摘要:

Alpha‐ray ionization is perhaps the most variable single component of the ionization of the lower atmosphere. Many measurements have been made to determine the ionization from airborne sources of alpha rays. This depends principally on the amount of radon and thoron in the atmosphere. An attempt is made here to evaluate the role of alpha rays originating from the surface of the ground and other naturally occurring surfaces. It was found that about ten per cent of the small ions observed at one meter above ground are originally produced at the ground and carried upward by convecti

ISSN:0002-8606    

DOI:10.1029/TR035i006p00869

年代:1954

数据来源: WILEY

摘要:

The mass transport of the Florida Current across the Key West‐Havana section has been studied by means of the associated electrical potential due to the geomagnetic field. An analysis of the seasonal, daily, and short‐term variations of the transport is presented, as well as a critical discussion of the limitations of the method of measurement emplo

ISSN:0002-8606    

DOI:10.1029/TR035i006p00872

年代:1954

数据来源: WILEY

摘要:

In geodesy, several methods will be applied for solving the crucial problems of geodesy: (1) determination of the dimensions of the reference ellipsoid, (2) the shape of the geoid, and (3) the computation of the geodetic control points. Therefore, the possibilities, limitations, and relative significance of the different methods used or planned to be used in geodesy, such as classic, flare, and rocket‐star triangulation; arc‐measuring. Shoran and Hiran, the solar eclipse, occultation and Moon photographing (Markowitz) methods, as well as the gravimetric method, will be discus

ISSN:0002-8606    

DOI:10.1029/TR035i006p00883

年代:1954

数据来源: WILEY

摘要:

The results of ten months of measurements of waves, longshore currents, and beach conditions for Santa Margarita River Beach are presented. Tables and graphs give the height, period, and steepness of the incident waves as measured by a subsurface, differential‐type pressure recorder; breaker heights as computed from these data; observed wave directions; longshore current measurements, both magnitude and direction, as obtained by tracing dye thrown into the water; and beach profiles measured along three ranges 500 ft apart from the berm to a depth of about 25 ft. It was found that the three sets of profiles were not consistent in regard to their relationship with varying wave conditions, and further that the type of beach profile (storm or ordinary) apparently did not bear the same relationship to the wave steepness as has been found in laboratory studie

ISSN:0002-8606    

DOI:10.1029/TR035i006p00887

年代:1954

数据来源: WILEY

摘要:

When the shore line and offshore contours are straight and parallel, wave refraction is governed by Snell's law, which states that the sine of the angle between the wave crest and the bottom contour is proportional to the velocity of wave propagation. Shell's law was verified in this study by analyzing the photographic records of wave refraction at a model beach with 1/40 slope and a straight shore line in a ripple tank. This study covers uniform waves with three different periods, non‐uniform waves, and three initial angles of wave approach. For the longest period waves, the experimental results seemed to give a refraction angle smaller than that indicated by Snell's la

ISSN:0002-8606    

DOI:10.1029/TR035i006p00897

年代:1954

数据来源: WILEY

摘要:

The problem of unsteady flow in porous media was investigated for the two‐dimensional case by a model analogy consisting essentially of an oil flowing through a narrow glass channel. The apparatus, known as a Hele‐Shaw viscous fluid model, avoided the difficulties of measuring flow in porous media. The model was calibrated by steady flow measurements. Unsteady flows, composed of sudden releases of oil into and out of the channel, were recorded and analyzed. Results were presented in graphical form using dimensionless parameters. Agreement with numerical solutions of the basic nonlinear differential equation, as applied to gas flow through porous media, was obtained. A study of a series of solitary sine waves was made as a model analogy of the damping of a flood hydrograph in a ground‐water table adjacent to a stream. Results indicated that the damping rate was independent of both amplitude and period of the flood wave and that the damping distance was a function of the period but not of the ampl

ISSN:0002-8606    

DOI:10.1029/TR035i006p00905

年代:1954

数据来源: WILEY

摘要:

Potential distributions are found for steady wells idealized as sinks, and tapping uniform confined aquifers into which there is leakage in proportion to the drawdown. Several plane regions are treated, along whose boundaries the potential, flux, or both are specified. The ratio of the conductivity of the aquifer to that of the confining bed is assumed very large so that the refraction of flow lines may be assumed complete as they cross the contact. The leakage, thus considered vertical through the confining bed, is assumedly distributed throughout the thickness of the aquifer as it thus aguments or diminishes the horizontal flow, which is then treated as two dimensional.Starting with the fundamental solution for an infinite plane region, the solutions for other plane regions are built up by the method of images. The Green's functions for leaky systems are thus obtained for infinite half‐planes (two cases), infinite quadrants (three cases), infinite strips (three cases), infinite half‐strips (six cases). and rectangles (six cases). Several graphs are given showing potential distributions in special cases and showing the magnitude of drawdown at the well face for various values of the parameters.The result obtained in Part I of this paper for the infinite plane is extended by the method of images to find solutions for infinite strips, infinite half‐strips and for rectangles, in Part II. These solutions are put in forms of series which are convenient for computations. These series are uniformly convergent for all values of x and y except when both are simultaneously taken at the center of the well in which case the series diverges logarithmically to negative infinity. Each of these solutions satisfies the properties of one of the three different types of Green's functions—the first, the second, or the mixed type, but instead of being a harmonic function it satisfies the equation of motion of ground water with linear leakage. Accordingly these solutions may be considered as the Green's functions for systems with linear

ISSN:0002-8606    

DOI:10.1029/TR035i006p00917

年代:1954

数据来源: WILEY

摘要:

Soil‐filled gasoline drums (55 gal) have been used to measure maximum evapotranspiration at Waynesville, North Carolina. Installation involves no mechanical devices, and maintenance is at a minimum. Water is added manually to prevent water supply to the plants from becoming a limiting factor. Tensiometers are used to indicate when water must be added. Tanks are placed in the center of areas of the same vegetation. Data for one year under grass cover are presented and compared with values calculated from Thornthwaite's and Penman's formulas. The latter appears, upon statistical analysis, to fit the data better than the forme

ISSN:0002-8606    

DOI:10.1029/TR035i006p00937

年代:1954

数据来源: WILEY

摘要:

This paper is a partial report on the quality of irrigation water. It is principally concerned with the salts of irrigation water which form salines in the soil. A method has been suggested for calculating the potential salinity of water and listed as ‘effective salinity.’ New conversion factors have been listed for changing from milliequivalents to parts per million or pounds of salt per acre foot for the soluble salts of effective salinity. A new standard has been suggested for the total salts of irrigation water based on the effective salinity, followed by a discussion concerning the application of this standard to irrigated agricult

ISSN:0002-8606    

DOI:10.1029/TR035i006p00943

年代:1954

数据来源: WILEY

摘要:

This determination of the size of material on the bed of a stream is based upon an analysis of the relative area covered by particles of given sizes. The method is applicable to those rivers which flow on coarse material and may be waded during periods of low water. Sampling consists of measuring the intermediate axis of 100 pebbles picked from the bed of the channel on the basis of a grid system. From this sample a frequency distribution is drawn from which the desired size parameters are read. The advantages of the areal sampling procedure over bulk sampling are (1) that it is applicable to very coarse materials, and (2) that it provides a more representative sample of an entire reach of a stream.

ISSN:0002-8606    

DOI:10.1029/TR035i006p00951

年代:1954

数据来源: WILEY