen ions while protons are being lost. Meanwhile, densities of oxygen ions and protons near the equator are increasing together, almost in phase. The largest enhancements in ion density develop at latitudes near 45 deg invariant for both oxygen and hydrogen.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 10233-10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 28
    facet.materialart.
    Unbekannt
    A model study of the effects of intermittent loss on odd nitrogen concentrations in the lower troposphere (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A time-dependent box model of the lower troposphere which includes a description of photochemical and physical processes has been developed. This model has been applied to the calculation of nitric acid and NO(x)(NO + NO2) concentrations over a diurnal cycle which includes precipitation. Nitric acid concentrations and the HNO3/NO(x) ratio are found to be highly variable under the assumptions regarding the frequency, duration, and intensity of precipitation employed in this model. The chemistry of odd nitrogen compounds during the night is potentially important in establishing the level of nitric acid in the lower troposphere. These calculations also indicate that relatively large errors may occur when the continuity equation describing nitric acid variations is averaged over a diurnal cycle which includes precipitation. Interpretation of simultaneous measurements of HNO3 and NO(x) will require some knowledge of the history of the observed air mass and may require an improved understanding of nighttime odd nitrogen chemistry.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 10697-10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 29
    facet.materialart.
    Unbekannt
    Observation of wave-wave interactions in the stratosphere (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Data from the LIMS instrument for January 1979 are used to provide further evidence for the often observed vacillation between the amplitudes of waves 1 and 2 in the stratosphere. The vacillation is shown to result primarily from nonlinear wave-wave interactions within the stratosphere. Two ways of interpreting nonlinearity are discussed. In the first, the basic state is defined to include large amplitude waves as well as the mean zonal wind. A forced wave propagates with respect to this asymmetric basic state, which can lead to changes in the conventional zonal wavenumber measured at one latitude. The other view of nonlinearity, interaction of wave with the zonal flow and with other wavenumbers are considered separately. Wave-wave interactions among waves 1, 2 and 3 are calculated. The derivation and computation of wave-wave interaction terms in the potential enstrophy balance are given. The observations indicate that enstrophy transfer among waves can be substantial even when the amplitude of one of the contributing waves is small. The computed enstrophy balance also demonstrates that wave-wave interactions can have a large effect on the interaction of waves with the mean flow.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of the Atmospheric Sciences (ISSN 0022-4928); 40; 2484-249
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 30
    facet.materialart.
    Unbekannt
    Stratospheric temperature profile from balloon-borne measurements of the 10.4-micron band of CO2 (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The technique of nonlinear least squares spectral curve fitting has been used to derive the stratospheric vertical temperature profile from balloon-borne measurements of the 10.4 micron band of CO2. The spectral data were obtained at sunset with the approximately 0.02 per cm resolution University of Denver interferometer system from a float altitude of 33.5 km near Alamogordo, New Mexico, on 23 March 1981. The r.m.s. deviation between the retrieved temperature profile and correlative radiosonde measurements is 2.2 K.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Quantitative Spectroscopy and Radiative Transfer (ISSN 0022-4073); 30; 327-334
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 31
    facet.materialart.
    Unbekannt
    Electric field measurements at the magnetopause. I Observation of large convective velocities at rotational magnetopause discontinuities (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Large convective electric fields of the order of 10 mV/m (sometimes as high as 22 mV/m) are observed at rotational magnetopause discontinuities. These observations were made with the long cylindrical (179-m base line) probes carried on the ISEE 1 satellite. These electric field observations yield convective velocity magnitudes (equal to the cross product of the vector E and the vector B, the latter divided by the square of the magnitude of B) of the order of 150 km/s. In this format for the convective velocity magnitudes, some of these observations are similar to the high speed plasma velocity observations that were made at the magnetopause with the plasma experiment carried on the ISEE 1 satellite. It is shown that, for many of these magnetopause crossings, there exists a special moving coordinate system where the observed electric fields vanish. Such a unique reference system is often used in theoretical studies of magnetic discontinuities. This special coordinate system does not move at the local plasma velocity but moves instead at a velocity intermediate between the convective velocity and the local Alfven velocity. It is used here as a diagnostic tool for the experimental investigation of rotational discontinuities at the magnetopause.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 10000-10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 32
    facet.materialart.
    Unbekannt
    Estimation of lower crust magnetization form satellite derived anomaly field (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-19
    Beschreibung: Various lines of evidence point to the lower crust as the source of the long-wavelength magnetic anomaly field measured by the POGO and Magsat satellites. Using seismically determined lower crust thicknesses and equivalent source inversion of the satellite anomaly data, magnetization for the lower crust for much of the United States has been calculated. The average magnetization for two hundred sixty-six 150 x 150 km areas is 3.5 A/m with a standard deviation of 1.1 A/m. These values are consistent with laboratory measurements of mafic-ultramafic rocks expected in the lower crust, and in agreement with previous estimates of lower crust magnetization based on long-wavelength aeromagnetic data. Average lower crust thickness for the same areas is 18.2 km (sigma = 6.4). Thus, over large regions, it appears that variation in magnetization and variation in magnetic layer thickness contribute almost equally in causing the anomaly field variation at satellite altitude.
    Schlagwort(e): GEOPHYSICS
    Materialart: Tectonophysics (ISSN 0040-1951); 93; 33-45
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 33
    facet.materialart.
    Unbekannt
    Cold plasma distribution above a few thousand kilometers at high latitudes (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-19
    Beschreibung: Great advances with respect to the study of the earth's magnetosphere could be achieved in connection with the launch of the Dynamics Explorer (DE) 1 and 2 spacecraft. These advances were made possible partly because of the unique combination of coplanar orbits which simultaneously sample the low altitude ionospheric and atmospheric signature (DE-2) and the high altitude phenomena of the inner magnetosphere (DE-1). It was, thus, feasible to obtain new measurements of the coupling of plasmas and fields between these fundamentally important regions. One basic element of the coupling involves the interchange of low energy plasma between the ionosphere and magnetosphere. The flow characteristics of the low energy plasma are indicators of the magnetospheric and ionospheric electric fields which drive the current system. The Retarding Ion Mass Spectrometer (RIMS) instrument has been designed for conducting measurements regarding this plasma population. Attention is given to details regarding RIMS, an example RIMS orbit, plasma trough characteristics, and polar cap phenomena.
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 34
    facet.materialart.
    Unbekannt
    Atmospheric density, temperature and wind measurement techniques during the 1980 Energy Budget Campaign (1981)
    In:  CASI
    Details
    Publikationsdatum: 2011-12-30
    Beschreibung: Super Loki rocketsonde systems are described. The datasonde telemeters data to a ground station where ambient temperatures are calculated between 20 and 70 km. The sphere is a passive, radar tracked system which allows density to be calculated between 30 and 90 km. When flown simultaneously the systems give redundant data in the altitudes between 30 and 70 km. The datasonde has a balloon parachute that descends more slowly than a conventional parachute and is more stable. Because of launch constraints the datasondes reached very high apogees, leading to very fast descent velocities. Aerodynamic heating reduced thermistor sensitivity. Anomalous parachute behavior influenced wind sensing until a denser layer was reached. The spheres collapsed above 60 km altitude, but their data, combined with dropsonde data give significant results for 21 flights. These show that the stratosphere is colder than Cospar 72 model predictions and the mesosphere is warmer.
    Schlagwort(e): GEOPHYSICS
    Materialart: Wuppertal Univ. Sounding Rocket Program Aeronomy Project: Energy Budget Campaign 1980. Expt. Summary; p 382-396
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 35
    facet.materialart.
