bluuebunny/crossref_metadata_2025 huggingface dataset:
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.
Long Term Changes in the Daily Variation of Cosmic Ray Intensity
Authors: Venkatesan D. , Dattner A.
Published: January 2012

Cosmic ray measurements at different stations for the period 1937–55 are analysed. The diurnal variation is found to be a world-wide phenomenon, thus giving the anisotropy of the primary radiation and its correlation with solar and geomagnetic activities.
On Certain Integral Constraints for the Time-Integration of Baroclinic Models
Authors: Wiin-Nielsen Aksel
Published: January 2012

On the basis of the general property of the vorticity equation that the net-production of vorticity vanishes in the average over a closed region it is in section 3 shown that provided this property should be fulfilled one should at the same time include or exclude the vertical advection of vorticity and the twisting effect in two-parameter models used for numerical weather prediction. The advection with the divergent part of the horizontal wind and the part of the divergence term which depends upon the relative vorticity has a similar opposing effect in the mean production of vorticity for the non-divergent level, but a vanishing production of thermal vorticity can only be obtained if one either include the advection with the divergent wind and the complete divergence term or exclude the advection with divergent wind, the part of the divergence term depending upon the relative vorticity and consider the Coriolis parameter in the remaining part of the divergence term as a constant. In section 4 it is shovn that the mean value over a closed region of the relative topography remains constant in a two-parameter model provided the vertical stability parameter is constant. It is further shown that the thermodynamic equation in the adiabatic case is far less sensitive to inconsistencies than the vorticity equation. Section 5 contains a comparison between the growth of “rotational energy” in general and simplified two-parameter models. It is shown that already the most simple model contains approximately the correct growth rate. A similar comparison with respect LO the rate of “occlusion” is made in section 6 with a similar result. Section 7 contains a comparison between the theoretical results and the experience from practical computations. The mechanism for production of kinetic energy of the nondivergent part of the wind is discussed in section 8.
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.
Morskoi Atlas (Marine Atlas), Vol. II Fiziko-Geograficheskiy (Physical Geography)
Authors: Dubacha Harold W.
Published: January 2012

In 1956 copies of the “Morskoi Atlas,” Volumes I and II, were purchased by the U.S. Hydrographic Office from a New York bookstore. Volume II of the atlas is of particular interest because it contains a comprehensive treatment of the marine environment of the earth.
On the Interpretation of Ionization in the Lower Ionosphere Occurring on Both Day and Night Side of the Earth within a Few Hours after some Solar Flares
Authors: Hultqvist Bengt
Published: January 2012

Some strong solar flares cause very strong absorption in high geomagnetic latitudes on both day and night sides of the earth. The absorption effect is measurable a few hours after the solar flare outbreak. It is shown that the effect can be interpreted as being caused by a high-energy-ion beam of very small density, emitted from the sun and moving in Störmer orbits.
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.
On Critical Regimes and Horizontal Concentration of Momentum in Ocean Currents with Two-Layered System
Authors: Ichiye Takashi
Published: January 2012

The principles of minimum momentum transport and minimum energy which are commonly used in hydraulics of an open channel are applied to the current in a two-layered ocean, in which the geostrophic relation holds. For a flow of a finite width over the motionless lower layer these principles with the constancy of total volume transport predict the critical values of current width and upper layer thickness which will be attained by the flow after losing momentum or energy by friction. The two principles lead to critical regimes with almost similar order of magnitude. The critical width thus determined is less than 100 km and the upper layer disappears at the left edge of the flow in the critical regime, being in good agreement with the Gulf Stream and the Kuroshio. The analysis is also applied to a model of vertically continuous density stratification. Further the momentum transport of double jets often observed in actual currents is shown to be the minimum among multiple jets, next to a single jet corresponding to the critical regime.
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.
Some further Results on Convective Currents
Authors: Haltiner G. J. , Chase E. M.
Published: January 2012

