ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Wind-induced atmospheric escape: Titan (2012)
    Wiley
    Details
    Publication Date: 2012-08-22
    Description: Rapid thermospheric flows can significantly enhance the atmospheric loss rates and structures of atmospheric coronae of planetary bodies. Using descriptions of atmospheric escape based on molecular kinetic models, we show that such flows at the exobase of Titan could significantly increase the calculated constituent thermal and nonthermal escape rates. In particular, we show here that the effect of thermospheric winds at the exobase cannot be ignored when calculating the escape of methane from Titan. Such enhancements are likely also relevant to Pluto and exoplanet atmospheres.
    Print ISSN: 0094-8276
    Electronic ISSN: 1944-8007
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Flux estimates of ions from the lunar exosphere (2012)
    Wiley
    Details
    Publication Date: 2012-07-03
    Description: We compare estimates for the ion fluxes of twelve expected constituents of the lunar exosphere with estimates for the ion fluxes ejected from the lunar surface by solar wind ions and electrons. Our estimates demonstrate that measurements of lunar ions will help constrain the abundances of many undetected species in the lunar exosphere, particularly Al and Si, because the expected ion flux levels from the exosphere exceed those from the surface. To correctly infer the relative abundances of exospheric ions and neutrals from Kaguya Ion Mass Analyzer (IMA) measurements, we must take into account the velocity distributions of local ions. The predicted spectrum underestimates the measured levels of O+ relative to other lunar ion species, a result that may suggest contributions by molecular ions to the measured O+ rates.
    Print ISSN: 0094-8276
    Electronic ISSN: 1944-8007
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Pickup ion distributions from three-dimensional neutral exospheres (2011)
    Wiley
    Details
    Publication Date: 2011-10-07
    Description: Pickup ions formed from ionized neutral exospheres in flowing plasmas have phase space distributions that reflect their source's spatial distributions. Phase space distributions of the ions are derived from the Vlasov equation with a delta function source using three-dimensional neutral exospheres. The ExB drift produced by plasma motion picks up the ions while the effects of magnetic field draping, mass loading, wave particle scattering, and Coulomb collisions near a planetary body are ignored. Previously, one-dimensional exospheres were treated, resulting in closed form pickup ion distributions that explicitly depend on the ratio rg/H, where rg is the ion gyroradius and H is the neutral scale height at the exobase. In general, the pickup ion distributions, based on three-dimensional neutral exospheres, cannot be written in closed form, but can be computed numerically. They continue to reflect their source's spatial distributions in an implicit way. These ion distributions and their moments are applied to several bodies, including He+ and Na+ at the Moon, H2+ and CH4+ at Titan, and H+ at Venus. The best places to use these distributions are upstream of the Moon's surface, the ionopause of Titan, and the bow shock of Venus.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    The Galileo probe mass spectrometer: composition of Jupiter's atmosphere (1996)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1996-05-10
    Description: The composition of the jovian atmosphere from 0.5 to 21 bars along the descent trajectory was determined by a quadrupole mass spectrometer on the Galileo probe. The mixing ratio of He (helium) to H2 (hydrogen), 0.156, is close to the solar ratio. The abundances of methane, water, argon, neon, and hydrogen sulfide were measured; krypton and xenon were detected. As measured in the jovian atmosphere, the amount of carbon is 2.9 times the solar abundance relative to H2, the amount of sulfur is greater than the solar abundance, and the amount of oxygen is much less than the solar abundance. The neon abundance compared with that of hydrogen is about an order of magnitude less than the solar abundance. Isotopic ratios of carbon and the noble gases are consistent with solar values. The measured ratio of deuterium to hydrogen (D/H) of (5 +/- 2) x 10(-5) indicates that this ratio is greater in solar-system hydrogen than in local interstellar hydrogen, and the 3He/4He ratio of (1.1 +/- 0.2) x 10(-4) provides a new value for protosolar (solar nebula) helium isotopes. Together, the D/H and 3He/4He ratios are consistent with conversion in the sun of protosolar deuterium to present-day 3He.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Niemann, H B -- Atreya, S K -- Carignan, G R -- Donahue, T M -- Haberman, J A -- Harpold, D N -- Hartle, R E -- Hunten, D M -- Kasprzak, W T -- Mahaffy, P R -- Owen, T C -- Spencer, N W -- Way, S H -- New York, N.Y. -- Science. 1996 May 10;272(5263):846-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Goddard Space Flight Center, Greenbelt, MD 20771, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8629016" target="_blank"〉PubMed〈/a〉
    Keywords: Ammonia/analysis ; *Atmosphere ; Carbon/analysis ; *Extraterrestrial Environment ; Helium/analysis ; Hydrogen/analysis ; *Jupiter ; Mass Spectrometry ; Nitrogen/analysis ; Noble Gases/analysis ; Oxygen/analysis ; Water/*analysis
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Venus upper atmosphere neutral gas composition: first observations of the diurnal variations (1979)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1979-07-06
