GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Articles  (122)
  • 2010-2014  (122)
Document type
  • Articles  (122)
Source
Publisher
Years
Year
Topic
  • 11
    Publication Date: 2014-08-13
    Description: VIIRS high-resolution infrared (IR) images of the rare super cyclone Phailin of the Northern Indian Ocean as well as 40 kHz sferics data as recorded over Kalyani have been analyzed in this paper with a view to investigate the characteristics of the super cyclone. The maximum IR brightness temperature in the eye of the cyclone was pretty warm and it was illuminated by airglow. The Phailin was one of the strongest cyclones with a peak estimated intensity of 140 kts. Our round-the-clock sferics data also reveals remarkable changes in the sferics record on October 10, 2013, when the super cyclone was active.
    Print ISSN: 0167-9295
    Electronic ISSN: 1573-0794
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 12
    Publication Date: 2014-08-08
    Description: Simultaneous, also called electrophonic sounds were widely reported by eye-witnesses to the Chelyabinsk fireball. The available data indicate that such sounds were heard at ranges to at least ~100 km from the fireball’s atmospheric path. We estimate that the fireball may have generated of order 625 W of energy in the form of very low frequency radiation, and we find some tentative evidence to indicate that the acoustic conversion efficiency at a 100 km range was of order 0.1 %. Numerical simulations of the atmospheric flight path indicate that electrophonic sounds should have commenced some 5 s after the fireball first became luminous and would have lasted for some 7.5 s prior to the moment of catastrophic break-up.
    Print ISSN: 0167-9295
    Electronic ISSN: 1573-0794
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 13
    Publication Date: 2014-08-08
    Description: We analyzed spectra, trajectories, orbits, light curves, and decelerations of eight Draconid meteors observed from Northern Italy on October 8, 2011. Meteor morphologies of two of the meteors are also presented, one of them obtained with a high resolution camera. Meteor radiants agree with theoretical predictions, with a hint that some meteors may belong to the pre-1900 meteoroid trails. The spectra confirm that Draconids have normal chondritic composition of main elements (Mg, Fe, Na). There are, nevertheless, differences in the temporal evolution of Na line emission. The differences are correlated with the shapes of the light curves and the deceleration rates. Our data confirm that Draconids are porous conglomerates of grains, nevertheless, significant differences in the atmospheric fragmentation of cm-sized Draconids were found. Various textures with various resistance to fragmentation exist among Draconid meteoroids and even within single meteoroids.
    Print ISSN: 0167-9295
    Electronic ISSN: 1573-0794
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 14
    Publication Date: 2014-08-07
    Description: In this work we summarize the initial results of a targeted effort of the ESA NEO Coordination Centre to obtain additional observational data in order to eliminate or reduce the impact probability estimate of a subset of the known near-Earth objects representing the highest fraction of the total known impact risk, as measured by the Palermo Scale.
    Print ISSN: 0167-9295
    Electronic ISSN: 1573-0794
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 15
    Publication Date: 2014-07-20
    Description: This paper presents observations of plasma blobs by nightglow OI 630.0 nm emissions using ground-based techniques, all sky imager and photometer from Kolhapur. The nightglow observations have been made at low latitude station, Kolhapur (16.42°N, 74.2°E, and 10.6°N dip lat.) during clear moonless nights for period of October 2011–April 2012. Generally, these occur 3 h after sunset (18:00 IST). Herein we have calculated velocities of plasma blobs using scanning method, introduced by Pimenta et al. (Adv Space Res 27:1219–1224, 2001 ). The average zonal drift velocity (eastward) of the plasma blobs were found to be 133 ms −1 and vary between 100 and 200 ms −1 . The width (east–west expansion) and length (north–south expansion) of plasma blobs is calculated by recently developed method of Sharma et al. (Curr Sci 106(08):1085–1093, 2014b ). Their mean width and length were in the range of 70–180 and 500–950 km respectively. The study shows that localized eastward polarization electric field plays an important role in the generation of plasma blobs.
    Print ISSN: 0167-9295
    Electronic ISSN: 1573-0794
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 16
    facet.materialart.
    Unknown
    Springer
    Publication Date: 2014-06-29
    Description: The ellipsoid shape model plays an important role in physical research on asteroids. However, its symmetric structure cannot practically simulate real asteroids. This article applies a general shape model, named the cellinoid, instead of the ellipsoid model to simulate the asymmetric shape of asteroids. The cellinoid shape model consists of eight octants of ellipsoids having different semi-axes, with the constraint that adjacent octants must have two equal semi-axes in common. Totally, the shape of the cellinoid model is controlled by six parameters, not three as in the case of the shape of the ellipsoid. Using this shape model, the brightness of asteroids observed from the Earth can be fitted numerically by the surface triangularization of the cellinoid. The Levenberg–Marquardt algorithm is also employed here to solve a nonlinear minimization problem. Owing to the asymmetric shape of the cellinoid, the physical parameters of asteroids, such as the rotation period and pole orientation, can be fitted more accurately than in the case of the ellipsoid model. Finally, this is confirmed numerically by applying the shape to both synthetic light curves and real light curves of asteroids. Additionally, the center of mass and moment of inertia of the cellinoid are analyzed explicitly.
