bluuebunny/crossref_metadata_2025 huggingface dataset:
Rich environments for active learning in action: problem-based learning
Authors: Grabinger Scott , Dunlap Joanna C. , Duffield Judith A.
Published: January 2012

In today's complex world of rapid change, of increasing innovation and of proliferating knowledge, employers and employees must be able to apply tools and knowledge to new situations with increasing frequency to remain productive and competitive (see Nash, 1994). Because we face an environment in which knowledge and skills become rapidly obsolete, people need to know how to be involved in a continual process of 'retooling' their knowledge and skill base (see Swanson et al, 1993). Consequently, learning to think critically, to analyse and synthesize information to solve technical, social, economic, political, and scientific problems, and to engage in lifelong learning, are crucial for successful and fulfilling participation in our competitive society. Learning environments which prepare learners for the complexities of the professional world utilize instructional activities reflecting the problemsolving and challenge-meeting process professionals use on their jobs. Learners need to: • determine for themselves what issues need to be addressed when facing a new problem; • identify knowledge and skills they already possess that can be applied to the situation; • determine which skill and knowledge areas are deficient, arid create learning plans to address those deficiencies; • create timelines, manage resources, and monitor their progress; • apply what they know to problems that may change substantially from one moment to another; and • assess their performance and make changes in personal processes for use to meet subsequent challenges.DOI:10.1080/0968776970050202
Quality criteria for multimedia
Authors: Rushby Nick
Published: January 2012

Almost every piece of multimedia software is extolled by those who developed it and those who publish it as being of the 'highest quality'. In practice, most multimedia packages contain content and software errors, and do not realize their full potential in terms of communicating a message that endures. This does not mean to say that the users are disappointed with their multimedia. They may not realize that the communication could be more effective, they may not notice some of the errors, or they may have been led to believe that this is the natural order of things. The accepted meaning of the term quality as used by workers 'in the field' has become devalued. Discussions with typical purchasers and users over recent months indicate that they are still remarkably tolerant of low quality. In this respect, multimedia lags behind much of the IT industry, and it is unlikely that the tolerance will last much longer. As users expectations and demands increase, those multimedia developers who have quality processes in place and are able to assure the quality of their products will have a clear business advantage.DOI:10.1080/0968776970050203
A pedagogical framework for embedding C&IT into the curriculum
Authors: Conole Grainne , Oliver Martin
Published: January 2012

A wide variety of communication and information technologies (C&IT) is now available, offering education a broad range of potential benefits, be they educational (Mapp, 1994; Lewis and Merton, 1996; HEFCE, 1997a), economic (HEFCE, 1997a), or in terms of competitiveness with other universities in an increasingly global market (Maier et al, 1997). The uptake and use of these resources is patchy at best (Laurillard et al, 1993; Lewis and Merton, 1996). This mismatch between potential and use has been seen as increasingly important, and incentives and recommendations are leading to an increasing use of C&IT, as illustrated by the recommendations of the recent Dealing report (Dearing et al, 1997) and the priorities of the TLT programme (HEFCE, 1997b). Concerns have been voiced, however, that the push towards a wider embedding of C&IT in education may ignore issues of the appropriate uses of these resources. What is needed is a convincing and practical pedagogically-driven (as opposed to technology-driven) methodology for integrating C&IT into courses.DOI:10.1080/0968776980060202
A unique style of computer-assisted assessment
Authors: Thelwall Mike
Published: January 2012

The Computer-Based Assessment project at the University of Wolverhampton has produced a number of tests built around a common framework. There are three main tests that are used by about 800 students per year, and they replace written tests. There are also two diagnostic tests that are not part of any formal assessment but are used by about 400 students per year. We have produced numerous special versions of these tests for short courses, different teaching techniques, and one for a Broadnet Online training module (Broadnet, n.d.). The tests are all written with 80,000 permutations built in to allow them to be made available for students to use and practise on at all times without compromising security. In fact, there are no serious security concerns because of the random factors, and so the same tests are used every year without the need to be hidden or rewritten. Similar advantages have been found on other projects using random factors; see for example Thoennessen and Harrison (1996).DOI:10.1080/0968776980060205
Editorial
Authors: Jacobs Gabriel
Published: January 2012

ALT-J has a new editorial team from this issue. I'm glad to say that Gabriel Jacobs will remain involved with the journal as Executive Editor. The new Editor is David Squires from King's College London but he will not be able fully to take over until the next issue. I have been appointed as Deputy Editor.DOI:10.1080/0968776980060301
Developing lifelong learners: a novel online problem-based ultrasonography subject
Authors: Minasian-Batmanian Laura C. , Koppo Anthony J. , Pearson Elaine J.
Published: January 2012

There have been significant advances in the practice of sonography since the introduction of the University of Sydney course in 1991. The entire knowledge base can no longer be taught within the constraints of time allotted to the subject. Moreover, encouraging students to be self-directed, independent learners is more important than ever, since the field of sonography has reached a stage where there is an urgent need for new skills.DOI:10.1080/0968776000080106
Erratum
Authors: Sharpe Rhona
Published: January 2012