An earlier theory of steady state, saturated convective currents is modified to include the drag of the condensed liquid water on the rising air. The system of equations is numerically integrated for several cases in which the entrainment is allowed to assume negative values. Results appear to indicate improvement over the earlier model.
Application of Numerical Prognostic Heights to Surface Temperature Forecasts
Authors: Klein William H. , Lewis Billy M. , Crockett Curtis W. , Enger Isadore
Published: January 2012

Multiple regression equations for predicting 5-day mean surface temperature in the United States from prior anomalies of 700-mb height and surface temperature are derived by a screening procedure for fall, winter, and spring. The heights required for an objective forecast are approximated with the aid of daily numerical prognoses prepared at the 500-mb level by a barotropic model and at the 700-mb level by a baroclinic model; the required temperatures are estimated by combining observed daily values with short-range prognoses. The resulting objective temperature predictions are verified on independent data at a number of cities, and the sources of error are analyzed. Comparison is made with forecasts prepared by local temperature persistence, continuity of error, and conventional methods. It is concluded that the objective method can produce in a short time temperature predictions which have appreciable skill beyond persistence. Thus a valuable aid and base for further improvement has been made available to the forecaster.
The Exchange of Kinetic Energy between Larger Scales of Atmospheric Motion
Authors: Saltzman Barry , Fleisher Aaron
Published: January 2012

The rate of transfer of kinetic energy between the different scales of eddies of the 500 mb geostrophic wind has been measured for each day of 1951. In the mean, there is a net transfer from intermediate (cyclone) scales to both longer and shorter scales.
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.
The baroclinic instability of a “2½ dimensional model atmosphere” in which the upper level is non-divergent
Authors: Mihaljan J. M.
Published: January 2012

The baroclinic instability of a “2½ dimensional model atmosphere” is examined by the method of small wave perturbations. The model is very similar to that of ESTOQUE (1966) but somewhat less restrictive. It is shown that the assumption of an upper isobaric level of non-divergence leads to the following unusual results: (1) Instability is impossible if the Rossby beta-parameter is zero. (2) The vertical shears required for instability increase linearly with the beta-parameter. (3) Only positive vertical shears lead to instability. (4) The instability is of the linear type as opposed to the more usual exponential type.
Note on the exchange rate between the northern and southern atmosphere
Authors: Junge C. E.
Published: January 2012

Differences in CO2 and CH3T data for the northern and southern hemispheres are used to estimate the net exchange rate between the hemispheres. The most likely exchange rate is found to be 0.3–0.5 year–1.
Fluctuations of climate and of general circulation of the atmosphere in extra-tropical latitudes of the Northern Hemisphere and some problems of dynamic climatology
Authors: Dzerdzeevskii B.
Published: January 2012

A problem of the methods involved in studying long-period climatic variations in the northern hemisphere is discussed. The data obtained at individual points are compared with circulation characteristics (ratio of the zonal and meridional components) for the whole hemisphere. In analysing the variability of the circulation use is made of the system developed by the author and his co-workers for typifying atmospheric processes over the hemisphere for the past 56 years. In view of the good agreement previously obtained between the long-period variations of these circulation types and solar activity it is considered that a continuous chain (sun-general circulation-climate of individual points) is set up by means of such a dynamic-climatological analysis. The existence during the first half of the 20th century of periods—“epochs”—differing in both circulation characteristics and average level of climatic values is established. The conclusion is drawn that it is for such epochs that climatic calculations and climatic classification should be made.
Relationship of central pressure of hurricane Esther (1961) and the sea surface temperature field
Authors: Perlroth Irving
Published: January 2012

In this report variations of central pressure of hurricane Esther are related to the sea surface temperature patterns along its track. There appears to exist a distinct relationship between central pressure variations, wall cloud intensity, and hurricane intensity to the temperature of the water over which it passes. The storm's central pressure appears to deepen over warm water and fill over cooler water.
A note on the propagation of tidal waves in a viscous fluid in a rotating system
Authors: Duty R. L.
Published: January 2012

The results presented in this note are an extension of classical results on tidal wave propagation. It is shown that the classical results obtained for an inviscid fluid are slightly modified when small viscosity is present. When large viscosity is present, however, it is shown that viscosity and rotation can interact to either prohibit, or encourage, wave propagation.
On the generation of wind streaks on the sea surface by action of surface film
Authors: Welander Pierre
Published: January 2012

It is difficult to explain the generation of wind streaks and the associated cellular motion in the sea by convective or shearing instability. It is suggested that the streaks are primarily caused by dynamic effects of an organic surface film. Variations in the film concentration over the sea surface have a feedback effect on the wind field through the associated variations in suface roughness, and a self-amplifying system can be obtained. Observations of wind streaks in the Baltic give some support for the idea. In particular, it was observed that the streaks and the associated motions disappear when the surface film was destroyed by rain.
On a method for parametric representation of the state of the atmosphere
Authors: Holmström Ingemar
Published: January 2012

In a discussion of possible parametric repreeentations of the state of the atmosphere it is shown that the common use in numerical prediction models of parameters directly given by the height of certain pressure levels is inefficient. An alternative method is suggested where atmospheric variables are expanded in empirical orthogonal functions. The expansion takes for height data the form Z (x, y, t, p) = F0 (p) + ∑1K zk (x, y, t) Fk (p), where F0 (p) represents an area average and the functions Fk (p) and the coefficients zk (x, y, t) are determined using a least square residual condition and a condition of finality. Expansions of this type have been made on height and wind data for eight days. Results from these expansions are given. The convergence is found to be surprisingly rapid and two or at most three modes are sufficient for an accurate description of the large scale structure of the troposphere and the lower stratosphere. The form of the pressure functions in the lowest modes is found to be approximately conservative. Finally, maps of the coefficient fields are presented and a brief discussion given of a case of pronounced baroclinic development.
Determination of the stream function from vertical motion
Authors: Nemchinov S. V. , Musaeljan Sh. A. , Sadokov V. P.
Published: January 2012

By means of the solution of the linearized equation for the vertical components of the vorticity, the stream function is estimated using the data for the vertical motion. The exact method for solving the finite-difference analogue of the differential equation by spherical coordinates is discussed.
Influence of adsorption on the formation of embryo lunules
Authors: Miloshev G. , Krastanov L.
Published: January 2012

This paper discusses from a theoretical standpoint the influence of the adsorption of capillarly active substances on the formation of liquid embryo lunulesl on the surface of imperfectly wetted spheric nuclei. By considering the thermodynamic potential of the system “nucleus-water vapour” before and after the formation of an embryo on the nucleus and, by using the method developed by Kaischew & Mutaftschiew, an expression is derived for the work of formation of an embryo lunule in the presence of adsorption. By taking into account the relation between the contact angle, changed by the decrease in specific surface energy due to adsorption, a general expression is given. This relation is expressed in terms of supersaturation, initial contact angle between the pure nucleus and the liquid, variation in specific surface energy caused by adsorption and between the radius of the nucleus and the radius of the embryo when no adsorption is involved. This formula is most general and under corresponding boundary conditions changes to all known expressions for the work of formation of embryos in homogeneous water vapour on a plane substratum and perfectly and imperfectly wetted condensation nuclei, respectively to those given by Gibbs, Volmer, Krastanov and Fletcher, as well as to the work of formation of embryos in homogeneous water vapour and plane substratum in the presence of adsorption, derived by Kaischew & Mutafschiew. In addition, this formula enables us to discuss embryo formation on condensation nuclei many times larger than the embryo formed at a corresponding supersaturation.
Distribution of sulfur and chlorine over Europe
Authors: De Bary E. , Junge C.
Published: January 2012

