bluuebunny/crossref_metadata_2025_split huggingface dataset:
The record of Late Pleistocene biogenic sedimentation in the eastern tropical Pacific Ocean
Authors: Lyle Mitchell , Murray David W. , Finney Bruce P. , Dymond Jack , Robbins James M. , Brooksforce Kathryn 
Published: February 2008

We have generated ∼300 Kyr records of biogenic opal, calcite, and organic carbon (Corg) for three cores in the eastern and central equatorial Pacific Ocean and have compared the records to determine whether common periods of biogenic sedimentation have occurred throughout the region. We find that Corg has been deposited in common pulses throughout the area, while opal has a much more local pattern of variation. Calcite varies regionally, but the record is shaped by superimposed dissolution and productivity processes. The most intense Corg peak occurs at 18 ka and can have greater than 2 times the Holocene Corg content. Other major Corg peaks occur 150 ka and perhaps at 280 ka. We have compared the Corg record in one of the cores, V19–28, to a model deepwater oxygen record developed from ∂13C data in the nearby V19–30 to test whether the Corg record has been mostly shaped by degradation or by the rain of organic matter from the euphotic zone. We found no coherence between the two records, implying that the Corg record is primarily a measure of productivity. By comparing the opal, calcite, and Corg records in V19–28, a core which is at or above the lysocline, we found that both increased calcite and opal deposition matches high Corg accumulation. We also found, however, that the calcite and opal records were uncorrelated, so that episodes of high opal deposition do not necessarily accumulate calcite rapidly. We hypothesize that at least two different plankton communities have been dominant in the waters above this site, one rich in opal‐secreting plankton and one more dominated by calcite producers. The opal‐rich plankton community was dominant during the intervals 10–15 ka and 35–60 ka.Supplement data (Table 2) is available with entire articleon microfiche. Order from American Geophysical Union,2000 Florida Avenue, N.W., Washington, DC 20009.Document P88001; $2.50. Payment must accompany order.
Experimental cumulus dynamics
Authors: Simpson Joanne , Simpson Robert H. , Andrews Donald A. , Eaton Max A. 
Published: February 2008

Cumulus dynamics is approached as an experimental science. Its development since 1947 is briefly reviewed and the current convection models described, in particular models evolved from laboratory studies, such as the ‘starting plume’.A preliminary series of experiments on real tropical cumuli has been conducted as a method for testing and improving models and for assessing the range of applicability of the laboratory results. A silver iodide seeding technique was used in a joint U. S. Weather Bureau‐U. S. Navy experimental program called Project Stormfury. Eleven tropical cumulus clouds were probed by instrumented aircraft on four days in August 1963. Six were seeded by dropping pyrotechnic silver iodide generators into their tops at intervals of 100 meters or less; five were studied as ‘controls.’ All control clouds died without further growth. Of the treated clouds, one was seeded by misunderstanding when its top was below 10,000 feet; it collapsed. The remaining five treated clouds grew. Of these, three were seeded at low enough elevations so that natural glaciation was unlikely; these are called the ‘test’ clouds. All three test clouds were observed to ‘explode’ in two phases. The first phase was a vertical growth of 10,000–20,000 ft, occupying 10–12 minutes; the second was a horizontal expansion, with the resulting giant cloud persisting more than 30 minutes. Using laboratory and theoretical results, we construct a dynamic model of the first growth phase and test it against the aircraft measurements and photographic data. The model predicts tower ascent rates, excess temperatures, and water contents, with environment and cloud base conditions as input. It predicts that unmodified clouds could not have attained the observed heights. Furthermore, the postulated effects of seeding (fusion heating, expansion, and altered precipitation fallout) are incorporated into the model and are shown able to account for the excessive growth of the test clouds following treatment. A set of extensive control calculations shows that the main deductions are insensitive to the existing uncertainties in the input data and the modeling assumptions. Improved experiments are suggested to resolve some of the basic questions in cumulus dynamics, as well as seeding effects.
A model for the evolution of strontium and lead isotopes in a dynamic Earth
Authors: Armstrong Richard Lee 
Published: February 2008

