bluuebunny/crossref_metadata_2025_split huggingface dataset:
Splitting stationary sets in
Authors: Usuba Toshimichi 
Published: January 2012

AbstractLetAbe a non-empty set. A setis said to be stationary inif for everyf: [A]<ω→Athere existsxϵSsuch thatx≠Aandf“[x]<ω⊆x. In this paper we prove the following: For an uncountable cardinal λ and a stationary setSin, if there is a regular uncountable cardinalκ≤ λ such that {xϵS:x∩κϵκ} is stationary, thenScan be split intoκdisjoint stationary subsets.
Borel reductibility and Hölder (α) embeddability between Banach spaces
Authors: Ding Longyun 
Published: January 2012

AbstractWe investigate Borel reducibility between equivalence relations E(X; p) = Xℕ/ℓp(X)'s where X is a separable Banach space. We show that this reducibility is related to the so called Hölder(α) embeddability between Banach spaces. By using the notions of type and cotype of Banach spaces, we present many results on reducibility and unreducibility between E(Lr; p)'s and E(c0; p)'s for r, p Є [1, +∞).We also answer a problem presented by Kanovei in the affirmative by showing that C(ℝ+)/C0(ℝ+) is Borel bireducible to ℝℕ/c0.
Dynamic topological logic of metric spaces
Authors: Fernández-Duque David 
Published: January 2012

AbstractDynamic Topological Logic is a modal framework for reasoning about dynamical systems, that is, pairs 〈X, f〉 where X is a topological space and f: X → X a continuous function.In this paper we consider the case where X is a metric space. We first show that any formula which can be satisfied on an arbitrary dynamic topological system can be satisfied on one based on a metric space; in fact, this space can be taken to be countable and have no isolated points. Since any metric space with these properties is homeomorphic to the set of rational numbers, it follows that any satisfiable formula can be satisfied on a system based on ℚ.We then show that the situation changes when considering complete metric spaces, by exhibiting a formula which is not valid in general but is valid on the class of systems based on a complete metric space. While we do not attempt to give a full characterization of the set of valid formulas on this class we do give a relative completeness result; any formula which is satisfiable on a dynamical system based on a complete metric space is also satisfied on one based on the Cantor space.
Performance Studies in Canada
Authors: Alvarez Natalie 
Published: January 2012

Performance Studies in Canada (Introduction to Views and Reviews), by Natalie AlvarezIn Search of PS North: Performance Studies in Canada, by Laura LevinOutskirts to Mainstream?: Performance Poetry on the Move, by Naila Keleta-Mae(No) Performance Studies in Canada, by Susan BennettTowards Locating the Alchemy of Convergence in the Native Theatre Classroom, by Jill CarterÉtudes théâtrales and Performance Studies in Quebec, by Erin HurleyCanadian Theatre Review Constitutes Performance Studies, by Ric Knowles
An Empirical Correction to the Barotropic Forecast
Authors: Williams Scott 
Published: January 2012

An investigation of error fields in 30 consecutive barotropic forecasts for the 500 mb surface has been performed. It is found that the error fields show persistence in the time to such an extent that a correction consisting of the mean error field for a number of preceding forecasts can be applied to a barotropic forecast with advantage. The improvement of the forecast depends upon the number of preceding forecasts included in the mean error field. The greatest increase in accuracy is found when 10–15 preceding forecasts are contributing to the correction field. The 24 hour forecasts are improved to the greatest extent by the correction, but the 48 hour-forecasts also show a significant increase in accuracy. The same is true to a smaller extent for the 72 hour-forecasts.
In section 3 an investigation is made as to whether the height change obtained by making barotropic forecasts from the time-averaged map for the period investigated or from the normal 500 mb map for the corresponding month can be used with the same success as the correction used in section 2. It it found that the correction from the mean chart consistently improved the forecasts. The overall effect is, however, small. The correction obtained from the normal chart did not affect the accuracy of the forecasts appreciably.
Scale Consideration of Planetary Motions of the Atmosphere
Authors: Burger Alewyn P. 
Published: January 2012

