摘要:

The oblateness of Jupiter, which was neglected in the standard inversion technique for radio occultation data, has a substantial effect on the refractivity profiles of the neutral Jovian atmosphere derived from the Pioneer 10/11 occultations. The geometry of the Pioneer 10 entry and exit occultations has the effect that oblateness should account for much of the discrepancy of the results with plausible atmospheric models. The effect of the oblateness on Pioneer 11 entry is smaller, where much of the discrepancy could be due to other effects, such as cycle‐slip in the spacecraft transponder. Theory indicates that the Pioneer 11 exit occultation should be affected by the oblateness in the opposite sense from the first three occultations; and, indeed, the data which had not been invertible under the spherical assumption produced reasonable results when an oblateness correction was applie

ISSN:0094-8276    

DOI:10.1029/GL002i007p00265

年代:1975

数据来源: WILEY

摘要:

Using Euler potentials, we construct a class of axisymmetric magnetic field models that exhibit the general features of the dayside Jovian field as observed by Pioneers 10 and 11. The particular model used for illustration contains a distended, disk‐like field along the equator, a blunt, Earth‐like magnetosphere boundary, and the possibility of multiple traping regions along a field line. The self‐consistent ring current is calculated, together with representative drift periods for energetic part

ISSN:0094-8276    

DOI:10.1029/GL002i007p00269

年代:1975

数据来源: WILEY

摘要:

Data from the ALSEP 12 and 14 seismometers of the Apollo Passive Seismic Experiment Network are used to determine the statistics of the mass distribution of meteoroids and their direction of approach in near earth space. The cumulative number of meteoroid impacts detected is analyzed as a function of phase of the moon, taking into account the sensitivity of the seismometer and the seismic wave propagation characteristics of the moon. We conclude that, in the mass range studied (>5 kg), (a) most meteoroid orbits lie near the plane of the ecliptic, (b) the orbits have aphelia between 2 and 5 a.u., and (c) the mass distribution statistics are described by the relation log10n = B + G log10m, where n = number of meteoroids of mass m grams or greater, B ∼ 0.9 and G = −

ISSN:0094-8276    

DOI:10.1029/GL002i007p00273

年代:1975

数据来源: WILEY

摘要:

We have detected the presence of plasma in the lobes of the geomagnetic tail from observations of magnetic induction in the Moon forced by time variations of the Earth's magnetotail lobe field. The magnitude of the Moon's tangential electromagnetic transfer function when the Moon is in the lobes of the geomagnetic tail is less than that when the Moon is in the solar wind or geomagnetic tail plasma sheet. The tangential transfer function when the Moon is in the magnetotail lobes decreases at frequencies above about 8 milliHz due to finite wavelength effects. This shows that the waves in the magnetotail lobes which drive the lunar magnetic induction must have speeds far less than the speed of light and wavelengths comparable to the size of the Moon.

ISSN:0094-8276    

DOI:10.1029/GL002i007p00277

年代:1975

数据来源: WILEY

摘要:

Protons with 50 keV

ISSN:0094-8276    

DOI:10.1029/GL002i007p00281

年代:1975

数据来源: WILEY

摘要:

Barium plasma was injected into the northern magnetospheric cleft twice during January, 1975. Lofted by rockets launched after local magnetic noon from Cape Parry, NWT, Canada, high‐explosive shaped charges compressed hollow barium cones to generate vapor jets moving upward with initial velocities near 13 km/s parallel to the geomagnetic field. Barium plasma streaks created by solar photoionization of the vapor were convected through the polar magnetosphere and were observed optically from airborne and ground‐based sites until about 40 min after injection. Numerous indicators were monitored to determine the degree of magnetospheric disturbance; ionosondes at Cape Parry and Sachs Harbour, NWT, monitored latitudinal cleft motions preceding rocket launch. Spectrometers in the payloads recorded charged‐particle fluxes during both flights. The first injection occurred poleward in the cleft with subsequent plasma convection antisunward across the polar cap; the second occurred centrally with plasma convection duskward at constant magnetic lat

ISSN:0094-8276    

DOI:10.1029/GL002i007p00285

年代:1975

数据来源: WILEY

摘要:

A continuous section of surface ozone concentration in the eastern equatorial and southern tropical Atlantic shows maximum values (30–48 ppbV) in the ITCZ with low uniform values (13–15 ppbV) in the southeast trades. The high values are associated with mesoscale downdrafts in the convergence region. The southerly data show diurnal variations with night‐time maxima the amplitude of which increases landwards. These are probably caused by atmospheric cooling over the warm

ISSN:0094-8276    

DOI:10.1029/GL002i007p00289

年代:1975

数据来源: WILEY

摘要:

In diffusion modeling, it is often imperative to solve partial differential equations describing the concentration distribution of a substance released into a fluid subject to various kinds of initial and boundary conditions. The use of Green's theorems to solve such problems is one of the most powerful and promising methods because there are almost no limitations on the type of source conditions and functions depicting boundary values once the corresponding Green's function is obtained. Green's functions for a steady state, three‐dimensional turbulent diffusion equation with variable coefficients are, therefore, systematically presented for Dirichlet and Neumann boundary value problems in a number of important regions. Within the framework of power law approximations for velocity and diffusivities, solutions for most of the diffusion problems can be obtained by the proper choice of Green's functions given in this letter and the adroit manipulation of an integra

ISSN:0094-8276    

DOI:10.1029/GL002i007p00293

年代:1975

数据来源: WILEY

摘要:

An analysis of the characteristics of the eddy diffusivity is made, and the equations for turbulent diffusion in shear flows are derived. It is shown that the coefficients of the eddy diffusion can be expressed in terms of the stress tensor of the turbulent motion, a characteristic time and the velocity shear of the mean flow, which can be readily determined.

ISSN:0094-8276    

DOI:10.1029/GL002i007p00297

年代:1975

数据来源: WILEY

摘要:

From the tritium to salinity relationship on stations occupied in early 1974 on both sides of the Strait of Gibraltar, a mean tritium concentration of 1.6 ± 0.2 TU (1 sigma) is derived for the original Mediterranean water that feeds the outflow. The same tritium concentration is observed in the Mediterranean near to the Strait (Alboran Sea) in about 700 m depth. The layers shallower than about 450 m have so much higher tritium concentration that it can be concluded that they contribute only a small fraction of the outflow

ISSN:0094-8276    

DOI:10.1029/GL002i007p00301

年代:1975

数据来源: WILEY