A magnetic field arising from the Jovian equatorial sheet current deduced from Voyager 1 and 2 observations has been added to a planetary dipole field to provide a model of magnetic field inside the magnetopause. This internal field was used to calculate the magnetopause surface in a cyclic process. During each cycle, the surface was calculated, and the resulting field due to currents on the magnetopause was calculated for inclusion in the total field used to calculate the next‐order surface. The resulting magnetopause is, as anticipated, flatter in shape than one resulting primarily from a dipole internal field source, but not dissimilar in overall height‐to‐width configuration to that of the magnetopause calculated for the larger inflated magnetopause observed by Pioneer 10. An array of magnetic field values for locations internal and external to the magnetopause due to currents on the surface has been computed by integrating over the entire magnetopause. A model for the total magnetospheric field of this semi‐inflated magnetosphere has been constructed by adding this latter contribution to the internal source fields to obtain a global model of a semi‐inflated Jovianlike magnetospheric field. The magnitude of the contribution of the surface currents to the total magnetic field in the region of the orbits of the Galilean satellites is calculated to be considerably larger for this Voyager model than for the Pioneer model.

Doppler shifts in zodiacal light are calculated for various eccentricities, dust sizes, and assumptions about radiation pressure. The purpose is to determine what effects in spectra might be observed which would enhance our understanding of the origin and lifetimes of interplanetary dust. The solar absorption line half-width in the scattered light is a much more difficult measurement to make, but it is a better indication of orbital eccentricity than the first moment of the line can ever be. While the first moment of the line (which is close to the displacement of the maximum of the line) is similar for both orbital eccentricity and radiation pressure and difficult to sort out from other effects like radial outflow, the line half-width tends to broaden most for elliptical orbits at all elongations especially in the Gegenschein (backward scattering angle) where all other effects (excepting radial outflow which reddens the line) cause no change in the original solar line.

Carcinoembryonic antigen is widely used as a tumor marker for gastrointestinal neoplasms. Its role in the management of other tumors is poorly defined. This review considers the place of carcinoembryonic antigen measurement in the management of breast cancer and concludes that sufficient data exist to support its use in clinical practice. Of the many potential uses, the major role for carcinoembryonic antigen measurement in breast cancer is in following patients with advanced disease, especially patients with bone metastases.

It has been shown recently that non-adiabatic particles in the Earth's magnetotail drift across the tail roughly as predicted for adiabatic particles with 90° pitch angles. In this paper we show that this result implies the existence of an approximate invariant of the motion. Adding the effect of convection associated electric fields, we can then obtain the approximate bounce averaged motion of non-adiabatic particles in the magnetotail. Thus the particle motion and energization due to combined magnetic and electric drifts in the magnetotail are easily predicted.

view Abstract Citations (1) References (17) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Solar pressure and molecular decay in cometary atmospheres Beard, D. B. ; Whelan, T. A. ; Gast, M. A. Abstract The effects of solar pressure and molecular decay on number density in cometary atmospheres are rigorously separated and scale lengths for each are determined from an analysis of observed brightness profiles in the solar and antisolar directions. It is found that the pressure scale length of CN is approximately 160,000 km and that of C2 is approximately 110,000 km. The scale length for molecular decay, heretofore incorrectly inferred from the observational data, is approximately 3 times as long as the pressure scale lengths. It is difficult to determine adequately from observations that extend no more than about 100,000 km from the comet nucleus. The scale length for molecular decay by photodissociation or whatever cause is found to be about 350,000 km for C2 and 500,000 km for CN. Publication: The Astrophysical Journal Pub Date: August 1985 DOI: 10.1086/163410 Bibcode: 1985ApJ...295..668B Keywords: Cometary Atmospheres; Molecular Interactions; Pressure Effects; Radiation Pressure; Solar Planetary Interactions; Brightness Distribution; Carbon; Comet Nuclei; Cyanogen; Photodissociation; Astrophysics full text sources ADS |

Observations de la polarisation de la couronne solaire a des longueurs d'ondes IR, afin de determiner la taille de la poussiere circumstellaire ou les limites de cette taille. De plus les observations peuvent reveler clairement la distance heliocentrique a laquelle la poussiere se vaporise et disparait. On obtient egalement l'albedo de la poussiere

Journal of Geophysical Research: Space PhysicsVolume 88, Issue A7 p. 5784-5784 CorrectionsFree Access Model field flux conservation and the beard magnetotail model: Two corrections Raymond J. Walker, Raymond J. WalkerSearch for more papers by this authorDavid J. Southwood, David J. SouthwoodSearch for more papers by this authorDavid B. Beard, David B. BeardSearch for more papers by this author Raymond J. Walker, Raymond J. WalkerSearch for more papers by this authorDavid J. Southwood, David J. SouthwoodSearch for more papers by this authorDavid B. Beard, David B. BeardSearch for more papers by this author First published: 1 July 1983 https://doi.org/10.1029/JA088iA07p05784Citations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume88, IssueA71 July 1983Pages 5784-5784 ReferencesRelatedInformation