Maps showing the mean concentration of sulfar and chlorine in air and precipitation over north western Europe in summer and winter have been constructed. Exess SO4 – S has been computed on the basis of the assumption that chloride is a conservative property of sea spray particles and that there are no other sources for chloride than sea spray. Finally, maps showing the ratio of concentration air/precipitation for sulfur and chlorine are presented.
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.
Techniques for rocket sampling of noctilucent cloud particles
Authors: Soberman R. K. , Chrest S. A. , Manning J. J. , Rey L. , Ryan T. G. , Skrivanek R. A. , Wilhelm N.
Published: January 2012

Particle sampling experiments utilizing sounding rockets were conducted in northern Sweden during August of 1962. Two successful flights were achieved, one in the presence of noctilucent clouds and one when no such clouds could be visually observed from the ground or from aircraft. The collecting surfaces were exposed between the altitudes of approximately 75 and 98 kilometers during ascent only. The instrumentation and performance of the rockets is discussed.
Sampling of noctilucent cloud particles
Authors: Hemenway C. L. , Soberman R. K. , Witt G.
Published: January 2012

Sampling of noctilucent cloud particles by means of sounding rockets has been successfully carried out from northern Sweden in the Summer of 1962. Two successful flights were achieved, one in the presence of noctilucent clouds and one when no such clouds could be visually observed from the ground or from aircraft. The collecting surfaces were exposed between the altitudes of approximately 75 and 98 kilometers during ascent only. The particle concentration in a vertical column through the noctilucent cloud display is found to be greater than 8 × 1010 particles per square meter which is at least one thousand times greater than in the case when no clouds were observed. The integral size distribution of the cloud particles is of the form N = Ad-p where 3 < p < 4. A significant fraction of the collected cloud particles had a volatile coating prior to collection. The particles were analyzed by electron diffraction, neutron activation, and electron beam microprobe techniques. Electron-beam microprobe analysis has given evidence for iron particles with high nickel content. Calcium films were used as indicators of moisture associated with the collected particles. Study of the exposed and unexposed films flown in the sampling experiments has revealed evidence for moisture. Laboratory simulation of a ring- or halo-patterns found in the electron microscopic examination of the noctilucent cloud particles has been attempted. This was done by impacting ice-coated nickel particles on collecting surfaces similar to those used in the sampling experiment. Ring patterns similar to those observed on the rocket sampling surfaces have been produced. The primary conclusions are that the cloud particles are probably of extraterrestrial origin and that a significant fraction appears to have been coated with terrestrial ice. Plans for future experiments are briefly outlined.
On the orographic influences of the Alps
Authors: Reuter H. , Pichler H.
Published: January 2012

The orographic influence of the Alps on 500 mb northerly or southerly flow has been studied, using the vorticity equation and a numerically evaluated mountain profile. The effects on trajectory deflection from orography and from the variation in the coriolis parameter have opposite signs for northerly flow but the same sign for southerly flow. Using the most frequent wind speed at 500 mb it is found that in the majority of cases a northerly current will pass the Alps without any significant deflection.
The angle of windrows in the ocean
Authors: Faller Alan J.
Published: January 2012

Direct observations of the angle of windrows in the ocean with respect to the direction of the wind within a few feet of the surface show that there is a systematic deflection of the row orientation to the right of the wind direction. The average angle of the data is 13 degrees with a standard error of estimate of 2.0 degrees. Observations were obtained from small boats or by measurements from aerial photographs of the angle between the wind and windrows as indicated by smoke flares and material in the water.This systematic angle and earlier measurements of row spacing as a function of wind speed are interpreted as evidence that the Langmuir circulations in the ocean are produced by shear-flow instability in the Ekman boundary layer.
Quantitative forecasting precipitation results obtained by means of three simplified computation methods for vertical velocities from amounts recorded at Bucharest and Cluj
Authors: Besleagă N. , Stoian Rodica , Doneaud A.
Published: January 2012

