摘要:

AbstractObservations of atmospheric pollution throughout Britain are considered in relation to the amounts of pollution emitted through the combustion of coal. The estimated weight of ash emitted into the air and the estimate, from deposit gauges, of the ash deposited, are considered likely to agree fairly well at a figure of rather over one million tons per annum (one million tonnes/yr).On the assumption that about 1.5 million tons of smoke are blown to sea each year, it is shown that about 1.1 million tons of sulphur dioxide are blown to sea each year; the remaining 0.8 million tons of smoke and 3.9 million tons of sulphur dioxide must be deposited in Britain, irrespective of the quantities measured in deposit gauges.The average life of a smoke particle before deposition on land is probably of the order of 1–2 days; that of a molecule of sulphur dioxide is estimated with rather more certainty to be less than 12 hours.Of the chlorides collected in deposit gauges more than half, as a rule, come from the sea, and less than half from the utilization of coal; but the ratio must vary with the position of the deposit gauge relative to the sea and to industrie

ISSN:0035-9009    

DOI:10.1002/qj.49707633002

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractTheoretical values of average annual evaporation from the British Isles are calculated from long‐term averages of air temperature, duration of sunshine, vapour pressure and wind speed for about 100 stations. Direct estimates of the same quantity are obtained from long‐term averages of annual rainfall and annual run‐off from about 40 catchment areas. The two kinds of estimate agree and are plotted on a map to show the geographical variation of evaporation. This shows an increase from 14 in. per annum in Scotland to 20 in. along the south

ISSN:0035-9009    

DOI:10.1002/qj.49707633003

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe connection between the development of depressions and anticyclones and the degree of vertical stability of the atmosphere is examined. It is concluded that in middle latitudes the damping due to stability is not important in the largest‐scale circulations of diameter greater than about 2,000 km, but has controlling significance for systems of diameter less than about 1,000 km. The difference in the rate of development between an ordinarily stable and a neutral atmosphere may be ten‐fold or more for the smaller systems. A very small degree of instability in depth will permit small‐scale cyclonic development to proceed rapidly.Furthermore, the damping effect of atmospheric stability is inversely proportional to the square of the Coriolis parameter. At 10° latitude, for example, the effect becomes dominant for all practical diameters, and it would appear difficult for cyclones or anticyclones of any reasonable size to develop significantly in low latitudes, with the exception of cyclones in a vertically unstable atmo

ISSN:0035-9009    

DOI:10.1002/qj.49707633004

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractFrom a classification of 50 years' daily weather maps (1898—1947) the outstandingly long spells of weather, lasting over 25 days, have been picked out. Frequency curves show the occurrences of these long spells on each day of the year and also the occurrences of each of the seven defined weather‐types individually. This leads to a suggested division of the year into five periods, to be considered as natural seasons, and appears to support the definition of more numerous shorter seasonal phases or episodes (singularities). Good correspondence is found with the long‐year daily or weekly mean figures of pressure, temperature, rainfall, sunshine, etc. The significance of these phenomena, their dependability as regards date and their secular persistence are disc

ISSN:0035-9009    

DOI:10.1002/qj.49707633005

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707633006

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractShade temperatures and humidities in a standard screen and at an arbitrary level of 15 cm in potato crops were continuously recorded during three summers, 1947–49.In dry sunny periods : (1) the maximum temperature in the crop was from 0° to 13°F higher than in the screen, and over a period of eleven weeks in 1947 averaged 6°F higher (2) the crop minimum was about 2°F lower than in the screen (3) over a period of five weeks in 1949 the average daily mean temperature in the crop was 2.2°F higher than in the screen, and (4) the average daily temperature range was 8°F greater than in the screen.Wind, wet soil and cloudy weather greatly reduced these contrasts; occasionally the crop minimum was higher than the screen minimum.By day, humidity was higher in the crop than in the screen, the average difference at the minima being 5 per cent in relative humidity, and 7°F in dew point. By night, the dew point in the crop was, on average, 2°F lower than in the screen, corresponding to the observed difference in mean minimum air temperatures.During 1948 and 1949, more precise discontinuous records were taken of temperature, humidity and wind speed in and above potato crops with different densities of foliage in a variety of weather conditions. Temperature and humidity were measured at 10, 20 or 30, and 60 cm; wind at 20, 30 and 200 cm above ground level. In the crop there was only a slight temperature gradient in the early morning and throughout cloudy days, but during sunny days gradients were produced, depending on crop density; it was hottest at 10 cm in an open crop, at 30 cm in a dense crop; in both it was usually coolest at 60 cm when the soil was dry, but over wet soil the lowest temperature was found at 10 cm. Except on cloudy days, temperature inversion took place before sunset whatever the foliage density or moistness of the soil.Humidity (dew point) was usually greatest at 10 cm, but in a dense crop over dry soil water vapour transpired from the leaves often caused the air at 30 cm to be more humid than that at 10 cm.Wind affected both temperature and humidity by increasing lapse rates and causing rapid fluctuations within the crop, particularly of humidity. Changes of wind speed within the crop took place every few seconds, the amplitude of the fluctuations depending on the speed of the wind above

ISSN:0035-9009    

DOI:10.1002/qj.49707633007

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707633008

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707633010

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractRelatively simple instruments for measuring the heat flux into or out of the soil are described together with methods of calibration. One form consists of a suitable metal disc of sandwich construction producing a thermal e.m.f. proportional to the heat flux through the disc, which is placed in the soil just below the surface.Details are also given of another form of flux plate which is suitable for continuous recording using a thread recording galvanometer.

ISSN:0035-9009    

DOI:10.1002/qj.49707633011

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

ISSN:0035-9009    

DOI:10.1002/qj.49707633012

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY