bluuebunny/crossref_metadata_2025 huggingface dataset:
Persistent sunward flow of ∼ 1.6 MeV protons at 1 AU
Authors: Marshall F. E. , Stone E. C.
Published: February 2008

It has been found that except during the onset of prompt solar particle events the diffusive flow of 1.3 to 2.3 MeV protons at 1 AU is predominantly sunward. The anisotropy of the proton intensity has been measured with the Caltech Electron/Isotope Spectrometer aboard IMP‐7 for periods between prompt solar particle events from 72/273 to 74/2. The diffusive anisotropy, which has been determined by subtracting the independently determined convective anisotropy from the observed anisotropy, is predominantly directed toward the sun with a mean radial component of 14%. This sunward diffusion is typical of intensities from 0.012 to 1.2 (cm² sec sr MeV)−1 for 1.3 ‐ 2.3 MeV protons and indicates that a positive radial gradient is characteristic of these modestly enhanced fluxes. The direction of the flow is opposite to that which would be produced by previously proposed models which involve a continuous solar source for the observed particles. A steady‐state propagation model which includes adiabatic energy loss with particle injection beyond 1 AU produces the average observed anisotropy for κrr∼4 × 1020 cm² sec−1.
An equation for potential evaporation from soil, water, and crop surfaces adaptable to use by remote sensing
Authors: Idso Sherwood B. , Reginato Robert J. , Jackson Ray D.
Published: February 2008

Data acquired on four crops growing in three different locations, plus data for a water surface, indicate that a technique we had previously developed for calculating potential evaporation from bare soil surfaces [Idso, et al., 1975] may work equally well for crops and water without modification.
Plasma electron measurements in the outer Jovian magnetosphere
Authors: Intriligator Devrie S. , Wolfe John H.
Published: February 2008

The existence of the plasma electrons in the outer Jovian magnetosphere reported by Intriligator and Wolfe [1974] is consistent with 1) the additional pressure needed to supplement the magnetospheric magnetic field in the outer magnetosphere so as to balance the solar wind and interplanetary magnetic field dynamic pressure across the magnetopause, 2) the drastic change in the plasma electron spectrum as soon as Pioneer 10 crossed the magnetopause from the magnetosheath into the magnetosphere, 3) the fact that the instrument aperture was at spacecraft ground, and 4) the fact that beyond ∼ 2 AU the continuous observations of all ambient electron fluxes (solar wind electrons, secondary electrons, photoelectrons, etc.) are below the instrument threshold.
A comparison of solar wind streams and coronal structure near solar minimum
Authors: Nolte J. T. , Davis J. M. , Gerassimenko M. , Lazarus A. J. , Sullivan J. D.
Published: February 2008

We examine the relationship between high speed streams of solar wind and coronal structure during the period September‐December, 1976. The solar wind streams during this period were generally of lower amplitude, lower maximum velocity, and shorter duration than those in the preceding Skylab period. Solar wind data are compared with X‐ray images of the corona taken on 16 September and 17 November, 1976. A moderate sized stream was seen during September when no equatorial coronal holes were observed. Although there was an equatorial extension from the North polar hole, it was smaller and less well‐defined than those of the Skylab period; thus it seems to be a poor candidate for the source of the stream. The November image shows a better‐defined extension from the South polar hole; it may well be the source of a small solar wind stream with peak of ∼ 510 km/sec. These results suggest that either there has been a change in the solar wind‐coronal hole relationship or that the relationship is not as general as might be inferred from the Skylab period.
Neutral atmospheric waves in the thermosphere and tropospheric weather systems
Authors: Rice C. J. , Sharp L. R.
Published: February 2008

Neutral atmospheric density profiles between 135 and 225 km obtained from a cold cathode ion gauge onboard the Atmosphere Explorer‐C spacecraft frequently exhibit considerable wave‐like structure, which is interpreted to be internal gravity waves. We have attempted to correlate the occurrence probability and amplitude of these waves with several parameters of geophysical importance. Only weak correlations are found with common parameters, such as Kp, for which strong correlations with the neutral atmospheric density are known to exist. However, the waves do appear over certain preferred geographical locations which tend to coincide with regions of high wind speeds and windshear in the upper troposphere. This relationship leads us to suggest that the majority of the waves observed in our data originate in the troposphere and subsequently propagate upwards into the thermosphere.
NOAA carbon dioxide measurements at Mauna Loa Observatory, 1974–1976
Authors: Peterson James T. , Komhyr Walter D. , Harris Thomas B. , Chin John F. S.
Published: February 2008

The Geophysical Monitoring for Climatic Change program of NOAA's Environmental Research Laboratories has measured atmospheric carbon dioxide concentrations at Mauna Loa Observatory, Hawaii, continuously since June 1974. The measurements through 1976 have been analyzed for recent secular concentration changes and show a continuing increase of about 0.9 ppm/year.
Spectral analysis of stratiform cloud radar observations
Authors: Henrion Xavier , Sauvageot Henri
Published: February 2008

The spectral analysis of microscale horizontal radar reflectivity fluctuations, created near the top of stratiform clouds by turbulent convection, shows that the fluctuations are not totally random; the spectrum exhibits meaningful spectral peaks, reflecting a dynamic organization of the cloud in several frequency domains. This analytic technic may yield the spectral signature of clouds.
Ozone transport from stratosphere to troposphere
Authors: Husain Liaquat , Coffey Peter E. , Meyers R. E. , Cederwall R. T.
Published: February 2008

