scholarly journals A Distributed Temperature Profiling System for Vertically and Laterally Dense Acquisition of Soil and Snow Temperature

2021 ◽  
Author(s):  
Baptiste Dafflon ◽  
Stijn Wielandt ◽  
John Lamb ◽  
Patrick McClure ◽  
Ian Shirley ◽  
...  
Keyword(s):  
Thermal Parameters ◽  
Temperature Measurements ◽  
Soil Freezing ◽  
Biogeochemical Processes ◽  
Vertical Resolution ◽  
Freezing And Thawing ◽  
Total Cost ◽  
Thawing Depth ◽  
Snow Temperature ◽  
Snow Thickness

Abstract. Measuring soil and snow temperature with high vertical and lateral resolution is critical for advancing the predictive understanding of thermal and hydro-biogeochemical processes that govern the behavior of environmental systems. Vertically resolved soil temperature measurements enable the estimation of soil thermal regimes, freeze/thaw layer thickness, thermal parameters, and heat and/or water fluxes. Similarly, they can be used to capture the snow thickness and the snowpack thermal parameters and fluxes. However, these measurements are challenging to acquire using conventional approaches due to their total cost, their limited vertical resolution, and their large installation footprint. This study presents the development and validation of a novel Distributed Temperature Profiling (DTP) system that addresses these challenges. The system leverages digital temperature sensors to provide unprecedented, finely resolved depth-profiles of temperature measurements with flexibility in system geometry and vertical resolution. The integrated miniaturized logger enables automated data acquisition, management, and wireless transfer. A novel calibration approach adapted to the DTP system confirms the factory-assured sensor accuracy of +/−0.1 °C and enables improving it to +/−0.015 °C. Numerical experiments indicate that, under normal environmental conditions, an additional error of 0.01 % in amplitude and 70 seconds time delay in amplitude for a diurnal period can be expected, owing to the DTP housing. We demonstrate the DTP systems capability at two field sites, one focused on understanding how snow dynamics influence mountainous water resources, and the other focused on understanding how soil properties influence carbon cycling. Results indicate that the DTP system reliably captures the dynamics in snow thickness, and soil freezing and thawing depth, enabling advances in understanding the intensity and timing in surface processes and their impact on subsurface thermal-hydrological regimes. Overall, the DTP system fulfills the needs for data accuracy, minimal power consumption, and low total cost, enabling advances in the multiscale understanding of various cryospheric and hydro-biogeochemical processes.

A Predictive Model of the Impact of the Skidding System on Forest Soil in Severe Climatic Conditions

2020 ◽  
pp. 131-144
Author(s):  
S.E. Rudov ◽  
◽  
V.Ya. Shapiro ◽  
O.I. Grigoreva ◽  
I.V. Grigorev ◽  
...  
Keyword(s):  
Forest Soil ◽  
Warm Season ◽  
Climatic Conditions ◽  
Soil Freezing ◽  
Class Iii ◽  
Freezing And Thawing ◽  
Metal Structures ◽  
Rapid Adjustment ◽  
Soil Freezing And Thawing ◽  
The Impact

In the Russian Federation logging operations are traditionally carried out in winter. This is due to the predominance of areas with swamped and water-logged (class III and IV) soils in the forest fund, where work of forestry equipment is difficult, and sometimes impossible in the warm season. The work of logging companies in the forests of the cryolithozone, characterized by a sharply continental climate, with severe frosts in winter, is hampered by the fact that forest machines are not recommended to operate at temperatures below –40 °C due to the high probability of breaking of metal structures and hydraulic system. At the same time, in the warm season, most of the cutting areas on cryosolic soils become difficult to pass for heavy forest machines. It turns out that the convenient period for logging in the forests of the cryolithozone is quite small. This results in the need of work in the so-called off-season period, when the air temperature becomes positive, and the thawing processes of the soil top layer begin. The same applies to the logging companies not operating in the conditions of cryosolic soils, for instance, in the Leningrad, Novgorod, Pskov, Vologda regions, etc. The observed climate warming has led to a significant reduction in the sustained period of winter logging. Frequent temperature transitions around 0 °C in winter, autumn and spring necessitate to work during the off-season too, while cutting areas thaw. In bad seasonal and climatic conditions, which primarily include off-season periods in general and permafrost in particular, it is very difficult to take into account in mathematical models features of soil freezing and thawing and their effect on the destruction nature. The article shows that the development of long-term predictive models of indicators of cyclic interaction between the skidding system and forest soil in adverse climatic conditions of off-season logging operations in order to improve their reliability requires rapid adjustment of the calculated parameters based on the actual experimental data at a given step of the cycles.

scholarly journals USING SMOS PASSIVE MICROWAVE DATA TO DEVELOP SMAP FREEZE/THAW ALGORITHMS ADAPTED FOR THE CANADIAN SUBARCTIC

2015 ◽  
Vol XL-1-W5 ◽  
pp. 365-368 ◽  
Author(s):  
P. Kalantari ◽  
M. Bernier ◽  
K. C. McDonal ◽  
J. Poulin
Keyword(s):  
Land Cover ◽  
Time Series Data ◽  
Passive Microwave ◽  
Soil Freezing ◽  
Series Data ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
The Impact

Seasonal terrestrial Freeze/Thaw cycle in Northern Quebec Tundra (Nunavik) was determined and evaluated with passive microwave observations. SMOS time series data were analyzed to examine seasonal variations of soil freezing, and to assess the impact of land cover on the Freeze/Thaw cycle. Furthermore, the soil freezing maps derived from SMOS observations were compared to field survey data in the region near Umiujaq. The objective is to develop algorithms to follow the seasonal cycle of freezing and thawing of the soil adapted to Canadian subarctic, a territory with a high complexity of land cover (vegetation, soil, and water bodies). Field data shows that soil freezing and thawing dates vary much spatially at the local scale in the Boreal Forest and the Tundra. The results showed a satisfactory pixel by pixel mapping for the daily soil state monitoring with a > 80% success rate with in situ data for the HH and VV polarizations, and for different land cover. The average accuracies are 80% and 84% for the soil freeze period, and soil thaw period respectively. The comparison is limited because of the small number of validation pixels.

