bluuebunny/crossref_metadata_2025 huggingface dataset:
Linking context and strategy in donor support for decentralisation: a diagnostic framework
Authors: Fritzen Scott A.
Published: February 2007

International donors, long‐standing supporters of decentralisation reforms in developing countries, often face the challenge of aligning programme assistance to the great variety of country governance settings in which many operate. This article presents a framework for assessing the implications of governance and institutional context for a range of programming challenges, with particular reference to the challenge of decentralised programming. The framework has three conceptual steps. Country governance and institutional change environments are first described in terms of how enabling governance capacities are for decentralised programming, and how rapid and predictable the rate of institutional change is. Second, these environmental considerations are associated with overall assistance modalities of donors, in areas such as the type of partners sought and interventions selected. Third, a range of options concerning the aims, scope and extent of decentralising programming are reviewed and linked to the diagnostic framework above. The framework is broadly derived from organisational contingency theory, which it is argued has been relatively neglected in the study of development administration due to a preponderance of analysis based on single‐case studies. Copyright © 2007 John Wiley & Sons, Ltd.
Does consolidation with autologous stem cell transplantation improve the outcome of children with metastatic or relapsed Ewing sarcoma?
Authors: Al‐Faris Nafisah , Al Harbi Talal , Goia Cristina , Pappo Alberto , Doyle John , Gassas Adam
Published: February 2007

Objective

To evaluate the role of high‐dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT) as consolidation therapy for children with high‐risk Ewing sarcoma (ES) treated at The Hospital for Sick Children (SickKids), Toronto.

Patients and Methods

The charts of children treated for high‐risk ES (defined as metastatic at diagnosis or relapsed) between 1990 and 2005 at SickKids were reviewed. Forty‐five children were identified. Twenty patients received ASCT after induction with vincristine, doxorubicin, ifosfamide, cyclophosphamide, and etoposide. Patients with resectable tumor or lung metastases underwent surgery and those with non‐resectable tumors were treated with irradiation. Twenty‐five patients were treated with conventional chemotherapy (CC). Primary metastatic patients were treated with either a local protocol or as per POG 9354. At relapse, patients were treated with topotecan, cyclophosphamide, then ifosfamide, carboplatin, and etoposide (ICE). Local control was attained with surgery and/or irradiation.

Results

Ten of the 20 patients treated with ASCT are alive (median follow‐up 6 years), with 8/10 being in remission more than 5 years from diagnosis. The 3‐year overall survival (OS) for ASCT was 59%, (95% CI: 36%, 81%) compared to 34% (14%, 53%) for patients treated with CC (P‐value = 0.06). The 3‐year event‐free survival (EFS) for the ASCT was 39% (17%, 60%) compared to 32% (13%, 50%) in the CC group (P = 0.08).

Conclusion

ASCT appears to add some benefit to conventional multimodality therapy for children with high‐risk ES. Randomized controlled trials are warranted. Pediatr Blood Cancer 2007;49:190–195. © 2007 Wiley‐Liss, Inc.
Translocation positive acute myeloid leukemia associated with valproic acid therapy
Authors: Williams David C. , Massey Gita V. , Russell E. Clifton , Riley Roger S. , Ben‐Ezra Jonathan
Published: February 2007

Valproic acid is an effective anti‐epileptic medication often used for long‐term control of seizure disorders that has been implicated in hematological toxicities, including rare reports of myelodysplasia and acute leukemia. Here, we report a case of valproic acid‐related leukemia‐like syndrome with a t(8;16) chromosomal translocation. After discontinuing valproic acid, the hematological findings completely resolved. Pediatr Blood Cancer 2008;50:641–643. © 2007 Wiley‐Liss, Inc.
Comparison of the capabilities of accelerated solvent extraction and sonication as extraction techniques for the quantification of kavalactones in piper methysticum (Kava) roots by high performance liquid chromatography with ultra violet detection
Authors: Warburton Emma , Norris Paul L , Goenaga‐Infante Heidi
Published: February 2007

A conventional extraction technique of sonication has been compared, in terms of extraction efficiency, extraction time and amount of solvent, with the more novel technique of accelerated solvent extraction for the extraction of kavain from the powdered roots of Piper methysticum (Kava) with acetone. The extracts were analysed using high‐performance liquid chromatography with ultra violet detection. The effects of varying solvent volume and extraction time upon the quantity of kavain extracted with sonication, and the effects of varying temperature upon the kavain extraction efficiency by ASE, were investigated. ASE was found to be more efficient with respect to time and solvent volume required; however, a good agreement was found between the kavain concentration obtained using both extraction techniques. © Crown Copyright 2007. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd.
Simultaneous determination of total hypericin and hyperforin in St. John's wort extracts by HPLC with electrochemical detection
Authors: Rückert Ulla , Likussar Werner , Michelitsch Astrid
Published: February 2007

An analytical procedure was developed for the simultaneous determination of total hypericin (protopseudohypericin, pseudohypericin, protohypericin and hypericin) and hyperforin in Hypericum perforatum (St. John's wort) extracts and its preparations. The determination of total hypericin and hyperforin in one step was achieved by exposing the samples to artificial daylight in amber glass vials. This procedure allows both the photoconversion of the protoforms into the appropriate hypericins and the protection of the photosensitive hyperforin. For quantification, an HPLC method with electrochemical detection was applied. As an example of the application of the principle, two preparations containing St. John's wort were assayed. Copyright © 2007 John Wiley & Sons, Ltd.
A single HPLC‐PAD‐APCI/MS method for the quantitative comparison of phenolic compounds found in leaf, stem, root and fruit extracts of Vaccinium angustifolium
Authors: Harris Cory S. , Burt Andrew J. , Saleem Ammar , Le Phuong Mai , Martineau Louis C. , Haddad Pierre S. , Bennett Steffany A. L. , Arnason John T.
Published: February 2007

A method was developed for the analysis of Vaccinium angustifolium Ait. (Lowbush blueberry), which is a widely used natural health product, particularly for the treatment of diabetic symptoms. While the anthocyanin content of the fruit has been well characterized, the chemistry of the vegetative parts used in supportive therapy for diabetes has been largely ignored. Using a metabolomics‐based approach for compound identification with an emphasis on phenolic metabolites, a single HPLC‐PAD‐APCI/MS method was developed for the separation and quantitation of the major metabolites found in the 95% ethanol extracts of leaf, stem, root and fruit. The leaf extract contained high concentrations of chlorogenic acid (∼100 µg/mg extract) and a variety of quercetin glycosides that were also detected in the fruit and stem extracts. Flavan‐3‐ol monomers (+)‐catechin and (−) ‐epicatechin were found in all plant parts but their procyanidin dimers were exclusively identified in the stem and root. The accuracy and precision of the presented method were corroborated by low intra‐ and inter‐day variations in quantitative results in all plant part extracts. Further validation of the extraction and analytical protocols focused on identified compounds with reputed anti‐diabetic activity, revealing recoveries greater than 80% and detection limits of 0.12–2.73 µg/mL. Copyright © 2007 John Wiley & Sons, Ltd.
A new method for estimating insolation based on PV‐module currents in a cluster of stand‐alone solar systems
Authors: Nieuwenhout Frans , van der Borg Nico , van Sark Wilfried , Turkenburg Wim
Published: February 2007

In order to evaluate the performance of solar home systems (SHSs), data on local insolation is a prerequisite. We present a new method to estimate insolation if direct measurements are unavailable. This method comprises estimation of daily irradiation by correlating photovoltaic (PV) module currents from a number of SHSs, located a few kilometres apart. The method was tested with a 3‐year time series for nine SHS in a remote area in Indonesia. Verification with reference cell measurements over a 2‐month period showed that our method could determine average daily irradiation with a mean bias error of 1·3%. Daily irradiation figures showed a standard error of 5%. The systematic error in this method is estimated to be around 10%. Especially if calibration with measurements during a short period is possible, the proposed method provides more accurate monthly insolation figures compared with the readily available satellite data from the NASA SSE database. An advantage of the proposed method over satellite data is that irradiation figures can be calculated on a daily basis, while the SSE database only provides monthly averages. It is concluded that the new method is a valuable tool to obtain information on insolation when long‐term measurements are absent. Copyright © 2007 John Wiley & Sons, Ltd.
Nucleophilic reactivity of the azide ion in various solvents
Authors: Phan Thanh Binh , Mayr Herbert
Published: February 2007

The kinetics of the reactions of the azide ion with benzhydrylium ions were investigated photometrically in different alcohol/acetonitrile mixtures and in DMSO at 20°C. Since the competing reactions of the benzhydrylium ions with the solvents are generally slower, the second‐order rate constants of the reactions of the benzhydrylium ions with the azide ion can unambiguously be determined to yield nucleophilicity parameters N and s for the azide ion in different alcohols. Several reactions of the benzhydrylium ions with the azide ion are reversible, which allowed the determination of the equilibrium constants and the rate constants of the reverse reactions. It is found that benzhydrylium ions with annelated six‐membered rings are better electrophiles and better electrofuges than the five‐membered ring analogs due to the lower intrinsic barriers of the former reactions. Copyright © 2007 John Wiley & Sons, Ltd.
Comparative evaluation of wound healing potency of Vitex trifolia L. and Vitex altissima L.
Authors: Manjunatha B. K. , Vidya S. M. , Krishna V. , Mankani K. L. , Singh S. D. Jagadeesh , Manohara Y. N.
Published: February 2007