    Print ISSN: 0167-9295
    Electronic ISSN: 1573-0794
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 17
    Publication Date: 2014-05-25
    Description: Some past October Draconid shower meteoroids fell apart in a spray of fragments at the end of their trajectory before slowing down, from which it was concluded that these were among the most fragile meteoroids known. In those instances, the dust could not be reliably traced to a particular return of the parent comet 21P/Giaconini-Zinner. On October 8th, 2011, Earth was predicted to transverse the 1900 A.D. dust ejecta of the comet. In 1900, the comet’s perihelion distance first moved significantly inwards to the Sun and ejection conditions could have been unusual. An airborne observing campaign was organized, with several teams contributing imaging and spectrographic cameras to study the manner in which these meteoroids released the volatile element sodium during the ablation process in the Earth’s atmosphere. IMCCE, ESA, and the SETI Institute contributed spectrographic cameras based on low-light WATEC 902H2 Ultimate, low-light LCC1, and GenII XX1332 image intensified cameras. An outburst was observed, much as predicted. Despite a lack of bright meteors, a total of 15 Draconid spectra were recorded. All show evidence of an early release of sodium. The loss of sodium was observed to coincide with the formation of a distinct wake of fragments. The observations show that 21P/Giacobini-Zinner ejected fragile meteoroids during the return in 1900. Those grains may have lost some sodium even before impacting Earth.
    Print ISSN: 0167-9295
    Electronic ISSN: 1573-0794
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 18
    Publication Date: 2014-05-23
    Description: This study determines the ages of 191 discrete lunar regolith samples from the Apollo, Luna, and meteorite collections. Model closure ages (for lithified breccias) and appearance ages (for unconsolidated soils) are calculated using the trapped 40 Ar and 36 Ar abundances of each sample, determined from published Ar data. Model closure ages of regolith breccias span ~3.9 to 0.01 Ga and appearance ages of soils range from ~3.6 to 0.03 Ga; 169 of these ages are published here for the first time, while 22 are recalculated ages. The regolith breccias with the oldest closure ages originate from the ancient highlands and oldest mare surfaces sampled by the Apollo missions. Soils generally have similar ages to each other, regardless of location and collection depth, with most model ages 〈2.0 Ga. Together, the soils and regolith breccias represent a record of regolith processes over the past 3.9 Ga. The data illustrate that individual landing sites can provide a diversity of ages, which has implications for planning future missions. Differences in maturity between older and younger regolith samples may reflect a change in collisional regimes over time. We note, too, that the closure ages published here are critical data needed for selecting temporally appropriate regolith samples used to decipher the diversity of impactors hitting the lunar surface over time and how the Sun has changed in time.
    Print ISSN: 0167-9295
    Electronic ISSN: 1573-0794
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 19
    Publication Date: 2014-05-23
    Description: A Draconid meteor shower outburst was observed from on board two scientific aircraft deployed above Northern Europe on 8th October 2011. The activity profile was measured using a set of photographic and video cameras. The main peak of the activity occurred around 20:15 ± 0:0.5 UT which is consistent with the model prediction as well as with the IMO network visual observations. The corrected hourly rates reached a value of almost 350. The brighter meteors peaked about 15–20 min earlier than the dimmer ones. This difference can be explained by different directions of the ejection of the meteoroids from the parent comet. One of the instruments was even able to detect meteors connected with the material ejected from the parent comet before 1900 and thus confirmed the prediction of the model, although it was based on uncertain pre-1900 cometary data. Another small peak of the activity, which was caused by material ejected during the 1926 perihelion passage of the parent comet, was detected around 21:10 UT. The mass distribution index determined using the narrow field-of-view video camera was 2.0 ± 0.1. This work shows that the observation of meteor outbursts can constrain the orbital elements, outgassing activity and existence of jets at the surface of a comet.
    Print ISSN: 0167-9295
    Electronic ISSN: 1573-0794
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 20
    Publication Date: 2014-05-22
    Description: The predicted Draconid meteor shower outburst during October 2011 had been observed by a portion of the Croatian Meteor Network whose stations encountered clear weather. A total of 95 Draconid orbits have been calculated from 18 contributing stations, and in this paper we present results for 63 orbits obtained from the fully automatic observation and processing pipeline. Two methods of trajectory estimation were applied, showing better fit results using a linearly changing velocity model versus a constant velocity model. The estimated mean radiant position has been found to be at RA = 262.6°, Dec = +55.7°, with estimated geocentric velocity Vg = 20.7 km/s.
    Print ISSN: 0167-9295
    Electronic ISSN: 1573-0794
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...