Contrasting interpretations of existing models of Sr and Pb isotope evolution can be eliminated with a model in which crustal material is recycled through the mantle. In this model the earth's crust and upper mantle (above approximately 500 km depth) are in a steady‐state system, and the volumes and bulk compositions of ocean, continent, and mantle have been nearly constant for at least the last 2.5 b.y. and probably for most of the earth's history.Sialic material is continuously eroded from continents into ocean basins and, as a consequence of this process, is isotopically homogenized. In continental‐margin orogenic belts and island arcs, the ocean basin, rise, and trench sediments are dragged into the mantle. Isotopic equilibration between sialic and simatic material takes place within the mantle, and the sialic material is returned to the continents or island arcs as juvenile‐appearing volcanics, thus completing the geochemical cycle. Most of the radioactive parent isotopes reside within the continental sial, whereas the mantle remains depleted and unable to sustain its observed isotope evolution.With this model it is possible to explain Pb isotope evidence of widespread ancient continents and common Pb evolution in a system which appears to have a very uniform U/Pb and Th/U ratio, even though most of the U and Th are highly enriched in the heterogeneous sialic crust. At the same time the model provides an explanation for Sr isotope evidence of continual addition of material to continents. Sr isotope evolution is dominated by the reservoir of Sr in the mantle; in contrast, Pb isotope evolution is dominated by isotopic mixing during erosion and sedimentation.The apparent differences in the evolutions of Sr and Pb isotopes are due to differing responses to various parts of the steady‐state cycle as a consequence of the differences in parent to daughter ratios in the sialic crust as compared with the upper mantle and in the degree of enrichment of parent and daughter products in the crust. Identical mathematical models may be used to describe the evolution of both isotope systems.
Marine seismicity
Authors: Macdonald Ken C. 
Published: February 2008

The use of sonobuoys and ocean bottom seismometers (OBS) to study oceanic earthquakes at close range has opened the way to more precise, more detailed studies of plate boundary seismicity and tectonics than ever before. Land‐based teleseismic studies of marine seismicity have continued to play a key role in mapping plate boundaries on a large scale and in unraveling plate kinetics and stresses.For monitoring microearthquake activity, sonobuoys (free floating hydrophones) are set out in arrays of three or more spaced several kilometers apart [Reid et al., 1973]. The data are telemetered back to the ship and recorded in real time.
Solar variability and terrestrial weather
Authors: Scherrer Philip H. 
Published: February 2008

The past four years have seen a growing interest in possible relations between terrestrial weather and solar or solar wind variability. Most of the work in sun‐weather (and climate) studies has sought correlations on three time scales: (1) climate changes over hundreds to thousands of years, related to longer term variations in the solar output, (2) climate changes correlated with the 22‐year solar cycle, and (3) weather variations on the scale of a few days, in response to transient solar events. While it has not been conclusively shown that there is a sun‐weather connection on any of these time scales, in each case there exists enough supporting evidence to suggest that further study is warranted.The most convincing evidence is that concerning long‐term climate changes which could be connected to changes in the solar luminosity below the threshold of all but the most recent observations, but still involving relatively large amounts of solar energy. Short‐term weather changes correlated with solar phenomena cannot be explained in this way, since the effect of such transient phenomena on the Sun's energy output is far too small. There remains, however, the possibility that such phenomena affect some sensitive links in the sun‐solar wind‐magnetosphere‐stratosphere‐troposphere causal chain, such that a small variation of the input can trigger relatively large‐scale consequences. Most of this review will be concerned with developments in the short‐time scale connections.
Research on snow and ice
Authors: Martinelli M. , Sommerfeld R. A. , Thomas Robert , Harrison Will , DenHartog S. , Frankenstein G. , Rango A. , Shartran Marilyn 
Published: February 2008

It seems to us that it would be arrogant to claim that this review contained everything of importance, nothing that was unimportant, with everything in proper balance in the complex and diverse fields which comprise the study of snow and ice. The best we can claim is that we tried to accomplish those objectives.Since this is to be a review of scientific research, most of the engineering studies were left out. In many cases, the decision was a difficult one, and each author drew the line somewhat differently in his section. Much of the basic research is inspired by practical problems and because of the complexities involved in dealing with snow and ice, many of the engineering studies are forced into basic research on one or another aspect of their problems. We therefore warn that people who want to delve deeply into some topic should also consult some of the engineering oriented sources.
Electromagnetic induction studies
Authors: Chave Alan D. , Booker John R. 
Published: February 2008

This report constitutes an attempt to review the major developments and identify important trends in the broad field of geophysical electromagnetic induction and related phenomena over the past four years. Following in the spirit of previous reports of this type [e.g.,Filloux, 1979;Hermance, 1983b;], the work of US researchers will be emphasized, although we will cover foreign research when appropriate. Many of the recent theoretical developments and the largest EM field program ever (EMSLAB) are the direct result of international cooperation, and strict adherence to the concept of national boundaries would result in an uninformative and incomplete review.Due to the fact that readers of this paper have diverse interests ranging from theory through field to laboratory studies, we have attempted to treat a variety of topics in EM induction and electrical geophysics. We begin by reviewing the state‐of‐the‐art in data collection, including new instrumentation. We continue by examining data analysis methods, with an emphasis on noise and bias reduction in the computation of the magnetotelluric and magnetic variations response functions. We then treat forward modelling developments, especially for two‐ and three‐dimensional induction problems. Recent progress has been made in EM induction inverse problems, and we assess the impact of this on the field. An overview of field measurements in North America is given, including the recent EMSLAB experiment which was carried out in 1985–1986 in the northwest US, southwest Canada, and contiguous offshore regions. This is followed by a review of developments in oceanic applications of EM principles.
Commission 4: Progress in Magnetospheric Radio
Authors: Fejer J. A. , Axford W. I. , Banks P. M. , Brace L. H. , Calvert W. , Carpenter D. L. , Farley D. T. , Gurnett D. A. , Kennel C. F. , Liemohn H. B. , Scarf F. L. 
Published: February 2008

Since the last report was written (in the spring of 1966), there has been a remarkable advance in our knowledge and understanding of the structure and behavior of the magnetosphere, especially with regard to the fundamental problems of the aurora and geomagnetic storms.The average structure of the quiet magnetosphere has been studied in considerable detail [Ness et al., 1966; Spieser and Ness, 1967; Behannon, 1968; Fairfield, 1968; Mihalov et al., 1968], and it has been shown that the tail and ‘neutral’ sheet extend well past the moon, and possibly to much greater distances [Ness et al., 1967]. The nature of the changes that occur in the geomagnetic field during disturbed periods has been observed, especially by magnetometers on the geostationary satellite ATS 1 [Brown et al., 1968; Cummings et al., 1968; Cummings and Coleman, 1968]. It has been found that the ring current, which is usually situated between 3 and about 10 RE depending on the degree of geomagnetic activity, commonly has a pronounced asymmetric component, with the maximum inflation of the geomagnetic field occurring in the evening sector.
Commission 8: Progress in Radio Noise of Terrestrial Origin
Authors: Pierce E. T. 
Published: February 2008

Since Commission 8 was only created on a provisional basis at the Munich General Assembly of URSI in 1966, and since also the U.S. National Committee does not maintain an organization for Commission 8 within the U.S.A., it seems appropriate for informative reasons to start this survey by listing the fields of scientific activity covered by the Commission. These are:1. Atmospherics, their source characteristics and location.2. Propagational influences on radio noise (with Commission 3).3. ELF noise from lightning (with Commission 4).4. Types of lightning flashes generating whistlers. Propagational effects, other than those in the whistler mode, influencing whistler characteristics (with Commission 4).5. Statistical properties of noise, noise interference with radio communications.6. Man‐made noise.This review will discuss work falling within the above fields of study carried out under U.S. auspices and described in 1966, 1967, and 1968. The survey will be confined to papers appearing in recognized journals and other sources of ready availability to which my attention has been drawn; reports of limited circulation and private information will not be considered.
Intermittency of Small‐Scale Structure
Authors: Dutton J. A. , Lane J. A. , Bean B. R. , Coulman C. E. , Fukushima M. , Montgomery A. , Swinbank W. C. 
Published: February 2008

