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  • Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army  (37)
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  • 1
    Series available for loan
    Series available for loan
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
    Associated volumes
    Call number: ZSP-202-27
    In: Research report / Cold Regions Research and Engineering Laboratory, 27
    Description / Table of Contents: Summary: The results of a study on the feasibility of mapping selected snow-cover characteristics for military purposes, taking into account both current synoptic and average conditions, are reported in detail. Problems associated with the construction of isolines for depicting individual or combination of snow-cover conditions are discussed; the need for other statistical parameters in addition to the means is stressed; and the adaptation of frequency and variability indices is suggested. The use of a regional technique, which identified areas somewhat homogenous or substantially different from adjacent areas, is investigated. Problems in mapping snow density are also considered as well as the possibility of estimating snow density from meteorological data. Three sets of codes for the systematic recording and transmission of data are proposed, including a code for ground observers, a simplified code for use where no instruments or trained personnel are available, and a code for aerial observations.
    Type of Medium: Series available for loan
    Pages: vi, 92 Seiten , Illustrationen , 27 cm
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 27
    Language: English
    Note: TABLE OF CONTENTS PREFACE LIST OF TABLES LIST OF ILLUSTRATIONS INTRODUCTION Chapter I. APPLICATION OF ISOLINES FOR DEPICTING ASPECTS OF THE SNOW COVER Visual Problems Use of a simplified base map Other solutions Substantive Problems Observational errors Sampling errors Bias error Effect of reliability of data on isolines Conclusion The ''reasoned distribution'' Effects of substantive problems Conclusion II. DEVELOPMENT OF OTHER MEASURES, INDICES, AND METHODS FOR DEPICTING SNOW COVER CONDITIONS Examples of Possible Normal Indices of Snow Cover Average snow depth at end of the maximum month Average monthly snow depths by superimposed or located line graphs Time aspects Snowfall Selected Statistical Parameters of a Particular Value Extreme values Frequency values Measures of variability Conclusion III. SNOW REGIONS: AN APPROACH TO MAPPING SNOW COVER Snow Region Concept Descriptions of Snow Regions 1. Pacific Coast and Coastal Valley Region 2. The Mountain Zone 3. Great Plains Region 4. The Mackenzie-Manitoba Region 5. Upper Ontario Region 6. Northern Great Lakes-St. Lawrence Region 7. Labrador Region 8. The Northern Arctic Region 9. Ungava-Baffinland Region Conclusions IV. CURRENT SNOW DATA MAPS Introduction Ground Observer's Code Suggested code for "Ground Observer's Snow Report" Comments Symbols for a comprehensive station model Air Observation Code Comments Station Model for Aircraft Snow Observations A Simplified Snow Observation Report . Introduction Proposed code and symbols for station model based on Simplified Snow Observation Report Conclusion Chapter V. MAPPING SNOW DENSITY Introduction Limitations of Data for Mapping Available data Reliability of the data Natural variations in density Snow Density Maps of Eastern Canada Statistical Investigation of Density: Eastern Canada Test for area differences Estimating regional trends in density: Orthogonal polynomials Regional density changes during the winter Conclusions: Statistical investigations Estimating Snow Density from Meteorological Data Relation of density to wind speed and temperature Application of Dmitrieva's equation Conclusion VI. CONCLUSION Snow Cover Maps: Small Scale Compilations of Various Aspects of Their Parameters Preparation of Synoptic Current Snow Data Maps Snow Density Research Investigation of Drift and Erosional Surfaces Initiation of Systematic Collection and Recording of Snow Data Internationally Research Reports Based on Existing Literature .
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  • 2
    Series available for loan
    Series available for loan
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
    Associated volumes
    Call number: ZSP-202-46
    In: Research report / Cold Regions Research and Engineering Laboratory, 46
    Description / Table of Contents: Summary: The results of studies in the summer of 1957 on ice samples taken from the ice tunnel at TUTO, core samples obtained by drilling in the ice cap at Site 2, and snow samples, using the transverse vibration method and a new portable meter, are reported. Young's modulus was determined from the resonance frequency of flexural vibrations of samples cut in the form of rectangular bars; the loss factor was measured from damping; and the coefficient of viscosity calculated using the Maxwell model. The modulus of elasticity of samples of a density from 0.917 - 0.90 g/cm^3 (tunnel ice) decreased sharply with slight deviations of the density from that of pure ice. At densities from 0.90 - 0.50 g/cm^3 (deep-pit and drill-core samples) the relation between the modulus of elasticity and density was linear, while in the density range from 0.50-0.25 g/cm^3 (surface snow) the modulus of elasticity decreased exponentially. The viscosity-density relation of the samples was similar to that of elasticity vs density. Young's modulus increased slightly with decreasing temperature, while viscosity increased exponentially. The activation energy was calculated as 18.7 kcal/mol for old ice-cap ice, 13.9 kcal/mol for tunnel ice with elongated bubbles, and 13.5 kcal/mol for super-imposed ice.
