ISSN:0035-9009    

DOI:10.1002/qj.49708335802

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractThe effects of changes in solar radiation on the climate of the earth are discussed with special reference to glacial phases in high latitudes and to pluvial periods which are common to the Earth as a whole. The relationship between the radiation and the glacial and pluvial phases is expressed in tabular form. Adopting the chronology of the glacial and pluvial phases during the Pleistocene Period, as published by K. P. Oakley, a curve of solar radiation is constructed using only the glacial phases; this proves to be a periodic curve with three complete oscillations between the begining of the Pleistocene Period and the present day. Using this radiation curve the periods of heavy and light precipitation are determined and compared with the pluvial periods. Three periods of heavy precipitation during the Pleistocene are indicated and a correlation of these with the observed pluvial periods in Africa is suggested.

ISSN:0035-9009    

DOI:10.1002/qj.49708335803

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractAverages of the wind vector at four times of the day were evaluated for 29 suitable days during the summer of 1951 at Wichita, Kansas, and Oklahoma City. The periodic portion of the wind variation vector is an ellipse at all levels with the major axis approximately in the direction of the wind vector. The amplitude reaches a maximum at 2,500 ft above the ground.The cause of the variation is sought by theoretical methods, first by finding what periodic variations would occur when the eddy viscosity is periodic in time and constant with height, and secondly by finding solutions with the aid of an electronic analogue computer for cases when the eddy viscosity is distributed arbitrarily with height. It is concluded that variations of the type which were observed can occur only when both the average value of the eddy viscosity and the amplitude of its variations decrease rapidly with height above the lowest third of the friction layer.

ISSN:0035-9009    

DOI:10.1002/qj.49708335804

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractDroplets of radius exceeding 30 μ are sometimes found in concentrations of order 100/lin non‐precipitating cumulus less than 5,000 ft in depth and having, on average, liquid‐water contents of only a few tenths of a gramme per m3. It is shown that droplets of this size may be produced by condensation and coalescence on hygroscopic nuclei of mass greater than 10−11g entering the bases of such shallow clouds, provided that these last for at least one hour. The published concentrations of giant salt nuclei seem only just sufficient to account for the observed numbers of large droplets, but simultaneous measurements of both are urgently re

ISSN:0035-9009    

DOI:10.1002/qj.49708335805

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractAn experimental technique has been established for measuring the rise of a plume from a stack, the ground‐level concentrations produced and the rates of deposition of dust emitted in the plume. It can be applied over distances where plumes from power stations are not normally visible. It can be used to give a result before weather and station conditions have changed appreciably and therefore produces information which can conveniently be compared with theoretical estimate

ISSN:0035-9009    

DOI:10.1002/qj.49708335806

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49708335807

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractA method is described for the separation and determination of hydrogen in air samples of approximately 200 litres N.T.P. by volume. The hydrogen is fractionally distilled from the bulk of the sample, oxidized to water by passing over heated copper oxide and finally condensed in a trap cooled in liquid oxygen. After freeing from the contaminating gases by pumping, the water is released from the trap and measured as vapour in a small calibrated volume.Although the accuracy of the method in its present form is not better than ± 10 per cent, the results seem to indicate that the hydrogen content of atmospheric air is a varying quantity.The average hydrogen content of air at ground level is 0.6 parts per million

ISSN:0035-9009    

DOI:10.1002/qj.49708335808

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractDaily measurements of freezing‐nucleus concentrations at 10,000 ft over southern England during January 1956 revealed no well‐marked peaks. The results also indicated, however, that the earth's surface was not the main source of freezing nuc

ISSN:0035-9009    

DOI:10.1002/qj.49708335809

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49708335810

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractReported failures of a generalized wind‐profile equation to predict correctly the shearing stress under certain conditions are found to be associated with low wind speeds close to the surface. The increase of drag coefficient of the surface‐roughness elements (e.g., grass blades) at low Reynolds numbers is the source of these discrepanc

ISSN:0035-9009    

DOI:10.1002/qj.49708335811

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY