摘要:

Bulk compositions, petrology, and mineralogy of lithic fragments discovered in polished sections of Apollo 17 drill core samples 70007, 70008, and 70009 and Luna 24 soil 24077, 43 are described. The fragments have unambiguous affinities to mare basalts, but are exceptionally low in TiO2(<1.0 wt.% TiO2). Apollo 17 rake sample 78526 is a green glassy rock of similar composition. Together the samples represent a distinct variety of mare basalts. Bulk compositional relationships suggest that they are related to Apollo 15 green glass, but the data do not permit us to discern the precise nature of the relationship. Both fractional crystallization and partial melting models can explain the observed compositional trends.

ISSN:0094-8276    

DOI:10.1029/GL004i006p00207

年代:1977

数据来源: WILEY

摘要:

We qualitatively examine the effects of changes in the solar wind dynamic pressure on the structure of a centrifugally driven planetary wind from Jupiter. We suggest that dynamic pressure variations can induce a transition between a super‐Alfvenic wind and sub‐Alfvenic breeze on Jupiter's dayside, which could possibly account for the observed large scale changes in the structure of Jupiter's outer magnetosph

ISSN:0094-8276    

DOI:10.1029/GL004i006p00211

年代:1977

数据来源: WILEY

摘要:

We attempt to merge conceptually planetary wind models of Jupiter's outer magnetosphere with reconnection models of Jupiter's outer magnetosphere. Solar wind reconnection scaling arguments predict 2‐4 AU for the length of the Jovian tail, consistent with that inferred from Jovian cosmic ray propagation arguments. Two conceivable limits of solar wind reconnection driven internal magnetospheric convection emerge, depending upon whether or not the centrifugally driven planetary wind transports magnetic flux radially outwar

ISSN:0094-8276    

DOI:10.1029/GL004i006p00215

年代:1977

数据来源: WILEY

摘要:

We use high time resolution data from the magnetometer, LEPEDEA and plasma wave analyzer on IMP‐7 to examine the microstructure of a long‐duration magnetotail fireball event observed during an extended quiet period on November 9, 1972. We demonstrate that the magnetic field is turbulent with fluctuation time scales down to several seconds. These findings suggest that the magnetic merging process may be a highly turbulent one, possibly associated with a form of the tearing mode instabil

ISSN:0094-8276    

DOI:10.1029/GL004i006p00219

年代:1977

数据来源: WILEY

摘要:

The Air Force Geophysics Laboratory (AFGL) computer program SARRA (Short Arc Reduction of Radar Altimetry) has been used for geoid determination with altimetric observations from the GEOS‐3 satellite. A unique feature of SARRA is the simultaneous recovery of the orbit parameters and the surface coefficients as defined by the kernel function analysis. Orbits good to approximately 20 meters are adequate for precise geoid determinations by virtue of the orbital adjustment in the reductions. Altimetric data over adjacent areas of the Indian and South Pacific Oceans and a portion of the North Atlantic have been processed with the SARRA program. Preliminary results indicate that highly accurate reference orbits are not a stringent requirement for the AFGL SARRA reductions. The recovered geoid in the GEOS‐3 calibration area shows good agreement with gravimetric geoids in that a

ISSN:0094-8276    

DOI:10.1029/GL004i006p00223

年代:1977

数据来源: WILEY

摘要:

Balloon‐borne infrared sunset solar spectra in the 780 cm−1region have been used to derive upper limits for the amount of ClONO2in the stratosphere. These upper limits for the volume mixing ratio are 4 × 10−11to 2 × 100−9between 15 and 30 km with an error factor of 2. These values only show that the postulate that ClONO2is a temporary reservoir for ClO and NO2cannot be

ISSN:0094-8276    

DOI:10.1029/GL004i006p00227

年代:1977

数据来源: WILEY

摘要:

Minimum levels of solar EUV fluxes appear to have occurred about 14 months before July 1976, the month designated as the start of Cycle 21 (minimum of monthly mean value of sunspot number, RZ). The EUV minimum, observed by the EUVS experiment on AE‐C, occurred around 20 April 1975 under conditions of a spotless disk and of a simultaneous minimum in F10.7. Another rise of quiet‐disk EUV, observed a few months before July 1976, was found in the low‐excitation lines such as 584 Å He I and 1026 Å H Ly‐β. The transition‐region lines of Fe X at 174.5 and 177.2 Å showed a substantial gradual rise later, toward the end of 1976 and mainly in early 1977, when periods of spotless disk with simultaneously minimal F10.780) on different sides of the sunspot minimum show drastically different relat

ISSN:0094-8276    

DOI:10.1029/GL004i006p00231

年代:1977

数据来源: WILEY

摘要:

The total odd nitrogen mixing ratio experiment has been conducted successfully for a second time on a balloon flight of PROJECT STRATOPROBE launched on August 17, 1975 from 51°N. The measured NOyprofile was found to be similar to the first profile measurement from 58°N on July 22, 1974 with a maximum mixing ratio of 13 ppbv at 32 km decreasing at lower altitudes to less than 2 ppbv at 16 km. This result was not unexpected, since the ozone mixing ratio profile was similar on both flight dates. Both measurement sets were carried out at mid latitudes during late summer, an excellent time for measurements of ozone layer photochemistry since the ozone layer is very stable during this seaso

ISSN:0094-8276    

DOI:10.1029/GL004i006p00235

年代:1977

数据来源: WILEY

摘要:

Controlled source magnetic induction experiments in the Adirondack Precambrian shield region of northern New York State indicate that the electrical conductivity in both the upper and lower crust are in conformity with laboratory studies of moist, igneous rock and in serious discord with such measurements on dehydrated rock. A two order of magnitude increase in the conductivity found at 20 km depth suggests a structural or phase change there. A single turn loop of wire 1.5 km in diameter was used to generate an oscillating magnetic dipole source field over the frequency range 0.4 to 390 Hertz. The amplitude and phase of the resulting fields were measured as a function of distance to 90 km from the source. Analysis of these measurements indicates approximate horizontal stratification of the electrical conductivity. The uppermost layer, which is no more than a few hundred meters thick, has a conductivity thickness product of 0.4 (ohms)−1. It is underlain by a conductivity of about 8 × 10−5(ohm meters)−1to a depth of about 15 km. The conductivity between 15 and 20 km is approximately 10−3(ohm meters)−1; the conductivity is greater than 10−2(ohm meters)

ISSN:0094-8276    

DOI:10.1029/GL004i006p00239

年代:1977

数据来源: WILEY

ISSN:0094-8276    

DOI:10.1029/GL004i006p00243

年代:1977

数据来源: WILEY