    Type of Medium: Series available for loan
    Pages: v, 29, A4 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 46
    Language: English
    Note: CONTENTS Preface Summary Introduction Principle of measuring the visco-elastic nature of snow and ice by the vibration method Experimental method for determination of visco-elastic properties of snow and ice Visco-elastic properties of tunnel ice Elastic properties of snow samples from the deep pit Elastic properties of core samples obtained by drilling Elastic properties of snow near the ice-cap surface Vertical variation of Young's modulus near the surface Wind-packed snow Peter snow Relation between Young's modulus and density of snow Relation between Young's modulus and density over the range from surface snow to ice Supplementary experiments on the elastic nature of snow and ice at Site 2 Anisotropy of Peter snow Age hardening Temperature dependence of Young's modulus of core ice Viscosity measurement of snow and ice in Greenland Further experiments on the elastic nature of tunnel ice Temperature dependence of Young's modulus Frequency dependence of Young's modulus Further experiments on the viscous nature of tunnel ice Temperature dependence of loss factor Activation energy Frequency dependence of loss factor and viscosity Relation between viscosity and density Conclusions References Appendix: Experimental data
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  • 3
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    Series available for loan
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
    Associated volumes
    Call number: ZSP-202-18
    In: Research report / Cold Regions Research and Engineering Laboratory, 18
    Description / Table of Contents: Summary: Various strength properties of naturally compacted high-density snows, in the density range of from 0.40 to 0.75 g/cm^3, are reported. Test results are given for: unconfined compression; unconfined and confined double shear; ring, flexural, and centrifugal tensile strength; torsional shear; and work of disaggregation. The work of disaggregation per unit volume was related to crushing, tensile, and shear strength at various lateral pressures, using the same empirical relationship. The results of the various tests measuring the tensile strength of the snow compare favorably with each other. An attempt was made to use the direct shear strength results in Coulomb’s equation for the determination of Mohr’s envelope of rupture for snow. These tests yield higher values than those obtained in unconfined compression tests. However, angles of internal friction obtained considering Mohr’s envelope to be straight line seem to agree with measurements taken on an unconfined compression specimen.
    Type of Medium: Series available for loan
    Pages: 19 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 18
    Language: English
    Note: CONTENTS Page Preface Summary Introduction Temperature correction factors Crushing strength Tensile strength · Shear strength Torsional shear strength Work of disaggregation of snow Angle of internal friction and apparent unit cohesion Discussion of results References
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  • 4
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    Series available for loan
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
    Associated volumes
    Call number: ZSP-202-21
    In: Research report / Cold Regions Research and Engineering Laboratory, 21
    Description / Table of Contents: Limited studies of white-outs on the Greenland Ice Cap indicate that five major types of low visibility have been reported as white-out. They are: 1.) Overcast white-out, caused by a continuous cloud cover. 2.) Water-fog white-out, produced by supercooled water droplets in the air. 3.) Ice-fog white-out, produced by ice crystals suspended in the air. 4.) Blowing snow white-out, produced by wind-driven, wind-eroded snow. 5.) Precipitation white-out, produced by falling snow. The first three types are interrelated and appear to be produced by upslope, convective lifting of warm maritime air and the advective transport of the cooled saturated air over the cold snow field. Radiation heat losses from the snow surface may contribute to more rapid formation of the white-out. The fact that there is a shift in the prevailing wind direction prior to the development of a white-out indicates that certain changes in upper air circulation may be associated with white-out formation and duration. There is reason to believe that upper air and surface observations might make it possible to forecast white-outs on the Greenland Ice Cap with some degree of reliability.
