scholarly journals On the Thermal Regime of an Arctic Valley Glacier: A Study of White Glacier, Axel Heiberg Island, N.W.T., Canada

1987 ◽  
Vol 33 (114) ◽  
pp. 200-211 ◽  
Author(s):  
Heinz Blatter
Keyword(s):  
Climatic Conditions ◽  
Temperature Profiles ◽  
Two Dimensional ◽  
Temperature Minimum ◽  
Climatic Warming ◽  
Simple Scheme ◽  
Glacier Surface ◽  
Temperature Distributions ◽  
Valley Glacier ◽  
Simple Numerical Model

AbstractFrom 1974 to 1981, a total of 32 bore holes was drilled on White Glacier and vertical ice-temperature profiles measured. The data obtained allowed the construction of three longitudinal and four transverse profiles of the two-dimensional temperature distributions. Thus, an extensive layer of temperate or near-temperate ice was discovered close to the bedrock in the lowest part of the glacier tongue. It was also found that the temperature distribution cannot be in a steady state, since there is a temperature minimum 100–150 m below the glacier surface in the accumulation area. A simple numerical model calculation shows that this minimum can be mostly explained by the general climatic warming since 1880. The 10 m temperatures show diffuse relations to climatic conditions and balance zones. A simple scheme for extrapolating “surface temperatures” is discussed.

scholarly journals On the Thermal Regime of an Arctic Valley Glacier: A Study of White Glacier, Axel Heiberg Island, N.W.T., Canada

1987 ◽  
Vol 33 (114) ◽  
pp. 200-211 ◽  
Author(s):  
Heinz Blatter
Keyword(s):  
Climatic Conditions ◽  
Temperature Profiles ◽  
Two Dimensional ◽  
Temperature Minimum ◽  
Climatic Warming ◽  
Simple Scheme ◽  
Glacier Surface ◽  
Temperature Distributions ◽  
Valley Glacier ◽  
Simple Numerical Model

AbstractFrom 1974 to 1981, a total of 32 bore holes was drilled on White Glacier and vertical ice-temperature profiles measured. The data obtained allowed the construction of three longitudinal and four transverse profiles of the two-dimensional temperature distributions. Thus, an extensive layer of temperate or near-temperate ice was discovered close to the bedrock in the lowest part of the glacier tongue. It was also found that the temperature distribution cannot be in a steady state, since there is a temperature minimum 100–150 m below the glacier surface in the accumulation area. A simple numerical model calculation shows that this minimum can be mostly explained by the general climatic warming since 1880. The 10 m temperatures show diffuse relations to climatic conditions and balance zones. A simple scheme for extrapolating “surface temperatures” is discussed.

Temperature Profiling with Highest Spatial and Temperature Resolution by Means of Scanning Thermal Microscopy (SThM)

1997 ◽  
Author(s):  
G. M. Fiege ◽  
R. M. Cramer ◽  
L. Balk ◽  
F. Reineke
Keyword(s):  
Spatial Resolution ◽  
Sample Surface ◽  
Temperature Profiles ◽  
Two Dimensional ◽  
Scanning Thermal Microscopy ◽  
Temperature Resolution ◽  
Contact Mode ◽  
Temperature Distributions ◽  
Topography Data ◽  
Nanometer Regime

Abstract As smallest feature sizes approach the 150 nm regime, the spatial resolution of a temperature measurement technique must be within the same range in order to resolve temperature distributions of single structures. In this work we present a system which has the capability to measure millikelvin temperature distributions while enabling a spatial resolution in the nanometer regime. The probe consists of a bent platinum wire which acts as a resistive probe. The probe is scanned over the sample in an SFM contact mode. The probe resistance changes caused by variations in the sample surface temperature are measured and recorded simultaneously with the topography data, thus producing two-dimensional temperature profiles. We have achieved a temperature resolution of 50 mK and a spatial resolution of less than 500 nm on passivated samples.

