Cold Regions Science Research Articles

Comparative analysis of machine learning techniques for accurate prediction of unfrozen water content in frozen soils

Unfrozen water content (UWC) plays a critical role in determining the thermal, hydraulic, and mechanical properties of frozen soils. Existing empirical, semi-empirical, and theoretical models for UWC estimation have limitations in terms of accuracy as well as generalizability. To address these challenges, the present study explored the application of six machine learning techniques to predict UWC in frozen soils: Random Forest (RF), eXtreme Gradient Boosting (XGBoost), Light Gradient Boosting Machine (LightGBM), K-Nearest Neighbors (KNN), Support Vector Regression (SVR), and Backpropagation Neural Network (BPNN). Considering the UWC hysteresis phenomenon between the freezing and thawing processes, experimental UWC data collected from the literature were separated into two sub-datasets: freezing branch dataset (FBD) and thawing branch dataset (TBD). Based on that, a comprehensive framework integrating Bayesian optimization and 10-fold cross-validation was established to optimize the six models' hyperparameters and to evaluate their performance. The results highlighted significant variations in the predictive capability among the six machine learning models, with ensemble methods (i.e., RF, XGBoost, LightGBM) generally demonstrating superior accuracy. Feature importance analysis, robustness checks, and uncertainty quantification further elucidated the strengths and limitations of each model. The present study provides profound insights into the selection and application of machine learning models for accurately modeling the properties of frozen soils for cold regions science and engineering.

A Scientometric Review of Research Status on Unfrozen Soil Water

Unfrozen soil water affects the physical, chemical, hydrological, and mechanical properties of frozen soils, and climate change makes these relationships more complicated. The objective of this study was to investigate the research status of unfrozen soil water using scientometrics. Publications on unfrozen water in frozen soil (UWFS) retrieved from the Web of Science were analyzed with scientometric software tools including VOSviewer, CiteSpace, and HistCite Pro. The annual publication trend, co-authorship of authors, organizations, and countries, and the co-occurrence of keywords were analyzed. The most utilized journals and high-impact publications were identified. The results showed that 2007 (the year the “Bali Road Map” was released) represents a turning point (from slow to rapid) in the development of research on unfrozen water in frozen soil. Researchers and organizations from China and the United States are the major contributors, while Cold Regions Science and Technology is the most utilized journal for publishing research pertaining to UWFS. Currently, there is still a lack of reliable and user-friendly methods and techniques for measuring unfrozen water content. Future efforts are required to understand the mechanisms governing the magnitude of unfrozen water content and to develop new approaches to accurately and rapidly measure unfrozen water content in both laboratory and in situ.

Edgar “Ed” L Andreas 1946–2015

Edgar Andreas died on 30 September 2015 in Lebanon, New Hampshire, USA. Ed was born on 6 December 1946 in Sterling, Illinois, USA. Known as an independent thinker, he made important advances in the development of instrumentation and methods of data analysis and he contributed substantially to improved understanding of boundary-layer meteorology (Fig. 1). Ed worked in a variety of fields within boundary-layer meteorology, concentrating on fluxes from water, ice, and snow surfaces; but he also published work on fluxes from snow-free land surfaces and even on fluxes from the surface of the moon. He published many valuable papers in atmospheric and geophysical journals but additionally published in the American Journal of Physics, Physics Today, Applied Optics, Journal of the Optical Society of America, Radio Science, and Cold Regions Science and Technology. He received his Ph.D. in physical oceanography at Oregon State University in 1977 under the direction of Clayton Paulson where he studied internal boundary layers over Arctic leads and published a pioneering paper on this subject. For this work, Ed participated as a major contributor in the first of what would become a dozen field programs during his career. In 1978, Ed was hired as a research physicist at the US Army Cold Regions Research and Engineering Laboratory (CRREL) in Hanover, New Hampshire, USA. At CRREL, Ed had two notable Antarctic firsts. In 1981, he was a member of the Weddell Polynya Expedition, which made the first deep penetration into the Antarctic ice pack and was the first time that American and Russian scientists worked together on the Antarctic sea-ice. In 1992, Ed was the lead American meteorologist on the American and Russian ice station Weddell, the first research ice camp ever deployed on drifting Antarctic sea-ice. It floated northward for 4months, paralleling the track of Ernest Shackleton’s legendary Endurance, and was the first human visit to this remote area in the 75years since Shackleton’s epic adventure. Additionally, Ed participated in several expeditions to the Arctic. Whilst at CRREL, Ed worked on surface fluxes over snow, ice, marginal ice zones and water surfaces.He continuedwork on instrumentation issues includingwork on the ship boom assembly, calibration and interpretation of hot-film data, the effective averaging inherent in