We apologize for not including an appropriate acknowledgement to the publisher of ActivStats in the paper entitled 'Active learning of statistics: a case study', by Erica Morris and Eileen Scanlon, which appeared in Volume 8, Number 1 of this journal. ActivStats is published by Longman Software Publishing. The ActivStats screen shots shown in Figure 2, Figure 3 and Figure 4 of that article are reproduced by permission of Longman Software Publishing.DOI:10.1080/0968776000080210
Teaching new media composition studies in a lifelong learning context
Authors: Jameson Jill , Squires David
Published: January 2012

The government 'spin' on lifelong learning, as expressed in the Green Paper, The Learning Age (DfEE, 1998), and taken forward in the White Paper, Learning to Succeed (DfEE, 1999), emphasizes knowledge acquisition, skills development and student-centred flexible education and training. The aim of the government, as expressed in the summary document, Education and Training Development Agenda 2000-2001, is to 'help develop a "learning society" in which everyone, in whatever circumstances, routinely expects to learn and upgrade skills throughout life' (DfEE, 1998). Central to this idealistic notion is the view that continuous updating in ICT skills will play a vital part in the self-empowerment of individual learners. In support of this vision the government is funding ventures such as the Information and Communication Technologies (ICT) Learning Centres initiative - 'a new programme designed to help bridge the gap between those in society who have access to ICT and those who do not' (DfEE, 1999). Community Access to Lifelong Learning is a parallel New Opportunities Fund programme which is designed to encourage adult learning. It focuses on improving access to learning opportunities through the use of ICT.DOI:10.1080/0968776000080306
Student 'voices' and course development: reading the signs on a distance course in educational technology
Authors: Slaouti Diane
Published: January 2012

Whether in face-to-face or distance mode, courses result not-simply from informed input and pedagogic planning from an academic team but, as Thorpe (1988: 120) maintains from 'a process of interaction between the learner and any materials, staff or facilities associated with the achievement of [those courses]'. This synergy suggests that learners have a pivotal role to play not only in revealing the short-term effectiveness of instructional design and teaching strategies but also in contributing to their long-term development. This is not disputed, as reflected in the place that formal evaluation tools have on most courses.DOI:10.1080/09687760108656776
Does gender matter in online learning?
Authors: McSporran Mae , Young Stuart
Published: January 2012

The image of a stereotypical computing student is still 'geeky' (Selby, Ryba and Young, 1997; Margolis, Fisher and Miller, 1999) or 'nerdy, unwashed and working incredibly long hours, pausing occasionally to drink coke and order a pizza' (Brook, Mann and Virtue, 2000). This might be the reason that only 20 per cent of undergraduate IT students are female (Brook et ah, 2000). Indeed over the years there have been many attempts to be proactive and promote women in IT, both by institutes and individuals.DOI:10.1080/0968776010090202
Almost as helpful as good theory: some conceptual possibilities for the online classroom
Authors: David Mike , Denning Kate
Published: January 2012

Current interest in the use of Communications and Information Technology (C&IT) in higher education and other settings is at a high level (for example, Framework V: Towards a User-Friendly Information Society; the ESRC Programme PACCIT) and while universities - in response to the Dearing Report - begin to exercise effort in restructuring course delivery methods to take advantage of the technology, there is a danger that the issue of the changes in the social dynamics that are a direct consequence of the transition from actual space to virtual space will be overlooked. Some work has been undertaken in this area (notably Rheingold, 1991; Cook, 1995; McConnell, Hardy and Hodgson, 1996) but there is need for additional research if we are to identify a clearer sense of how effective online learning might manifest itself.DOI:10.1080/0968776010090207
Note on Numerical Prediction of Intensity Changes of Disturbances with the Aid of the Quasi-Geostrophic Barotropic Model
Authors: Charasch Eliahu
Published: January 2012

It is shown by a simple analysis that the introduction of a small but systematic error in the evaluation of vorticity causes a significant aberration in the conversion process between disturbance and basic flow kinetic energy in barotropic motion. The neglect of the variation of the coriolis parameter in the geostrophic vorticity is shown to be responsible for large errors in the prediction of the intensity changes taking place in a barotropic model.
Vertical Circulation and Release of Kinetic Energy during the Development of Hurricane Hazel into an Extratropical Storm
Authors: Palmén E.
Published: January 2012

The thermal structure of the atmosphere over the eastern and central parts of the U. S. on October 15, 1954, when the tropical hurricane “Hazel” entered the American continent and rapidly was transformed into an extratropical cyclone of great intensity, is analyzed by the aid of upper air charts and vertical cross sections. The field of divergence and vertical velocity is determined from the horizontal wind field at different levels for the synoptic time October 15, 1500 GCT, and the results are used for computing the precipitation in the region of strongest ascent of the warm and moist air of the tropical disturbance and for a determination of the release of kinetic energy in the whole region due to vertical solenoidal circulations associated with the general sinking of the cold polar air masses and the simultaneous ascent of the warm tropical air masses. The production of kinetic energy is also computed directly from the work done by the horizontal pressure forces in the same area. Both methods give a production of kinetic energy of about 19 × 1010 kilojoules or 19 × 1020 ergs per second over an area 366 × 104 km2 large. Only a small part of the energy released is again dissipated due to friction in the same area, whereas the essential part is exported outwards from the source region, thus furnishing the surrounding atmosphere with large amounts of kinetic energy.

