摘要:

Formulas adapted to the rapid slide‐rule computation of the difference, geodetic distance minus shoran measurement, are developed, and numerical examples are given. The method offers adequate accuracy and adequate control of accuracy for all shoran reductions, eliminating a serious source of non‐random error in the reduction of line‐crossings by the conventional Canadian method. The effects of errors in the data, particularly those in the meteorological data, are consi

ISSN:0002-8606    

DOI:10.1029/TR034i005p00673

年代:1953

数据来源: WILEY

摘要:

Several experiments have been conducted since 1946 to measure skylight in the upper atmosphere. From the results, it appears that skylight consists of (1) sunlight scattered by the atmosphere and (2) day airglow (light originating in the upper air by other means than Rayleight scattering). The scattered‐light values are large at the ground but decrease rapidly (almost proportional to atmospheric density) until at about 30 km the sky is relatively black, the measured values being about two to three percent (depending on direction) of those recorded at the ground level. The scattered light becomes unimportant in comparison with airglow at about 35 to 40 km. Day airglow appears to be nearly constant in the range 40 to 130 km, and is much larger than expected. Photometers employing interference filters gave day‐airglow values which are of the order of 104 times the corresponding night‐airglow values. Further evidence of large light values at high altitudes is given by photographs of clouds made at an altitude of 70 km. The nature and exact locations of these clouds are to be determined. They appear near enough to have been in the cold layer at about

ISSN:0002-8606    

DOI:10.1029/TR034i005p00680

年代:1953

数据来源: WILEY

摘要:

A body of experimental radio and meteorological data taken over Cardigan Bay, on the British west coast, is examined to ascertain how radar propagation is affected by the microwave duct lying next to the sea surface. The boundary‐layer meteorological profiles are analyzed in terms of a semi‐empirical relation due to E. L. Deacon, and propagation is predicted according to a method of S. A. Schelkunoff. At three‐cm wave‐lengths, it is found that the agreement between observation and theory becomes steadily better as wind speed increases, until at speeds above 15 mi/hr (7 m/s) the consistency is truly striking. At lower wind speeds there is a definite tendency to follow the theoretical pattern, but a great deal of scatter is noted. Possible explanations for this scatter are offered.More scatter is observed at nine cm than at three cm, and the transition to trapping conditions is less definite. The nine‐cm waves appear to “feel” the effects of the duct some time before trapping occurs.An interpretation is offered of the fact noted by McPetrie and Starnecki that, in general, high signals are associated with large positive air‐sea temperature differences, while low signals are accompanied by large negative differences. Also, Jones' observation that, under unstable conditions, high winds are accompanied by high signals is n

ISSN:0002-8606    

DOI:10.1029/TR034i005p00695

年代:1953

数据来源: WILEY

摘要:

Probable maximum precipitation is defined and a distinction is drawn between it and probable maximum storm. The maximizing procedure used in the derivation of probable maximum precipitation for specific areas consists chiefly of moisture adjustment and, when justifiable, transposition of observed storms. Moisture adjustment of a storm involves the estimation of the increased precipitation that would be expected if maximum atmospheric moisture were available. Transposition involves the adjustment of the precipitation of storms observed outside the problem area for differences in meteorological and topographic effects between their original sites and the problem area. It is in effect an extrapolation of the record of storm experiences for the area.

ISSN:0002-8606    

DOI:10.1029/TR034i005p00701

年代:1953

数据来源: WILEY

摘要:

Horizontal fluid deformation is a basic linear property of motion appearing in two forms: stretching and shearing deformation. The resultant deformation, rate and direction, is found by rotating the coordinates through an angle dependent upon the relative values of the two primitive types of deformation in the initial coordinates. Several methods for measuring horizontal deformation in the wind field are introduced and discussed. These employ arbitrary Cartesian coordinates, the latitude‐longitude grid of the Earth, the local north‐south kinematic directions, and the area outlined between three observation points. The field distribution of deformation for an actual wind field is represented by two methods: (1) by scalar patterns of direction and of rate of deformation, and (2) by a vector method at selected points. The geostrophic deformation is obtained graphically from the geometry of the pressure pattern. The field distribution of deformation is illustrated for several hypothetical pressure patterns simulating common conditi