IGBT Junction Temperature Measurements: Inclusive of Dynamic Thermal Parameters

2019 ◽  
Vol 19 (2) ◽  
pp. 333-340 ◽  
Author(s):  
Jiangyong Zhang ◽  
Mingxing Du ◽  
Lei Jing ◽  
Kexin Wei ◽  
William Gerard Hurley
Keyword(s):  
Thermal Parameters ◽  
Temperature Measurements ◽  
Junction Temperature

scholarly journals A PZT-Based Electromechanical Impedance Method for Monitoring the Soil Freeze–Thaw Process

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1107 ◽  
Author(s):  
Jicheng Zhang ◽  
Chuan Zhang ◽  
Jiahao Xiao ◽  
Jinwei Jiang
Keyword(s):  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Soil Freezing ◽  
Impedance Method ◽  
Active Sensing ◽  
Freezing And Thawing ◽  
Engineering Structures ◽  
Electromechanical Impedance ◽  
Freeze Thaw ◽  
Wave Signal

It is important to conduct research on the soil freeze–thaw process because concurrent adverse effects always occur during this process and can cause serious damage to engineering structures. In this paper, the variation of the impedance signature and the stress wave signal at different temperatures was monitored by using Lead Zirconate Titanate (PZT) transducers through the electromechanical impedance (EMI) method and the active sensing method. Three piezoceramic-based smart aggregates were used in this research. Among them, two smart aggregates were used for the active sensing method, through which one works as an actuator to emit the stress wave signal and the other one works as a sensor to receive the signal. In addition, another smart aggregate was employed for the EMI testing, in which it serves as both an actuator and a receiver to monitor the impedance signature. The trend of the impedance signature with variation of the temperature during the soil freeze–thaw process was obtained. Moreover, the relationship between the energy index of the stress wave signal and the soil temperature was established based on wavelet packet energy analysis. The results demonstrate that the piezoceramic-based electromechanical impedance method is reliable for monitoring the soil freezing and thawing process.

scholarly journals Simulation of Soil Freezing and Thawing for Different Groundwater Table Depths

2019 ◽  
Vol 18 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Junfeng Chen ◽  
Xuguang Gao ◽  
Xiuqing Zheng ◽  
Chunyan Miao ◽  
Yongbo Zhang ◽  
...  
Keyword(s):  
Groundwater Table ◽  
Soil Freezing ◽  
Freezing And Thawing ◽  
Soil Freezing And Thawing

Seepage and Heat Flow in Soil Freezing

1982 ◽  
Vol 104 (2) ◽  
pp. 323-328 ◽  
Author(s):  
P. E. Frivik ◽  
G. Comini
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Seepage Flow ◽  
Soil Freezing ◽  
Temperature Fields ◽  
Laboratory Model ◽  
Experimental Measurements ◽  
The Finite Element Method ◽  
Freezing And Thawing ◽  
Velocity And Temperature Fields

In this paper we describe a system of computer programs based on the finite element method, which can be used for the calculation of coupled velocity and temperature fields during freezing and thawing of soils in the presence of seepage flow. In the programs, the mass and energy conservation equations are solved simultaneously, without the use of too limiting assumptions. The results of the computations are compared with experimental measurements made on a laboratory model of a soil freezing system, and the agreement between measured and computed values is good.

scholarly journals GEOtop 2.0: simulating the combined energy and water balance at and below the land surface accounting for soil freezing, snow cover and terrain effects

2014 ◽  
Vol 7 (6) ◽  
pp. 2831-2857 ◽  
Author(s):  
S. Endrizzi ◽  
S. Gruber ◽  
M. Dall'Amico ◽  
R. Rigon
Keyword(s):  
Snow Cover ◽  
Land Surface ◽  
Three Dimensional ◽  
Soil Surface ◽  
Soil Freezing ◽  
Energy Budgets ◽  
Freezing And Thawing ◽  
Terrain Effects ◽  
Synthetic Simulation ◽  
Soil Freezing And Thawing

Abstract. GEOtop is a fine-scale grid-based simulator that represents the heat and water budgets at and below the soil surface. It describes the three-dimensional water flow in the soil and the energy exchange with the atmosphere, considering the radiative and turbulent fluxes. Furthermore, it reproduces the highly non-linear interactions between the water and energy balance during soil freezing and thawing, and simulates the temporal evolution of the water and energy budgets in the snow cover and their effect on soil temperature. Here, we present the core components of GEOtop 2.0 and demonstrate its functioning. Based on a synthetic simulation, we show that the interaction of processes represented in GEOtop 2.0 can result in phenomena that are significant and relevant for applications involving permafrost and seasonally frozen soils, both in high altitude and latitude regions.

Sign in / Sign up

Export Citation Format

Share Document