The wound healing potency of ethanol leaf extracts of V. trifolia L. and V. altissima L. was evaluated in excision, incision and dead space wound models. Both plants were found to possess significant wound healing activity which was evidenced by a decrease in the period of epithelialization, an increase in the rate of wound contraction, skin breaking strength, granulation tissue dry weight, hydroxyproline content and breaking strength of granulation tissue. Histopathological study of the granulation tissue also showed an increased collagenation when compared with the control group of animals. Of the two extracts, the ethanol leaf extract of V. trifolia showed maximum wound healing activity compared with the leaf extract of V. altissima. However, on comparison with the control group, both leaf extracts were found to possess significant wound healing potency. Copyright © 2007 John Wiley & Sons, Ltd.
Carbenoxolone and triterpenoids inhibited mucin secretion from airway epithelial cells
Authors: Heo Ho Jin , Kim Cheolsu , Lee Hyun Jae , Kim Young Sik , Kang Sam Sik , Seo Un Kyo , Kim Yun Hee , Park Yang Chun , Seok Jeong Ho , Lee Choong Jae
Published: February 2007

This study investigated whether carbenoxolone, oleanolic acid and ursolic acid affect ATP‐induced mucin secretion from cultured airway epithelial cells. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled using 3H‐glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of each agent to assess the effects on 3H‐mucin secretion. The possible cytotoxicity of each agent was investigated with a lactate dehydrogenase assay. The results were as follows: (1) carbenoxolone, oleanolic acid and ursolic acid significantly inhibited the secretion of airway mucin induced by ATP; (2) none of the compounds showed significant cytotoxicity at any concentration. This result suggests that carbenoxolone, oleanolic acid and ursolic acid can regulate ‘mucin secretion induced by ATP’ – a phenomenon simulating mucus overproduction from inflamed airway epithelial cells – by directly acting on airway mucin‐secreting cells. Copyright © 2007 John Wiley & Sons, Ltd.
Forecasting the coastal rainfall of burma
Authors: Kha Maung Maung
Published: February 2007

This paper describes an attempt to drive forecasting formulae for the mansoon rainfalls during the season, June to August, for the Arakan Coast, the Irrawaddy Delta and the Tenasserim Coast of Burma.

The method used is partly synoptic and partly statistical. In the first place, the anomalies (i.e., deviations from long‐period mean values) of monthly pressure and temperature over the world from January to May in the years of extraordinarily deficient and excessive rainfalls are plotted on world maps. These maps are then examined with a view to finding features which are common to years of deficient rainfall and which are reversed in years of excessive rainfall.

When such features have been found, the appropriate arithmetical data representing these features are correlated with the rainfalls of the three regions. Sir Gilbert Walker's methods are then employed for evaluating regression equations connecting the rainfall with the factors correlated.

Forecasting formulae (regression equations) are developed separately for the Arakan Coast rainfall, the Irrawaddy Delta rainfall and the Tenasserim Coast rainfall. The total theoretical correlation coefficients between the forecast and actual rainfall are .80, .80 and .87 respectively.
Inclined streamline flow
Authors: Schaffer T. W.
Published: February 2007

Equations of motion for air‐currents flowing at an angle to the horizontal are derived. From these an equation is developed relating the veering or backing of the wind with height to the rate of ascent of the air and the local rate of rise of temperature. An implication concerning the upper pressure field is briefly investigated and finally some simple illustrative examples are given.
Rainless days of London
Authors: Belasco J. E.
Published: February 2007

The incidence of the 12,616 rainless days which have occurred at London (Kew) during the 70 years, 1878 to 1947, has been examined, a rainless day being one on which less than 0·1 mm. of rain has fallen.

The average number of rainless days is greatest in June and least in November. On the average just under half the days in the year are rainless.

For the 70 years, the frequency of rainless days on each day of the year has been found, that on May 21 being the greatest, that on October 28 the least. Many of the days when this frequency is exceptionally high or low are associated respectively either with the anticyclonic or stormy “singularities” of C.E.P. Brooks, or with large positive and negatives departures from the mean daily pressure at Kew.

The shortest rainless spells (1 and 2 days) are most frequent in October, the longest (exceeding 14 days) in July. Spells of more than 14 days have not been recorded between October 28 and January 22. Spells exceeding 6 days' duration occur at all seasons of the year. They are to be expected most frequently in June and least so just after Christmas. The odds to one against the occurence of a rainless day being included in a rainless spell exceeding 14 days are about 10 in June and July and 118 in January.

An examination has been made of the synoptic succession which marks the onset, course and termination of the nine longest rainless spells and a brief summary given.
Heat transport and zonal stress between latitudes
Authors: Priestley C. H. B.
Published: February 2007

The meridional flux of heat, water vapour, and momentum can be directly evaluated at any station where regular radio soundings and upper wind measurements are made. Physically and mathematically it is convenient to separate the flux into an eddy flux, due to the migrant pressure systems, a standing‐eddy flux attributed to the semi‐permanent systems, and a third component arising from the toroidal circulation.

The first and third have been evaluated for a two‐year period at Larkhill. Certain earlier conjectures concerning the general circulation and internal heat adjustment of the atmosphere are hereby directly confirmed. The distribution of eddy flux with height and with season are studied. Among the more important new results is that, in this region at least, the eddy‐flow of heat at some levels is from regions of low towards higher mean temperature and that the eddy‐fluxes of heat in sensible and latent form are approximately equal.

The horizontal eddy stress is not uniquely determined by the direction of increasing angular momentum, and its sense may vary from season to season.

The main purpose of this preliminary work is to draw attention to the method and its potential importance in physical climatology, and to appeal for a global investigation which is beyond the capacity of any one individual.
Vertical diffusion in the lowest layers of the atmosphere
Authors: Deacon E. L.
Published: February 2007

A semi‐empirical treatment of the vertical diffusion of matter in the lowest layers of the atmosphere is given in the following and shown to be in good agreement with the results of carefully conducted field experiments made over two different types of natural land surface. The present work extends the treatment of diffusion in an adiabatic atmosphere given by Calder (1948) by allowing for the effects of thermal stratification.

The treatment is based on the results of an extensive investigation of vertical profiles of mean wind velocity in the lowest ten metres of the atmosphere (mainly carried out at the Chemical Defence Experimental Station, Porton, Salisbury Plain). A complete account of this study will probably be published as aGeophysical Memoirof the Meteorological Office.
Constant‐Height Balloons – Calculation of Geostrophic Departures
Authors: Durst C. S. , Gilbert G. H.
Published: February 2007

The accelerations observed during the flight of seven constant‐height balloons are examined.

These observations extended over periods of 2 to 4 1/2 hr. It is found that the values of the geostrophic departures determined from the accelerations are closely comparable with the values deduced independently from contour charts and observed winds.

The variations in the acceleration are greater than would be expected from errors in wind determination alone; it is deduced that this is due to the wind at the level of flight being affected by eddies giving rise to fluctuations of the order of 3 to 4 kt in the value of the mean wind determined over half‐hour intervals.
A study of the transfer of heat and water vapour above a surface of short grass
Authors: Rider N. E. , Robinson G. D.
Published: February 2007

The profiles of temperature, humidity and wind have been determined by conventional methods in the lowest 2 m of the atmosphere above a close‐cut grass surface, with simultaneous observations of the heat absorbed in the soil and of the short‐wave and long‐wave radiative flux of heat. Twentynine sets of observations were made; the details are given in Appendix I.

The ratio of the gradients of temperature and humidity is found to be independent of height, and changes with height of the vertical convective flux of heat and of water vapour are relatively small; the ratio of the coefficients of eddy diffusion of heat and water vapour is therefore independent of height. These coefficients are then assumed equal and the convective fluxes of heat and of water vapour determined (Bowen's method). The fluxes are also determined by an aerodynamic method which assumes equality of the eddy viscosity and the appropriate diffusion coefficient. The results of the two methods agree in most cases, in both stable and unstable stratifications, but there are some exceptions which cannot be explained.

Absorption of radiation by the air is investigated. It is shown that this is comparable in effect with convection in the control of temperature and relative humidity. Particular attention is paid to four occasions with very light wind (including two with fog formation) when horizontal mixing appeared to be of major importance.

Some examples are presented of wind profiles which do not conform to the law proposed by Deacon. A value between 0.5 and 1.5 is suggested for the critical Richardson number.
On the direct measurement of humidity mixing ratio and its fluctuations
Authors: Sheppard P. A. , Elnesr M. K.
Published: February 2007

An apparatus is described for the direct measurement of humidity mixing ratio. It is designed primarily for recording the turbulent fluctuations in the mixing ratio in the lower atmosphere, and is based on an electrical analogue of the wet‐bulb equation, using dry‐ and wet‐bulb thermocouples.

Field tests give agreement with Assmann psychrometer values to within less than 1 per cent under favourable conditions for comparison.
Synoptic properties of frontal surfaces
Authors: Godson W. L.
Published: February 2007

The mathematical consequences of a first‐order temperature discontinuity at a front are developed for the fields of pressure, temperature, and geostrophic wind. These results are applied to determine the correct construction of synoptic charts in the vicinity of fronts, and to determine criteria for obtaining the boundary levels of frontal surfaces, as well as their orientations and slopes. Techniques for qualitative and quantitative evaluation of vertical motions at fronts are also presented. These concepts, and analytical methods based on them, are illustrated by reference to the synoptic situation over North America on 4 April 1950. Particular attention is paid to the structure of occluded frontal waves, their three‐dimensional analysis and representation.
The slopes of cumulus clouds in relation to external wind shear
Authors: Malkus Joanne S.
Published: February 2007

An equation for the slope of cumulus clouds is derived. It is shown to depend upon the vertical ascent rate, the external wind shear and the horizontal frictional forces between the cloud and its surroundings. These frictional forces are of two origins: one due to entrainment or mixing with the outside air, and the other due to form or body drag.

