摘要:

AbstractTwo years' study of the Helm Wind of the N. Pennines has led to certain conclusions, based on reconnaissance methods and direct observations, with which the somewhat contradictory features of earlier descriptions can be reconciled.The Helm Wind and its accompaniments form one example of a group of phenomena found in various parts of the world. In each case when a wind blows transverse to a range of mountains, a marked increase in the strength of the wind is noted by surface observers down the leeward slope and for a varying distance across the lowlands below, compared with that which prevails over the country as a whole.It is shown that this local increase in wind force arises inasmuch as the air descends the slopes to the lowlands with a velocity of the same order as that which would otherwise obtain in the free air at the summit level. Taking all the observations into account it appears that the circumstances necessary are (1) the existence of a sufficiently vigorous surface current with, by inference, a well‐developed inversion at a height which provisionally must be not more than three times that of the range from its base; (2) the crest of the range should be fairly even, and the leeward slope of the range must not be too steep or too broken‐up. The phenomena then resembles those which occur at a submerged weir with inclined faces; a “standing‐wave” is formed in the surface stream to leeward of the range. Vigorous downward and upward currents are found which may be dangerous to aircraft, but which may also be utilised. The conclusions reached are borne out by other authorities.Further study and investigation by more intensive methods on the ground, by the use of wind tunnels, and by gliders, would appear to be worth while. It is proposed to publish a further paper on certain aspects of the p

ISSN:0035-9009    

DOI:10.1002/qj.49707130901

出版商:John Wiley&Sons, Ltd    

年代:1945

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707130902

出版商:John Wiley&Sons, Ltd    

年代:1945

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707130903

出版商:John Wiley&Sons, Ltd    

年代:1945

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707130904

出版商:John Wiley&Sons, Ltd    

年代:1945

数据来源: WILEY

摘要:

AbstractThis paper deals with the general meteorology of Nigeria and adjacent territory. Part I describes the air masses and prevailing winds and the characteristic weather of four weather zones. Part II describes dust haze and just storms which occur and discusses the question of forecasting the onset and clearance of dust haze. Part III deals with instability phenomena in the form disturbance lines and local thunderstorms; a theory of their mechanism is put forward which agrees well with observed phenomena.

ISSN:0035-9009    

DOI:10.1002/qj.49707130905

出版商:John Wiley&Sons, Ltd    

年代:1945

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707130906

出版商:John Wiley&Sons, Ltd    

年代:1945

数据来源: WILEY

摘要:

AbstractThe paper describes a method of reducing atmospheric pollution by varying the emission of the offending material with meteorological conditions. The details of the application of this principle by the Trail plant of the Consolidated Mining and Smelting Co. of Canada, Ltd., located in southern British Columbia, are given. The problem there is to prevent damage by sulphur dioxide to vegetation in the state of Washington. An investigation of the distribution of winds and SO2in the Columbia River valley near Trail shows that, during growing season, the majority of fumigations are brought about by differential heating of the valley sides by the sun.Measured values of atmospheric turbulence and of wind speed and direction are fundamental in the control régime prescribed by the Arbitral Tribunal set up by governments of Canada and the United States. The possibility of applying this principle in other situations, and especially over level country, is discussed

ISSN:0035-9009    

DOI:10.1002/qj.49707130907

出版商:John Wiley&Sons, Ltd    

年代:1945

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707130908

出版商:John Wiley&Sons, Ltd    

年代:1945

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707130909

出版商:John Wiley&Sons, Ltd    

年代:1945

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707130910

出版商:John Wiley&Sons, Ltd    

年代:1945

数据来源: WILEY