Modelling of Moisture Movement in Wood during Outdoor Storage

2001 ◽  
Vol 6 (2) ◽  
pp. 3-14 ◽  
Author(s):  
R. Baronas ◽  
F. Ivanauskas ◽  
I. Juodeikienė ◽  
A. Kajalavičius
Keyword(s):  
Experimental Data ◽  
Finite Difference ◽  
Climatic Conditions ◽  
Two Dimensional ◽  
Moisture Movement ◽  
Finite Difference Technique ◽  
Long Term Storage ◽  
Space Formulation ◽  
Term Storage

A model of moisture movement in wood is presented in this paper in a two-dimensional-in-space formulation. The finite-difference technique has been used in order to obtain the solution of the problem. The model was applied to predict the moisture content in sawn boards from pine during long term storage under outdoor climatic conditions. The satisfactory agreement between the numerical solution and experimental data was obtained.

The Effect of Bench Arrangements on the Natural Ventilation of a Multispan Greenhouse

2013 ◽  
Author(s):  
Sunita Kruger ◽  
Leon Pretorius
Keyword(s):  
Fluid Dynamics ◽  
Natural Ventilation ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Low Velocity ◽  
Lower Velocity ◽  
Cfd Models ◽  
Temperature Distributions ◽  
Computational Fluid Dynamics Cfd ◽  
Plant Level

In this paper, the influence of various bench arrangements on the microclimate inside a two-span greenhouse is numerically investigated using three-dimensional Computational Fluid Dynamics (CFD) models. Longitudinal and peninsular arrangements are investigated for both leeward and windward opened roof ventilators. The velocity and temperature distributions at plant level (1m) were of particular interest. The research in this paper is an extension of two-dimensional work conducted previously [1]. Results indicate that bench layouts inside the greenhouse have a significant effect on the microclimate at plant level. It was found that vent opening direction (leeward or windward) influences the velocity and temperature distributions at plant level noticeably. Results also indicated that in general, the leeward facing greenhouses containing either type of bench arrangement exhibit a lower velocity distribution at plant level compared to windward facing greenhouses. The latter type of greenhouses has regions with relatively high velocities at plant level which could cause some concern. The scalar plots indicate that more stagnant areas of low velocity appear for the leeward facing greenhouses. The windward facing greenhouses also display more heterogeneity at plant level as far as temperature is concerned.

The Effect of Froude Number on Entrainment in Two-Dimensional Line Plumes

1981 ◽  
Vol 103 (3) ◽  
pp. 471-477 ◽  
Author(s):  
W. F. Phillips
Keyword(s):  
Froude Number ◽  
Large Distance ◽  
Universal Constant ◽  
Temperature Profiles ◽  
Two Dimensional ◽  
Development Length ◽  
High Discharge ◽  
Entrainment Coefficient ◽  
Theoretical Results

Theoretical results are presented which predict the entrainment coefficient in a forced plume as a function of the local Froude number. The model does not require any external specification of the velocity and temperature profiles. The Froude number for any plume, in a motionless isothermal ambient, approaches a universal constant, at a large distance above the source. However, it is shown here that the development length for the Froude number, in plumes with high discharge Froude number, is of the order of a few hundred times the discharge width.

Pleistocene stratigraphy, paleopedology, and paleoecology of a multiple till sequence exposed on the Little Bear River, Western District of Mackenzie, N.W.T., Canada

1993 ◽  
Vol 30 (4) ◽  
pp. 851-866 ◽  
Author(s):  
O. L. Hughes ◽  
C. Tarnocai ◽  
C. E. Schweger
Keyword(s):  
Transition Zone ◽  
Ice Sheet ◽  
Climatic Conditions ◽  
Canadian Shield ◽  
Laurentide Ice Sheet ◽  
Spruce Forest ◽  
River Section ◽  
Valley Glacier ◽  
Bear River ◽  
Late Wisconsinan

The Little Bear River section lies in a transition zone between Mackenzie Lowland and Canyon Ranges of Mackenzie Mountains. Within the transition zone, the maximum extent of the Laurentide ice sheet overlaps the former extent of montane glaciers that emanated from the higher parts of Canyon Ranges or from the still higher Backbone Ranges to the southwest. Five montane tills, each with a paleosol developed in its upper part, indicate five separate glaciations during each of which a valley glacier emanating from the headwaters of Little Bear River extended eastward into the transition zone. The uppermost of the montane tills is overlain by boulder gravel containing rocks of Canadian Shield origin deposited by the Laurentide ice sheet.Solum and B horizon depths, red colours, and lack of leaching and cryoturbation indicate that although each successive interglacial interval was cooler than the preceding one, even the last of the intervals was warmer than the Holocene. Climatic conditions during one of the intervals inferred from the paleobotanic data, particularly spruce forest development, are consistent with conditions inferred from the associated paleosol.The uppermost of the montane tills is thought to correlate with till of Reid (Illinoian) age in central Yukon. The paleosol developed on that till is, accordingly, thought to correlate with the Diversion Creek paleosol developed on drift of Reid age. The Laurentide boulder gravel is assigned to a stade of Hungry Creek Glaciation of Late Wisconsinan age. The Laurentide ice sheet reached its apparent all-time western limit during the Hungry Creek Glaciation maximum.