7Be produced by the interaction of cosmic rays with oxygen and nitrogen, predominantly in the stratosphere, has been used to identify and measure stratospheric ozone at the ground level. Simultaneous measurements at Whiteface Mountain, New York, in July 1975 show that the maximum 7Be concentrations are accompanied by increased ozone concentrations. Peaks in 7Be concentrations occurred on July 5‐6, 11‐12, 16‐17, 23, and 27. Ozone peaks were observed on July 7‐9, 11, 18, 24, and 27. Isentropic trajectory calculations also showed that the trajectories reaching Whiteface Mountain on July 11‐12, 15‐16, 23, and 27 had stratospheric origin. One‐day delay in ozone peaks on July 7‐9, 18, and 24 is attributed to increased tropospheric ozone production. The observed relationship between 7Be and ozone is used to deduce an upper limit of 37 ppb stratospheric ozone at Whiteface Mountain during July 1975. Thus, even during midsummer months, when stratospheric‐tropospheric mass exchange is not at a maximum, stratospheric ozone may contribute substantially to the national ambient air quality standard of 80 ppb.
Determination of the N2+ recombination rate coefficient in the ionosphere
Authors: Orsini N. , Torr D. G. , Brinton H. C. , Brace L. H. , Hanson W. B. , Hoffman J. H. , Nier A. O.
Published: February 2008

Measurements of aeronomic parameters made by the Atmosphere Explorer‐C satellite are used to determine the recombination rate coefficient of N2+ in the ionosphere. The rate is found to increase significantly with decreasing electron density. Values obtained range from ∼ 1.4 × 10−7 to 3.8 × 10−7 Cm³S−1. This variation is explained in a preliminary way in terms of an increase in the rate coefficient with vibrational excitation. Thus, high electron densities depopulate high vibrational levels reducing the effective recombination rate, whereas, low electron densities result in an enhancement in the population of high vibrational levels, thus, increasing the effective recombination rate.
Systematic deviations of Nimbus‐5 atmospheric temperature fields from radiosonde data over the winter Antarctic
Authors: Asgeirsson Vigfus , Stanford John L.
Published: February 2008

Atmospheric temperature fields derived from inversions of Nimbus 5 radiance data are compared with radiosonde data from 15 antarctic stations during the period 1 July ‐ 6 September 1973. Unexpectedly large systematic differences are found in the upper troposphere and lower stratosphere over eastern Antarctica. The satellite‐derived temperatures are typically 3‐4 K too warm at 200 mb. Because many atmospheric model calculations depend critically on the accuracy of the temperature fields used as input data, and especially on horizontal temperature variations, these results are of importance and will be of interest to those researchers involved in temperature retrievals from satellite radiance data and to those who may wish to utilize Nimbus‐5 temperature fields for model calculations in high southern latitudes.
A persistent subauroral scintillation enhancement observed in Alaska
Authors: Fremouw E. J. , Rino C. L. , Livingston R. C. , Cousins M. C.
Published: February 2008

The most persistent, identifiable feature on intensity and phase scintillation records of coherent beacon signals recorded near Fairbanks, Alaska during several months in 1976 is a narrow region of enhanced scintillation to the south of the station. On high‐elevation passes the feature occurs near the magnetic zenith, suggesting that it could be a geometric enhancement produced by field‐aligned irregularities. The feature also occurs, however, on medium and low‐elevation passes when the minimum off‐field angle is several tens of degrees. The observations, therefore, represent evidence for either (1) a hitherto unrecognized irregularity enhancement or layer thickening in the subauroral ionosphere, or (2) longitudinally extended irregularity sheets.
Geologic interpretation of new observations of the surface of Venus
Authors: Saunders R. Stephen , Malin Michael C.
Published: February 2008

New radar observations of the surface of Venus provide further evidence of a diverse and complex geologic evolution. The radar bright feature "Beta" (24°N, 85°W) is seen to be a 700 km diameter region elevated a maximum of approximately 10 km relative to its surroundings with a 60 × 90 km wide depression at its summit. "Beta" is interpreted to be a large volcanic construct, analogous to terrestrial and martian shield volcanoes. Two large, quasi‐circular areas of low reflectivity, examples of a class of features interpreted to be impact basins by previous investigators who were without the benefit of actual topographic information, are shown in altimetry maps to be depressions. Thus the term "basin" can be applied, although we urge a non‐genetic usage until more complete understanding of their origin is achieved through analysis of future observations.
Discovery of He2+ and O2+ ions of terrestrial origin in the outer magnetosphere
Authors: Young D. T. , Geiss J. , Balsiger H. , Eberhardt P. , Ghielmetti A. , Rosenbauer H.
Published: February 2008

Using the Ion Composition Experiment (ICE) on board ESA'S GEOS satellite we have observed He2+ and O2+ ions of terrestrial origin in the outer magnetosphere predominantly in the energy range ∼ 1 ‐ 100 eV. Data were obtained near the equatorial plane at geocentric distances of 3 to 7 earth radii in the local time sector 1500 ‐ 2100 hours. During periods when doubly charged ions are observed typical abundances are O2+/O+ ∼ 30% and He2+/He+ ∼ 0.5% ‐ 10%. The proportions of the major constituents H+, He+, and O+ are highly variable with He+ occasionally the dominant species at higher altitudes.
Comparison of Chatanika Radar and optical measurements of E‐region neutral winds
Authors: Perreault P. D. , Baron M. J. , Stenbaek‐Nielsen H. C.
Published: February 2008

Coordinated optical and incoherent‐scatter radar observations were made during an aluminum vapor trail rocket experiment conducted at the Poker Flat Research Range. Altitude profiles of E‐region neutral winds, deduced from optical tracking of the aluminum vapor trail, were compared with profiles derived from the Chatanika radar data. The radar was operated in a multipulse mode that provided an altitude resolution of about 8 km over an altitude region of 80 to 200 km. The radar data show more than a 360‐degree rotation of the neutral‐wind direction over a 30‐km altitude interval. Good agreement was found between the radar‐derived and optically‐derived neutral‐wind profiles over most of the altitude region (105 to 129 km) of the aluminum trail release. This close agreement verifies the ability of the radar to monitor E‐region neutral winds, with a resolution approximately equal to the local scale heights.
The chemical form of cosmogenic radioactive 38Cl and 39Cl in the lower stratosphere
Authors: Rowland F. S.
Published: February 2008

The cosmogenic radioisotopes 38Cl (t ½ = 37.3 min.) and 39Cl (t ½ = 55.5 min.) are formed in the stratosphere in detectable quantities, and participate in the stratospheric chlorine cycles. The predominant expected chemical forms for these radioisotopes are ClO and/or ClONO 2 throughout most of the stratosphere. The rates for formation of HCl are sufficiently slow that most 38Cl and 39Cl atoms undergo radioactive decay before ever reacting to form HCl.

The measurement of the fraction of 38Cl and 39Cl in the forms ClO and ClONO 2 , with a concurrent NO 2 measurement, can be used to measure in situ the stratospheric formation rate for ClONO 2 . Such experiments could be conducted at altitudes accessible to aircraft experiments.
Mars: Regolith adsorption and the relative concentrations of atmospheric rare gases
Authors: Fanale Fraser P. , Cannon W. A. , Owen Tobias
Published: February 2008

Laboratory measurements of Kr and Xe adsorption on samples of ground montmorillonite, limonite and basalt at −77°C have been performed. Results suggest that 1) most degassed martian Xe could be adsorbed on a regolith with a large effective surface area, and 2) if this is the case the elemental composition of martian nonradiogenic rare gas (counting that in the regolith) may be virtually identical to that of ordinary chondrites.
On the magnetic field of Mars: Mars 5 Evidence
Authors: Dolginov Sh. Sh.
Published: February 2008

The measurements obtained by Mars 5 reaffirm the conclusion of an intrinsic Martian magnetic field based on the Mars 2 and 3 data. The bow shock positions are equivalent to those observed on the earlier missions. Furthermore, a magnetotail is observed whose direction is independent of interplanetary sector structure.
Comparison of protonospheric electron content measurements from the American and European sectors
Authors: Kersley L. , Klobuchar J. A.
Published: February 2008

Average protonospheric electron contents, line integral measurements determined from observations of the ATS‐6 satellite radio beacon at Hamilton, U.S.A. and Aberystwyth, U.K. are compared. It is shown that the two sets of data would be expected to be representative of measurements obtained at mid‐latitude stations in North America and Europe respectively. The American protonospheric content magnitudes are lower than those from Europe and show a diurnal variation maximizing at night in winter through equinox in contrast to the daytime maximum found consistently in the Aberystwyth data. It is suggested that the differences may be interpreted in terms of ionospheric/protonospheric interactions in both local and conjugate hemispheres and the similarities in the forms of the diurnal variation of the American results with those of peak density in the conjugate ionosphere are noted.
Particle track based irradiation and accretion history of the Luna‐24 regolith column
Authors: Goswami J. N.
Published: February 2008

Regolith materials from Mare Crisium, sampled by the Luna‐24 deep drill core, have widely varying cosmic ray irradiation records, as revealed by the particle track records in six samples taken from different depths in the core. The observed track records are typical of mare materials and are similar to those observed in Apollo 12 and 15 sites. The soils in the upper zone (74‐162 cm) of the drill core column consist of highly mature to submature soils, whereas there is a preponderanceof immature soils in the lower zone (162‐208 cm). The track data are consistent with either a slow deposition rate or a high level of pre‐depositional irradiation for the regolith material in the upper zone and a fast deposition rate for the lower part of the regolith column at this site.
Lack of effects of solar magnetic sector crossings on the troposphere
Authors: Bhatnagar V. P. , Jakobsson Thor
Published: February 2008

The response of the troposphere at 500 mb level to solar magnetic sector crossings (SMSC) has been investigated in terms of two dynamical atmospheric indices, kinetic energy density and square of the vorticity of the main motion. Daily values of these indices at high and middle latitudes in the Northern Hemisphere for quiet and active solar conditions have been computed using the geostrophic wind approximation. No relationships were found between SMSC and these particular atmospheric indices irrespective of solar activity, latitude, season and interplanetary magnetic field (IMF) polarity. The present investigations lead to conclude that if any effect associated with SMSC is accepted, it should be associated only with the vorticity area index for low pressure trough areas in winter.
Effects of wave‐induced diffusion on thermospheric acoustic‐gravity waves
Authors: Del Genio Anthony D. , Straus Joe M. , Schubert Gerald
Published: February 2008

When wave‐induced diffusion is included in the equations governing acoustic‐gravity wave propagation in an atmosphere in diffusive equilibrium, it is found that phase and amplitude relationships between the density fluctuations of individual atmospheric constituents agree with AE‐C satellite observations of wavelike structure only over a narrow range of wave periods. For a 400 km horizontal wavelength, the observations are consistent with internal gravity waves of periods 11.5‐22 minutes propagating at phase speeds 300‐600 m/sec.
Comments on “Is the Moon really as smooth as a billiard ball?…”
Authors: Pillinger C. T. , Jull A. J. T.
Published: February 2008

Hapke and Cassidy (1978), in describing their ideas concerning sputter deposition, have criticised a number of aspects of a model for chemical fractionation and metallic iron production which is based on preferential sputtering. Questions referring to the fate of sputtered atoms, the surface roughness of the moon and the existence of metal rich layers may all be answered. Doubts may be expressed concerning the validity of some arguments used by Hapke and Cassidy since the regolith in their model is predominantly static with only episodic turnover. Some effects associated with gardening and comminution processes, and solar wind irradiation angle need to be considered. Chemical fractionation and metallic iron formation at the lunar surface is likely to be a complex process; preferential sputtering, sputter deposition and agglutination may all be involved.
Electrical conductivity of dunite during shock compression from 12.5 to 45 GPa
Authors: Schulien Sigmar , Hornemann Ulrich , Stöffler Dieter
Published: February 2008

The electrical conductivity of 7 dunites (Addie, Åheim, Balsam Gap, Corundum Hill, Dun Mountain, Mooihoek and Twin Sisters) in the pressure range 12.5 ‐ 45 GPa has been studied using the shock wave technique. In this pressure range the measured conductivity varies from 2.8·10−5 to 2.6·10−2Ω−1cm−1. Differences in the total olivine content, Fe‐content of the olivines, Fe2O3− and chromite content and grain sizes of the dunites lead to differences in their conductivity. All dunites show an increase of about 105Ω−1cm−1 of the electrical conductivity in the pressure range 0 ‐ 40 GPa, thus approaching semiconductor behavior. This increase is due to both temperature and pressure effects and possibly also to a partial phase transition of olivine.
Effect of sediment mixing on the rate of calcite dissolution by fossil fuel CO2
Authors: Peng T.‐H. , Broecker W. S.
Published: February 2008

As the CO2 produced by the combustion of fossil fuels reaches the deep sea it will attack the calcite stored in abyssal sediments. This reaction will significantly augment the ocean's capacity for this combustion product. Hence it is of interest to define the kinetics of this dissolution process. One aspect, the role of bioturbation, is dealt with in this paper. We show that the bioturbation rates obtained from the core top 210Pb and 14C distributions are sufficiently rapid so that the turbated zone can be treated as well mixed in dissolution models. No significant buildup of the non‐calcite residue will occur in the upper few millimeters of sediment where dissolution takes place. Rather it will be "stirred" into the mixed layer with sufficient rapidity that its influence will not become significant until the mixed layer as a whole drops in calcite content.
Radiative equilibrium temperatures in the stratosphere and mesosphere ‐ A comparison for the stellar occultation and BUV ozone data
Authors: Kuhn W. R. , Kraemer D. , Cicerone R. J. , Liu S.
Published: February 2008

Recently published ozone densities in the equatorial stratosphere and mesosphere from satellite stellar occultation measurements are appreciably larger than previous independent midlatitude measurements and ozone densities predicted by photochemical theory. We have calculated radiative equilibrium temperature profiles with a stratosphere‐mesosphere optimized model for each of these ozone profiles and find that the stellar occultation studies cannot be discounted on energy balance grounds.
Ion acoustic stability analysis of the Earth's bow shock
Authors: Greenstadt E. W. , Formisano V. , Russell C. T. , Neugebauer M. , Scarf F. L.
Published: February 2008

Application of a marginal ion acoustic stability criterion to five thin bow shock observations provides new evidence in support of the criterion as the basis for determining the thickness of the magnetic gradients of subcritical, quasi‐perpendicular shock structures.
First comparison of simultaneous Iris, Buv, and ground‐based measurements of total ozone
Authors: Prior Edwin J. , Oza Bharat J.
Published: February 2008

This paper presents the first comparison of the zonally‐averaged global distribution of total ozone obtained simultaneously using measurements from the Nimbus IV BUV experiment (refined as of December 1977), the Nimbus IV IRIS experiment, and the ground‐based Dobson and ozonometer instruments of the World Meteorological Organization. The measurements are compared with respect to differences between the measured latitudinal and seasonal variations of total ozone, with emphasis on any systematic discrepancies that appear to be related to differences in the sensing methodologies or instruments. While the zonal averages of the two satellite techniques agree quite well at low latitudes, the results are consistently higher for IRIS than for the BUV above mid‐latitudes in both the Northern and Southern Hemispheres. The differences grow larger with increasing latitude, becoming as great as 23 percent at 75°N during July through October. In the Southern Hemisphere, 49 out of 50 IRIS zonal averages between 25°S and the South Pole are greater than the BUV averages. These persistent differences may be evidence of disparities between the infrared and ultraviolet methodologies or instrumentation. The BUV and ground‐based ultraviolet averages agree better in general with each other than with the infrared IRIS averages. Inclusion of ozonometer data is found to generally improve the agreement between the Northern Hemisphere ground‐based and satellite zonal averages.
The distribution of orbits of cosmic dust particles detected by Pioneers 8 and 9
Authors: Weidenschilling S. J.
Published: February 2008