Four observational cases are presented, one concerning trade cumulus, and three involving clouds in mid‐latitudes. In two of these, measurement of updraught speed, wind shear, and cloud slope permit an estimate of the magnitude of the friction forces. The minimum contribution due to entrainment is approximately equal to that inferred by Stommel for trade cumulus.
Orographic cirrus clouds
Authors: Ludlam F. H.
Published: February 2007

Observations are described from which it is inferred that the air flowing over small hills (1,000 ft high) may even in the cirrus levels suffer vertical displacements of 2,000 ft or more, which cause the formation of clouds able to travel away from the hills, and may be responsible for a diurnal variation in cirrus frequency.
The evaluation of infra‐red radiative fluxes due to atmospheric water vapour
Authors: Godson W. L.
Published: February 2007

An empirical technique is developed for obtaining the flux transmission, over a narrow spectral interval, of an assembly of layers of varying pressure and temperature. Although verified only for a regular spectrum of the type proposed by Elsasser (1942), the technique should be valid for any type of spectrum. Using this technique as a check, an empirical method of sufficient accuracy is developed for evaluating the integrated flux transmission of an assembly of layers. This latter method enables the radiation‐chart procedures, advocated by Elsasser (1942), Robinson (1947), and Yamamoto (1952), to be tested for simply‐stratified atmospheric models. Such tests reveal that the effects of temperature are inadequately taken into account. A principle advocated by Cowling (1950b) is developed into a radiation‐chart procedure, in which the absorbing mass of each individual layer is corrected to a standard temperature and pressure. The coordinates of such a radiation chart are presented, but unfortunately adequate experimental data for the construction of such a chart are not yet available.
Turbulence in clouds as a factor in precipitation
Authors: East T. W. R. , Marshall J. S.
Published: February 2007

Visual and radar observations of the height of formation of precipitation in shower clouds in relation to temperature, and measurements of droplet population, show that when cumulus clouds produce showers it is often by coalescence, rather than by an ice‐phase process.

Langmuir's work gave the conditions necessary for collisions to take place between droplets. The droplets of young cumulus clouds are less than 20 microns in radius and calculation shows that they are too small and settle too slowly by gravity alone to grow at an appreciable rate by colliding with each other.

The updraught in a cumulus cloud is highly turbulent so that the air containing the droplets is being perpetually accelerated in a random way. An analysis of random acceleration in one dimension shows that it would produce collisions if violent enough, and in conjunction with gravity would start droplets into growth. Once their radii reached about 20 microns they would continue to grow with or without turbulence. Such a mechanism is consistent with the observed changes in droplet size distribution.

Provided that sufficient energy were available in a suitable frequency range, turbulence would initiate a shower in a cumulus cloud. Numerical confirmation of the mechanism awaits suitable measurements of small‐scale turbulence in cloud, but meanwhile an alternative approach through macroscopic energy considerations might prove fruitful.
The terminal velocity of snowflakes
Authors: Langleben M. P.
Published: February 2007

Measurements of the terminal velocity of aggregate snowflakes at the ground indicate that the velocity is approximately proportional to the one‐tenth power of the mass. The constant of proportionality is dependent on the basic crystal types in the aggregates. It is moreover greatly increased by riming or by slight melting of the snowflakes.

When snow grows markedly at a generating level, the rate of fall of the snow particles as determined from radar observations is found to correspond to the velocities of aggregates. It is thus inferred that aggregation can occur at temperatures far below the freezing point.
Provisional maps of the reliability of annual rainfall in East Africa
Authors: Glover J. , Robinson P. , Henderson J. P.
Published: February 2007

East Africa is a dry country. Its increasing population, which is dependent on agriculture, seeks expansion into new agricultural lands. Most of the available land lies in regions of low and variable rainfall. One of the most important requirements in the selection of sites for future development is that they should be subject to a reasonably reliable rainfall suited to the potential crop.

Earlier investigations have shown that the distribution of annual and seasonal rainfall in East Africa can be assumed to be normal for all practical purposes. On this basis it is possible to calculate the probabilities of receiving certain selected minimum values suited to a crop, and these can be combined for mapping purposes. Maps of the reliability of annual rainfall at two selected levels illustrate the potentialities of the method. The meteorological background to the maps and their application to agricultural development are briefly discussed.
Electrostatic field‐changes due to lightning discharges
Authors: Pierce E. T.
Published: February 2007

Extensive observations are described of the changes of electrical field produced by lightning discharges at distances of less than 100 km; in this range electrostatic effects are dominant. The results are analysed in detail.

A long series of capillary‐electrometer records obtained with auxiliary amplifying equipment give statistical information upon the magnitude‐distance and sign‐distance relationships for the total electrostatic field‐change due to a lightning flash. From oscillographic observations it is shown that most of this change in field occurs comparatively slowly. It has proved possible to separate field‐changes into distinct groups; these are considered in turn and values given for such quantities as the electric moment and the times involved in each stage, etc.

Finally, meteorological influences and the relative frequency of occurrence of cloud and ground discharges are investigated.
A working theory of the bent‐over plume of hot gas
Authors: Priestley C. H. B.
Published: February 2007

An ascending plume of hot gas is initially diffused by the turbulence which is induced by its own motion and later, but before all upward motion and buoyancy are lost, by the natural turbulence of the environment. A working solution is put forward for the first phase in terms of a spreading coefficient c and for the second in terms of a mixing rate k, and it is shown that the transition from one phase to the other should be quite well marked. Proposed laws for c and k as functions of wind speed lead to good agreement with Bosanquet's measurements of plume heights downwind from factory chimneys.

The theory extends to conditions of thermal stratification. It shows that a final equilibrium level should always exist except when very light winds coincide with unstable stratification, and it indicates the buoyancy and stratification factors appropriate for scaling down to wind‐tunnel experiments. The relative roles of initial impetus and initial buoyancy are characterized by a modified form of the Froude number.
The empirical relation between solar radiation and hours of bright sunshine in the high‐altitude tropics
Authors: Glover J. , McCulloch J. S. G.
Published: February 2007

The relationship between total solar radiation on a horizontal surface (Q), as measured by a pyranometer, and hours of bright sunshine (n), as measured by a Campbell‐Stokes recorder, has been examined and it is shown that there is little practical gain in weighting the hourly sunshine records by the sine of the apparent solar altitude.

In the non‐dimensional equation

values of a and b derived from daily records are shown to vary widely from month to month but their distribution appears to be substantially normal. Actual mean values of a and b, for a five‐year period (1938–1943) at Kabete, Kenya (altitude 6,000 ft) differed slightly but non‐significantly according to the length of period in which the data were grouped, the slope of the equation increasing with increased smoothing.

The sum of a and b has been shown to be approximately constant (≃ 0·82) at Kabete, where the optical air mass varies little throughout the year. For checking the consistency of the data from various parts of the world, it is essential to reduce the differing apparent transmission coefficients to standard measure. In practice, a simple correction to optical air‐mass unity has proved adequate for the records available at this station.
Numerical experiments in the integration of the meteorological equations of motion
Authors: Knighting E. , Jones D. E. , Hinds Mavis K.
Published: February 2007

It is usual to use finite‐difference methods in carrying out the time integration of the equations of motion as adapted to the prediction of the large‐scale atmospheric pattern, and this implies a choice of the mesh length and time increment to be used. The effect of changing the size and orientation of the mesh upon the computed values of the vorticities and their advection is examined, and the resulting differences between 24‐hr predictions are shown to be important.
William Bulkeley's record of the weather of Anglesey 1734–1743, 1747–1760
Authors: Oliver J.
Published: February 2007

The study of climatic fluctuations before the nineteenth century is hindered by the paucity and poor distribution of instrumental records, and increasing reliance must be placed upon diaries and other descriptive sources. The diary of William Bulkeley of Anglesey, over the period between 1734 and 1760, has been examined. From the information it contains, resultant wind directions and constancy have been calculated. Frequencies of days with rain, snow, hail, frost and thunder are tabulated. A comparison is made between the general monthly rainfall serial values calculated for England and Wales and data derived from the diary. The record of the aurorae observed is given.
Absorption and emission in the atmospheric window from 770 to 1,250 cm−1
Authors: Roach W. T. , Goody R. M.
Published: February 2007

Combined absorption and emission spectra have been recorded in the atmospheric window from 770 to 1,250 cm−1 both in London and in the relatively clean air of Ascot, Berks. The absorption spectra have been partially analysed in terms of selective and continuous extinction. The continuous extinction outweighs the selective in both Ascot and London. There is good agreement between the observed selective absorption and existing theoretical and laboratory data upon gases known to be present in the atmosphere.

The opacity of the continuum shows an increase towards low frequency, and it is much greater in London than in Ascot; in both places it is positively correlated with water vapour. The average effective emission temperature of the continuum is not significantly different from that of water vapour.

The only hypothesis which seems to fit all the observations is that in London the continuum extinction is largely caused by aerosol extinction while in Ascot this is only of minor importance. This requires that the extinction at Ascot be caused by wings of distant lines; this old suggestion of Elsasser is re‐examined and found to be plausible.

Attention is drawn to the important contribution which the continuum can make to the heat balance of the atmosphere below 2 km.
The effect of stability on computed tendencies and vertical velocities
Authors: Knighting E. , Gilchrist A.
Published: February 2007

The two‐parameter models used in numerical prediction of the contour height field usually assume a constant value of the hydrostatic stability, about −0·04°C mb−1. The effect of varying this value over the field is investigated and it is shown that as the stability approaches zero the computed tendencies and the vertical velocities are increased.
Snowfall measurements in northern Canada
Authors: Jackson G. I.
Published: February 2007

Sources of error in Canadian snowfall records are discussed, with particular reference to the six‐hour interval between measurements. Very slow rates of fall are usual at high latitudes and these cause ‘traces’ of snow to be recorded frequently which are not included in precipitation totals. Experience on Ellesmere Island suggests that the contribution from these traces may form a high proportion of total winter snowfall, and a longer interval between measurements seems desirable.
Radar scatter by large hail
Authors: Atlas D. , Harper W. G. , Ludlam F. H. , MacKlin W. C.
Published: February 2007

Radars with wavelengths of 3·3 and 4·67 cm have been used to measure the back‐scatter cross‐sections of individual artificial hailstones and their variations as melting occurs. The measurements confirm the cross‐sections computed theoretically. An ice sphere is a better scatterer than a liquid water sphere of equal size when its diameter exceeds 0·8 wavelengths; when the diameter lies between 1·2 and 2·3 wavelengths it is better by a factor of 10 or more. This behaviour of ice is supported by scatter measurements on a set of plexiglass (perspex) spheres with refractive index close to that of ice.