In this paper are computed the recorded precipitations in 24 hrs from the Bucharest and Cluj stations, making use of three simplified methods for the estimation of the vertical velocities and of their variations with height.The methods differ from one another in that the first assumes the atmosphere as adiabatic and saturated, whereas the second and the third take into account the individual variations of temperature and specific humidity, using thus in the calculus only “useful” vertical velocities.There have been analysed 29 rainy periods in the cold season of the years 1957, 1958 and 1962. The results have shown that the computation methods for the vertical velocities using the Laplace operator and its variation with time, and those using a diabatic atmosphere divided into layers, have yielded the best results.
Stability of a non-divergent Ekman layer
Authors: Barcilon Victor
Published: January 2012

The stability of a non-divergent Ekman layer generated by the horizontal motion of a rigid lid lying on the surface of a rotating fluid is investigated for large αR where α is the wave number of the perturbation and R the Reynolds number. On the assumption that whenever instability occurs rolls are formed at an angle β to the direction of motion of the lid, it is shown that the solutions of the sixth order differential equations governing the perturbation fields can be expressed in terms of the four solutions of the Orr-Sommerfeld equation for a two-dimensional plane parallel flow. The velocity profile of this flow is obtained by projecting the velocity vector of the Ekman flow onto a vertical plane perpendicular to the rolls.As the angle β is varied, the nature of the instability (viz. inviscid or viscous) is discussed by examining the upper branch of the neutral stability curve for infinite Reynolds number.The Coriolis force which affects the structure of the perturbation fields does not influence the nature of the neutral stability curve which is similar to that of a plane parallel flow having the same velocity profile as the component of the Ekman layer flow perpendicular to the direction of the rolls.
Thoron (Rn-2 20) measurements in the atmosphere and their application in meteorology
Authors: Israȅl Gerhard W.
Published: January 2012

With new equipment which allows the continuous recording of the atmospheric thoron content down to 0.5·10−14 C/l, the thoron content of the atmosphere, at different levels was measured at the Meteorologisches Observatorium des Deutschen Wetterdienstes in Aachen. The measurements were carried out from June until September 1964.The results show a close relation between the thoron content and the meteorological variables. The thoron concentration and its decrease with height shows a remarkable diurnal variation with a maximum at noon and a minimum during the night. The thoron at this station is influenced by wind direction. Rain diminished the thoron content by 50%; the recovery time to reach the initial concentration is about 10 hours.It could be shown that the turbulent diffusion coefficient K increases linearly between 1 m and 4 m. A mean value of K = 330 ± 30 cm2/s at 1 m level was found.
Note on the global variation of stratospheric turbidity since the eruption of Agung Volcano
Authors: Volz F. E.
Published: January 2012

Available data of attenuation due to dust from the eruption of Agung Volcano on Bali in March 1963 are compared with turbidity from earlier great eruptions. While abnormal twilights have been observed first in September 1963 in U.S.A., and in November in Europe, measurements of twilight at Weissenau indicate a small increase of stratospheric turbidity already in May 1963. Relevant investigations are summarized.
Deuterium and oxygen-18 in precipitation and other natural waters Some theoretical considerations
Authors: Eriksson Erik
Published: January 2012

In the paper an attempt is made to express the isotope concentration in precipitation as a function of the atmospheric process which transport water vapor. It is found that the fractionation which takes place is considerably less when the atmospheric transport is due to eddy motion than when transport is simply advective. In the latter case fractionation follows the Rayleigh condensation formula. In the case of eddy transport fractionation may under special circumstances follow the same formula although with a factor (√α − 1) instead of (ɑ − 1). More complicated transport patterns in the atmosphere are rather difficult to express mathematically.As to the vertically integrated transport it is at present difficult to derive explicit relations over ocean areas because of the exchange which takes place between air and water. Over continents, however, the relation can be formulated more explicit under certain conditions.Available data show a general relation between oxygen-18 and precipitable water which indicates that eddy transport is of major importance for distributing water vapor in the atmosphere.As to isotope concentrations in surface waters, exchange of water between air and liquid water is rather important and cannot be neglected in cases where data are applied to specific hydrologic problems.
On a finite difference scheme for solving the non-linear primitive equations for a barotropic fluid with application to the boundary current problem
Authors: Fischer Güinter
Published: January 2012