Response to discussion on “Exceptional snowfalls and the assessment of accidental loads for structural design” from M. Kasperski [Cold Regions Science and Technology 101 (2014) 83–86

The use of the Weibull plotting position is briefly described outlining related analysis of exceptional snow loads. The occurrence of exceptional snow loads is illustrated by the variability of small size sample realizations of extreme value distribution functions. The quality of available snow load data as related to the spatial dependency analysis is mentioned.

Discussion of “Exceptional snowfalls and the assessment of accidental loads for structural design” by Sadovsky et al. [Cold Regions Science and Technology 72 (2012) 17–22

In Europe, an observed value is treated as exceptional snow load “if the ratio of the largest load value to the characteristic load determined without the inclusion of that value is greater than 1.5”. While these exceptional values are neglected for the specification of the characteristic value, they form the basis of separate statistics with the basic aim of identifying extremely rare events with an annual exceedance probability of 1/10,000 which then are treated as an accidental load. The exceedance probability of the limiting value depends on the type of probability distribution and the variation coefficient V. If the annual extremes follow the Gumbel distribution, the annual exceedance probability of the limiting value is about 1/1000 for V=0.5 and 1/500 for V=1. As a matter of fact, the probability of observing values larger than the limiting value increases with the number of observation years and the number of independent stations. If all observations are treated as independent observations – as is done in the Sadovsky paper – it can be shown that a larger number of stations will show exceptional snowfalls just randomly. Therefore, there is no justification for the introduction of a separate accidental load case. Furthermore, the identified exceptional values do not form an appropriate basis for the identification of the 1/10,000 event.

Erratum to “RAMMS: Numerical simulation of dense snow avalanches in three-dimensional terrain” [Cold Regions Science and Technology, Volume 63/1–2 (2010) pp. 1–14

Erratum to “RAMMS: Numerical simulation of dense snow avalanches in three-dimensional terrain” [Cold Regions Science and Technology, Volume 63/1–2 (2010) pp. 1–14

Corrigendum to “A field study of suspended frazil ice particles” [Cold Regions Science Technology. Volume 55/1 (2008) pp. 86–102

Abstract This note is written to correct an erroneous interpretation of acoustic intensity made by the authors during the writing of the paper “A field study of suspended frazil ice particles” by Brian Morse and Martin Richard. The correct interpretation is presented and the impacts on the findings are quantified.

An overview of river ice problems: CRIPE07 guest editorial

Abstract This special issue of the Journal of Cold Regions Science and Technology presents selected papers emanating from the 14th River Ice Workshop hosted by the Canadian Geophysical Union — Hydrology Section's (CGU-HS) Committee on River Ice Processes and the Environment (CRIPE) in Quebec City, Canada in June 2007. Eight papers in total are presented in this issue, covering the complete ice season from freeze-up to breakup, encompassing field, experimental and numerical investigations, and representing the latest advances in knowledge of river ice processes and dynamics. As an introduction for those readers new to the field of river ice engineering, this introductory paper provides an overview of the river ice cycle, highlighting both the typical and the unusual phenomena encountered. From frazil ice to ice jams, this is truly a dynamic and fascinating research field and it is our hope that these papers will encourage readers to renew or initiate their own river ice research endeavours. The Committee on River Ice Processes and the Environment (CRIPE) extends its sincere thanks to the Journal of Cold Regions Science and Technology for making the Special Issue on River Ice possible.

Guest editorial: Cryospheric science and engineering

Abstract : This Special Issue of Cold Regions Science and Technology contains a sampling of papers that were presented at the Cryospheric Science and Engineering Symposium held at the U.S. Army ERDC Cold Regions Research and Engineering Lab in Hanover, NH on 19 October 2006. The Symposium brought together cold regions engineers and scientists to share results on topics spanning many cold regions issues. Some of the topics have been important endeavors for many decades. Other topics are new areas arising from innovations in sensing and technology to address issues driven by climate change and/or the impact of human activity on the environment. The most detailed naturally-archives records of environment and climate are found in ice cores drilled in polar and high-altitude regions. How did ice coring science get its start? The Langway paper provides a description of the IGY-era activities and international development of the early polar ice cores.