The intermittency associated with fine‐scale structure and motion of the atmosphere was a central and significant theme of the papers and discussions of the meeting. The mathematical and physical problems raised by the intermittency of atmospheric phenomena appear to be difficult and complex.Most of the statistical analysis of atmospheric data at the present time is not specifically aimed at the study of intermittency. The major conclusion of the working group is that considerable information about the properties of intermittency could be obtained by suitable analysis of available data; the major recommendation is that this work be started.
Mercury: Epilith Physical Parameters and a Hermocentric Longitude Dependence of its 3.3‐mm Radiation
Authors: Epstein Eugene E. , Dworetsky Michael M. , Fogarty William G. , Montgomery John W. , Cooley Robert C. 
Published: February 2008

Observations of Mercury at 3.3 mm were made on 35 days in 1967 and 82 days in 1968 to (1) search for a dependence of the disk‐average brightness temperature TB on hermocentric longitude and (2) to provide constraints on the range of values of the thermal parameters of the epilith (subsurface layers) of Mercury. The observations can be represented by

urn:x-wiley:00486604:media:rds223:rds223-math-0001
where the statistical standard errors are indicated, ϕ is the phase angle, and l′ is the hermocentric longitude of the subearth point. The estimated over‐all system calibration error is 10%. The longitude dependence is demonstrated more clearly when individual phase variation curves are plotted for separate longitude intervals. The ratio of electrical to thermal skin depths (normalized by the wavelength) δ/λ (cm−1) is 1.3 (+ 1.4, ‐ 0.8); the error estimate is very conservative. The observations have been compared with the series of models by Morrison [1969]; of these models, the one with δ/λ = 1.37 and a conductivity independent of temperature best represents the data.
Design considerations for the Upper Atmosphere Observatory incoherent scatter radar
Authors: Evans J. V. , Moorcroft D. R. 
Published: February 2008

A new large incoherent scatter radar system has been proposed as the principal element in a binational center for studies of the upper atmosphere. The radar has been designed to yield a sensitivity comparable to the best now available and yet provide a latitude coverage of the F region of ±13°.The radar shall comprise a 100‐m diameter parabolic reflector antenna that can be tilted in the magnetic meridian plane by ±85° from the zenith. This antenna will be coupled to a UHF pulse transmitter with a peak power of 10 Mw, and will serve for both transmitting and receiving. Two auxiliary fully steerable antennas will be located northeast and northwest of the main antenna and will also receive the signals. This will enable the velocity of the ion drift to be studied, permitting measurements of neutral winds, electric fields, and fluxes of ions into or from the magnetosphere. The auxiliary antennas will form 10 coplanar pencil beams, so that these drift measurements may be made at 10 heights simultaneously.The paper describes how the above concept was developed and the work of selecting a site for the radar. By locating the main station near L = 4, and the auxiliary stations about 550 km distant, it will be possible to measure the electric fields in the F region over the range 3 ≤ L ≤ 8 to an accuracy of ±2 mv m−1. Thus, the radar should be able to map the electric fields produced by substorms at auroral and subauroral latitudes. In addition, the properties of the ionosphere and many parameters of the atmosphere will be determined over the altitude range 100 to 1000 km.
Report on the magnetic observations made at the magnetic observatory at Val‐Joyeux, France, during the total solar eclipse of May 17, 18, 1901
Authors: Moureaux M. Th. 
Published: February 2008

J'ai l'honneur de vous adresser, le relevé, de 3 minutes en 3 minutes, des valeurs de la déclinaison et des deux composantes H et Z, obtenue le 18 Mai dernier, de 2h à 9h du matin, temps moyen de Greenwich.Vous remarquerez que ces observations ne proviennent pas du Parc Saint‐Maur. Le développement des lignes de tramways électriques à trolley autour de l'observatoire a fait de grand progrès dans le deuxième‐semestre de 1900, et le dépouillement des courbes de variations n'y pré sente plus la garantie nécessaire.
Report on the magnetic observations made at the De Bilt meteorological and magnetic observatory near Utrecht, Holland, during the total solar eclipse of May 17, 1901
Authors: Snellen Maurits 
Published: February 2008