The orbits of cosmic dust particles detected by Pioneers 8 and 9 have large eccentricities, and semimajor axes < 1 AU. For prograde orbits, this distribution is shown to be due to a combination of impact probabilities and detector response. The presence of dust in larger "cometary" orbits is not excluded by the data. The reported retrograde orbits are improbable, and may be spurious.
Global simulation of the time‐dependent magnetosphere
Authors: Leboeuf J. N. , Tajima T. , Kennel C. F. , Dawson J. M.
Published: February 2008

We present preliminary results from time dependent 2‐dimensional numerical modeling of the magnetohydrodynamic interaction of the solar wind with the magnetosphere. A southward solar wind field produces a magnetospheric topology consistent with Dungey's model. The interaction appears to be fundamentally unsteady; the shock, magnetosheath, and magnetopause are highly turbulent. We model a "substorm" as the passage of a rotational discontinuity over the magnetosphere; we observe that the onset of enhanced reconnection in the magnetospheric tail produces a closed magnetic island which convects downstream.
Interpretation of the low velocity zone in terms of the presence of thermally activated point defects
Authors: Shaw George H.
Published: February 2008

Experimental and theoretical work indicates that point defects can significantly affect sound velocities. Since point defects may exist in thermal equilibrium, their effect on sound velocities may be calculated as an activation phenomenon. Alternatively, activation parameters may be calculated from sound velocity data. Because of the shape of the goetherm it is possible to treat the low velocity zone using the theory of activated processes. The activation parameters calculated from Vp and Vs are in reasonable agreement with one another and with values determined from laboratory experiments on electrical conductivity of olivine and orthopyroxene.
Composition measurements of stratospheric positive ions
Authors: Arnold F. , Böhringer H. , Henschen G.
Published: February 2008

Three composition measurements of stratospheric positive ions conducted during daytime at 33‐37 km altitude by use of balloon‐borne mass spectrometers revealed the presence of two families of ion species, proton hydrates (PH) and non‐proton hydrates (NPH ) having about equal abundances. The major PH are H+(H2O)3 H+(H2O)4 and H+(H2O) 5 among which the fourth hydrate is by far most abundant. Among the NPH which possibly have the form H+x1(H2O)m, with x having mass 41 ± 1,96 ± 1, (H+ x(H2O)33) is most abundant. Arguments are put forward inferring a formation of NPH from PH reacting with a stratospheric trace gas x whose proton affinity exceeds that of water and whose concentration is estimated to be 7 · 104 cm−3 at 37 km altitude. The possibility of probing atmospheric trace gases by in situ ion composition measurements is discussed and upper abundance limits are given for various gases.
Short‐term disturbances in the carbon dioxide record at Mauna Loa Observatory
Authors: Miller John M. , Chin John F. S.
Published: February 2008

Short‐term disturbances in the carbon dioxide record at Mauna Loa Observatory have been observed since measurements were begun in 1958. These variations are easily recognized and documented on the CO2 record and must be deleted if only the baseline data are to be analyzed. By use of a simple wind analysis technique it was shown that the probable source of these CO2 disturbances since 1976 is venting in the crater of the Mauna Loa volcano during southerly flow.
The photoelectron flux in the Earth's ionosphere at energies in the vicinity of photoionization peaks
Authors: Jasperse John R. , Smith Ed. R.
Published: February 2008

In this paper we apply Boltzmann‐Fokker‐Planck (BFP) theory to analyze the (isotropic) photoelectron flux in the Earth's ionosphere at energies in the vicinity of photoionization peaks where the electron impact cross sections are slowly varying functions of energy. We give a Green's function solution for the photoelectron flux which shows that the energy derivative terms in the BFP method dominate the solution in spectral regions of high slope. Analytical results for the photoelectron flux and the forward and backward half widths in the vicinity of isolated photoionization peaks are given which explain the observed asymmetry and shift of the photoionization peaks with increasing altitude. At low altitudes these results indicate that the theoretical width of an isolated photoionization peak is less than the experimental resolution of recent AE‐E data. A comparison between the theoretical photoelectron flux averaged using the experimental resolution and the experimental photoelectron flux from 15 to 35 eV at 182 km shows reasonable relative agreement.
Near bottom water temperature anomalies: Mid‐Atlantic Ridge Crest at latitude 26°N
Authors: Rona Peter A.
Published: February 2008

Six water temperature anomalies were measured along two profiles each about 10 km in length at the TAG Hydrothermal Field on the east wall of the rift valley of the Mid‐Atlantic Ridge at latitude 26°N. The temperature anomalies were measured using a 3 m‐long vertical array of four thermistors towed within 20 m of the ocean bottom. The anomalies exhibit increases in potential temperature up to 0.127°C above ambient and inverse gradients warming downwards as great as 4.2 × 10−2°C m−1. The temperature anomalies are distributed as point sources in a linear pattern about 7 km in length along known fault zones in the east wall of the rift valley between depths of 2750 and 3200 m below sea level associated with hydrothermal mineral deposits. The characteristics of the temperature anomalies and their geologic setting indicate an origin by discharge of hydrothermal solutions through the faults in the rift valley wall. The magnitudes of the anomalies are consistent with values previously used to estimate a heat output of the order of several megawatts per kilometer of ridge at the TAG Hydrothermal Field.
The Sahara as a possible sink for trace gases
Authors: Pierotti David , Rasmussen L. E. , Rasmussen R. A.
Published: February 2008