scholarly journals Analysis of spatial thermal field in a magnetic bearing

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 52-56
Author(s):  
Dawid Wajnert ◽  
Bronisław Tomczuk
Keyword(s):  
Temperature Field ◽  
Mathematical Models ◽  
Computer Simulations ◽  
Thermal Field ◽  
Three Dimensional ◽  
Magnetic Bearing ◽  
Field Analysis ◽  
Two Dimensional ◽  
Temperature Distributions ◽  
Dimensional Simulation

AbstractThis paper presents two mathematical models for temperature field analysis in a new hybrid magnetic bearing. Temperature distributions have been calculated using a three dimensional simulation and a two dimensional one. A physical model for temperature testing in the magnetic bearing has been developed. Some results obtained from computer simulations were compared with measurements.

scholarly journals Net Budget and Flow of South Cascade Glacier, Washington

1965 ◽  
Vol 5 (41) ◽  
pp. 547-566 ◽  
Author(s):  
Mark F. Meier ◽  
W. V. Tangborn
Keyword(s):  
Steady State ◽  
Surface Elevation ◽  
Elevation Change ◽  
Glacier Surface ◽  
Surface Elevation Change ◽  
Long Valley ◽  
Valley Glacier ◽  
Ice Velocity ◽  
The Mean ◽  
Velocity Averages

AbstractIce velocity, net mass budget and surface elevation change data were collected over the length and width of a small (3.4 km. long) valley glacier from 1957 to 1964. Ice velocities range up to about 20 m./yr.; three prominent velocity maxima along the length of the glacier correspond to maxima in surface slope. Net mass budgets averaged over the glacier surface range between − 3.3 m. of water equivalent (1957–58) and +1.2 m. (1963–64). Except for the year 1960–61, curves of net budget versus altitude are parallel. During the period 1958–61 the glacier became thinner at a rate averaging 0.93 m./yr. The net budget and thinning data are internally consistent. Relations between emergence velocity, net budget and surface elevation change are examined at four specific points on the glacier surface and as functions of distance along the length of the glacier. Emergence velocity averages about −0.5 m. in the upper part of the glacier and about +1.0 m. in the lower part. Ice discharge and ice thickness are also calculated as functions of distance. The discharge reaches a peak of 8.8 × 105m.3of ice per year 2.2 km. from the head of the glacier. The mean thickness of the glacier is about 83 m. A steady-state distribution of net budget is used to calculate a steady-state discharge, which is 2.2 times larger than the present discharge.

Transient temperature distribution in insulated pavements—predictions vs. observations

1970 ◽  
Vol 7 (3) ◽  
pp. 275-284 ◽  
Author(s):  
D. M. Ho ◽  
M. E. Harr ◽  
G. A. Leonards
Keyword(s):  
Transient Temperature ◽  
Site Conditions ◽  
Two Dimensional ◽  
Ambient Conditions ◽  
Layered Systems ◽  
Temperature Variations ◽  
Finite Difference Technique ◽  
Transient Temperature Distribution ◽  
Temperature Distributions ◽  
Number Of Layers

Based on a finite difference technique, computer programs have been developed whereby temperature variations in layered systems as a function of position and time may be computed under conditions of both one- and two-dimensional heat flow by conduction. No limitations are imposed on the number of layers, or on the form of the initial and boundary temperature conditions. Variations in thermal properties of the materials with temperature and location, and the non-linear relation between amount of water frozen as a function of temperature, are directly taken into account. Comparison of predictions with actual measurements demonstrate that accurate forecasts of temperature distributions as a function of time can be made when prevailing ambient conditions are known. Even if the site conditions can be evaluated only approximately sufficiently reliable predictions can be made for design purposes.

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