In this paper a finite difference scheme for solving the primitive equations for a barotropic fluid is proposed. This scheme is an extension of a method investigated thoroughly by the author in a recent paper (1965). It has certain advantages against the commonly used leap frog scheme insofar as it occupies less space in the computer and avoids fictitious numerical solutions. To test the finite difference scheme computations are performed with an ocean model where the circulation is generated by a prescribed meridional distribution of zonal winds. The β-plane approximation has been applied. The solutions behaved well and showed no instabilities.
Pyrheliometric measurements with special regard to the circumsolar sky radiation
Authors: Ångström Anders , Rodhe Bertil
Published: January 2012

In the present article the influence of aperture and atmospheric turbidity on the readings of pyrheliometers, used within the meteorological network, has been considered on the basis of measurements and observations concerning the radiation intensity within the solar aureole now available. We have emphasized the fact that the constants of secondary pyrheliometers, as these constants generally are determined, are dependent on apertures of involved instruments and on the atmospheric turbidity at the occasion when the standardization is made, and also that secondary instruments generally, if the derived constants are applied to the readings, must show differences from one another which are dependent upon turbidity and aperture conditions. As the effect of these factors is of systematic character, they must be seriously considered if an accuracy surpassing about ± 1.5 per cent shall be reached. Observations made in connection with the International Comparisons of Pyrheliometers at Davos 1964 are found to confirm the ideas expressed here and in previous notes by the present authors. Applications are suggested as regards (1) the difference found to exist between the old pyrheliometric standard scales, as regards (2) the future organization of Intenational Pyrheliometer Comparisons and (3) concerning the desirability of standardizing, to a greater extent than has been made up to now, the aperture conditions of pyrheliometers within the meteorological network.
Three-dimensional oscillations in a jet at high Reynolds numbers
Authors: Kao S.-K.
Published: January 2012

An analysis is made of the three-dimensional periodic oscillations in a jet at high Reynolds numbers. It is shown that there are two physically significant solutions: one is a symmetric and the other an antisymmetric function of the lateral coordinate; both involve a Lommel function. In the case of the symmetric solution, the maximum amplitude of the vertical velocity occurs near the inflection points of the velocity profile of the jet, whereas in the case of the antisymmetric solution, it occurs near the center as well as the inflection points of the jet.
On the Dispersion of Planetary Waves in a Barotropic
Atmosphere1
Authors: Rossby C.-G.
Published: January 2012

In this paper an attempt is made to investigate the rate of dispersion of
solitary, quasihorizontal atmospheric disturbances with the aid of a simple barotropic
model of the atmosphere. In low latitudes the dispersion is found to be extremely rapid,
in good agreement with the observed absence of all but the smallest solitary
disturbances. In high latitudes the dispersion is slow, permitting the establishment of
persistent solitary circulation patterns. The theory appears so throw some light on the
geographic distribution of the interdiurnal variability in the height of the 500 mb
surface and on the relatively frequent occurrence of planetary waves with a wave length
of 120 longitude degrees.A fuller treatment is now being published by my associate, Dr.
T. C. Yeh.
The Problem of Artificial Control of Rainfall on the Globe1.
I. Geiieral Effects of Ice-Nuclei in Clouds.
Authors: Bergeron Tor
Published: January 2012