    Unbekannt
    Radiative-photochemical response of the mesosphere to dynamical forcing (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Combination of the chemical continuity equation for odd oxygen with the second law of thermodynamics yields analytic solutions which describe the coupled behavior of temperature and ozone perturbations in response to an externally specified forcing. The results appear in a form which allows easy physical interpretation of the coupling between radiative and photochemical processes. When the forcing is chosen to mimic a planetary scale wave, the theory shows that photochemical acceleration of radiative damping reduces the amplitude of the temperature perturbation by an amount which increases with the wave period. Although ozone fluctuations are anti-correlated with those in temperature, minima in ozone do not coincide exactly in longitude with temperature maxima. The percentage variation in ozone increases upward and is always larger than that in temperature at the same pressure. This demonstrates that variations in ozone on constant pressure surfaces may serve as a sensitive indicator of wave activity in the mesosphere.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; June 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 36
    facet.materialart.
    Unbekannt
    Particles above the tropopause - Measurements and models of stratospheric aerosols, meteoric debris, nacreous clouds, and noctilucent clouds (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: An outline is presented of the present status of knowledge of stratospheric aerosols, meteoric debris, nacreous clouds, and noctilucent clouds. Considerable progress has been made in studies of these particles during the previous decade and it is appropriate to synthesize the information to provide a background for studies planned for the 1980s. Numerical models of the formation, growth, and evolution are considered and a description is given of the physical processes involved, taking into account aspects of nucleation, coagulation, condensational growth, sedimentation, and questions of dynamical transport. A schematic outline of the physical and chemical processes included in a model of stratospheric aerosols is provided.
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 37
    facet.materialart.
    Unbekannt
    The CAMEO barium release - E/parallel/ fields over the polar cap (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Four successive thermite barium releases at an altitude of 965 km over polar cap invariant latitudes 84 to 76 deg near magnetic midnight were conducted from the orbiting second stage of the vehicle that launched Nimbus 7; the releases were made as part of the CAMEO (Chemically Active Material Ejected in Orbit) program. This was the first opportunity to observe the behavior of conventional barium release when conducted at orbital velocity in the near-earth magnetic field. The principal unexpected characteristic in the release dynamics was the high, 1.4 to 2.6 km/s, initial Ba(+) expansion velocity relative to an expected velocity of 0.9 km/s. Attention is also given to neutral cloud expansion, initial ion cloud expansion, convective motion, and the characteristics of field-aligned motion. The possibility of measuring parallel electric fields over the polar cap by observing perturbations in the motion of the visible ions is assessed.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; May 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 38
    facet.materialart.
    Unbekannt
    Very low frequency waves stimulated by an electron accelerator in the auroral ionosphere (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The sounding rocket, Polar 5, carrying a 10 keV electron accelerator in a mother-daughter configuration and other diagnostic instruments, was launched into a slightly disturbed ionosphere with weak auroral activity on February 1, 1976 from Northern Norway to study VLF wave phenomena. The rocket trajectory crossed two auroral regions: one, between 86 and 111 s flight time, and a secondary region between 230 and 330 s. The daughter, carrying the accelerator, was separated axially from the mother in a forward direction at an altitude of 90 km. The VLF experiment, carried by the mother payload, recorded both electromagnetic and electrostatic waves. The receiving antenna was an electric dipole, 0.3 m tip-to-tip, oriented 90 degrees to the rocket spin axis. The onboard particle detector recorded increased electron fluxes in the two auroral regions. A double peaked structure was observed in the fluxes of 4-5 and 12-27 keV electrons within the northern auroral form. The number density of thermal plasma varied during the flight, with maximum density within the main auroral region. To the north of this aurora a slow, steady decrease in the density was observed, with no enhancement in the region of the second aurora.
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 39
    facet.materialart.
    Unbekannt
    An analytic formulation for heating source memory in the thermospheric composition (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Numerical calculations from a spectral circulation model are utilized to construct an analytic Green's function formulation describing the meridional, time-dependent thermospheric composition and temperature response during magnetic storms. The purpose is to develop a formulation that embodies source memory while being sufficiently simple to serve as a heuristic guide for empirical modeling. By passing from the discrete Fourier series representation, utilized for the numerical circulation model, to a continuous Fourier integral representation, explicit waves are obtained for the thermospheric response times. The response times are altitude and species dependent and can exceed two days below 200 km. Thus, for certain storm scenarios, pronounced source memory signatures for the composition and temperature are predicted. Response times obtained from the formulation are shown to give a response consistent with previously published neutral composition data from AE-C for the February 1974 storm when an ap dependent heat source is employed.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; May 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 40
    facet.materialart.
    Unbekannt
    Semiempirical modeling of thermospheric magnetic storms (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: An improved formulation for empirical modeling of magnetic storm effects in neutral thermospheric composition and temperature is utilized in a study of two disturbed periods. The formulation, which incorporates the prior history of the heat input rather than a single phase delay, is based on a Fourier integral representation of an existing theoretical model. This results in an improved representation of the detailed time variations and a better carry-over of model parameters from one storm to the other and provides a basis for theoretical interpretation.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; May 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 41
    facet.materialart.
    Unbekannt
    Inference of the ring current ion composition by means of charge exchange decay (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The analysis of data from the Explorer 45 (S3-A) electrostatic analyzer in the energy range 5-30 keV has provided some new results on the ring current ion composition. It has been well established that the storm time ring current has a decay time of several days, during which the particle fluxes decrease nearly monotonically. By analyzing the measured ion fluxes during the several day storm recovery period and assuming that beside hydrogen other ions were present and that the decays were exponential in nature, three separate lifetimes for the ions were established. These fitted decay lifetimes are in excellent agreement with the expected charge exchange decay lifetimes for H(+), O(+) and He(+) in the energy and L value range of the data.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; May 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 42
    facet.materialart.
    Unbekannt
    SAS 2 observations of the earth albedo gamma radiation above 35 MeV (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The earth albedo gamma radiation above 35 MeV in the equatorial region is investigated using observations from the second Small Astronomy Satellite. The zenith angle distribution of the gamma radiation has a peak toward the horizon which is about an order of magnitude more intense than the radiation coming from the nadir, and nearly two orders of magnitude more intense than the gamma radiation from most parts of the sky. The gamma radiation originating from the western horizon is a factor of four more intense than the radiation from the eastern horizon and a factor of three more intense than that from the northern and southern directions. This reflects the geomagnetic effects on the incident cosmic rays whose interactions produce the albedo gamma rays. The variation of the upcoming gamma ray intensity with vertical cutoff rigidity is consistent with the empirical relationship found by Gur'yan et al. (1979).
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Mar. 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 43
    facet.materialart.
    Unbekannt
    Coherent- and incoherent-scatter radar (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The ionized regions of the atmosphere were studied using high power backscatter radars at VHF and UHF frequencies were studied. The first year of data from the Urbana coherent-scatter radar were analyzed. It is suggested that the VHF scattered power profile from the mesosphere over Urbana depends on the existence of short vertical wave length tidal components to generate turbulence. Short period altitude and amplitude variations are believed to be due to gravity wave interacting with the tidal components.
    Schlagwort(e): GEOPHYSICS
    Materialart: Res. in Aeronomy; p 47-81
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 44
    facet.materialart.
    Unbekannt
    Partial reflection (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Differential-absorption electron concentration and drifts wind data were collected on a daily basis along with daily winds data. The daily winds data are compared with the daily electron concentration data on the meridional prevailing wind are compared with the electron concentration. Results are briefly discussed.