    Type of Medium: Series available for loan
    Pages: iv, 12 Seiten , Illustrationen , 27 cm
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 21
    Language: English
    Note: CONTENTS Preface Summary Introduction Results at Site 2 Discussion References
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  • 5
    Series available for loan
    Series available for loan
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
    Associated volumes
    Call number: ZSP-202-26
    In: Research report / Cold Regions Research and Engineering Laboratory, 26
    Description / Table of Contents: Summary: The results of temperature, density, ram-hardness and grain-size measurements at 118 test sites along a 300-mi. traverse, ranging in elevation from 2000 to 8000 ft, are reported in detail, and their meteorological and climatic implications are discussed. Four types of diagenetically produced facies were recognized: ablation facies, extending from the snout of the glacier to the firn line; soaked facies, extending from the firn line to the saturation line; percolation facies, extending from the saturation line to the dry-snow line; and dry-snow facies, extending across the glacier above the dry-snow line. The well defined saturation line shows marked discontinuities in temperature, density, and ram hardness, while the dry-snow line is a transition 1 zone 10-20 mi. wide. The recognition of facies allows greater resolution of glacier characteristics than Ahlmann's classification, permitting quantitative subdivision of all types of large glaciers. Regional precipitation (entirely from cyclonic storms) is about 5 times greater than at Thule; and the prevailing katabatic winds control the vertical component of the temperature gradient in the snow and firn. The depth density curve of the firn at elevations where melt is negligible is invariant with time, as in Sorge's law, so that the densification can be treated as a steady-state situation with load as the only significant variable.
    Type of Medium: Series available for loan
    Pages: vii, 62, A4, B2, C2 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 26
    Language: English
    Note: CONTENTS Preface Summary Chapter I. Introduction Greenland Glaciers and stratigraphy The Greenland ice sheet - a rock formation Region of investigation Chapter II. Methods of investigation Stratigraphy Accumulation measurements Work program at pit stations General description of pits Temperature Hardness Density, stratigraphy, and grain size Accuracy of density measurements Photography Core drilling Air permeability and mechanical tests Elevation measurements Barometric altimetry Transit leveling Chapter III. Basic concepts and definitions Summer melt Soaking Complete soaking Localized percolation Stability Diagenetic facies Chapter IV. Presentation and discussion of results Grain size and morphology Grain size Morphology Temperature Seasonal variation and mean annual temperature Thermal effect of an open pit Constancy of climate Facies in terms of temperature data Hardness Continuity of strata Effect of wind Increase in R with depth below snow surface Facies in terms of hardness data Density Depth vs density data Depth vs load data Attempts to formulate depth vs density Facies in terms of density data Glacier facies - a classification of glaciers Chapter V. Stratigraphy and accumulation Stratigraphy Stratigraphic interpretation at station 1-0 Correlation between stratigraphic and meteorological records Accumulation Integrated qepth-density curves Measurement of accumulation on surface marker plates Pole-marker measurements Stratigraphic correlation Selection of a reference datum in the annual stratigraphic sequence Correlation across the traverse Effects of topography Chapter VI. Meteorological and climatological implications Winds Precipitation Annual heat exchange References Appendix A: Stratigraphy, meteorology and glaciology Appendix B: Logistics and development of the research program Appendix C: Tables
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  • 6
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    Series available for loan
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
    Associated volumes
    Call number: ZSP-202-29
    In: Research report / Cold Regions Research and Engineering Laboratory, 29
    Description / Table of Contents: Summary: A microscopic method for the determination of particle-size distributions of pulverized snow was worked out. The method gives satisfactory distribution curves, presenting the number of particles as a function of their cross-sectional "areas". The measurements were made by means of a filar micrometer eyepiece, the snow particles being placed on a ruled glass slide, which was submerged in silicone oil to prevent evaporation. The time for the determination of a distribution can be appreciably shortened by estimating the size of the particles instead of measuring them, though the accuracy is not so high in this case.
    Type of Medium: Series available for loan
    Pages: iv, 8 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 29
    Language: English
    Note: CONTENTS Preface Summary Introduction Experimental Snow samples Procedure Experimental results Fraction 150-300 µ Fraction 0-150 µ Mixture of fractions Conclusions
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  • 7
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    Series available for loan
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
    Associated volumes
    Call number: ZSP-202-34
    In: Research report / Cold Regions Research and Engineering Laboratory, 34
    Description / Table of Contents: Summary: The compressive strength of snow cylinders was investigated as a function of age of snow, snow-particle size, and age of the cylinders. The effect of gases such as carbon dioxide, methane, and ammonia on the strength of snow cylinders has also been studied. The experimental results show that the older the snow from which snow cylinders are made, the smaller the compressive strength. The compressive strength of cylinders decreases with the snow particle size. An equation describing the aging curves for snow cylinders is presented. Whereas carbon dioxide and methane in small quantities have no effect on the compressive strength, ammonia appreciably lowers the compressive strength of snow cylinders. All strength measurements were carried out at -10°C.
    Type of Medium: Series available for loan
    Pages: iv, 16 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 34
    Language: English
    Note: CONTENTS Page Preface Summary Introduction Experimental Materials Apparatus and technique Preparation of snow fractions Experimental results Aging of snow cylinders Compressive strength as a function of particle size Mixture of fractions Influence of gases on the compressive strength of snow Discussion References
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  • 8
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    Series available for loan
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
    Associated volumes
    Call number: ZSP-202-43
    In: Research report / Cold Regions Research and Engineering Laboratory, 43
    Description / Table of Contents: Summary: Charts of mean annual air temperature and precipitation over the ice cap are constructed on the basis of snow-profile studies at 8 locations, data collected for several years after 1953 at two U.S. Air Force weather stations, and records from expeditions since 1930. The warming trend in the Arctic appears to have occurred to a lesser degree on the ice cap, possibly because of the effect of the snow cover. The lowest mean annual temperature in South Greenland is estimated to occur within the area bounded by the 2500 m contour and the -18°C isotherm; mean annual temperature at 2700 is estimated as -20.9°C. In North Greenland, the mean annual temperature at 1700 m is estimated at -22°C. The presence of ice glands in the snow and daily max summer temperatures, estimated from records of coastal stations, indicate a potentially high incidence of melting at about 1300 m elevation and some melting at 1700 m in North Greenland, and melting up to 2700 m in the South. Annual accumulation is 2-3 times as great at 2500 m on the west side of the ice cap as at the crest. South of 66°N, precipitation may be about twice as great on the east side of the crest as in the west.
    Type of Medium: Series available for loan
    Pages: iv, 9 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 43
    Language: English
    Note: CONTENTS Preface Summary Introduction Derivation of mean annual air temperature data Annual accumulation References
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  • 9
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    Series available for loan
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
    Associated volumes
    Call number: ZSP-202-51
    In: Research report / Cold Regions Research and Engineering Laboratory, 51
    Description / Table of Contents: Summary: The study was made in order to simulate the deformation of a tunnel in glacier ice and compare the results with the theoretical value derived from compression or tension tests. The plastic deformation of commercial polycrystalline ice and manufactured snow-ice was determined by measuring the discharge of oil from the cavity of closed hollow ice cylinders subjected to high external pressure in an oil-filled pressure chamber. The deformation vs time curves were similar to those obtained in compression or tension tests. The relationships between minimum strain rate and applied pressure, or between minimum strain rate and the circumferential stress at the surface of the inner cavity, were found to differ from the power law ϵ ̇= ασⁿ, the value of n being an increasing function of stress. Analysis of time deformation curves indicates that viscoelastic models proposed by former investigators do not apply to the mechanism of the plastic deformation of ice.
    Type of Medium: Series available for loan
    Pages: iv, 10 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 51
    Language: English
    Note: CONTENTS Preface Summary Introduction Apparatus Specimens Experimental procedures and results Analysis of the data Discussion References
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  • 10
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    Series available for loan
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
    Associated volumes
    Call number: ZSP-202-52
    In: Research report / Cold Regions Research and Engineering Laboratory, 52
    Description / Table of Contents: Summary: The results of studies on the physical properties of fog whiteout, as it occurred at Site 2 on the Greenland Ice Cap in the summers of 1956 and 1957, are reported and compared with the results of other studies; the instruments, methods of measurement, and data-reduction techniques used are described; and attempts at dissipating whiteout by AgI (silver iodide) seeding are discussed briefly. Emphasis was given to measurements of fog-particle size distribution, liquid-water content, relative humidity, visibility, and atmospheric nuclei. The data are tabulated. The synoptic situations for 2 selected cases of fog whiteout at relative humidities of less than 100% (possibly because of the presence of salt solutions) are described; and the balance between the rate at which water is made available in the air as it is lifted over the Ice Cap and the rate of water flux to the snow surface is computed using various equations. Efforts at fog dispersal by AgI seeding from the ground were inconclusive.
    Type of Medium: Series available for loan
    Pages: iv, 18, A1 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 52
    Language: English
    Note: CONTENTS Preface Summary Introduction Definition of whiteout Scope of this study Instrumentation and observations Location of project: Fog particle measurements Atmospheric humidity measurements Visibility measurements Air temperature measurements Radiation measurements Atmospheric nuclei Observations of fog whiteout Conditions prior to onset of whiteout Conditions at time of arrival and during whiteout Micro-structure of fog whiteout Analysis of moisture balance during two selected cases Synoptic situation for case 1 Synoptic situation for case 2 Computations Attempts at fog whiteout dispersal References Appendix A - Freezing nuclei observations Appendix B - Absolute humidity gradient data
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