Recently evidence has been accumulating pointing to the possibility of a sink for atmospheric trace gases in the desert areas of the world, specifically the Sahara. The proposed mechanism involves adsorption of molecules onto silicate surfaces, and photolysis of the adsorbed molecules by long‐wave solar radiation (λ > 300 nm). To obtain data on this possible sink mechanism we took part in flights over East Africa, the Mediterranean Sea, and the Atlantic Ocean. We collected air samples in dust clouds over East Africa, and in non‐dusty air over Africa, the Mediterranean, and the Atlantic. The results of our measurements show that the samples of air collected in the dust clouds have significantly lower concentrations of N2O, CCl4, and CH3CCl3, whereas there is no significant difference between the dusty and non‐dusty air samples for CF2Cl2 and CFCl3. This is in general agreement with the experimental results, which found that CCl4 is photolyzed much more rapidly than CFCl3 and CF2Cl2. However, the differences in N2O, CCl4, and CH3CCl3 concentrations between dusty and non‐dusty air samples are relatively small, and the number of samples is insufficient to support any firm conclusions. The most that can be said is that the results of our measurements are consistent with the hypothesis that desert regions may be acting as sinks for a number of atmospheric trace gases, and that further research is clearly needed in this area.
Vertical distribution of H2O in the stratosphere as determined by UV fluorescence in‐situ measurements
Authors: Bertaux Jean‐Loup , Delannoy Alain
Published: February 2008

The stratospheric H2O mixing ratio profile in the 10‐24 km altitude range is derived from in‐situ measurements, using a new technique: OH fluorescence produced when H2O molecules are photodissociated by a V.U.V. light source. The flight instrument and its calibration are described in some details. A decrease of the mixing ratio is observed below 24 km, down to 21 km. The stratospheres‐troposphere transition shows vertical structure.
A comparison of ground level cosmic ray enhancements of November 22, 1977 and February 25, 1969
Authors: Mathews T. , Agrawal S. P. , Venkatesan D.
Published: February 2008

The anisotropic solar flare increases observed by neutron monitors on November 22, 1977 and February 25, 1969 are discussed. These events occurred at quite different modulation levels of galactic cosmic rays. The characteristics of the events such as anisotropy, rise and decay times are not significantly different from one event to the other. This implies that the interplanetary conditions for propagation of cosmic rays of a few GeV (109 eV) energy are comparable at the sunspot maximum and minimum of solar cycle 20. Therefore, the near‐earth environment does not play a major role in the modulation of galactic cosmic ray intensity and the cause of its 11‐year variation has to be sought in the regions off the ecliptic plane and/or farther out in the ecliptic plane.
Measurements of radiation from lightning at 2200 MHz
Authors: Rust W. David , Krehbiel Paul R. , Shlanta Alexis
Published: February 2008

Measurements of radiation from lightning at 2200 MHz have been made using a high gain, 1.4° beamwidth, parabolic antenna. For discharges to ground, radiation was observed to occur: (1) as a burst of impulsive activity during preliminary breakdown preceding the initial return stroke, (2) in conjunction with the initial return stroke, and (3) during the dart leaders of subsequent strokes. The latter two are similar to previous observations made at lower frequencies. The burst of 2200 MHz radiation during the preliminary breakdown generally occurred several tens of milliseconds prior to the first return stroke and lasted from 5 to 10 ms. We interpret the burst to be caused by breakdown passing through or near the main beam of the antenna.
Atmospheric OH production—The O(¹D) + H2O reaction rate
Authors: Lee L. C. , Slanger T. G.
Published: February 2008

Successful modeling of the chemistry of the troposphere and stratosphere requires accurate knowledge of the production rate of the OH molecule, since it occupies a central position in a number of chemical cycles. The reaction between O(¹D) and H2O is believed to be the principal primary OH source, and an evaluation of the literature shows a discrepancy of about a factor of two between two of the most recent rate coefficients for this reaction. We have generated O(¹D) from pulsed 1600 Å photolysis of O2, and observed the 6300 Å O(¹D → ³P) transition. The rate coefficient for H2O quenching of O(¹D) has been directly determined, and found to be (2.6 ± 0.5) × 10−10 cm³molec−1s−1 at 300°K, in good agreement with the measurements of Streit, Howard, Schmeltekopf, Davidson, and Schiff.
Determination of stratospheric ozone at ground level using 7Be/ozone ratios
Authors: Dutkiewicz Vincent A. , Husain Liaquat
Published: February 2008

The 7Be and O3 concentrations were measured and the 7Be/O3 ratios calculated for air particulates collected on several flights of two specially equipped commercial B747 jetliners between altitudes of 10 and 12 km and latitudes of 21° to 55° N. Upper tropospheric 7Be concentrations averaged about 520 pCi/10³m³, whereas the stratospheric average was about 4,700 pCi/10³m³. The 7Be/O3 ratio at 35° ‐ 42° N was determined to be 10.78 pCi/10³m³/ppbv for April‐June 1978. Concentrations of 7Be and O3 were also measured daily during June and July 1977 at Whiteface Mountain, New York. Daily variations in 7Be data indicated the arrival of a stratospheric air mass on June 15‐16. Comparison of 7Be concentrations show approximately a tenfold dilution of the stratospheric air during tropospheric descent. The 7Be/O3 ratio on June 15‐16 was 9.8 pCi/10³m³/ppbv within experimental error of the stratospheric value. This suggests that at least at times, stratospheric air, although diluted, reaches ground level without significant relative fractionation of 7Be and O3. Assuming this to be true on days when 7Be concentration is > 200 pCi/10³m³ (or ≥ 5% of the stratospheric value), we have determined the stratospheric ozone concentration at Whiteface Mountain to vary between 19 and 47 ppbv for summer months. Thus at a remote location such as Whiteface Mountain both stratospheric and the tropospheric sources play an important role.
Plasma diffusion in a space‐simulation beam‐plasma‐discharge
Authors: Szuszczewicz E. P. , Walker D. N. , Holmes J. C. , Leinbach H.
Published: February 2008