    Schlagwort(e): GEOPHYSICS
    Materialart: Res. in Aeronomy; p 24-29
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 45
    facet.materialart.
    Unbekannt
    Laser radar (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A laser radar system to measure the altitude distribution of atmospheric sodium in the 80 to 100 km altitude region was constructed. The system consists of a high power pulsed dye laser, large aperture receiving telescope, and photon counting and signal processing equipment. The receiving system development, and the construction and development of the dye laser are discussed. Spatial and temporal filtering of the data to enhance the resolution of the sodium lidar profiles is described as well as computer model studies of the sodium density response to gravity wave perturbations.
    Schlagwort(e): GEOPHYSICS
    Materialart: Res. in Aeronomy; p 82-94
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 46
    facet.materialart.
    Unbekannt
    Meteor radar (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Experimental and theoretical studies of the dynamics of the meteor region (75-105 km) were conducted using a meteor radar system. The radar was operated for approximately 700 hours. The data were fully analyzed to yield the north/south and east/west horizontal wind components, and curve fitting routines are used to yield the daily mean winds, and the diurnal and semidiurnal tides.
    Schlagwort(e): GEOPHYSICS
    Materialart: Res. in Aeronomy; p 30-46
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 47
    facet.materialart.
    Unbekannt
    Rocket experiments (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Payloads designed to study the ionization and the ionizing sources (energetic particles) during periods of auroral activity are described. These include a probe experiment to measure the variation in electron concentration, to measure electron temperature, and to measure the vehicle potential; a propagation experiment to obtain the electron concentration and the electron collision frequency; and an energetic particle experiment to measure particle energy spectra.
    Schlagwort(e): GEOPHYSICS
    Materialart: Res. in Aeronomy; p 6-23
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 48
    facet.materialart.
    Unbekannt
    X-band atmospheric noise temperature statistics at Goldstone, DSS 13, 1979 and 1980, and clear air noise temperature models for Goldstone (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Superhigh frequency (X band) noise temperature data are presented which illustrate the noise temperature increase above quiescent baseline for the years 1979 and 1980. Clear air models are also given which shows the seasonal noise temperature effects of changing surface water vapor densities for a particular atmospheric model.
    Schlagwort(e): GEOPHYSICS
    Materialart: The Telecommun. and Data Acquisition Progr. Rept. 42-64; p 161-167
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 49
    facet.materialart.
    Unbekannt
    A frequency and timing subsystem for the ORION mobile unit (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A mobile surveying instrument in support of the crustal dynamics program measures the length and direction of the distance between sites on the Earth's surface using VLBI techniques operating at microwave frequencies and extragalactic radio sources. The frequency and timing subsystem uses as a frequency standard the hydrogen maser. An important part of the subsystem is a sophisticated automatic system to monitor frequency stability and accumulated clock error.
    Schlagwort(e): GEOPHYSICS
    Materialart: Telecommun. and Data Acquisition; p 3-10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 50
    facet.materialart.
    Unbekannt
    Calculation of atmospheric loss from microwave radiometric noise temperature measurements (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Microwave propagation loss in the atmosphere can be inferred from microwave radiometric noise temperature measurements. The relevant equations are given and a derivation and calculation is made assuming various physical models. Comparison is made with the commonly used lumped element atmospheric model (isothermal and uniform loss) and the model with linear temperature and exponential loss distributions. The results are useful for estimating the integral inversion differences due to the model selection. This indicates that the commonly used lumped element atmospheric model is a very good approximation with judicious choice of the effective physical temperature. For the worst case comparison, the lumped element model agrees with the variable parameter model within 0.2 dB up to a propagation loss of 3 dB.
    Schlagwort(e): GEOPHYSICS
    Materialart: Telecommun. and Data Acquisition; p 73-80
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 51
    facet.materialart.
    Unbekannt
    Influence of gravity field uncertainties on the results from POGO and Magsat geomagnetic surveys (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Errors in the gravity models used in satellite position calculations are examined as a possible source of the 0 to 100% variance found between POGO and Magsat magnetic data and the extrapolations of aerial magnetic survey data to satellite heights. For POGO data obtained over the New York Bight region using a relatively poor gravity field (a hybrid spherical harmonic model of degree 7 and order 6 with three higher order resonance terms), the magnitude of the error in the satellite height component is found to be sufficient to account for the amplitude of the discrepancy, however the frequency of the quasi-periodic orbital error is too large to explain the localized nature of the differences. For the case of the Magsat satellite, in which a more accurate gravity model was used, it is found that a 30 mgal gravitational anomaly distributed over a 5 x 5 deg area will produce insufficiently large position errors to account for the variations. The agreement between the two sets of satellite data in the New York Bight region suggests either a consistent error in satellite measurements, or problems with the reduction and processing of the aeromagnetic data.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Dec. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 52
    facet.materialart.
    Unbekannt
    Stratospheric measurements of continuous absorption near 2400 per cm (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Measurements of continuous absorption near 2400 per cm by N2 and CO2 over long path lengths in the lower stratosphere are presented. The continua were measured in a stratospheric solar spectrum obtained during sunset with a balloon-borne Michelson interferometer in the 2380-2500 per cm region, and transmittances were calculated by ratioing the amplitudes to those of a high-sun spectrum in order to eliminate the wavelength dependence of the measured flux. Comparison of the measured transmittances with those calculated for a multilayered atmospheric model using laboratory absorption measurements results in a fair agreement, and reveals the primary component of the absorption throughout most of the range to be N2, with the CO2 contribution equal to that of N2 only at the CO2 band head. In this region, the shape of the continuum is very sensitive to the sub-Lorentzian line shape assumed in the calculations, and so, if the shape of the N2 continuum at low temperatures can be determined through laboratory measurements, may be used to infer air-broadened far-wing CO2 line shape.
    Schlagwort(e): GEOPHYSICS
    Materialart: Applied Optics; 20; Dec. 15
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 53
    facet.materialart.
    Unbekannt
    Evidence for 18.6 year Mn signal in temperature and drought conditions in North America since AD 1800 (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: It is found that, since 1800, the mean discrepancy in epoch between maxima in temperature and maxima in the Drought Area Index (DAI) for the western United States with respect to maxima in the lunar modal tide is 0.9 and 0.1 year, respectively. It is suggested, in light of the fact that a cluster of nine stations in western Canada yields the 18.6-year lunar nodal term out of phase with 30 stations in eastern North America, that (1) enhanced drought conditions in the western United States are neither recurrent nor rhythmic on a time scale of 20 years, but rather periodic with a period of 18.6 years, and (2) the Rocky Mountain system is an influence for atmospheric tidal phenomena at epochs of maximum in the lunar nodal tide as well as for maxima in the temperature records of the DAI.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Nov. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 54
    facet.materialart.
    Unbekannt
    Atmospheric carbon dioxide and chlorofluoromethanes - Combined effects on stratospheric ozone, temperature, and surface temperature (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The effects of combined CO2 and CFCl3 and CF2Cl2 time-dependent scenarios on atmospheric O3 and temperature are described; the steady-state levels of O3 and surface temperature, to which the chlorofluoromethane scenario tends in the presence of twice and four time ambient CO2, are examined; and surface temperature changes, caused by the combined effects, are established. A description of the model and of the experiments is presented. Results indicate that (1) the total ozone time history is significantly different from that due to the chlorofluoromethane alone; (2) a local ozone minimum occurs in the upper stratosphere about 45 years from the present with a subsequent ozone increase, then decline; and (3) steady-state solutions indicate that tropospheric temperature and water vapor increases, associated with increased infrared opacity, cause significant changes in tropospheric ozone levels for 2 x CO2 and 4 x CO2, without the addition of chlorofluoromethanes.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; June 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 55
    facet.materialart.
    Unbekannt
    Deconvolution of wide field-of-view radiometer measurements of earth-emitted radiation. I - Theory (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The theory of deconvolution of wide field-of-view (WFOV) radiometer measurements of earth-emitted radiation provides a technique by which the resolution of such measurements can be enhanced to provide radiant exitance at the top of the atmosphere with a finer resolution than the field of view. An analytical solution for the earth-emitted radiant exitance in terms of WFOV radiometer measurements is derived for the nonaxisymmetric (or regional) case, in which the measurements and radiant exitance are considered to be functions of both latitude and longitude. This solution makes it possible to deconvolve a set of WFOV radiometer measurements of earth-emitted radiation and obtain information with a finer resolution than the instantaneous field of view of the instrument. It is shown that there are tradeoffs involved in the selection between WFOV and scanning radiometers.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of the Atmospheric Sciences; 38; Mar. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 56
    facet.materialart.
    Unbekannt
    Artificial particle and wave stimulation in the Trigger experiment (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The Trigger experiment, designed to test the response of the auroral ionosphere to an impulsive release of a hot, dense plasma, and consisting of a sounding rocket payload (launched on February 11, 1977) divided into two parts, an instrumented diagnostic section and a cesium-doped high-explosive canister, is described. When the two sections were separated by about 1 km, the cesium high-explosive was ignited and the plasma around the payload was observed to increase briefly by a factor of 4 in density and a factor of 2 in temperature, upon which various particle and field phenomena occurred in rapid succession. A large increase in the field-aligned charged particle flux was observed over the approximate energy range of 10 eV to more than 300 keV, starting about 150 ms after the release and lasting about 1 second. A second particle burst started one second after the release and lasted for tens of seconds. A transient electric field pulse of 200 mV/m appeared just before the particle flux increase began.
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 57
    facet.materialart.
    Unbekannt
    Deconvolution of wide field-of-view radiometer measurements of earth-emitted radiation. II - Analysis of first year of Nimbus 6 ERB data (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The theory of deconvolution considered by Smith and Green (1981) is applied to Nimbus 6 data in order to interpret the data with the maximum obtainable resolution. Attention is given to the data sample, sun-contaminated measurements, the measurement model, the deconvolution, the degree variance, the spherical harmonic coefficients, the geographical distribution of longwave radiation, time histories of zonal coefficients, and the effect of a grid system. Degree variance plots for 12 months of longwave radiation data show that the limit for a spherical harmonic representation of the Nimbus 6 wide field-of-view longwave data is 12th degree. The degree variance plots also reveal that most of the power is in the lower degree terms. Contour maps of the radiation field show the geographical distribution of earth emitted radiant exitance for each month.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of the Atmospheric Sciences; 38; Mar. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 58
    facet.materialart.
    Unbekannt
    Water vapor in the stratosphere - Preliminary results of the LIMS experiment aboard Nimbus 7 (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 59
    facet.materialart.
    Unbekannt
    Simultaneous measurements of NO/x/, NO, and O3 production in a laboratory discharge - Atmospheric implications (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Simultaneous measurements of NO(x) (NO + NO2), NO, and O3 production in a laboratory discharge show that within the uncertainties of the experiment, all of the NO(x) produced was NO, and no detectable enhancement of O3 after the discharge was observed. The laboratory experiments described gave an NO production rate of 5 + or - 2 x 10 to the 16th molecules/joule mole for a 100,000-1,000,000 joules/m spark. Assuming that the global dissipation of lightning energy is about 10 to the -8th joules/sq cm per sec (Dawson, 1980; and Hill et al., 1980), the NO production rate results in a global source of NO due to lightning of about 1.8 Mt(N)/yr, which is considerably lower than earlier estimates. This lower value for NO(x) production by lightning suggests that NO(x) emissions from anthropogenic sources, estimated to be at least 20 MT(N)/yr, may be the dominant source of NO(x) to the global troposphere. Furthermore, since most of the anthropogenic sources of NO(x) are located in the Northern Hemisphere, this new interpretation of the relative source strengths of this species favors a highly skewed asymmetric distribution of NO(x).
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Apr. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 60
    facet.materialart.
    Unbekannt
    Dependence of tropospheric temperature on the parameterization of cumulus convection in the GLAS model of the general circulation (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Analysis of the simulation of seasonal change by the GLAS model of the general circulation reveals deficiencies in the simulation of tropospheric temperature and of convective cloud cover. These interrelated deficiencies are due to a spurious doubling from January to July in the convective cloud cover of the Northern Hemisphere. The spurious doubling, in turn, is due to the oversensitivity of cumulus convection, in the GLAS model, to the specific humidity of the lower atmosphere. The oversensitivity is enhanced by a feedback mechanism which perpetuates the existence of deep, penetrative convective clouds at certain preferred locations. The cumulus parameterization scheme has been modified to more realistically relate the onset of cumulus convection to the relative humidity of the lower atmosphere. The modified parameterization has improved the simulation of tropospheric temperature, planetary albedo and convective cloud cover as well as their seasonal variations. Comparison of this experiment with its control has shown a high degree of interrelation among these fields in the GLAS model and has demonstrated the sensitivity of the atmospheric heat budget to the design of the cumulus parameterization scheme. Also, the modification to the cumulus scheme has demonstrated a plausible mechanism to explain the correlation between convective cloud cover and relative humidity in the real atmosphere.
    Schlagwort(e): GEOPHYSICS
    Materialart: Monthly Weather Review; 109; Jan. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 61
    facet.materialart.
    Unbekannt
    Rapid inversion of limb radiance data using an emissivity growth approximation (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The time-consuming nature of limb relaxation-type inversion algorithms is due primarily to the numerous integrations over an absorption band to obtain forward radiance values with which to compare measured values. A new method has been devised for the quick and accurate (0.5% error) calculation of single gas broadband (approximately 100 per cm) limb radiance. The method uses a precalculated data base consisting of homogeneous path emissivity vs mass path data for a wide range of temperature and pressure. A 50-km altitude range, 1-km resolution, constituent inversion employing this method requires under 1 sec of computational time when run on modern computer hardware. The method does not rely upon a priori statistical knowledge.
    Schlagwort(e): GEOPHYSICS
    Materialart: Applied Optics; 20; Mar. 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 62
    facet.materialart.
    Unbekannt
    Stratospheric ozone response to a solar proton event - Hemispheric asymmetries (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Large-scale stratospheric ozone reduction due to precipitating energetic solar protons is examined, based on the backscattered ultraviolet experiment on the Nimbus 4 satellite during the 1972 solar flare. Some chemical equations for the processes are outlined. Distinct asymmetries in the columnar ozone content, the amount of ozone depression, and their temporal variation above 4 mb level (about 38 km) were observed between the two hemispheres. These asymmetries are ascribed to the differences mainly in dynamics and partly in the solar illumination and the vertical temperature structure between the summer and the winter polar atmospheres.
    Schlagwort(e): GEOPHYSICS
    Materialart: Pure and Applied Geophysics; 119; 1, 19; 1980-81
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 63
    facet.materialart.
    Unbekannt
    Improved airborne measurements of OH in the atmosphere using the technique of laser-induced fluorescence (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Feb. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 64
    facet.materialart.