The application of scale considerations to atmospheric motions indicates that the equations hitherto used in numerical prediction are unfit for detailed prognosis on the planetary (or very large) scale.
It appears that the dominant terms of the vorticity equation in this case are the divergence term and the β-term, which means that the vorticity equation here displays the same quasistationary character as the undifferentiated equations of motion. An attempt at expressing more than the quasistationary character of the planetary flow leads to undue complication of the equation, even requiring inclusion of the twisting terms.
As for the application of the geostrophic approximation, it is confirmed that the β-term in the divergence equation is important in the representation of the planetary scale. Further, though metrical terms (containing the reciprocal of the earth's radius) are important on this scale in spherical coordinates, it is shown that, in using the geostrophic approximation and a square grid on a conformal plane projection of the earth's surface, no metrical terms appear.
Remarks are also included on a relation of Prandtl, which loses its validity on the planetary scale, and also on the use of the Richardson number to characterize large-scale atmospheric motion.
The Break Down of Zonal Circulation during the Period January 8 to 13, 1956, the Characteristics of Temperature Field and Tropopause and its Relation to the Atmospheric Field of Motion
Authors: Defant Friedrich 
Published: January 2012

I. An introductory outline of earlier work (Fr. Defant and H. Taba, 1957, 1958, 1958) on hemispheric changes in the type of General Circulation by means of tropopause maps is presented to make the reader familiar with the main features of tropopause and its intimate relation to the main windcores of the westerlies. The prehistory of the period from Jan. 8 to 13, 1956, which we studied in this paper, is described in detail.
II. Tropopause maps for each day (Jan. 8 to 13, 1956) are presented. By means of these maps it was shown, how the zonal type of Circulation (zonal with respect to a zonal polarfront jet) changes during this period into a meridional (meandering) type. The behaviour of subtropical jet (in a characteristic way different from that of polarfront jet) is simultaneously discussed.
III. A selection of soundings with respect to the breaklines in the tropopause level or according to the location of the belts of maximum wind of the westerlies was made for each day. Different characteristic groups of soundings (different with respect to the total vertical temperature distribution and the form as well as the height of tropopause) are discussed and characteristic mean soundings for each group are computed.
IV. A computation of standard deviation of the individual vertical temperature distributions from the mean one for each group is presented. An important conservatism of the sounding type in each group is shown.
Meridional temperature differences between different groups inform the reader about the possible locations of baroclinity in tropo- and stratosphere.
V. A statistical investigation of tropopause level by use of 2,513 atmospheric soundings from Jan. 1 to 13, 1956 is presented. The structure of tropopause is discussed.
VI. A synoptic vertical cross section clarifies the relationship between subtropical break in the tropopause level and the existence of the subtropical jet. Important aspects of form of subtropical jet are outlined.
The Diurnal and the Semidiurnal Atmospheric Solar Tide
Authors: Thrane P. 
Published: January 2012