Electron density and temperature profiles have been measured in a large‐facility beam‐plasma‐discharge (VB = 1.3 KeV, IB = 63 ma) at low pressure (P = 2‐4 (10−6)Torr) and low magnetic fields (B = 1.2 G). The results follow an exponential behavior and are found to be in good agreement with a simple diffusion model. The favorable comparison between theory and experiment yields the first estimate of cross‐field electron diffusion (De⊥(nom) = 2.2(106) cm²/sec) under conditions intended to simulate Spacelab‐borne beam‐plasma investigations. This value for De⊥ is orders of magnitude larger than would be expected for a cross‐field collisional diffusion process, a result which is identified with the turbulent state of collective beam‐plasma interactions.
Paleomagnetism of varved sediments from western New England: Secular variation
Authors: Verosub Kenneth L.
Published: February 2008

A paleomagnetic study of a 2500 year sequence of varved sediments from western New England has provided detailed information about the late Wisconsinan geomagnetic field. The resulting curves of secular variation are compared to a model of the recent secular variation in New England produced by drifting the present geomagnetic field past an observation point. In terms of both major and minor features the two fields appear to be remarkably similar, attesting to the long‐term persistence of the basic structure of the field. The principal difference between the two fields is that the late Wisconsinan field exhibits a slightly greater range of secular variation. This difference implies that either the late Wisconsinan field had a lower intensity than the present field or that the total magnetic energy external to the earth’s core has decreased since the late Wisconsinan.
The recovery of paleomagnetic polarities from cyclothemic sediments in the carboniferous Appalachian Basin, USA
Authors: Cain B. , Payne M. A. , Shulik S. , Donahue J. , Rollins H. B. , Schmidt V. A.
Published: February 2008

Using a cryogenic magnetometer, reliable paleomagnetic polarities may be recovered for a wide variety of lithofacies present in Carboniferous cyclothemic sediments from the Appalachian Basin. The most reliable recorders are shales and limestones whose clastic fractions are dominated by silt and fine sand‐sized terrigenous grains. Coarse sandstones and limestones whose clastics are dominated by clays are poor recorders, while fine‐grained sandstones will generally yield polarities but not good pole positions. A comprehensive magneto‐stratigraphy for the Carboniferous should be obtainable.
Sodium and other minor constituents of meteoric origin in the atmosphere
Authors: Liu S. C. , Reid G. C.
Published: February 2008

The photochemistry of sodium species is examined. It is shown that the dominant species below the well known sodium layer is NaOH which is abundant enough in the middle stratosphere to explain the existence of NaOH‐cluster positive ions as proposed by Ferguson (1978). A range of total flux of meteoric species entering the stratosphere of 5 × 105 to 5 × 106 cm−2s−1 can be deduced from our model calculations. The implication of metals in these meteors on the formation of stratospheric aerosols is discussed.
The implications of CO production in electrical discharges
Authors: Chameides W. L.
Published: February 2008

The high temperature chemistry of the N‐O‐H‐C system has been studied to determine the production of NO and CO by atmospheric lightning. The yield of NO is found to be equivalent to results obtained for a pure N2/O2 atmosphere. The CO yield is highly dependent upon the detailed cooling processes within the discharge and thus an experiment designed to measure the CO source in discharges could yield useful insights into the discharge itself. An upper limit of 3.5×1011 g CO yr−1 is estimated for the global CO source from lightning.
Measurements of upper atmosphere water vapor made in situ with a new moisture sensor
Authors: Chleck David
Published: February 2008

The stratospheric and upper tropospheric water vapor levels have been measured with a new aluminum oxide sensor: Aquamax II®. This sensor is briefly described along with details of its calibration and performance. Data obtained from six balloon flights are shown. Almost all the results show a constant water vapor mixing ratio, in agreement with other data for the mid‐latitude regions. Moreover, considerable structure is seen in the present results.
Geomagnetic Sq variation at satellite altitudes: Is Sq correction important in Magsat data analysis?
Authors: Sugiura Masahisa , Hagan M. Patricia
Published: February 2008

By a spherical harmonic expansion of the magnetic potential the geomagnetic Sq variation is shown to have peak‐to‐peak amplitudes of a few tens of nanotesla at 400 km altitude. It is shown, in particular, that for harmonics of degree n up to about 4, with which Sq can be well represented, the vertical component of the magnetic field at altitudes to about 400 km is virtually the same as on the ground. Even though the NASA's Magnetic Field Satellite (Magsat), scheduled for launch in September 1979, is planned to be placed in a twilight sun‐synchronous orbit, Sq over certain areas of the earth can be of comparable magnitude as magnetic anomalies of geological origin sought in the data. Due consideration should be given to Sq as well as to the effects from magnetospheric sources in analyzing the Magsat data. The Sq effect is expected to be large during the period of Magsat operation which is near the predicted solar maximum.
The measurement of 10Be in manganese nodules using a tandem Van De Graaff accelerator
Authors: Turekian K. K. , Cochran J. K. , Krishnaswami S. , Lanford W. A. , Parker P. D. , Bauer K. A.
Published: February 2008