    Unbekannt
    The accommodation of relative motion at depth on the San Andreas fault system in California (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Plate motion below the seismogenic layer along the San Andreas fault system in California is assumed to form by aseismic slip along a deeper extension of the fault or may result from lateral distribution of deformation below the seismogenic layer. The shallow depth of California earthquakes, the depth of the coseismic slip during the 1906 San Francisco earthquake, and the presence of widely separated parallel faults indicate that relative motion is distributed below the seismogenic zone, occurring by inelastic flow rather than by aseismic slip on discrete fault planes.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Feb. 10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 65
    facet.materialart.
    Unbekannt
    Radiative properties of the background stratospheric aerosols and implications for perturbed conditions (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A series of Mie scattering calculations has been performed to define the wavelength-dependent, single scattering properties of aerosols present in the stratosphere during July 1979. Additional radiative transfer computations were conducted to assess the impact of aerosols on the earth's radiation budget. For these purposes, an extensive set of measurements of aerosol characteristics that were obtained in Alaska from aircraft and satellite platforms was used. At that time, the optical depth was too small for aerosols to significantly impact earth's climate. But the optical depth of the stratospheric aerosol layer has been large enough during some volcanically perturbed periods for the aerosols to have caused a noticeable warming of the stratosphere and cooling of the troposphere.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Jan. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 66
    facet.materialart.
    Unbekannt
    Implications of stratospheric aerosol measurements for models of aerosol formation and evolution (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Calculations of the distribution of stratospheric sulfur gases and of stratospheric aerosols are compared with measurements obtained in Alaska during July 1979. Generally, the measurements are reasonably consistent with the model results. COS is the major sulfur-bearing gas in the stratosphere while CS2 plays a lesser role in the formation of sulfate aerosols. Ammonia, which earlier measurements suggested was a major aerosol constituent, is found to be a contaminant, so models without ammonia chemistry may be justified. The model and the measurements suggest that stratospheric sulfuric acid aerosols nucleate just above the tropopause, but they are older and have grown to larger sizes at higher altitudes.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Jan. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 67
    facet.materialart.
    Unbekannt
    A study of stratospheric aerosol maturity (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A sampling and analysis technique that uses the binomial distribution to characterize stratospheric aerosol populations at the 95% level of confidence is described. Particle samples obtained over Alaska during July 15-19, 1979, are used; the results show the presence of more small particles at lower altitude than at high altitudes. Calculations of the surface area and volume distributions for all aerosol samples collected are given. Evidence from these data suggests either that Aitken nuclei are injected or diffused across the tropopause and rise into the stratosphere, where they mature into larger particles, or nuclei form in the lower stratosphere and become mature aerosols at high altitude. Samples obtained at another site give the same results, supporting the view that the process of injection or nucleation and maturing of aerosols with altitude may be global and need not occur only in locations exhibiting unique meteorologic features.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Jan. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 68
    facet.materialart.
    Unbekannt
    Comparison of stratospheric aerosol measurements over Poker Flat, Alaska, July, 1979 (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Stratospheric aerosols were collected at Poker Flat, Alaska, in July, 1979, to determine particle properties, confirm coincident satellite SAGE measurements, and compare similar results obtained with different airborne samplers. Because of the steep slopes in size-distribution curves for larger particles, it is found that properties such as concentrations, aerosol mass, and optical extinction are very sensitive to small errors in radii. It is calculated that the concentration measurements agree with photoelectric particle counter results when a 16% radius change is introduced. An 8% radius change matches our calculated sulfate mass with filter mass measurements. And a 13% radius change results in agreement between the calculated optical extinction and coincident SAGE satellite results. Recognizing that different instruments can produce 10-20% differences in measured sizes, it is believed the results of these comparative measurements of SAGE and in situ instruments are essentially in agreement.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Jan. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 69
    facet.materialart.
    Unbekannt
    SAM II aerosol profile measurements, Poker Flat, Alaska; July 16-19, 1979 (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: SAM II satellite measurements during the July 1979 Poker Flat mission, yielded an aerosol extinction coefficient of 0.0004/km at 1.0 micron wavelength, in the region of the stratospheric aerosol mixing ratio peak (12-16 km). The stratospheric aerosol optical depth for these data, calculated from the tropopause through 30 km, is approximately 0.001. These results are consistent with the average 1979 summertime values found throughout the Arctic.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Jan. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 70
    facet.materialart.
    Unbekannt
    Size distributions and mineralogy of ash particles in the stratosphere from eruptions of Mount St. Helens (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Samples from the stratosphere obtained by U-2 aircraft after the first three major eruptions of Mount St. Helens contained large globules of liquid acid and ash. Because of their large size, these globules had disappeared from the lower stratosphere by late June 1980, leaving behind only smaller acid droplets. Particle size distributions and mineralogy of the stratospheric ash grains demonstrate inhomogeneity in the eruption clouds.
    Schlagwort(e): GEOPHYSICS
    Materialart: Science; 211; Feb. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 71
    facet.materialart.
    Unbekannt
    Characterization of aerosols from eruptions of Mount St. Helens (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Measurements of mass concentration and size distribution of aerosols from eruptions of Mount St. Helens as well as morphological and elemental analyses were obtained between 7 April and 7 August 1980. In situ measurements were made in early phreatic and later, minor phreatomagmatic eruption clouds near the vent of the volcano and in plumes injected into the stratosphere from the major eruptions of 18 and 25 May. The phreatic aerosol was characterized by an essentially monomodal size distribution dominated by silicate particles larger than 10 micrometers in diameter. The phreatomagmatic eruption cloud was multimodal; the large size mode consisted of silicate particles and the small size modes were made up of mixtures of sulfuric acid and silicate particles. The stratospheric aerosol from the main eruption exhibited a characteristic narrow single mode with particles less than 1 micrometer in diameter and nearly all of the mass made up of sulfuric acid droplets.
    Schlagwort(e): GEOPHYSICS
    Materialart: Science; 211; Feb. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 72
    facet.materialart.
    Unbekannt
    Measurements of the volcanic plumes of Mount St. Helens in the stratosphere and troposphere - Introduction (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Schlagwort(e): GEOPHYSICS
    Materialart: Science; 211; Feb. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 73
    facet.materialart.
    Unbekannt
    Gaseous constituents in the plume from eruptions of Mount St. Helens (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Measurements in the stratosphere of gaseous constituents in the plume of Mount St. Helens were obtained during five flights of the NASA U-2 aircraft between 19 May and 17 June 1980. Mixing ratios from gas chromatographic measurements on samples acquired about 24 hours after the initial eruption show considerable enhancement over nonvolcanic concentrations for sulfur dioxide (more than 1000 times), methyl chloride (about 10 times), and carbon disulfide (more than 3 times). The mixing ratio of carbonyl sulfide was comparable to nonvolcanic mixing ratios although 3 days later it was enhanced two to three times. Ion chromatography measurements on water-soluble constituents are also reported. Very large concentrations of chloride, nitrate, and sulfate ions were measured, implying large mixing ratios for the water-soluble gaseous constituents from which the anions are derived. Measurements of radon-222 present in the plume are also reported.
    Schlagwort(e): GEOPHYSICS
    Materialart: Science; 211; Feb. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 74
    facet.materialart.
    Unbekannt
    Trajectories of the Mount St. Helens eruption plume (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The plume of the major eruption of Mount St. Helens on May 18, 1980 penetrated 10 to 11 km into the stratosphere, attaining heights of 22 to 23 km. Wind shears rapidly converted the plume from an expanding vertical cone to a thin, slightly inclined lamina. The lamina was extruded zonally in the stratosphere as the lower part moved eastward at jet stream velocities, while the upper part slowly moved westward in the region of nonsteady transition from the westerlies to the summer stratospheric easterlies. Trajectories computed to position the NASA U-2 aircraft for sampling in the plume are described. Plume volume after 8 hours of strong volcanic emission is estimated at 2,000,000 cu km. Only about 1% of this volume is attributed to the volcano; the rest was entrained from the environment.