World-wide oscillations generated by the sun are examined by applying the hydrodynamical equations to a rotating spherical model atmosphere. The oscillations are described as small perturbations on a static state in which the atmosphere is at rest relative to the earth's surface. Let q denote the heat supplied per unit mass and unit time. Let p and α denote perturbations in pressure and specific volume of a particle of air and let the displacement of the particle from its equilibrium position be given by θ, φ z, i.e. the variations of its colatitude, longitude and height, respectively. Consider the simplest oscillation of 24-hour period rotating with the sun:
q̇ = Cq sin (Ψ + nq), x = Cx sin (Ψ + nx),
where Ψ denotes local time reduced to angle and x denotes any one of the variables p, α, z, φ, θ. The amplitudes and phase angles are variable with latitude and height. q, p, α, z, Ψ are symmetric with respect to the equator.
It is shown that, if Ca, Cq are given as analytic functions of latitude and height, then the quantities Cx, ηx are determined by the equations of motion, the equation of continuity and the first law of thermodynamics.
Considering in like manner the simplest oscillation of 12-hr. period rotating with the sun:
q̇ = Cq sin (2Ψ + nq), x = Cx sin (2Ψ + nx),
we find that, when Cq, ηq are given, the Cx, ηx satisfying the above mentioned equations contain an arbitrary function of height, f(Z).
The absence in the first case of an arbitrary function which might be adapted to boundary conditions, may partly explain the weak development of the 24-hr. wave as a global phenomenon in spite of the marked diurnal period in the heat supply q.
A special case of non-linear equations is considered in order to study certain relations between the 24-hr. and the 12-hr. wave. A heat supply of 24-hr. period of the form q̇ = Cq sin (Ψ + ηq) can generate a wave of 12-hr. period.
Sur le taux de variation adiabatique de la température en fonction de la pression dans une masse d’air contenant un cristal de glace sphérique
Authors: Dufour L. 
Published: January 2012

The formula giving the rate of variation is established under the assumption: 1) that the transformation is adiabatic (equ. 8); 2) that this transformation is reversible (equ. 15).
After having examined the order of magnitude of the different terms of the equations in order to determine those which can be neglected one can deduce the rate of variation (equ. 18).
One can show that the formulae in the classical thermodynamics giving the rate of variation for saturated (equ. 21) and for dry air (equ. 22) are special cases of the general formula.
On Systematic Errors in the Least Squares Regression Analysis, with Application to the Atmospheric Effects on the Cosmic Radiation
Authors: Trefall Harald , Nordö Jack 
Published: January 2012

It is shown that if the variables employed in a least squares regression analysis are subject to random errors of measurement, the expectation values of the partial regression coefficients, of the partial correlation coefficients and of the multiple correlation coefficient may all differ from those which would have existed, had no errors been present. If there is no intercorrelation between the errors of different variables, random errors in a given variable always reduce the numerical expectation values of the corresponding partial regression and correlation coefficients. Coefficients corresponding to other variables may, however, be influenced in either direction depending on the intercorrelations between the variables. The expectation value of the multiple correlation coefficient is reduced by errors in any variable. The general case, in which the errors of different variables are intercorrelated, has also been briefly discussed.
The problem of determining the atmospheric effects on the cosmic radiation is then discussed. It is shown that some previously unexplained discrepancies between empirical and theoretical estimates, and also between empirical estimates obtained from the study of day-to-day variations, and such obtained from the seasonal variations of the cosmic-ray intensity, are probably due to systematic effects of random errors in the aerological data employed in the regression analysis.
Estimates of error variances and covariances of aerological data from the upper troposphere and the lower stratosphere have been obtained by analysing differences between data from two closely situated stations on Spitzbergen. They have then been used to obtain corrected estimates of the cosmic-ray atmospheric effects, which are now found to agree fairly well with the theoretical ones.
The Yearly Circulation of Chloride and Sulfur in Nature; Meteorological, Geochemical and Pedological Implications. Part I
Authors: Eriksson Erik 
Published: January 2012