When melting begins, the 3·3 cm cross‐sections drop sharply toward the all‐liquid values; those at 4·67 cm decrease gradually, and sometimes not at all. The rate of decrease of the cross‐sections during melting is also more variable at 4·67 cm than at 3·3 cm. Most of the 3·3 cm change appears to occur during the initial growth of the liquid coat to a maximum thickness of about 0·01 cm, while the major drop in 4·67 cm cross‐sections occurs well beyond this stage of melting. The implications are that: (1) a water coat of 0·01 cm thickness has a major effect at 3·3 cm and a minor one at 4·67 cm; (2) liquid continues to collect in subsurface cracks and cavities in the ice and causes a further decrease in the cross‐sections after the maximum thickness of water coat has formed. The final cross‐sections are generally within 2 db of the all‐liquid value after 7 to 10 minutes of melting at 3·3 cm and after 15 to 20 minutes at 4·67 cm. Possible reasons for these results are discussed.
Measurements on the electricity of precipitation
Authors: Ramsay M. W. , Chalmers J. Alan
Published: February 2007

Measurements have been made of the electricity of precipitation, the potential gradient and the rate of rainfall. The results for the winter of 1957/58 show general agreement with those of earlier workers, in giving a linear relation between potential gradient and precipitation current, but those of the summer of 1958 are less crdered. Comparisons have been made of the currents to open and shielded receivers, and show general agreement. The ‘mirror‐image effect’ and time delays connected with it have also been studied, without any complete explanation.
Satellite cloud pictures of a cyclone over the Atlantic Ocean
Authors: Fritz S.
Published: February 2007

A composite of Tiros 1 pictures describing the cloud system in a mature cyclone, centred in the Atlantic Ocean to the west of Ireland, is described. Comparison of the pictures with conventional meteorological data shows that a stratiform cloud surrounding the storm was identical in position with a warm moist tongue of air flowing around the storm. In the centre of the storm where the clouds were more broken, giving the appearance of cumuliform clouds, a large mass of cold, dry air extended from the surface up to the tropopause above 400mb. A few areas of steady precipitation were present in the stratiform cloud regions while more scattered showers existed in the central cumuliform region. An area of relatively high winds circled the storm, in conformity with the expectations from the thermal wind relation when cold air and warm air layers reside side by side. A brief comparison is made between the vertical motion computations based on conventional data and the cloud areas.
The absorption of solar radiation by water vapour and carbon dioxide in a cloudless atmosphere
Authors: Roach W. T.
Published: February 2007

A method of computation of the direct absorption of solar radiation by the near infra‐red bands of water vapour and carbon dioxide in a cloudless, non‐scattering atmosphere using recent laboratory data compiled by Howard, Burch and Williams (1955) is described.

Three applications of this computation are discussed:

(i) Heating rates in an atmosphere whose water‐vapour distribution is given by radiosonde or aircraft observations.

(ii) Instantaneous heating rates as a function of solar zenith angle, altitude and precipitable water vapour.

(iii) A climatological study of heating rates in a cloudless atmosphere integrated over a 24‐hr period as a function of latitude, season, altitude and precipitable water vapour. The relative contributions to heating by water vapour and carbon dioxide are assessed between 10 and 1,000 mb.

The mixing ratio of carbon dioxide was assumed constant throughout the atmosphere, while idealized vertical distributions of water vapour mixing ratio were used in (ii) and (iii).
Accretion in mixed clouds
Authors: Macklin W. C.
Published: February 2007

An object on which ice is deposited when it moves through a supercooled cloud is warmer than its environment owing to the release of heat of fusion. If the rate of accretion is sufficiently great, the temperature of the object is raised to 0°C and its surface becomes wet. It has often been assumed that water in excess of that which can be frozen is shed into the wake of the object. The present experiments show that, at temperatures below – 2°C, the excess water is not shed but is incorporated into the ice structure, giving a ‘spongy’ deposit. Even in the temperature range – 2 to 0°C, the excess water can be retained if a sufficient concentration of ice particles is introduced into the droplet cloud. It has also been found that over a wide range of conditions, considerable quantities of ice particles may be accreted in addition to the supercooled droplets, and the crystalline structure of the deposit is modified accordingly. It is considered that at temperatures near 0°C, and possibly at lower temperatures the presence of ice particles in the supercooled cloud is necessary in order that none of the unfrozen water is shed.

