ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Other Sources  (2,540)
  • GEOPHYSICS  (1,522)
  • METEOROLOGY AND CLIMATOLOGY  (1,018)
  • Analytical Chemistry and Spectroscopy
  • Humans
  • 1990-1994  (2,540)
  • 1992  (1,155)
  • 1990  (1,385)
Collection
Source
Years
  • 1990-1994  (2,540)
Year
  • 1
    Publication Date: 2019-08-28
    Description: Spherical harmonic expansions to degree 360 have been developed that combine satellite potential coefficient information, terrestrial gravity data, satellite altimeter information as a direct tracking data type and topographic information. These models define improved representations of the Earth's gravitational potential beyond that available from just satellite or terrestrial data. The development of the degree 360 models, however, does not imply a uniform accuracy in the determination of the gravity field as numerous geographic areas are devoid of terrestrial data or the resolution of such data is limited to, for example, 100 km. This paper will consider theoretical and numerical questions related to the combination of the various data types. Various models of the combination process are discussed with a discussion of various correction terms for the different models. Various sources of gravity data will be described. The new OSU91 360 model will be discussed with comparisons made to previous 360 models and to other potential coefficient models that are complete to degree 50. Future directions in high degree potential coefficient models will be discussed.
    Keywords: GEOPHYSICS
    Type: In: From Mars to Greenland: Charting gravity with space and airborne instruments - Fields, tides, methods, results (A93-55951 24-46); p. 93-106.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2019-08-28
    Description: As shown from ground-based measurements and satellite-borne imagers, one type of global auroral pattern characteristic of quiet (usually northward IMF) intervals is that of a contracted but thickened emission region of a pattern referred to as 'horse-collar' aurora (Hones et al., 1989). In this report we use the Dynamics Explorer data set to examine a case in which this horse-collar pattern was observed by the DE-1 auroral imager, while at the same time DE-2, at lower altitude, measured precipitating particles, electric and magnetic fields, and plasma drifts. Our analysis shows that, in general, there is close agreement between the optical signatures and the particle precipitation patterns. In many instances, over scales ranging from tens to a few hundred kilometers, electron precipitation features and upward field-aligned currents are observed at locations where the plasma flow gradients indicate negative V-average x E. The particle, plasma, and field measurements made along the satellite track and the 2D perspective of the imager provide a means of determining the configuration of convective flows in the high-latitude ionosphere during this interval of northward IMF. Recent mapping studies are used to relate the low-altitude observations to possible magnetospheric source regions.
    Keywords: GEOPHYSICS
    Type: Journal of Geomagnetism and Geoelectricity (ISSN 0022-1392); p. 1225-1237.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2019-08-28
    Description: It is shown that the pattern of temperature trend with height in the upper troposphere and lower stratosphere is consistent with that calculated from a model incorporating the observed ozone changes. The magnitude of the observed temperature decrease is less than that determined from the numerical model. It is found that the obverse ozone-temperature relationship does not hold. If the temperature at 20 km decreases, this by itself would result in an increase in the ozone values through the inverse temperature sensitivity of the chemical reactions. In the lower stratosphere a positive correlation between ozone and temperature tends to exist through the dynamics. Ozone-rich air moving downward undergoes an increase in temperature through adiabatic compression and vice-versa. That the temperature trends indicate no apparent variation with latitude suggests a nondynamic cause.
    Keywords: GEOPHYSICS
    Type: In: Conference on the Middle Atmosphere, 8th, Atlanta, GA, Jan. 5-10, 1992, Preprints (A93-49361 21-47); p. 70-73.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2019-08-28
    Description: Results are presented of numerical experiments performed to determine what constitutes preconditioning for stratospheric sudden warmings. A number of 20-d runs were performed with a 3D primitive equation model. Runs varied in that they had different (zonally symmetric) initial fields and different lower boundary planetary wave fields, both based on NMC data for particular days. Initial and boundary data were used from the two minor and the sole major sudden warmings of January-February 1979 and some minor and the sole major sudden warmings of January-February 1989. To isolate the properties of the initial conditions from preconditioned cases and those with no warming, hybrid initial fields were created by combining data from two different days, one preconditioned and the other not. Runs with the hybrid initial conditions indicate that it is the lower stratospheric winds that are important in characterizing a preconditioned flow. It is suggested that it would be possible for a preconditioned state to exist for at least a short time without a warming occurring.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: In: Conference on the Middle Atmosphere, 8th, Atlanta, GA, Jan. 5-10, 1992, Preprints (A93-49361 21-47); p. 8-10.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2019-08-28
    Description: To obtain a theoretical model which provides a rationale for the observed high values of velocity variations, the effect of a 0.1 to 0.2 percent partially molten volatile-rich material in various geometries which are heterogeneously dispersed in the lower mantle is examined. Data obtained indicate that, depending on aspect ratio and geometry, 0.1-0.2 percent partial melting in conjunction with about 100 K thermal anomalies can explain the seismic variations provided the compressibility of the melt differs by less than about 20 percent from the surrounding solid.