    Schlagwort(e): GEOPHYSICS
    Materialart: Science; 211; Feb. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 75
    facet.materialart.
    Unbekannt
    Laser remote sensing of atmospheric temperature by observing resonant absorption of oxygen (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A dual-frequency system is used to demonstrate the measurement of atmospheric temperature, through laser energy absorption monitoring at the center of an O2 resonant absorption line near 770 nm. It is shown that the average temperature of a 1 km path can be determined within 1.0 C, with a noise level of 0.3 C. An iterative algebraic expression for this method was developed, and is shown to be applicable in the troposphere; the effects of pressure and humidity on temperature determination were made clear by the algorithm and found to be small near the earth's surface.
    Schlagwort(e): GEOPHYSICS
    Materialart: Applied Optics; 20; June 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 76
    facet.materialart.
    Unbekannt
    Jikiken /EXOS-B/ observation of Siple transmissions (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Preliminary results of observations by the Japanese magnetospheric satellite Jikiken (EXOS-B) of Siple transmissions and VLF emissions triggered by the Siple signals are reviewed. The experiments discussed were carried out in July, August, and September of 1979 and in December 1979 and January 1980. Only four events concentrated within the period from August 14 to 18 were found in which triggered emissions were associated with Siple transmissions. The electron distributions observed on the equatorial crossing passes, when Siple triggered emissions were detected, suggest that the cyclotron resonance condition is satisfied for Siple signals and electrons of energy around 1 keV or less, provided the interaction region is inside the plasmapause. It is noted that if these emissions were generated outside the plasmapause, electron energies much higher than 10 keV would be necessary for the cyclotron interaction, which were above the range of the measurements. For the high latitude passes of August 14 and 17, the electron fluxes were found to be very small.
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 77
    facet.materialart.
    Unbekannt
    A magnetospheric signature of some F layer positive storms (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Calculations of electron density distributions in the global thermosphere-ionosphere system perturbed by high-latitude thermospheric heating are presented which indicate a link between the heating and magnetospheric plasma disturbances near the equator. The calculations were made using a self-consistent model of the global sunlit thermosphere-ionosphere system describing the evolution of equatorial plasma disturbances. The heat input is found to cause electron density enhancements that propagate along magnetic field lines from the F2 maximum over mid-latitudes to the equator in the magnetosphere and which correspond to the positive phase of an F layer storm. The positive phase is shown to be generated by the induction of equatorward winds that raise the mid-latitude F layer through momentum transfer from neutral atoms to ionospheric ions, which ions pull electrons with them. Model results are used to identify plasma signatures of equatorward winds and an intensified magnetospheric electric field in Explorer 45 and Arial 4 measurements taken during the positive phase of an F layer storm.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; May 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 78
    facet.materialart.
    Unbekannt
    Photochemical processes induced by a major warming of the upper atmosphere - Variations in mesospheric trace constituents (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The temperature rise and enhanced winds during an upper atmospheric warming cause substantial changes in the high level ozone profile of the sunlit winter hemisphere. Calculations based on a photochemical model, using temperatures measured at Fort Churchill during a major warming, predict a factor of 2 variation in the ozone number density near 60 km over a time period of approximately 3 weeks. This temporal variability at a fixed location results from the planetary wave structure of the temperature field and reflects a similar longitudinal behavior at a given time. The ozone number density at fixed altitude is a maximum when the temperature is greatest at and below this level. This is due primarily to thermal expansion of the atmosphere which results in a large increase in pressure at constant altitude. However, chemical activity during a warming decreases the mesospheric ozone mixing ratio at fixed pressure. The ozone mixing ratio at constant pressure during the peak of the event studied is near 75% of its unperturbed value. The predicted variability of ozone in longitude and time demonstrates the need for hemispheric scale information on trace gas abundances, temperature, and winds in order to delineate adequately the response of upper atmospheric composition to a major perturbation.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Apr. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 79
    facet.materialart.
    Unbekannt
    Computer simulation of a geomagnetic substorm (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A global two-dimensional simulation of a substormlike process occurring in earth's magnetosphere is presented. The results are consistent with an empirical substorm model - the neutral-line model. Specifically, the introduction of a southward interplanetary magnetic field forms an open magnetosphere. Subsequently, a substorm neutral line forms at about 15 earth radii or closer in the magnetotail, and plasma sheet thinning and plasma acceleration occur. Eventually the substorm neutral line moves tailward toward its presubstorm position.
    Schlagwort(e): GEOPHYSICS
    Materialart: Physical Review Letters; 46; Apr. 13
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 80
    facet.materialart.
    Unbekannt
    Simultaneous measurements of magnetotail dynamics by IMP spacecraft (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Pressure in the magnetotail is investigated using observations obtained by IMP spacecraft. Using combined field and plasma data, the approximate balance of pressure between the high beta plasma sheet and the low beta tail lobes is demonstrated. The changes in this pressure during substorms and the characteristics of the plasma and field that produce it are discussed. A distance of about 15 earth radii separates an inner region where the plasma sheet thins during the hour before substorm onset from an outer region where the plasma sheet thins within 5 or 10 min of the time of onset. Substorm onset and plasma sheet expansion in the inner region are simultaneous if the spacecraft is near the equatorial plane. This expansion may be delayed as much as a few tens of minutes if the spacecraft is at high latitudes.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Mar. 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 81
    facet.materialart.
    Unbekannt
    The effect of data analysis techniques on the interpretation of wide-angle longwave radiation measurements (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Three different data analysis techniques - shape factor, parameter estimation, and deconvolution - have been applied to the same set of satellite radiation measurements to determine their effect on the estimated radiation field. The measurements are from a wide-angle, horizon-to-horizon, nadir-pointing sensor. The shape factor technique reduces each measurement to a radiant exitance at the top of the atmosphere by simple division by a constant. The parameter estimation technique processes all measurements together as a batch and defines the radiant exitance as a least-squares fit to the data. The deconvolution technique takes advantage of the fact that spherical harmonics are the eigenfunctions of the measurement operator. All three techniques are derived, and their assumptions, advantages and disadvantages are discussed. Their results are compared globally, zonally, regionally and on a spatial spectrum basis. All three techniques give comparable results for global parameters; however, results on a regional scale were quite different. The standard deviations of the regional differences in radiant exitance varied from 7.4 to 13.5 W/sq m. Of the three techniques, the parameter estimation technique produced the best regional results and is the choice of the author.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of the Atmospheric Sciences; 38; Sept
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 82
    facet.materialart.
    Unbekannt
    A simple model of the Lagrangian-mean flow produced by dissipating planetary waves (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A simple equation for the Lagrangian-mean flow induced by damped planetary waves is derived. The flow computed for stationary planetary waves of a beta-plane is found to be generally poleward and downward during winter and appears to be about twice as strong as the diabatic circulation in the lower stratosphere. An important factor in determining the high-latitude Lagrangian-mean flow field is the subtropical jet stream which blocks planetary wave propagation toward the equatorial regions. Computations using two types of Lagrangian-mean boundary conditions at the surface show that incorrect orographic forcing distorts the Lagrangian-mean flow up to three scale heights or more above ground.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of the Atmospheric Sciences; 38; Sept
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 83
    facet.materialart.