In his interesting analysis of aurora, magnetic storms, and other geomagnetic phenomena in terms of a closed magnetogphere, oeiddington [1979] has made some stimulating and intriguing points that are well worth examining further.Unfortunately, his analysis is seriously flawed by mistakes in sign and concept which may discourage further development.It is the purpose of this brief comment to straighten this out and promote further interest.

view Abstract Citations (9) References (9) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Cometary Tails Beard, D. B. Abstract The density of cometary molecules is substantially decreased by the effect of solar radiation pressure and decreases Sunward from the comet nucleus in a much shorter distance than previously anticipated when the effect of radiation pressure was neglected. Either photoionization or charge transfer by electron pickup of protons from cometary molecules would gradually slow the solar wind and heat it. On the other hand, the inhomogeneity of mass and field in the solar wind will cause a fast shock to be created on the surface of the ionized cometary atmosphere. Fast electrons in the shock further ionize the cometary atmosphere much faster and more copiously than the charge-transfer process is able to. Hot plasma then travels out along the magnetic field lines, confining the cometary ions and thus generating type 1 cometary tails. The pressure of the solar wind acting on the tubes of isotropically distributed hot plasma causes the plasma to accelerate anti-Sunward in a way that makes the tall rays straight and makes the plasma collapse on the anti-Sunward axis in the observed time of about one day. Publication: The Astrophysical Journal Pub Date: April 1981 DOI: 10.1086/158849 Bibcode: 1981ApJ...245..743B Keywords: COMAE; COMET TAILS; MOLECULES; DENSITY; SOLAR RADIATION; MAGNETIC FIELDS; PRESSURE; PHOTOIONIZATION; PROTONS; SOLAR WINDS; SHOCK; ELECTRONS; PLASMAS; MATHEMATICAL MODELS; CARBON MONOXIDE; FORMATION; ACCELERATION; COMETS; IONIZATION; IONS; Comets full text sources ADS |

The magnetic vector potential for points throughout the magnetosphere has been obtained by integrating over a model magnetotail current system. Parameterized functions of x, y, z have then been fit to the potential at these points. The curl of the resultant vector potential function matches the computed magnetic field closely. The final expression for the field presented in this work is a good representation of the field from an arbitrarily thick (or thin) current sheet which diminishes antisolarward from the earth and returns on the surface of the magnetosphere.

Earlier attempts to model the Hermean magnetospheric field based on a planet‐centered magnetic multipole field have required the addition of a quadrupole moment to obtain a good fit to space vehicle observations. In this work we obtain an equally satisfactory fit by assuming a null quadrupole moment and least squares fitting of the displacement of the planetary dipole from the center of the planet. We find a best fit for a dipole displacement from the planet center of 0.033 RM away from the solar direction, 0.025 RM toward dawn in the magnetic equatorial plane, and 0.189 RM northward along the magnetic dipole axis, where RM is the planet radius. Therefore the presence of a magnetic quadrupole moment is not ruled out. The compressed dipole field more completely represents the field in the present work than in previous work where the intrinsic quadrupole field was not included in the magnetopause surface and field calculations. Moreover, we have corrected a programing error in previous work in the computation of dipole tilt λ away from the sun. We find a slight increase for the planet dipole moment of 190 γ RM³ and a dipole tilt angle λ of only 1.2° away from the sun. All other parameters are essentially unchanged.

The wide-spread belief that the neutral sheet current in Earth's magnetotail creates an accumulation of charge at the boundary with the magnetosheath is erroneous. Current continuity is maintained by the magnetization current on the upper and lower surfaces of the magnetotail. Hence no electric fields arise from charge separation supposedly brought about by the flow of particles between the neutral sheet and the magnetosheath. Claims to the contrary are based on the oversight of forgetting the current on the magnetopause.

The geomagnetic field, suitably scaled down and parameterized, is shown to give a very good fit to the magnetic field measurements taken on the first and third passes of the Mariner 10 space probe past Mercury. The excellence of the fit to a reliable planetary magnetospheric model is good evidence that the Mercury magnetosphere is formed by a simple, permanent, intrinsic planetary magnetic field distorted by the effects of the solar wind. The parameters used for a best fit to all the data are (depending slightly on the choice of data) 2.44–2.55 for the ratio of Mercury's magnetic field strength at the subsolar point to that of the earth's subsolar point field (this results in a dipole moment of 170 γ RM³ (RM is Mercury Radius), i.e., 2.41 × 1022 G cm³ in the same direction as the earth's dipole), ∼−113 γ RM4 for the planetary quadrupole moment parallel to the dipole moment, 10°–17° for the tilt of the planet dipole toward the sun, 4.5° for the tilt of the dipole toward dawn, and 2.5°–7.6° aberration angle for the shift in the tail axis from the planet-sun direction because of the planet's orbital velocity. The rms deviation overall for the entire data set compared with the theoretical fitted model for the magnetic field strength was 17 γ (∼4% of the maximum field measured). If the data from the first pass that show presumed strong time variations are excluded, the overall rms deviation for the field magnitude is only 10 γ (∼2.5% of the maximum field measured).