    Keywords: GEOPHYSICS
    Type: ; : Analysis of optica
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2019-08-28
    Description: An overview of the current state of anomalous diffusion research at the magnetopause and its role in the formation of the magnetopause boundary layer is presented. Plasma wave measurements in the boundary layer indicate that most of the relevant unstable wave modes contribute negligibly to the diffusion process at the magnetopause under magnetically undisturbed northward IMF conditions. The most promising instability is the lower hybrid drift instability, which may yield diffusion coefficients of the right order if the highest measured wave intensities are assumed. It is concluded that global stationary diffusion due to wave-particle interactions does not take place at the magnetopause. Microscopic wave-particle interaction and anomalous diffusion may contribute to locally break the MD frozen-in conditions and help in transporting large amounts of magnetosheath plasma across the magnetospheric boundary.
    Keywords: GEOPHYSICS
    Type: IEEE Transactions on Plasma Science (ISSN 0093-3813); 20; 6; p. 833-842.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2019-08-28
    Description: The formation of acoustic double layers in the presence of two ion species is examined via a particle simulation in a 1D bounded system. The effect of having two ion components, an H(+) and an O(+) beam, on double-layer evolution from ion acoustic turbulence driven by an electron drift relative to the H(+) beam of about 0.5 u sub e, where u sub e is the electron thermal speed, is examined. It is found that acoustic double layers form in either ion species on a time scale of about 100 omega sub ps exp -1, where omega sub ps is the ion plasma frequency for species 's' and s = H or O, and for drifts relative to the electrons lower than that required for double layer formation in simulations of single ion component plasma.
    Keywords: GEOPHYSICS
    Type: IEEE Transactions on Plasma Science (ISSN 0093-3813); 20; 6; p. 745-755.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2019-08-28
    Description: The volume of impact melt relative to that of the transient cavity is known to increase with the magnitude of the impact event. This paper investigates the influence of that phenomenon on the nature of terrestrial impact craters. A model of impact melting was used to estimate the volume of melt produced during the impact of chondritic projectiles into granite targets at velocities of 15, 25, and 50 km per sec. The results were compared with observed melt volumes at terrestrial craters, which were collated from the literature and paired with the transient-cavity diameters of their respective craters. Results show that the record on terrestrial craters is not inconsistent with the predictions of the model.
    Keywords: GEOPHYSICS
    Type: Meteoritics (ISSN 0026-1114); 27; 5; p. 526-538.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2019-08-28
    Description: Airborne radiometric measurements at frequencies near 92 GHz and 183 GHz were conducted over two precipitation events near Wallops Island, Virginia during February, 1986. The measured brightness temperatures are compared with those from calculations to estimate the snowfall and rainfall rates for both events. The estimated rates over water surface are within a factor of two of those derived from the concurrent measurements by the SPANDAR radar at the NASA Wallops Flight Facility. These estimated rates, however, suggest that both snowfall events are light and close to the threshold of radiometric detection especially over land surface. Observations of additional snowfall events with lower frequency channels are needed to demonstrate the approach and to account for cloud effects.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Geocarto International (ISSN 1010-6049); 7; 3; p. 25-31.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2019-08-28
    Description: The International Satellite Cloud Climatology Project dataset is used to correlate variations of cloud optical thickness and cloud temperature in today's atmosphere. The analysis focuses on low clouds in order to limit the importance of changes in cloud vertical extent, particle size, and water phase. Coherent patterns of change are observed on several time and space scales. On the planetary scale, clouds in colder, higher latitudes are found to be optically thicker than clouds in warmer, lower latitudes. On the seasonal scale, winter clouds are, for the most part, optically thicker than summer clouds. The logarithmic derivative of cloud optical thickness with temperature is used to describe the sign and magnitude of the optical thickness-temperature correlation. The seasonal, latitudinal, and day-to-day variations of this relation are examined for Northern Hemisphere clouds in 1984. In cold continental clouds, optical thickness increases with temperature, consistent with the temperature variation of the adiabatic cloud water content. In warm continental and in almost all maritime clouds, however, optical thickness decreases with temperature.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Climate (ISSN 0894-8755); 5; 12; p. 1484-1495.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...