    Unbekannt
    Diffusion of cold magnetospheric ions (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The paper investigates conditions under which a diffusion equation is a valid description of the transport across magnetic field lines of low energy magnetospheric plasma. The case in which the guiding center drift and its fluctuating component are comparable in size to the particle thermal speed is considered. It is concluded that a two-dimensional diffusion equation is valid in the alpha-beta space of the Euler potentials, provided that the fluctuations have a short enough correlation time so that the guiding center drifts remain negligible, and ions in Jupiter's Io plasma torus can thus be described by a diffusion equation if the correlation time is no more than a few rotation periods of the planet.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Oct. 1
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 84
    facet.materialart.
    Unbekannt
    OCS photolysis and absorption in the 200- to 300-nm region (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A continuum source with three different interference filters and two different monochromatic sources were used to photolyze OCS in the region from 200 nm to 300 nm. The total quantum yield for the production of CO was measured, and the results indicate a primary quantum yield of 0.72 + or - 0.08. Absorption cross sections for OCS measured at 0.5-nm intervals are reported as well as the percent change in absorption upon cooling to 195 K. The structured features in the absorption are reinvestigated and discussed.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Oct. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 85
    facet.materialart.
    Unbekannt
    Stratospheric observations of the attenuated solar irradiance in the Schumann-Runge band absorption region of molecular oxygen (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A spectrometer flown on the first Solar Absorption Balloon Experiment (SABE-1) observed the attenuated solar irradiance between 184 and 202 nm from an altitude near 40 km. These measurements provide a check on the absorption cross sections of molecular oxygen in the spectral region of the Schumann-Runge bands. Comparison of the measurements with calculations based on cross sections derived from laboratory data shows a general agreement although the irradiance measurements have large error bars near the centers of the absorption bands. The results imply that the 184-200 nm solar irradiance that penetrates to the stratosphere can be computed to an accuracy of + or - 30% or better by using presently available cross sections.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Oct. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 86
    facet.materialart.
    Unbekannt
    The solar irradiance from 200 to 330 nm (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The full disk solar spectrum over the wavelength range 200-330 nm is measured with a spectral resolution of 0.12 nm. The measurement is performed by using a double monochromator pointed at the sun from a high altitude parachute. Only small corrections are required to account for atmospheric absorption. Good agreement is obtained with previously reported measurements.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Oct. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 87
    facet.materialart.
    Unbekannt
    Global ozone long-term trends from satellite measurements and the response to solar activity variations (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Analysis of global ozone variations for the period April 1970 to December 1975 was performed by using the reprocessed Nimbus 4 backscattered ultraviolet (BUV) measurements of total ozone. A correlation coefficient of 0.97 is found between the 6-month running mean of global mean total ozone (filtered for mean semiannual, annual, and quasibiennial variations) and the 10.7-cm solar activity index. Correcting ozone for a time-dependent latitudinal bias relative to Dobson ozone measurements reduces to 2-3% the global mean ozone variation over the solar cycle. The solar ultraviolet variability required in a one-dimensional time-dependent radiative photochemical model to account for the observed ozone variation appears to be consistent with recent solar UV observations.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Oct. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 88
    facet.materialart.
    Unbekannt
    Parameterization of linear wave chemical transport in planetary atmospheres by eddy diffusion (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Two-dimensional transport by linear waves is parameterized by wave velocity and temperature correlations and nonconservative properties of the atmosphere in a residual Eulerian framework. Explicit expressions derived for the eddy tracer flux vector are written in eddy diffusion tensor form, but it is demonstrated that strong coupling of chemistry and temperature through the rate constants, as is the case for ozone, requires additional terms proportional to the mixing ratio and not to its gradient. A variety of limiting cases are discussed. In the residual Eulerian framework the K(yz), K(zy) components are nonzero for a nonconservative atmosphere and/or a reactive tracer. Tracers have common transport coefficients in the limit where their chemistry is negligible in comparison to transience. It is shown that the usual one-dimensional vertical eddy diffusion continuity equation is rigorously valid only when the temperature dependence of the rate constants is negligible and the tracer has strong vertical stratification relative to its horizontal variability.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Oct. 20
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 89
    facet.materialart.
    Unbekannt
    Repeatability and measurement uncertainty of the United States meteorological rocketsonde (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: It is pointed out that rocketsondes provide the only in situ 'ground truth' data for altitudes above 30 km. The need for precise temperature information has, therefore, led to a study of rocketsonde instrument repeatability and measurement uncertainty. Results obtained from root-mean-square difference and linear regression techniques are consistent and strongly suggest that the Datasonde precision is better than 1 C up to an altitude of 53 or 54 km. This result excludes atmospheric variability, which may occur within 5 min, and effects owing to spatial differences, which are small for paired measurements. At altitudes of 55 km and higher it is possible that sensor and flight-related anomalies, differences in radiation corrections owing to differing solar angles because of varying launch times, or even seasonal variations may create conditions that affect the magnitude of the standard corrections.
    Schlagwort(e): GEOPHYSICS
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 90
    facet.materialart.
    Unbekannt
    Seasonal dependence of large-scale Birkeland currents (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Seasonal variations of large-scale Birkeland currents are examined in a study of the source mechanisms and the closure of the three-dimensional current systems in the ionosphere. Vector magnetic field data acquired by the TRIAD satellite in the Northern Hemisphere were analyzed for the statistics of single sheet and double sheet Birkeland currents during 555 passes during the summer and 408 passes during the winter. The single sheet currents are observed more frequently in the dayside of the auroral zone, and more often in summer than in winter. The intensities of both the single and double dayside currents are found to be greater in the summer than in the winter by a factor of two, while the intensities of the double sheet Birkeland currents on the nightside do not show a significant difference from summer to winter. Both the single and double sheet currents are found at higher latitudes in the summer than in the winter on the dayside. Results suggest that the Birkeland current intensities are controlled by the ionospheric conductivity in the polar region, and that the currents close via the polar cap when the conductivity there is sufficiently high. It is also concluded that an important source of these currents must be a voltage generator in the magnetosphere.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Oct. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 91
    facet.materialart.
    Unbekannt
    Error in Dasibi flight measurements of atmospheric ozone due to instrument wall-loss (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Theory suggests that in laminar flow the percent loss of a trace constituent to the walls of a measuring instrument varies as P to the -2/3, where P is the total gas pressure. Preliminary laboratory ozone wall-loss measurements confirm this P to the -2/3 dependence. Accurate assessment of wall-loss is thus of particular importance for those balloon-borne instruments utilizing laminar flow at ambient pressure, since the ambient pressure decreases by a factor of 350 during ascent to 40 km. Measurements and extrapolations made for a Dasibi ozone monitor modified for balloon flight indicate that the wall-loss error at 40 km was between 6 and 30 percent and that the wall-loss error in the derived total ozone column-content for the region from the surface to 40 km altitude was between 2 and 10 percent. At 1000 mb, turbulence caused an order of magnitude increase in the Dasibi wall-loss.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Oct. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 92
    facet.materialart.