ISSN:0002-8606    

DOI:10.1029/TR034i005p00709

年代:1953

数据来源: WILEY

摘要:

Relationships have been developed from laboratory experiments which show the effect of side slope, wave steepness (H/L), relative depth (d/L), and the structure porosity on wave run‐up. Maximum wave run‐up occurs, for the range of angles examined, at approximately 30°. As the wave steepness (H/L) increases, the wave run‐up increases, and as the relative depth parameter (d/L) decreases, the wave run‐up increases. The wave approach was restricted to the direction perpendicular to the axis of the s

ISSN:0002-8606    

DOI:10.1029/TR034i005p00720

年代:1953

数据来源: WILEY

摘要:

The steady‐state stream function for the vertical circulation produced by a uniform horizontal wind stress on the surface of a canal of semicircular cross‐section is derived analytically. The streamlines have been calculated and a comparison is made with some experimental results obtained by Hidaka and Koizumi in 1950 using a thin elastic‐plate

ISSN:0002-8606    

DOI:10.1029/TR034i005p00725

年代:1953

数据来源: WILEY

摘要:

Surface temperature and density observations in Charleston Harbor indicated a sharp decrease in salinity beginning in 1942. It was at this time that a hydroelectric plant began diverting some of the waters from the Santee River into the Cooper River which flows into Charleston Harbor. Long‐period tide observations at Charleston and at other places along the Atlantic Coast were examined to detect related changes in sea level and range of tide. They indicate that about 0.09 ft of the rise in sea level in Charleston Harbor can be attributed to the diversion of the Santee River and that the tidal range may have been increased about 0.05 f

ISSN:0002-8606    

DOI:10.1029/TR034i005p00729

年代:1953

数据来源: WILEY

摘要:

The major floods which occurred in the Fraser system in 1948 and 1950 had a peak‐discharge difference of 100,000 cfs, but the maximum river stage at Mission was nearly the same for both floods. One of the explanations advanced for this behavior has been thoroughly investigated on the Fraser River model. The phenomenon studied was that of the effect of tides on the mean stage of the river. This is not to be confused with the hourly rise and fall stages resulting from tides. It has been deduced that both the mean tide and the range of tide in the Strait of Georgia affect the river mean stage. Natural long‐term variation in both of these quantities cause small variations in river stage. It is shown from the differential equation of motion that the second effect is a direct result of size of the non‐linear

ISSN:0002-8606    

DOI:10.1029/TR034i005p00733

年代:1953

数据来源: WILEY

摘要:

Using the Angstrom principle, a new apparatus for measuring the thermal diffusivity of soil was designed. In order to give the sinusoidal boundary condition, the apparatus was constructed to change the applied voltage of a heater. A simple auto transformer and a special cam were used for this purpose. Using this apparatus, the thermal diffusivity of frozen soil as well as wet soil was measured. In the case of frozen soil, the samples were prepared under the conditions similar to natural frost formation. Thermal conductivity was computed from the diffusivity thus obtained and the volume specific heat of the soil. Moisture relationship of the thermal diffusivity and the thermal conductivity of frozen soils are represented by an empirical formula of exponential form. The formula holds only in the range of moisture content below the saturation. These relationships are shown graphically. Similar measurements were carried out with wet soil at room temperature. In nature, we often observe the segregation of ice in frozen soil. Such a frozen soil usually contains more water than that of saturation. Samples of various modes of segregation of ice were artificially prepared and their thermal diffusivity was measured. For the moisture ratio above saturation, the rate of increase of the thermal diffusivity with respect to moisture ratio is smaller than that expressed by the above formula. The variation of the thermal diffusivity of the frozen soil in relation to the direction of heat flow is comparatively small.

ISSN:0002-8606    

DOI:10.1029/TR034i005p00737

年代:1953

数据来源: WILEY