The restriction formerly thought to be imposed on the growth rate of hailstones in the wet condition may now be removed.
Total ozone and perturbations in the middle stratosphere
Authors: Boville B. W. , Hare F. K.
Published: February 2007

Total ozone amounts are shown to vary with the motion systems of the stratospheric polar vortex. Two cold outbreaks, one over Europe in 1959 and the other over North America in 1960, produced similar pronounced minima in the total ozone records. The results support the hypothesis that major anomalies in the horizontal and seasonal distributions of total ozone are related to dynamical activity in the polar‐night vortex and the stratospheric warm belt.
Multi‐wavelength radar reflectivity of hailstorms
Authors: Atlas D. , Ludlam F. H.
Published: February 2007

Computations are made of the radar reflectivity Ze of particles present in hailstorm updraughts in exponential size spectra. The reflectivity varies substantially according to the radar wavelength and according to whether the particles are wet or dry. In severe storms a very strong echo may be observed aloft. Partly by reference to a particular example it is shown that its magnitude at the shorter wavelengths (Ze ± 107 mm6 m–3), and the variation of its intensity with wavelength, can reasonably be explained only if the responsible particles are large dry hailstones of almost uniform size. The dryness and sorting of the large stones is attributed to fall outside the updraught through a wind shear, and the decrease of echo intensity lower down to their re‐entry into the updraught and wetting. It appears that the likelihood and size of hail at the ground are indicated by echo intensity aloft at 3 cm, and less sensitively at 4·7 cm, but not at 10 cm. Measurements of echo intensity at several wavelengths are helpful in the study of severe storms.
Radiative transfer in the lower stratosphere due to the 9.6 micron band of ozone
Authors: Hitschfeld W. , Houghton J. T.
Published: February 2007

Precise numerical calculations of the flux divergence due to narrow regions of the ozone 9.6 micron band were made, using the relative strengths and positions of the spectral lines calculated by Kaplan, Migeotte and Neven (1956). The absolute line strength was estimated on the basis of Walshaw's (1957) laboratory measurements. Spectral models or Curtis's approximation were not used, but Lorentz shapes and uniform widths were assumed for all lines. Calculations up to a height of 33 km were made for two ozone ascents of Brewer and Milford (1960). The atmospheric heating rates obtained for narrow regions of the band were then combined to estimate the heating rate by the whole band with results in qualitative agreement with, though nearly twice as great as those of Plass (1956a). The effect of the radiative temperature of the atmosphere below the ozone layer (whether of ground or cloud top) appears to be great. The radiative heating by ozone in the 10‐20 km region is 0·2 or 0·3 degrees C per day for a ground temperature of 10°C, but may disappear altogether, if cloud is present just below the tropopause.

Using a larger computer, the procedure could be extended to cover the whole band, thereby avoiding the approximate extrapolation employed in this paper. The procedure could be applied to any absorption band, and is flexible to permit the use of any desired pressure and temperature dependence of the shape, width and strength of the spectral lines; results from it might serve as a standard against which conclusions reached by approximate methods can be checked.
Wind profiles over hills (in relation to wind‐power utilization)
Authors: Frenkiel J.
Published: February 2007

Following a previous country‐wide wind survey, two sites – each typical of one of the following two topographical categories: (a) a hill forming a part of a mountain ridge athwart the prevailing wind direction with steep leeward slopes, and (b) an isolated peak in a valley in the general direction of prevailing winds – were chosen for detailed investigation of wind behaviour with the purpose of correlating the characteristics of the wind flow over the hill to its topography. At each site, wind vertical gradient, wind direction, and temperature vertical gradient were measured in the height interval of interest to wind‐power utilization (10 m to 40 m above the hilltop) for a period of about a year.

These measurements have shown:

There is no close relationship between mean wind profile and mean temperature profile over hills.

Whilst the directional wind profiles are practically uninfluenced by wind speed, they are largely determined by: (a) the hill profile in the immediate neighbourhood of the site of measurements, and (b) the hill profile further upwind in relation to that near the measurements site.

The effect of thermal stratification is important for all wind speeds with the curves of wind ratio as a function of temperature gradient exhibiting a both minimum and a maximum, the location of which on the scale of temperature gradient depending on the hill profile.

A classification of wind‐power sites is given based on a single criterion, i.e., mean wind vertical gradient for the height interval from 10 m to 40 m. For optimal conditions for wind‐power utilization this gradient must vanish, a flow condition resulting from: (a) small hilltop area; (b) regular and smooth slopes of about 1 in 3 1/2 in the nearest few hundred metres from the hilltop.
Two‐dimensional mountain waves – a method for the rapid computation of lee wavelengths and vertical velocities
Authors: Foldvik A.
Published: February 2007

Lee wavelengths and vertical velocities have been computed for twenty‐six airstreams where reliable observations of the wave motion behind mountain ridges are available. The actual distribution of wind and stability has been modified in each case in order to approximate the internal parameter in the lee‐wave equation by an exponential function, as recommended by Palm and Foldvik (1960). There is good accordance between the computed wave motion and the observations.
The rise of an isolated thermal in wind shear
Authors: Hall W. S.
Published: February 2007

Using formulae derived by dimensional analysis from experiments on thermals in still surroundings, a theory is built up which predicts the motion of a thermal rising in various wind shears. A criterion to give the limits of applicability of the theory is put forward. Finally, the theory is applied to calculating the coefficients of heat and momentum transfer, where transfer is due solely to the rise of thermals.