    Unbekannt
    Revised age estimates of Brunhes palaeomagnetic events - Support for a link between geomagnetism and eccentricity (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Revisions in the dates of reported geomagnetic excursions during the Brunhes Epoch are proposed in light of possible correlations between a section at Gioia Tauro, Italy, deep-sea cores, a core from Lake Biwa, Japan, and some lava flows. The anomalously long, double Blake Event reported at Gioia Tauro is here correlated with the Blake Event (approximately 110 kyr) and the Biwa 1 event (180 plus or minus 5 kyr); an hiatus may be present in the section between these two events. The alpha event at Gioia Tauro is correlated with the Biwa 2 event at about 295 kyr; the beta event with the 'Biwa 3' event at about 400 kyr; the gamma event with the Snake River event at 480 plus or minus 50; and the delta event, not recorded elsewhere, is estimated to have occurred at approximately 620 kyr. These proposed refinements in the age estimates of the excursions suggest an approximately 100 kyr cyclicity. If the events are real and the revised dating is correct, the timing of the geomagnetic events seems to coincide with times of peak eccentricity of the earth's orbit, suggesting a causal connection.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Oct. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 93
    facet.materialart.
    Unbekannt
    Greenhouse effect of trace gases, 1970-1980 (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Increased abundances were measured for several trace atmospheric gases in the decade 1970-1980. The equilibrium greenhouse warming for the measured increments of CH4, chlorofluorocarbons and N2O is between 50% and 100% of the equilibrium warming for the measured increase of atmospheric CO2 during the same 10 years. The combined warming of CO2 and trace gases should exceed natural global temperature variability in the 1980's and cause the global mean temperature to rise above the maximum of the late 1930's.
    Schlagwort(e): GEOPHYSICS
    Materialart: Geophysical Research Letters; 8; Oct. 198
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 94
    facet.materialart.
    Unbekannt
    Solute partitioning under continuous cooling conditions as a cooling rate indicator (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A model of solute partitioning in a finite body under conditions of continuous cooling is developed for the determination of cooling rates from concentration profile data, and applied to the partitioning of zirconium between ilmenite and ulvospinel in the Apollo 15 Elbow Crater rocks. Partitioning in a layered composite solid is described numerically in terms of concentration profiles and diffusion coefficients which are functions of time and temperature, respectively; a program based on the model can be used to calculate concentration profiles for various assumed cooling rates given the diffusion coefficients in the two phases and the equilibrium partitioning ratio over a range of temperatures. In the case of the Elbow Rock gabbros, the cooling rates are calculated from measured concentration ratios 10 microns from the interphase boundaries under the assumptions of uniform and equilibrium initial conditions at various starting temperatures. It is shown that the specimens could not have had uniform concentrations profiles at the previously suggested initial temperature of 1350 K. It is concluded that even under conditions where the initial temperature, grain sizes and solute diffusion coefficients are not well characterized, the model can be used to estimate the cooling rate of a grain assemblage to within an order of magnitude.
    Schlagwort(e): GEOPHYSICS
    Materialart: Journal of Geophysical Research; 86; Oct. 10
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 95
    facet.materialart.
    Unbekannt
    Absorption of visible radiation in atmosphere containing mixtures of absorbing and nonabsorbing particles (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The presence of a strongly absorbing material, tentatively identified as graphitic carbon, or 'soot', is indicated by measurements of single-scattering albedo of tropospheric aerosols. Although theoretical calculations based on models of the ways in which soot may mix with other aerosol materials yield the single-scattering albedo values of 0.6, accounted for by a minimum 20% soot by volume, in urban regions and 0.8, yielded by 1-5% soot by volume, in rural settings, it is found that these same values can be produced by similar amounts of the iron oxide magnetite. Magnetite is shown to be indistinguishable from soot by optical measurements performed on bulk samples, and calculation of various mixtures of soot indicate the difficulty of determining aerosol composition by optical scattering techniques.
    Schlagwort(e): GEOPHYSICS
    Materialart: Applied Optics; 20; Oct. 15
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 96
    facet.materialart.
    Unbekannt
    High-latitude stratospheric aerosols measured by the SAM II satellite system in 1978 and 1979 (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Results of the first year of data collection by the SAM (Stratospheric Aerosol Measurement) II satellite system are presented. Almost 10,000 profiles of stratospheric aerosol extinction in the Arctic and Antarctic regions are used to construct plots of weekly averaged aerosol extinction versus altitude and time and stratospheric optical depth versus time. Corresponding temperature fields are presented. These data show striking similarities in the aerosol behavior for corresponding seasons. Wintertime polar stratospheric clouds that are strongly correlated with temperature are documented. They are much more prevalent in the Antarctic stratosphere during the cold austral winter and increase the stratospheric optical depths by as much as an order of magnitude for a period of about 2 months. These clouds might represent a sink for stratospheric water vapor and must be considered in the radiative budget for this region and time.
    Schlagwort(e): GEOPHYSICS
    Materialart: Science; 214; Oct. 16
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 97
    facet.materialart.
    Unbekannt
    Determination of water-soluble ions in soils from the dry valleys of Antarctica (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The soil chemistry of the dry valleys of Antarctica was studied. These valleys furnish a terrestrial analog for the surface of Mars. The abundance of the water-soluble ions magnesium, calcium, potassium, sodium chloride, and nitrate in soil samples was determined. All samples examined contained water-soluble salts reflecting the aridity of the area. Movement of salts to low-lying areas was verified. Upward ionic migration was evident in all core samples. Of all cations observed, sodium showed the greatest degree of migration.
    Schlagwort(e): GEOPHYSICS
    Materialart: Houston Univ. The 1981 NASA ASEE Summer Fac. Fellowship Program, Vol. 1; 16 p
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 98
    facet.materialart.
    Unbekannt
    Influence of surface-albedo in subtropical regions on July circulation (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A simulation study to examine the influence of surface-albedo on July circulation in subtropical regions is presented. The results are based on two 47-day integrations. In the first integration, called the control run, surface albedos were normally prescribed, whereas in the second integration, called the anomaly run, the surface albedo was modified in four regions: the Sahel in Africa, the Great Plains in the United States, the Thar Desert border in the Indian subcontinent, and Brazil in South America. Each run was started from observed initial conditions for June 15, 1979 based on NMC analysis. The surface albedo in each of the regions was arbitrarily made 30%.
    Schlagwort(e): GEOPHYSICS
    Materialart: Modeling and Simulation Facility: Res. Rev., 1980 - 1981; p 237-240
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 99
    facet.materialart.
    Unbekannt
    Integrated and spectral energy flows of the GLAS GCM (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Methods to analyze the generation, transport, and dissipation of energy to study geophysical fluid flows are discussed. Energetics analyses are pursued in several directions: (1) the longitudinal and time dependence on the energy flow to the stratosphere was examined as a function of geographical sector; (2) strong and weak energy flows were correlated by medium range forecasts; (3) the one dimensional spectral results (Fourier services around latitude circles) were extended to spherical harmonics over a global domain; (4) the validity of vertical velocities derived from mass convergence was examined for their effect on the conversion of eddy available potential energy to eddy kinetic energy.
    Schlagwort(e): GEOPHYSICS
    Materialart: Modeling and Simulation Facility: Res. Rev., 1980 - 1981; p 142-144
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
  • 100
    facet.materialart.
    Unbekannt
    The role of zonally asymmetric heating in the vertical and temporal structure of the global scale flow fields during FGGE SOP-1 (1981)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The global scale structure of atmospheric flow is best documented on time scales longer than a few days. Theoretical and observational studies of ultralong waves have emphasized forcing due to global scale variations of topography and surface heat flux, possibly interacting with baroclinically unstable or vertically refracting basic flows. Analyses of SOP-1 data in terms of global scale spherical harmonics is documented with emphasis upon weekly transitions.
    Schlagwort(e): GEOPHYSICS
    Materialart: Modeling and Simulation Facility: Res. Rev., 1980 - 1981; p 132-141
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    NASA TECHNICAL REPORTS
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...