The circulation of air borne oceanic constituents is discussed to the extent available data permit. From data on sea salt particles in the atmosphere and their fall rate it is estimated that they are produced at a rate of the order of magnitude 1000 million tons a year over the ocean areas. About 90 per cent of this is precipitated over the oceans, the rest is carried into continents and is brought back to the sea in rivers. The estimated residence time for sea salt particles in the atmosphere is only a few days, higher for smaller particles, which lose their identity through coalescence, and lower for larger particles, lost by rainout or fallout. From the rate of production of sea salt particles in breaking waves it is concluded that about 0.3 per cent of the ocean areas is covered by breaking waves. On land the residence time of sea salt may vary from a few years in peripherally, drained humid areas to thousands of years in arid areas or areas without peripheral run-off.
Geochemical balance computations indicate that a major part of the sulfur in the atmosphere is of oceanic origin but does not originate as chloride through spray emitted from breaking waves. Of chemical reactions taking place in the atmosphere between sea salt constituents the release of HCl from sea salt particles due to absorption of oxidized sulfur dioxide seems to be quantitatively important and mainly responsible for variations in the Cl/Na ratio in precipitation. The deposition of chloride in precipitation over continents shows nicely the main areas of inflow of maritime air. Dry deposition of sea salt components seems to be an important process. The rate of which these constituents are carried to the ground from the air is about 1–2 cm per second, a figure concordant with the turbulent nature of air close to the ground.
As for proportions of sea salt components in precipitation some fractionation processes seems to take place at the sea surface (probably involving organic matter derived from surface films). In typical maritime areas there is always an excess cations over inorganic anions suggesting association of some cations with organic acid material in precipitation. The presence of sea salt components in groundwater can be taken advantage of in the estimation of regional evaporation using chloride as an indicator. Reduction of sulfur in groundwaters can cause precipitation of calcium and magnesium, thus modifying the chemical properties of groundwaters considerably. The role of air borne sea salt components for the development and properties of soils is discussed in principle.
Tropospheric Geopotential and Velocity Variances over the Arctic
Authors: Godson Warren L. , MacFarlane M. Aylmer 
Published: January 2012

As an elaboration of recent studies by BUELL (1954, 1957) and JENKINSON (1956), the relation between the standard deviation of contour height and the vector standard deviation of geostrophic wind velocity is formulated, both for point values (variations in time) and for chart values (variations in space). The relation between wind and contour variances for a simple schematic contour pattern is examined, from the point of view of both space and time statistics.
The relationship between the space variance of contour height (S2) and the space variance of the geostrophic wind (σ2) was evaluated over the Arctic (north of about 60° N) at the 500-mb level. A high degree of correlation was found to exist between these two quantities, although the form of the relationship (σ2 proportional to S) did not agree with the results of previous studies (BUELL, JENKINSON, loc.cit.) of time variances. However, a reanalysis of such data for northern latitudes yielded results virtually identical with those of the present study.
In both cases, the standard error of estimate was too large to enable one to calculate accurately the wind variance from the height variance for synoptic purposes, but the relationships do allow climatological estimates (seasonal, etc.) to be made of the mean kinetic energy and of the size and amplitude of the dominant wave systems.
A Study of the Dynamics of a Stratified Fluid in Relation to Atmospheric Motions and Physical Weather Prediction
Authors: Arnason Geirmundur 
Published: January 2012

The persistent skill of the 500 mb barotropic forecasts in routine numerical weather prediction is emphasized in contrast to the failure of baroclinic prediction models to furnish useful low-level forecasts. In the belief that this failure is first of all a result of lack of control mechanism capable of ensuring well-behaved development, the author suggests the possibility of designing a multi-level prediction model capable of realistic displacements of pressure systems but containing no mechanism for development.
For this purpose, a one-layer model consisting of a stratified fluid is exposed to theoretical analysis by means of the technique of small perturbations. This analysis shows that owing to the stratification of the fluid, the perturbations have a vertical structure resembling that of the atmosphere. The dynamics of the perturbations is studied in some detail. One of the results is an expression for wind divergence applicable to non-linear prediction. It is shown that the stratified model is capable of more realistic displacement of planetary waves than either version of the barotropic models (Rossby, 1939; Cressman, 1958).
More important than this improved control of the planetary waves is the model’s apparent capability of realistic displacements of pressure systems at low levels. In application, however, there is the problem of how to best interpret concepts from the perturbation theory such as basic current, thickness of the layer, and the static stability of the basic flow.
Circulation and Energy Balance in a Tropical Monsoon
Authors: Berson F. A. 
Published: January 2012