In the last section some general conclusions are made concerning the budget of kinetic energy in the whole Northern Hemisphere, considering the net effect of the disturbances in the westerlies, the mean meridional circulations, the mean meridional flux of kinetic energy and the frictional dissipation.
Eccentric Circumpolar Vortices in a Barotropic Atmosphere
Authors: Barrett Earl W.
Published: January 2012

Recent investigations (LA SEUR, 1954) have shown that on many occasions the circulation of the middle troposphere possesses a marked eccentricity; i.e., the center of symmetry of the flow is found at a considerable distance from the geographic pole.
Penetrative Downdraughts in Cumuli
Authors: Squires P.
Published: January 2012

Observations of cumuli have shown that the adiabatic model is quite inadequate, and that dry air must mix with the condensing upcurrent. Theories of the interaction between cumuli and their environment are discussed. The hypothesis that dry air enters these clouds chiefly from above is examined quantitatively. It is found that, as a result of evaporative cooling, such air could penetrate several kilometres into a growing cloud. This hypothesis accounts for the fine structure which is observed, and provides a natural and simple explanation for the fact that the lapse rate in cumuli is steeper than the wet adiabatic, and indeed approximates closely to that of the environment. Unlike alternative theories, it provides a means whereby the liquid water content may be automatically self-limiting, as the observations seem to require, for the motions which introduce dry air deep into the cloud depend for their energy supply on the presence of liquid water, and have velocities which are roughly proportional to its concentration.
The Spatial Variation of Liquid Water and Droplet Concentration in Cumuli
Authors: Squires P.
Published: January 2012

Measurements of liquid water content and droplet concentration in cumuli over path lengths of about one metre have been used to investigate the structure of these clouds. The measurements indicate that the cloud process is far from adiabatic, and that a dominating role is played by the admixture of drier air from outside the cloud. They suggest, further, that the main source of this dry air may be the region above the cloud top.
Soluble Salts in a Temperate Glacier
Authors: Gorham Eville
Published: January 2012

In a recent paper on gas enclosures in a temperate glacier (Storbreen in the Jotunheim district of Norway) COACHMAN, HEMMINGSEN and SCHOLANDER (Tellus, 1956) report some specific conductivity and pH measurements made on melted samples as chemical tests of ice purity (conductivity giving some indication of the amount of dissolved ions).
An Investigation of Systematic Errors in the Barotropic Forecasts
Authors: Martin Donald E.
Published: January 2012

Forecast-errors in the 24- and 48-hour barotropic 500-mb prognostic charts prepared by JNWPU for the winter of 1957 were investigated. Certain large-scale forecast-errors were found to persist from day-to-day in fairly localized geographical areas. In general, the numerical prognoses exhibited a tendency to forecast excessively high values off the southeastern coasts and excessively low values off the northwestern coasts of the continents. Little forecast-error was observed in the continental interiors. A Fourier analysis revealed that the forecast-errors were largely due to incorrect phase forecasts for wave numbers 1 through 4. The forecast-errors associated with wave number 1 usually “positioned” the large-scale systematic forecast-errors near Japan and Scandinavia and contributed materially to their intensities. Relationships between forecast-error fields and topography, geography, synoptic situation, and “non-adiabatic” heating are discussed. Hemispheric fields of “non-adiabatic” heating, computed using a two-level graphical model, are shown. Charts illustrating the dependence of “non-adiabatic” heating on the general circulation are also shown.
Observed Secular Tilting Motion of the Ground which Preceded the Occurrence of Several Destructive Earthquakes
Authors: Nishimura Eiichi , Kishimoto Yoshimichi , Tanaka Yutaka
Published: January 2012

Some details of tilting motion of the ground continuously observed for a long period with the aid of the highly sensitive, fused-silica tiltmeter of horizontal pendulum type at the Kamigamo Geophysical Observatory is described in this paper, with regard especially to the secular ground-tilting in connection with seismic activity in the surrounding area of the Observatory. It was consequently clearly ascertained, after the careful examination and perfect exclusion of various disturbing effects, that the ground commenced a characteristic tilting motion downward to the direction of the epicenter several months before the occurrence of the destructive earthquakes, and showed a recovering motion after the quakes, so far as the present cases of the five destructive earthquakes around the Observatory concern.
On Density and Isotropy of an Ionized Gas in a Magnetic Field
Authors: Åström Ernst
Published: January 2012

The relation between the density on the surface |v| = constant in the velocity space and the density in the space is treated. The relationship is given by an integral equation. First the three-dimensional case for homogeneous magnetic field is treated, then a two-dimensional case in a magnetic field the intensity of which varies linearly with the space coordinate to show the dependence on the inhomogeneity in the field.
Droplet Sampling in Cumulus Clouds
Authors: Durbin W. G.
Published: January 2012

An analysis is made of 150 cloud droplet samples obtained by the impaction method in cumulus clouds varying in vertical depth from 750 to 7000 ft.

From a consideration of the spectra relating numbers of droplets with droplet diameter, a mode diameter of about 8 µ, is found. A secondary mode diameter of about 15 µ is in evidence in some clouds. In the main numbers of droplets are between 100 and 300 per cm3 but extreme values of about 20 and 1000 occur.

Spectra relating water content with droplet diameter show that in clouds between about 750 and 2500 ft thick the mode diameter is about 8 µ, whereas in clouds between about 4000 and 7000 ft thick the mode diameter is about 18 µ. The highest value of water content found is about 5 g m−3.

Evidence is found that mean volume diameter tends to increase with height above cloud base and that high values of water content are due to larger droplets rather than to greater numbers of droplets per cm3.

A droplet distribution formula given by Best is examined and the constants involved are found to depend on the largest size of droplet present.
The Moving Flame Experiment
Authors: Stern Melvin E.
Published: January 2012

When a flame is rotated around the outside bottom rim of a cylindrical pan of water initially at rest, D. Fultz has observed that the fluid acquires a net vertical component of angular momentum opposite to the rotation of the heat source. We have repeated this experiment in a cylindrical annulus in order to restrict the radial motions and have found that the same phenomenon occurs. Using a simple model based on the latter experiment we investigate the mechanism by which a fluid can acquire and maintain this momentum, considering that friction is the only force which can exert a net torque about the vertical.

The effects of the heat source are replaced by a forced temperature field which has sinusoidal variations in the circumferential direction and which rotates about the vertical axis at a constant rate. The correlation between vertical and horizontal velocity components in the equilibrium state has been computed from the linearized two-dimensional vorticity equation. It is shown that when the viscosity is small or when the speed of the heat source is large there is a convergence of horizontal momentum towards the center of the channel which is balanced by the viscous stress of the induced mean motion. The total momentum of the fluid is computed from the conservation principle and is found to vary inversely as the square root of the molecular viscosity and inversely as the 5/2 power of the speed of the heat source.
Note Concerning the Influence of Rotation on Convection
Authors: Starr Victor P.
Published: January 2012

My purpose in writing this note is not to present a model of an actual convective process, but instead to work with a articularly simple hypothetical scheme with the intent of illustrating the action of one single factor, namely, rotation.
An Advective Model of the Ocean Thermocline
Authors: Welander Pierre
Published: January 2012

A theoretical study is made of the density field and the associated velocity field produced in an unlimited ocean by a prescribed density distribution at the surface. It is assumed that all motions take place under geostrophic and hydrostatic balance, and that the density is simply advected by the motions occurring. The computation is carried out for a spherical earth. The theory gives a depth of penetration of the surface disturbances of the order of 1000 m, if one assumes a relative density variation of the order 10−3 and a characteristic velocity below the boundary layer of the order 1 cm. sec−1. The depth of penetration is proportional to the sine of the latitude. Assuming a stable ocean with a surface density increasing from the equator to the pole the theory gives a meridional distribution of density of the form observed in the real oceans. The associated zonal velocities are westerlies at high latitudes, easterlies near the equator.

To permit a more precise check of the theory by laboratory experiments the corresponding solution is derived for a rotating “dishpan”. The solution is found to be of the same type as the one studied in the spherical case, but it is pointed out that fundamental differences between the spherical and parabolic cases are likely to occur in more general solutions than those studied here.
The Band Structure of the Atmosphere
Authors: Kuettner Joachim
Published: January 2012

A general characteristic of the atmosphere is its streakiness. It manifests itself in many phenomena such as the “cloudstreets” of polar outbreaks and tradewinds, the radar bands of hurricanes and certain precipitation patterns, the squall lines and the jet stream cirrus.

The banded structure can be traced back to convection in heated air flows with a curved velocity profile of rather uniform direction. The typical vertical curvature was found to be 10−7 (cm−1 sec−1). A preliminary note deals with some theoretical considerations.

Synoptic cloud analysis by weather satellites will greatly profit from the wide spread existence of cloud bands.
The Diurnal Variation of the Wind
Authors: Haltiner G. J.
Published: January 2012

The equations of motion are numerically integrated under assumptions which represent the diurnal variation of the wind. The coefficient of eddy viscosity varies periodically with time as well as nonlinearly with height. The time variation is represented by two trigonometric terms giving a 20-fold change between maximum and minimum eddy viscosity. Several different functions were used to depict the vertical variation of the eddy viscosity, among which were an increasing, but bounded, exponential function, and also an exponential function which first increased with height and then decreased to a residual value. The boundary conditions imposed were, firstly, that the wind vanishes (or approaches a constant value) at the lower boundary; and, secondly, that the wind becomes geostrophic at some arbitrarily selected upper level. The solutions were in general agreement with observed data and showed the spiral characteristic of the planetary boundary layer. However, there is disagreement between theory and observation in some important features.
On the Maintenance of the Large-Scale Quasi-Permanent Disturbances in the Atmosphere
Authors: Saltzman Barry
Published: January 2012

It is proposed that large-scale quasi-permanent flow systems are maintained against dissipative effects by a transfer of kinetic energy from smaller, cyclone-scale, disturbances which have baroclinic energy sources, the processes involved being non-linear and barotropic. To illustrate how such processes can operate, an example is given based on an idealized flow consisting of a limited number of double-Fourier components.
On the Dynamics and Energy Transformations in Steady-State Hurricanes
Authors: Malkus J. S. , Riehl H.
Published: January 2012

A dynamic model of the inflow layer in a steady mature hurricane is evolved, relating wind speed, pressure gradient, surface shearing stress, mass flow, and convergence. The low-level air trajectories are assumed to be logarithmic spirals. With this hypothesis, properties such as maximum wind and central pressure are determined through choice of a parameter depending on the inflow angle: a moderate hurricane arises with inflow angles of about 20°, while 25° gives an intense or extreme storm.

Most of this study treats the moderate storm. In order to maintain its core pressure gradients, an oceanic source of sensible and latent heat is required. As a result, latent heat release in the inner hurricane area occurs at higher heat content (warmer moist adiabats) than mean tropical subcloud air. The heat transfer from the ocean and the release of latent heat in the core determine the pressure gradient along the trajectory, and this prescribes the particular trajectory selected by the air among an infinite number available from the logarithmic spiral family.

This selection principle is evolved using recent work on “relative stability” of finite aniplitude thermal circulations. Of an infinite number of dynamically possible spirals, the one is realized which maximizes the rate of kinetic energy production under the thermodynamic constraints, here formulated in terms of the relation between heat release and pressure gradient.

Finally, rainfall, efficiency of work done by the storm, and kinetic energy budgets are examined in an attempt to understand the difference between the hurricane—a rare phenomenon—and the common sub-hurricane tropical storm.
Periodical Variations of the Atmospheric CO2-content in Scandinavia
Authors: Bischof Walter
Published: January 2012

From the CO2-data of the years 1955—59 for Scandinavia the annual cycle was determined. The picture is changing from year to year showing time displacements of the maxima and minima, which can, however, be placed “in phase” by shift of the time axis. One gets a mean value of the annual cycle of the years 1955—59 with two maxima and two minima. The total annual mean value obtained for Scandinavia is for 1955 326 ppm, 1956 321 ppm, 1957 323 ppm, 1958 315 ppm, 1959 331 ppm.
The “Salt-Fountain” and Thermohaline Convection
Authors: Stern Melvin E.
Published: January 2012

A “gravitationally stable” stratification of salinity and temperature, such as is observed in the oceans, is actually unstable due to the fact that the molecular diffusivity of heat is much greater than the diffusivity of salt. We discuss this stability characteristic and the form of the convective motion in the laminar regime. Future studies of this model relative to the amplitude of the motion and the subsequent transition to turbulence should lead to the formulation of critical observational questions, which will determine whether the proposed mechanism is significant in the vertical mixing of the sea.
Further Examples of Stationary Planetary Flow Patterns in Bounded Basins
Authors: Faller Alan J.
Published: January 2012

Laboratory experiments which supplement those presented by STOMMEL, ARONS and FALLER (1958) are described. Extension of the analysis to include the effects of bottom friction shows that the characteristic spreading of zonal currents, apparent in the original experiments, is due to bottom friction combined with the radial depth variation. The experiments confirm the theoretical prediction of an intense “recirculation” from the western boundary (similar to the “wind-spun vortex” of MUNK, 1950) when a localized interior source or sink is present. Application of the basic concepts of the earlier paper to the geometrically more complicated case with a partial radial barrier gave good agreement between theory and experiment, but the limiting effects of bottom friction were made evident in other examples.

An eastern boundary current was found to occur in a situation geometrically similar to the intrusion of Mediterranean water into the Atlantic Ocean. Simple transformations illustrate the application of the equations developed in polar coordinates to the flow of a uniform fluid on a sphere, and examples of “recirculation” and the spread of zonal flow are worked out for a barotropic ocean of uniform depth.
A Preliminary Study of the Potential to Kinetic Energy Conversion Process in the Stratosphere
Authors: White Robert M. , Nolan George F.
Published: January 2012

The potential to kinetic energy conversion process in the lower stratosphere associated with the vertical exchange of warm and cold air is evaluated using adiabatically derived vertical velocities for the North American region for a five-day period. Preliminary results suggest the possibility that on the average the kinetic energy of stratospheric motions may not result from a conversion of potential energy within the stratosphere by this process. The further implication is that stratospheric motions are maintained by the motions in the adjacent layers of the atmosphere.
Some Estimates of the Effects of Heating on Large Scale Disturbances
Authors: Fleagle Robert G.
Published: January 2012

Effects of heating on large scale disturbances are studied by assuming that heating is tuned to the disturbances, with rate of heating proportional to individual pressure change but displaced by an arbitrary phase angle. The linearized two-layer baroclinic model reveals that the heating which accompanies condensation in the middle troposphere may lead to marked increase in instability and to shift of maximum instability from five to three thousand kilometer wavelengths, and this calls attention to a serious defect in the two-layer model which must influence the accuracy of numerical calculations using the non-linear equations.
Wet and Dry Deposition of Fallout Materials at Kjeller
Authors: Small S. H.
Published: January 2012

Daily measurements of fallout air activity and deposited activity at Kjeller, Norway, from I Sept. 1956 to 30 Sept. 1959 are given as monthly means for days with and without obvious precipitation. It seems that significant concentrations of fallout particles reach the earth about 3 months after high-yield test explosions. Dry deposition may reduce the amounts of fallout materials available for capture by precipitation.
On the Exchange of Carbon Dioxide between the Atmosphere and the Sea
Authors: Bolin Bert
Published: January 2012

The physical and chemical processes responsible for exchange of carbon dioxide between the atmosphere and the sea are analyzed. It is shown that the rate of transfer is considerably decreased due to the finite rate of hydration of CO2 in water. This is the case both for a smooth water surface where molecular diffusion plays a rôle in the first few hundredths of a millimeter as well as for a rough sea where turbulence extends all the way to the surface. A general agreement is found between the transfer rate deduced in this way and the rate of exchange estimated on the basis of the C14/C12 ratio in the atmosphere and the sea.
Radiocarbon Concentration in Pacific Ocean Water
Authors: Bien G. S. , Rakestraw N. W. , Suess H. E.
Published: January 2012

Results of C14 determinations in surface water from the Pacific were in agreement with those reported by Rafter and Fergusson. However, abnormal C14 concentrations seem to exist locally, for which no oceanographic explanation can be given. It seems premature to draw conclusions from existing determinations as to the rate of increase of C14 in surface ocean water resulting from the uptake of C14 produced in the atmosphere by atomic bombs.

Samples from a constant depth of about 3,500 meters show a C14 content decreasing from south to north. This decrease may be attributed to radioactive decay of C14 during the time of migration. From this the northward component of the rate of water movement of about 0.06 cm/sec can be calculated. The C13 determinations, for the purpose of correcting the C14 values for isotope fractionation effects. were found to be remarkably consistent, although made on reburned acetylene.
Cellular Cloud Patterns revealed by Tiros I
Authors: Krueger Arthur F. , Fritz Sigmund
Published: January 2012

In this report some satellite (TIROS I) photographs of cellular cloud patterns are related to conventional meteorological observations. These cellular patterns occurred at the top of convective layers which were heated from below; and through which there was little vertical variation in wind velocity.
Techniques of Determinig the Turbidity of the Atmosphere
Authors: Angström Anders
Published: January 2012

After a short survey I of the principles underlying the determination of the turbidity coefficient β, earlier introduced by the author as a measure of the atmospheric turbidity, a condensed summary II is given of earlier and also of more recent determinations of β. The variation of the turbidity with the time of the year, the airmass and with latitude is discussed. Finally a simple method of determining the wave length dependence of the extinction by atmospheric aerosol is outlined. The method is founded upon measurements of integral radiation values with aid of pyrheliometers and glass filters, III. Accuracy and probable error are considered, IV.
On the Distribution of Temperature Relative to Height in Stationary Planetary Wave?
Authors: Wiin-Nielsen A.
Published: January 2012

It is shown that some gross features of the distribution of the mean temperature relative to the mean height on the normal maps for January can be computed from the vertically integrated linearized vorticity equation, if the effects of surface friction and mountains are included in the equation for the stationary case. By a mathematical analysis supplemented by certain numerical experiments it is shown that it is necessary to assume a meridional scale parameter corresponding to less than 90 degrees of latitude in order to obtain the correct phase-lag. An empirical determination of the meridional wave-length was carried out using 500 mb data for a single month (January 1959).

Section 6 contains some comments on the assumptions made in this study. It is especially pointed out that the effect of horizontal advection of vorticity and the effects of the lower boundary condition (friction and topography) cannot be neglected in comparison with the beta-effect in studies of stationary motion on the planetary scale.
Height, structure and displacements of noctilucent clouds
Authors: Witt Georg
Published: January 2012

Observations of noctilucent clouds have been carried out during the summer of 1968 at Torsta (63.3° N ; 14.6° E) in Central Sweden as part of the IGY working program of the Institute of Meteorology, University of Stockholm. Simultaneous pairs of cloud photographs have been taken with accurate phototheodolite cameras from the endpoints of a geodetically determined base-line of length 51.6 km. The picture pairs were subsequently analyzed in stereo instruments (autograph) by which Cartesian space coordinates were obtained for various points in the cloud system. These coordinates, duly corrected for atmospheric refraction, were used for determination of the height of the individual features. Through the stereoscopic effect, measurements could be made on diffuse parts of the cloud system as well as on marked details. Additional information about movements of the cloud system was obtained from a time-lapse film in Kodachrome. The results were plotted and analyzed by conventional methods and maps of the cloud topography at consecutive time intervals could be prepared. In addition to these maps, vertical cross-sections through the cloud system were made as well as detailed studies of particularly interesting cloud features. This paper gives a presentation and interpretation of the results obtained so far and a brief description of the photogrammetric technique applied.

The results presented below were obtained during a very bright cloud display with good visibility conditions on August 10-11th, 1958. Thirty pairs of pictures were taken of various parts of the cloud system, which covered the entire northern horizon. Eight of these have been analyzed 80 far. The results can be summarized as follows. The cloud system moved in a direction north-east to south-west with velocities of the order of 50 to 100 m/s. It consisted of a continuous diffuse layer interchanging with regions of sharply defined features such as systems of parallel billows and bands, blobs and other smaller-scale irregularities of various shapes. The measured heights varied between 81.6 and 86.6 km. The long parallel bands were identified as a system of waves with wavelengths of the order of 60 km and amplitudes up to 4 km which propagated in a direction nearly opposite to that of the cloud system with absolute velocities of the order of 10 to 20 m/s. The wave crests were oriented nearly perpendicular to the main air flow and were continuous over distances of hundreds of kilometers and exhibited local refraction effects. The smaller billows had wavelengths of the order of 6-10 km and amplitudes about 0.5-1.0 km; they moved with the cloud sysem. The billows showed no preferred orientation and were observed to pass through the crests of the longer waves. It is indicated by the analysis the regular changes in the brightness of these clouds are due to changes of the optical thickness of the cloud layer, particularly at the rear slope of the long waves. The measured details had well-defined lower boundaries.
The effect of turbulence on fog formation
Authors: Rodhe Bertil
Published: January 2012

Of prevalent conceptions of the physics of fog formation, the “classical” theory of the mixing of air masses of different temperatures seems to the present author to be the most convincing. In view of the fact that turbulent exchange implies a mixing of eddies of different origins, it is clear that the theory of turbulence applied to saturated air should result in some basic ideas of fog formation. For simplification of the problem to be studied, the author assumes that the inertia of the drops of fog can be neglected and that they are transferred by eddies in the same way as vapour. On that assumption, the mixing ratio of the total water content, i.e. the mixing ratio of liquid water plus vapour, and the potential wet-bulb temperature are two elements of air that remain constant in eddies irrespective of whether these are saturated or unsaturated by vapour. By putting each of the elements into the differential equation of eddy exchange, the basic formulae for estimation of fog density are obtained. The boundary conditions of integration determine the alternative kinds of fog, for example advection fog and radiation fog. Finally, some important modifications are obtained if regard is paid to the black-body emissivity of the drops of the fog. Thus, the density of the fog is considerably increased by a rise of the level of radiative heat loss from the ground surface to the top of the fog.
On the diurnal variation of surface temperature
Authors: Lönnqvist Olov
Published: January 2012

The global short-wave radiation is the main external factor which determines the diurnal temperature variation at the surface of the earth. Therefore, there should be a close connection between the diurnal variation of the global radiation, which is normally quasi-symmetrical relative to noon, and that of the surface temperature, which on the contrary has a very characteristic non-symmetrical appearance. It is assumed that the surface temperature can be represented with sufficient approximation by a small number of terms of a Fourier series, and that the energy loss by various effects, such as evaporation, is proportional to the surface temperature. In doing so it can easily be shown that each harmonic term of the temperature variation is determined by the respective term of the diurnal variation of the global radiation; the changes in amplitude and phase angle of each term being functions of the heat capacity and thermometric conductivity of the soil and the coefficient for the rate of loss of energy by non-conduction. The formulae arrived at are successfully tested against observed data published by Franssila. In doing so the first four terms of the Fourier series are used.
Mean vertical motion and non-adiabatic heat sources over India during the monsoon
Authors: Das P. K.
Published: January 2012

The mean vertical velocity in pressure coordinates, and the corresponding height tendency, was computed at intervals of 100 mb from 1000 mb to 50 mb on a mesh covering India and most of southeast Asia. The rate of non-adiabatic heat supply was expressed as a function of the computed height tendency. The results showed pronounced ascent over northeast India and a zone of subsidence over northwest India. The rate of ascent decreased uniformly with pressure suggesting force ascent on account of orographic features to the north of India. The computed values of the height tendency indicated that non-adiabatic heat sources must be capable of producing an average warming at the rate of 1.6 C(12hr)-1 in northeast India, and an average cooling by 1.2 C(12hr)-1 in northwest India.
Standard errors of cosmic ray data corrected for atmospheric effects
Authors: Dyring E. , Lindgren S.
Published: January 2012

A formula is obtained for the standard error of cosmic ray data which have been corrected for atmospheric effects. It is used to estimate standard errors of the nucleonic and meson components corrected by different methods. The relative standard error is found to decrease with increasing counting rate up to an approximate value of 106 counts per time interval if simultaneous meteorological measurements are available for each recording interval. Above that counting rate the relative standard error is essentially constant.
Latitude effect and atmospheric attenuation of the cosmic ray nucleon component
Authors: Sandström Arne Eld , Pomerantz Martin A. , Grönkvist Bengt-Olov
Published: January 2012

The latitude effect has been studied by means of a shipboard neutron monitor during 12 passages of the so-called knee. The latter remained in a fixed position (46.0° ± 1.0° N, 7° W) between Oct. 1956 and Feb. 1959. Above the knee there exists a plateau due to the atmospheric attenuation of the nucleon component. The horizontal part of this plateau extends to a threshold rigidity of 3.2 ± 0.5 GeV/c.
Vertical and radial motions in a tropical cyclone
Authors: Estoque Mariano A.
Published: January 2012

The vertical and radial motions associated with a given tangential velocity and temperature distribution corresponding to a tropical cyclone are calculated using a diagnostic equation. The equation is derived by introducing the hydrostatic and gradicnt wind approximations systematically into the meteorological equations. The computed circulation pattern appears to reproduce most of the important characteristics of a mature cyclone such as the eye and the eyewall. The results also show that the sinking motion in tho eye is thermally controlled.
Further aspects on the diurnal temperature variation at the surface of the earth
Authors: Lonnqvist Olov
Published: January 2012

From a number of independent clear-sky observations of global radiation and temperature at the surface of the earth, typical values are derived for the diurnal variation of these elements for certain specified lengths of the day. An attempt is made to relate the typical variation of radiation with that of surface temperature by the aid of a formula recently suggested by the author. The agreement is good and the constants used in the formula resemble those previously used by the author.

Depending on the actual conditions (type of soil, humidity gradient in the air, etc.) various combinations of the two constants should be used in the formula. It is demonstrated how the choice of constants affects the amplitude and phase lag of the temperature curve. Also discussed is the possibility of incorporating turbulence effects in the formula.
On the dissipation of kinetic energy in the atmosphere
Authors: Holopainen Eero O.
Published: January 2012

After a discussion of some general aspects of the atmospheric energy cycle results from computations of the frictional changes of kinetic energy are given. Large losses of kinetic energy are found in the boundary layer and in the region near the tropopause below the level of maximum wind. The total rate of dissipation of kinetic energy in the troposphere amounts to 10 watts m-2, of which 4 watts m-2 are dissipated below 900 mb. The mean kinetic energy in the troposphere was 24 × 105 joules m-2. The rate of dissipation of the kinetic energy in the first kilometer above the ground and its dependence upon the geostrophic wind speed are studied.
Topographic Influences on the Path of the Gulf Stream
Authors: Warren Bruce A.
Published: January 2012

Meander patterns observed in the Gulf Stream east of Cape Hatteras exhibit correlations with bottom topography. An examination of the orders of magnitude of terms in the Gulf Stream vorticity balance suggests that if the current extends to the ocean bottom, as implied by some recent deep velocity measurements, its path must indeed be controlled principally by the topography of the Continental Rise, with a generally smaller constraint imposed by the meridional variation of the Coriolis parameter. Approximate current paths calculated according to this mechanism-steady-state conservation of potential vorticity-agree sufficiently well with observed paths to confirm the topographic explanation of large-scale meanders.

The observed variety in meander patterns is attributed to fluctuations in current direction and path curvature near Cape Hatteras.

These conclusions make doubtful any direct relation between large-scale meanders and possible instabilities of the Gulf Stream east of Cape Hatteras, and between the distribution of wind stress and the separation of Stream from coast.
Stratospheric ice nucleus measurements from balloons
Authors: Bigg E. K. , Miles G. T.
Published: January 2012

The ice nucleus content of stratospheric air was measured at one height in the range 13 to 27 km, on each of 13 experiments, by means of a vacuum pump and filters carried on large balloons.

The concentrations were in close agreement with those found by TELFORD (1960) using an expansion cold chamber in an aeroplane and, per unit mass of air, were comparable with the extreme maxima recorded at the ground in long sequences of measurements in Australia. It is suggested that localised rapid transfer of air from stratosphere to lower troposphere is a probable cause of some ice nucleus storms at the ground. The source of the stratospheric ice nuclei is uncertain but reasons are given for supposing the nuclei to be of extra-terrestrial origin.