Different kinds and degrees of colloidal and thermodynamical instability of
diverse systems of cloud-particles, partly leading to release of precipitation, are
discussed, aiming at estimating the possible effect of “seeding” clouds artificially
with ice-nuclei. – A low ratio v of supercooled cloud-droplets versus ice-crystals (v ≤
1) would ensure very rapid glaciation of the cloud, but no precipitation release and no
substantial improvement of visibility within it: overseeding. High values of v (<
106) would lead to the formation of big, though very sparse precipitation elements, but
not noticeably improve visibility within the cloud: underseeding. Favourable values of v
seem to lie around 103. – Cases of successful artificial seeding may be explained by
natural seeding indirectly caused by the artificial one: double release. – Lastly, an
inventory of the actual tropospherical clouds and cloud systems indicates that the main
possibility for causing considerable artificial rainfall might be found within certain
kinds of orographic cloud systems, to be treated in a following article.
Late Ceriozoic Climatic Charges as Recorded by the Equatorial Current System
Authors: Arrhenius Gustaf
Published: January 2012

Dear Sir: Since the preparation of the above indicated paper (Tellus, 2, 2) additional petrographical and palaeontological information has become available which gives a still more detailed picture of the marked stratification mentioned therein. With regard to one detail the statements of the previous paper must however be changed.
Some Measurements of the Distribution of Water Vapor in the Stratosphere
Authors: Barrett Earl W. , Herndon, Jr. Lee R. , Carter Howard J.
Published: January 2012

The results of three high-altitude ascents of an experimental radiosonde incorporating an electronic dew point hygrometer and carried by a large plastic balloon are presented. Significant features of the moisture distribution in the stratosphere revealed by these nights include at least one saturated layer in the vicinity of the tropopause on each occasion, and marked increases of the mixing ratio with height in the layer between 16 and 30 km in the two summer soundings. Charts and tabulations of the data from the three soundings are presented.
On the Solar Work of the Stockholm Observatory
Authors: Öhman Yngve
Published: January 2012

A brief report is given on the regular solar work or the Stockholm Observatory started in 1947. Besides scientific research in special fields the purpose of this work is an attempt to furnish Swedish geophysical institutions and the Royal Swedish Board of Telegraph with solar data in addition to the information given in the Ursigrams. In consequence of its high geographic latitude Sweden is exposed to aurora zone disturbances, and therefore a local and more detailed solar service has been held in high estimation in our country. The observations may be of a general interest, however, as they show that a fairly complete record of many of the principal features of solar activity can be obtained with a modest equipment. Some special methods of observation have been developed which are well adapted for this kind of work.
Two-dimensional Flow around a Circular Barrier in a Rotating Spherical Shell
Authors: Fultz Dave , Long Robert R.
Published: January 2012

An experiment has been recently set up in the hydrodynamics laboratory to study the flow of fluid around a circular barrier. In a rotating spherical shell of liquid, a small cylindrical obstacle is moved zonally in mid-latitudes and observations are made of the resulting perturbed flow. If the flow relative to the obstacle is westerly, a strong anticyclonic circulation is set up faround the barrier and wave motions exist around the globe. When the basic flow is easterly with the same relative speed, no circulation is found, but the wake is very long and broad and the fluid in it has little motion relative to the obstacle. When viewed with respect to the shell, the obstacle moving eastward creates a strong westerly jet at its latitude.
The Blue Sun of September 1950
Authors: Ångström Anders
Published: January 2012

Two causes for a coloured sun are discussed, namely refraction and absorption. The importance of integrating the refraction effects arising from different parts of the sun’s disk as light sources is emphasized. It is shown that by such integration of ring phenomena around the sun, many observed peculiarities may be explained. Important conditions for that some types of coloured suns shall arise are homogeneity of the particles of the scattering medium, and also that the particles shall be large enough to give rise to rings of sufficiently small radius. Transfer of air masses at long distances but without a sideward mixture taking place is in favour of the creation of dust sheets of homogeneous character, as the vertical sedimentation has then time to come into action.
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.