    Description: Measurements of the composition, temperature, and diurnal variations of the major neutral constituents in the thermosphere of Venus are being made with a quadrupole mass spectrometer on the Pioneer Venus orbiter. Concentrations of carbon dioxide, carbon monoxide, molecular nitrogen, atomic oxygen, and helium are presented, in addition to an empirical model of the data. The concentrations of the heavy gases, carbon dioxide, carbon monoxide, and molecular nitrogen, rapidly decrease from the evening terminator toward the nightside; the concentration of atomic oxygen remains nearly constant and the helium concentration increases, an indication of a nightside bulge. The kinetic temperature inferred from scale heights drops rapidly from 230 K at the terminator to 130 K at a solar zenith angle of 120 degrees , and to 112 K at the antisolar point.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Niemann, H B -- Hartle, R E -- Hedin, A E -- Kasprzak, W T -- Spencer, N W -- Hunten, D M -- Carignan, G R -- New York, N.Y. -- Science. 1979 Jul 6;205(4401):54-6.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17778900" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Venus upper atmosphere neutral composition: preliminary results from the pioneer venus orbiter (1979)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1979-02-23
    Description: Measurements in situ of the neutral composition and temperature of the thermosphere of Venus are being made with a quadrupole mass spectrometer on the Pioneer Venus orbiter. The presence of many gases, incluiding the major constituents CO(2), CO, N(2), O, and He has been confirmed. Carbon dioxide is the most abundant constituent at altitudes below about 155 kilometers in the terminator region. Above this altitude atomic oxygen is the major constituent, with O/CO(2) ratios in the upper atmosphere being greater than was commonly expected. Isotope ratios of O and C are close to terrestrial values. The temperature inferred from scale heights above 180 kilometers is about 400 K on the dayside near the evening terminator at a solar zenith angle of about 69 degrees . It decreases to about 230 K when the solar zenith angle is about 90 degrees .〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Niemann, H B -- Hartle, R E -- Kasprzak, W T -- Spencer, N W -- Hunten, D M -- Carignan, G R -- New York, N.Y. -- Science. 1979 Feb 23;203(4382):770-2.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17832991" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Ionosphere of venus: first observations of day-night variations of the ion composition (1979)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1979-07-06
    Description: The Bennett radio-frequency ion mass spectrometer on the Pioneer Venus orbiter is returning the first direct composition evidence of the processes responsible for the formation and maintenance of the nightside ionosphere. Early results from predusk through the nightside in the solar zenith angle range 63 degrees (dusk) to 120 degrees (dawn) reveal that, as on the dayside, the lower nightside ionosphere consists of F(1)and F(2) layers dominated by O(2)(+) and O(+), respectively. Also like the dayside, the nightside composition includes distributions of NO(+), C(+), N(+), H(+), He(+), CO(2)(+), and 28(+) (a combination of CO(+) and N(2)(+)). The surprising abundance of the nightside ionosphere appears to be maintained by the transport of O(+) from the dayside, leading also to the formation of O(2)(+) through charge exchange with CO(2). Above the exobase, the upper nightside ionosphere exhibits dramatic variability in apparent response to variations in the solar wind and interplanetary magnetic field, with the ionopause extending to several thousand kilometers on one orbit, followed by the complete rertnoval of thermal ions to altitudes below 200 kilometers on the succeeding orbit, 24 hours later. In the upper ionosphere, considerable structure is evident in many of the nightside ion profiles. Also evident are horizontal ion drifts with velocities up to the order of 1 kilometer per second. Whereas the duskside ionopause is dominated by O(+) H(+) dominates the topside on the dawnside of the antisolar point, indicating two separate regions for ion depletion in the magnetic tail regions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Taylor, H A Jr -- Brinton, H C -- Bauer, S J -- Hartle, R E -- Cloutier, P A -- Daniell, R E Jr -- Donahue, T M -- New York, N.Y. -- Science. 1979 Jul 6;205(4401):96-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17778915" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    Ionosphere of venus: first observations of the dayside ion composition near dawn and dusk (1979)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1979-02-23
    Description: The first in situ measurements of the composition of the ionosphere of Venus are provided by independent Bennett radio-frequency ion mass spectrometers on the Pioneer Venus bits and orbiter spacecraft, exploring the dawn and duskside regions, respectively. An extensive composition of ion species, rich in oxygen, nitrogen, and carbon chemistry is idenitified. The dominant topside ion is O(+), with C(+), N(+), H(+), and He(+) as prominent secondary ions. In the lower ionosphere, the ionzization peak or F(1) layer near 150 kilometers reaches a concentration of about 5 x l0(3) ions per cubic centimeter, and is composed of the dominant molecular ion, O(2)(+), with NO(+), CO(+), and CO(2)(+), constituting less than 10 percent of the total. Below the O(+) peak near 200 kilometers, the ions exhibit scale heights consistent with a neutral gas temperature of about 180 K near the terminator. In the upper ionosphere, scale heights of all species reflect the effects of plasma transport, which lifts the composition upward to the often abrupt ionopause, or thermal ion boundary, which is observed to vary in height between 250 to 1800 kilometers, in response to solar wind dynamics.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Taylor, H A Jr -- Brinton, H C -- Bauer, S J -- Hartle, R E -- Donahue, T M -- Cloutier, P A -- Michel, F C -- Daniell, R E Jr -- Blackwell, B H -- New York, N.Y. -- Science. 1979 Feb 23;203(4382):752-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17832985" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Plasma observations near saturn: initial results from voyager 1 (1981)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1981-04-10
    Description: Extensive measurements of low-energy plasma electrons and positive ions were made during the Voyager 1 encounter with Saturn and its satellites. The magnetospheric plasma contains light and heavy ions, probably hydrogen and nitrogen or oxygen; at radial distances between 15 and 7 Saturn-radii (Rs) on the inbound trajectory, the plasma appears to corotate with a velocity within 20 percent of that expected for rigid corotation. The general morphology of Saturn's magnetosphere is well represented by a plasma sheet that extends from at least 5 to 17 Rs, is symmetrical with respect to Saturn's equatorial plane and rotation axis, and appears to be well ordered by the magnetic shell parameter L (which represents the equatorial distance of a magnetic field line measured in units of Rs). Within this general configuration, two distinct structures can be identified: a central plasma sheet observed from L = 5 to L = 8 in which the density decreases rapidly away from the equatorial plane, and a more extended structure from L = 7 to beyond 18 Rs in which the density profile is nearly flat for a distance +/- 1.8 Rs off the plane and falls rapidly thereafter. The encounter with Titan took place inside the magnetosphere. The data show a clear signature characteristic of the interaction between a subsonic corotating magnetospheric plasma and the atmospheric or ionospheric exosphere of Titan. Titan appears to be a significant source of ions for the outer magnetosphere. The locations of bow shock crossings observed inbound and outbound indicate that the shape of the Saturnian magnetosphere is similar to that of Earth and that the position of the stagnation point scales approximately as the inverse one-sixth power of the ram pressure.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bridge, H S -- Belcher, J W -- Lazarus, A J -- Olbert, S -- Sullivan, J D -- Bagenal, F -- Gazis, P R -- Hartle, R E -- Ogilvie, K W -- Scudder, J D -- Sittler, E C -- Eviatar, A -- Siscoe, G L -- Goertz, C K -- Vasyliunas, V M -- New York, N.Y. -- Science. 1981 Apr 10;212(4491):217-24.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17783833" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Plasma observations near saturn: initial results from voyager 2 (1982)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 1982-01-29
    Description: Results of measurements of plasma electrons and poitive ions made during the Voyager 2 encounter with Saturn have been combined with measurements from Voyager 1 and Pioneer 11 to define more clearly the configuration of plasma in the Saturnian magnetosphere. The general morphology is well represented by four regions: (i) the shocked solar wind plasma in the magnetosheath, observed between about 30 and 22 Saturn radii (RS) near the noon meridian; (ii) a variable density region between approximately 17 RS and the magnetopause; (iii) an extended thick plasma sheet between approximately 17 and approximately 7 RS symmetrical with respect to Saturn's equatorial plane and rotation axis; and (iv) an inner plasma torus that probably originates from local sources and extends inward from L approximately 7 to less than L approximately 2.7 (L is the magnetic shell parameter). In general, the heavy ions, probably O(+), are more closely confined to the equatorial plane than H(+), so that the ratio of heavy to light ions varies along the trajectory according to the distance of the spacecraft from the equatorial plane. The general configuration of the plasma sheet at Saturn found by Voyager 1 is confirmed, with some notable differences and additions. The "extended plasma sheet," observed between L approximately 7 and L approximately 15 by Voyager 1 is considerably thicker as observed by Voyager 2. Inward of L approximately 4, the plasma sheet collapses to a thin region about the equatorial plane. At the ring plane crossing, L approximately 2.7, the observations are consistent with a density of O(+) of approximately 100 per cubic centimeter, with a temperature of approximately 10 electron volts. The location of the bow shock and magnetopause crossings were consistent with those previously observed. The entire magnetosphere was larger during the outbound passage of Voyager 2 than had been previously observed; however, a magnetosphere of this size or larger is expected approximately 3 percent of the time.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bridge, H S -- Bagenal, F -- Belcher, J W -- Lazarus, A J -- McNutt, R L -- Sullivan, J D -- Gazis, P R -- Hartle, R E -- Ogilvie, K W -- Scudder, J D -- Sittler, E C -- Eviatar, A -- Siscoe, G L -- Goertz, C K -- Vasyliunas, V M -- New York, N.Y. -- Science. 1982 Jan 29;215(4532):563-70.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17771279" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...