摘要:

This paper deals with the planning and execution of a precision‐leveling program being carried on during the reconstruction of the Executive Mansion in Washington, D. C. Unusual accuracy requirements and unusual working conditions were responsible for many departures from established practice in precision leveling. Field methods, instrumental equipment, accuracy of leveling, and observed behavior of bench marks are discussed. Special emphasis is on the unusual features of the work rather than the description of just one more leveling projec

ISSN:0002-8606    

DOI:10.1029/TR033i001p00001

年代:1952

数据来源: WILEY

摘要:

Exact closed solutions of the following equation of diffusionwhere m and n are considered to be independent, are obtained for the following cases: (1) diffusion from a line‐source embedded in a smooth surface; (2) diffusion from a smooth surface; (3) vapor concentration in the wake of an evaporating surface. The solutions for Cases (1) and (2) belong to the similarity‐solution category. Dimensional analysis has been used in the systematic search for such solutions in as concise a manner as possible. The solution for Case (3) can be obtained from those for Cases (1) and (2). Diffusion in Couette flow is given as an exam

ISSN:0002-8606    

DOI:10.1029/TR033i001p00008

年代:1952

数据来源: WILEY

摘要:

Limits on the duration and rates of moisture accumulation in thunderstorm cells are estimated from computations based on the empirical results of Byers and Braham applied to idealized cells involving assumptions of radial symmetry, zero divergence of specific momentum, United States standard atmospheric temperature‐height curve, no horizontal density difference, initial saturation, and a steady‐state flow pattern applied instantaneously. Stationary cells of two sizes in a general area of no wind and another case of a cell in a general horizontal velocity field of ten miles per hour relative to the cell are considered. Maximum moisture‐accumulation rates of about one inch per hour are found for all three cells. The rate of accumulation becomes zero in about 90 minutes for the stationary cell of three‐mile radius, about five hours for the stationary one of five‐mile radius, and becomes constant after 30 minutes for the cell in the horizontal veloc

ISSN:0002-8606    

DOI:10.1029/TR033i001p00013

年代:1952

数据来源: WILEY

摘要:

Operational decisions are often based on a “calculated risk.” The probability accompanying this risk, when weather elements are the critical factors, can often be estimated from climatological data. If the available data are limited as to quantity and quality, the applied climatological problem is further complicated. Several such problems and a solution to each are presented as illustrations of this phase of applied climatology and of the use of statistical analysis in meteorological probl

ISSN:0002-8606    

DOI:10.1029/TR033i001p00021

年代:1952

数据来源: WILEY

摘要:

A stability test has been made of several elements of the North Atlantic air circulation which had previously been concluded by Smith and Groissmayr to influence the severity of the subsequent iceberg season south of Newfoundland. The test indicates that steeper‐than‐average pressure gradients between Belle Isle (near Labrador) and Ivigtut (in southern Greenland) during December to March continue as before to be associated with above‐normal, and less steep pressure gradients with below‐normal berg counts off Newfoundland during the following April–June season. On the other hand, steeper‐than‐average pressure gradients between Bergen in southern Norway and Stykkisholm in Iceland have ceased in recent years to be followed by above‐normal berg counts off Newfoundland, probably because of a very marked change in the circulation in the northeastern North Atlantic. Also, the average temperatures from December to March at St. John's (Newfoundland), Bermuda, and Uppsala (Sweden), when taken together, continue as before to show a marked connection with the following ice severity off Newfoundland.A formula relating the berg count to the relatively stable and mutually compensating series of average December‐to‐March Belle Isle‐to‐Ivigtut pressure gradients and St. John's, Bermuda, and Uppsala temperatures was derived using, as before, data up to and including 1926. Employing the recent 25‐year period (1927–1951) as a test, the correlation between the computed and actual deviations from the long‐term average berg cou

ISSN:0002-8606    

DOI:10.1029/TR033i001p00027

年代:1952

数据来源: WILEY

摘要:

A theory is developed and experimental verification is presented for the force exerted by surface waves on a submerged spherical object. The object was small compared to the wave length, and its position was near the bottom. The components of force consist of form drag and inertia forces.

ISSN:0002-8606    

DOI:10.1029/TR033i001p00032

年代:1952

数据来源: WILEY

摘要:

For deep‐water waves propagating from still water upstream against a moving current, complete breaking occurs when the velocity of the opposing current reaches 1/4 of the wave velocity. This was verified by experimental results. Partial breaking took place when the ratio was between 1/7 and 1/

ISSN:0002-8606    

DOI:10.1029/TR033i001p00039

年代:1952

数据来源: WILEY

摘要:

Plotting maximum yield in relation to maximum drawdown of a pumped well offers a method of evaluating the available porosity in the vicinity of the borehole. The process can be reversed by pumping a measured volume of water down the borehole. A distinction is made between pore space or storage around the borehole and the more difficult to determine, communicating pore space.

ISSN:0002-8606    

DOI:10.1029/TR033i001p00042

年代:1952

数据来源: WILEY

摘要:

A simple laboratory technique of evaluating desert soils for suitability to irrigation is outlined. Such laboratory observations are for the purpose of augmenting a field examination of physiographic and pedological limitations of the land. The method is based upon the premise that soil moisture retained against a tension of 100‐cm water tension, less the moisture retained against 15,000‐cm tension, gives an index of total available water in the soil. The importance of the relative distribution of available moisture within the tension range of 100 and 15,000 cm is indica

ISSN:0002-8606    

DOI:10.1029/TR033i001p00049

年代:1952

数据来源: WILEY

摘要:

Evaluations of several cloud‐seeding projects are discussed. These projects included portions of northeastern New Mexico, southeastern Colorado, and eastern Oregon, and were conducted during July to December 1950. These evaluations are statistical in nature and involve comparisons with the precipitation occurring in nearby unseeded areas. A multiple regression equation was developed from past data relating precipitation in seeded and unseeded areas. In six of the seven months of operation, actual rainfall in the seeded area exceeded the estimate provided by the regression equation. A suggestion of a possible smoothing effect in precipitation patterns due to seeding is also presente

ISSN:0002-8606    

DOI:10.1029/TR033i001p00053

年代:1952

数据来源: WILEY