Mean monthly meridional and zonal circulations in the region of the Indonesia-Australia summer monsoon and associated transfers of heat energy are investigated using upper air soundings, rainfall and other data from two seasons. Daily sounding data are used to determine also the eddy flux of latent heat. A large increase of meridional circulation strength and energy transfer from November to December on the northern side of the monsoonal trough suggests that establishment of the regime is associated with a comparatively abrupt southward shift and intensification of the Northern Hadley cell in the relevant longitude sector.
When the monsoon has become established latent heat relase in the region exceeds net export of sensible heat from it by a comparatively small amount. These quantities dominate the remaining ones in the heat balance, viz. net radiative cooling in the troposphere and sensible heat transfer from the ocean. Items in the heat budget are compared with those obtaining during the pre-monsoonal regime in the area and on the winter side of the equatorial trough zone at large, the latter according to RIEHL and MALKUS (1959).
Gain of sensible heat is also assessed separately for the lower and upper troposphere in terms of gain or loss of internal energy, the work done by horizontal pressure gradient forces and by vertical pressure gradient forces (gain of potential energy). The vertical upward flux of energy across mid-tropospheric level is deduced and the importance of buoyancy in bringing about this flux is indicated.
Interaction of a hurricane with the steering flow and its effect upon the hurricane trajectory
Authors: Kasahara Akira , Platzman George W. 
Published: January 2012

If the steering flow is defined at all times as the residual after subtraction of an axially symmetric vortex that moves with variable speed but invariant shape, then interaction terms appear in the prediction equation that governs the steering flow. The vortex is taken as the one that minimizes the kinetic energy of the steering flow in the initial data. The propagation velocity of the vortex is defined in such a way as to minimize interactions between vortex and steering flow, and is found to have a second-order dynamic part proportional to the gradient of steering-flow absolute vorticity. It also is shown that in a uniform steering flow, interaction terms give rise to an acceleration of cyclonic vortices in the direction of increasing steering-flow absolute potential vorticity.
Results are presented for numerical computations made from 600-mb data on hurricane Betsy 1966 with the proposed prediction model with and without the interaction terms. The interaction terms remove the major part of a systematic rightward bias found in earlier hurricane-trajectory forecasts based upon steering-flow models.
The Structure of Mean Circulations
Authors: James R. W. 
Published: January 2012

A discussion of the best mode of expressing the facts of the mean westerly flow in temperate latitudes parametrically leads to the result that over North America the shape of the vertical geostrophic westerly wind profile is nearly invariant with respect to time and place. The vertical wind profile can be expressed in terms either of the change pressure-gradient with height, or of contour-height gradient with pressure-level. In either case the profile shape is characteristic, and varies little with season, longitude or latitude over North America.
The intensity of the mean circulation varies rythmically with season, but that for any one month may vary markedly from year to year.
The profile shape for an oceanic region differs from that of a land region such as eastern North America in exibiting a lower ratio of high-level to surface wind, and in being much more variable from month to month.
It is shown that the pressure-difference at 7 km between two latitudes, or the difference in mean height of the 200 mb surface gives a measure of the total geostrophic momentum between those latitudes. The square of these quantities also gives a measure of the total kinetic energy of the westerlies between these two latitudes.
Age Determination of Pacific Chalk Ooze by Radiocarbon and Titanium Content
Authors: Arrhenius G. , Kjellberg G. , Libby W. F. 
Published: January 2012

Measurements have been carried out on the average radiocarbon activity of a sediment core of eupelagic chalk ooze and the age of the lower boundary was calculated by integration of the radiocarbon decay function.
In such cores where constancy of the rate of minerogenous accumulation is indicated and can be checked by lateral control, the titanium content, calibrated in terms of absolute age by means of radiocarbon measurement, can be used for dating as far back in time as the constancy of the rate of minerogenous sedimentation can be proved.