The growth rate of a manganese nodule from the South Atlantic Ocean (Rio Grande Ridge) has been determined using a 10Be profile as measured with a Tandem Van de Graaff accelerator. This rate is 4.5 mm/My. A correlation may exist between the 10Be flux and the Mn flux to nodules.
Rate constants for the reactions of OH with CℓO, Cℓ2, and Cℓ2O at 298K
Authors: Leu M. T. , Lin C. L.
Published: February 2008

The rate constants for the reactions of OH with CℓO, Cℓ2, and Cℓ2O at 298K have been determined in a discharge flow system using resonance fluorescence detection. The results are (9.1 ± 1.3) × 10−12, (5.5 ± 0.3) × 10−14, and (6.5 ± 0.5) × 10−12 (all in units of cm³ sec−1), respectively. In the reaction of OH and CℓO the reaction product HO2 has been detected indirectly, and a lower limit of 65% has been established for the OH + CℓO → HO2 + Cℓ channel.
Mechanical hysteresis loops of an anelastic solid and the determination of rock attenuation properties
Authors: Liu Hsi‐Ping , Peselnick Louis
Published: February 2008

We demonstrate that mechanical hysteresis loop shapes for a linear anelastic solid satisfying Q−1 ≅ constant over a wide frequency range are sensitive to the cycling stress waveform. Cusped or asymmetrical hysteresis loops are compatible with linear anelastic behavior for nonsinusoidal loading and do not necessarily imply a nonlinear attenuation mechanism. Because loop shape depends on the cycling stress waveform, we suggest that detailed observation of the stress time function, the hysteresis loop shapes, and experimental determination of the creep function over a time interval comparable to that of the cyclic loading experiment provide a direct and stringent test of the linearity of rock attenuation. Such detailed observation of hysteresis loop shapes during nonsinusoidal stress cycles can also provide a test in the linear range for theoretically constructed creep functions.
Sulfur chemistry in the E‐region
Authors: Swider William , Murad Edmond , Herrmann U.
Published: February 2008

Ions of mass 48 amu observed in the altitude range 94 km to 107 km during the 1976 Perseid meteor shower are interpreted as SO+ ions. It is suggested that the sulfur released in the E‐region by ablating meteoroids is rapidly converted to SO, this species being the principal form of sulfur above about 90 km, with [SO] ≫ [SO+] > [S] ≫ [S+].
Coherent anomalous resistivity in the region of electrostatic shocks
Authors: Lysak R. L. , Hudson M. K.
Published: February 2008

Evidence from the S3‐3 satellite indicates that parallel electric fields occur above 5,000 km altitude where electron drift velocity is highest for a current carrying plasma. Electrostatic ion cyclotron (EIC) turbulence is also observed in this altitude range. Previous models of current‐supported potential drops have neglected the role of turbulence. Large amplitude Alfvén waves can carry a current which drives the electrostatic ion cyclotron (EIC) mode unstable above 5,000 km. Anomalous resistivity associated with coherent EIC waves can support parallel electric fields in excess of 1 mV/m and may set up particle populations necessary to support oblique electrostatic shocks.
On the angle between the average interplanetary magnetic field and the propagation direction of plane large amplitude Alfvén waves
Authors: Lichtenstein B. R. , Sonett C. P.
Published: February 2008

The direction of the time averaged magnetic field
in a large amplitude Alfvén wave in the solar wind can be significantly different than the direction of the ambient interplanetary magnetic field
which is not directly observable. The theoretical properties of plane large amplitude Alfvén waves in the MHD approximation constrain the time averaged magnetic field to cluster around the direction of minimum variance
which is aligned with the wave normal
. Thusspacecraft magnetometer observations in the solar wind of minimum variance directions strongly peaked about the average magnetic field directionparticularly in the leading edges of fast streamsare entirely consistent with plane large amplitude Alfvén waves which have wave normals aligned with the directions of minimum variance. These observations also do not necessarily imply that geometrical hydromagnetic calculations for Alfvén wave propagation direction in the solar wind are incorrect. Howeverthere is a discrepancy between geometrical hydromagnetics theory and observations that IMF minimum variance directions tend to be aligned with the ideal Parker spiral instead of the radial direction.
Angular momentum of seasonally condensing atmosphereswith special reference to Mars
Authors: Philip J. R.
Published: February 2008

An atmosphere condensing and subliming seasonally about the poles of a planet loses and gains mass relatively more rapidly than it does angular momentum. An exploratory analysis indicates that a seasonal cycle of mean zonal winds is produced. These exert a seasonally variable torque on the surface of the planet which transfers angular momentum between the atmosphere and the solid planetinducing seasonal fluctuations in the planet's rotation. The analysis is applied to Mars. It yields seasonal variation in zonal wind direction consonant with that inferred from Viking Orbiter images of south polar regions; and it predicts cumulative seasonal fluctuations in the rotation of Mars of about ± 40 milliseconds. The measurement of such fluctuations appears feasible and would provide an independent source of insight into gross features of Martian meteorology.