I am glad to be able to submit herewith the results of magnetic observations made in de Bilt Observatory during the total solar eclipse of May 17, 1901. I have but to add the following remarks :A. EYE‐OBSERVATIONS.Declination. A variometer was made use of, consisting of a telescope with scale and a freely movable magnetic needle, one side of which was polished as a mirror. The distance from mirror to scale was such that one division represented 0.502 of a minute.
Report on the magnetic observations made at Vlissingen (Flushing), Holland, during the total solar eclipse of May 17, 18, 1901
Authors: van Rijckevorsel  
Published: February 2008

These observations were taken on a plot of grass land just inside the sea dyke, a little to the southwest of the house of the observer, for the Royal Meteorological Institute. The spot, being too near to the passage of the steamers between the river and the sea, was not to be considered as a perfectly safe one for absolute measurements. However, as it was in every other respect exceptionally convenient, and as it was thought that, if good note were taken of every suspicious circumstance, disturbances due to this cause could be readily separated from those of a cosmic origin, the locality was retained.A temporary shed was erected for me by the kindness of Mr. P. Hoogenbooin, engineer of the “waterstaat.” I avail myself of this opportunity to express my gratitude to him, as also to the gentlemen who volunteered to assist me, Mr. Engelenberg, C. E., my former very much valued assistant in Brazil; Mr. C. Schoute, the able assistant in the physical laboratory of Groningen University, who assisted me, with the kind permission of Professor Haga, and Messrs. H. I. I. Kress and H. Az. de Ruyter, the former a computer of the Meteorological Institute at de Bilt, and the latter, the observer at Vlissingen.
Die construction des geometrischen bildes des gauss'schen potentials, als methode zur erforschung der Gesetze des Erdmagnetismus
Authors: Umow N. 
Published: February 2008

Der Verfasser glaubt zu leicht fasslichen und scharf formulierten Gesetzen des Erdmagnetismus zu gelangen, indem er statt der Beschreibung einer Menge von magnetischen Curven, nur wenige geometrische Gebilde einführt, deren gegenseitige Lage und zeitliche Veränderungen zu erforschen sind. Die Gauss'sche Entwickelung des erdmagnetischen Potentials nach Kugelfunctionen giebt eine Reihe von magnetischen Potentialen 1., 2., 3., 4. Ordnung, welche respective 1, 2, 3, 4 Axen besitzen und ebenso jede ein magnetisches Moment derselben Ordnung (s. Maxwell, “Electricity and Magnetism” Part I, Art. 129 c).Wollen wir mit V das erdmagnetische Potential auf der Erdoberfläche, mit R den Radius der Erde bezeichnen, so haben wir die Reihe
eine Kugelflächenfunction nter Ordnung ist, mit 2nj+1 Constanten, von denen 2n die Lage ihrer n Axen bestimmen und eine das Moment nter Ordnung bezeichnet. Es seien μj der Cosinus des Winkels einer Axe mit dem Radius eines Punctes P der Erdoberfläche, λij der Cosinus des Winkels zwischen den Axen i, j, und δn das Moment der Function. So haben die Kugelflächenfunctionen folgende Ausdrücke:
Alle Axen gehen durch das Centrum der Erde. Wenn einige Axen in eine und dieselbe Richtung fallen, erhalten wir eine multiple Axe, deren Ordnung der Zahl der zusammenfallenden Axen gleich ist.
Specific electrical conductivity of the air at sea
Authors: Burbank J. E. 
Published: February 2008

Although many observations of potential and dispersion have been made along the sea shores very little has been done at a distance from land. A. Boltzmann,1 in the summer of 1904, obtained some observations on a voyage from Germany to New York and return. He obtained a high ratio of positive to negative ions in the atmosphere, especially at great distances from land.During a recent voyage of the Leyland Line Steamship “Cestrian” from Liverpool to Boston, the writer was able to obtain, under the auspices of the Department Terrestrial Magnetism of the Carnegie Institution of Washington, some observations of the specific electrical conductivity of the air by means of a new form of instrument recently devised by Dr. H. Gerdien, of Göttingen, Germany.2