Petroleum–hydrocarbon contamination and remediation by microbioventing at sub-Antarctic Macquarie Island

Natural attenuation of petroleum hydrocarbons in polar and subpolar soils is limited by low nutrients, low temperatures, and water availability. This study investigated three sites contaminated with diesel fuel and the use of aeration to remediate one of the sites at sub-Antarctic Macquarie Island. These sites were of differing ages and had different soil–water regimes. The most recent spill (New Main Power House) occurred in 2002 and resulted in ∼180 metric tons of highly-contaminated (∼7000 mg kg −1 ), moderately-drained, sandy soil. An older site (b1994; Old Main Power House) comprised ∼100 metric tons of moderatelycontaminated (∼2800 mg kg −1 ) water-saturated peaty soil. A third spill (b1994; Fuel Farm) contained approximately 600 metric tons of low- to moderately-contaminated (∼800 mg kg −1 ) sandy soil. Using a hydrocarbon distribution model (NAPLANAL) we determined that non-aqueous phase liquid droplets start to form in these soils at concentrations 50–1000 mg kg −1 mostly depending on organic carbon fraction. An in-field treatability evaluation with an air sparge port to increase oxygen concentration in the soils proved unsuccessful because the shallow water table and thin soil cover led to channel development. However, an easilyinstalled ‘microbioventing’ system, comprising many small air injecting rods, successfully aerated a wide area of soil. Field estimates of biodegradation rates under unamended aerobic conditions were ∼10–20 mg kg −1 d −1 . When considered with results from a nutrient optimisation respiration experiment [Walworth, J., Pond, A., Snape, I., Rayner, J.L. and Harvey, P.M., 2007-this issue. Nitrogen requirements for maximizing petroleum bioremediation in a sub-Antarctic soil. Cold Regions Science and Technology, In Press.], we conclude that in situ bioremediation for these sites should treat the soil to a target concentration of ∼200 mg kg −1 in approximately 1–2 years of continual operation at ambient temperatures. This simple methodology could have

Guest Editorial: Contaminant Source Zones: Remediation or Perpetual Stewardship?

Guest Editorial: Contaminant Source Zones: Remediation or Perpetual Stewardship?

Snow accretion on overhead wires

Although snow accretion on overhead wires is a serious problem, recognized physical models have not yet been established. In this paper, attempts directed at understanding the mechanism of snow accretion on wires are reviewed. Fundamentals of the meteorological conditions under which snow accretes on wires, inferred mechanisms, mechanics and heat balance of snow accretion are briefly reviewed. A short historical review of research works throughout the world is given. Wind–tunnel tests aiming at examining the dependence of various parameters on the characteristics of accreted snow on wires are introduced and defects of such tests are discussed. Finally, attempts to establish snow–load design on power lines, with some results of observations under natural conditions, are briefly discussed. It should be emphasized that the present paper is characteristic of an interim report and summary about snow accretion on overhead wires, with the purpose of avoiding repetition of the same kind of research efforts and therefore accelerating further progress.

Aircraft icing

Aircraft icing

Addendum to “Computational modelling of frost heave induced soil-pipeline interaction II. Modelling of experiments at the Caen Test Facility” [Cold Regions Science and Technology 29 (1999) 229–257

Addendum to “Computational modelling of frost heave induced soil-pipeline interaction II. Modelling of experiments at the Caen Test Facility” [Cold Regions Science and Technology 29 (1999) 229–257

Addendum to “Computational modelling of frost heave induced soil-pipeline interaction I. Modelling of frost heave” [Cold Regions Science and Technology 29 (1999) 215–228

Addendum to “Computational modelling of frost heave induced soil-pipeline interaction I. Modelling of frost heave” [Cold Regions Science and Technology 29 (1999) 215–228

Quasi–incompressible Cahn–Hilliard fluids and topological transitions

One of the fundamental problems in simulating the motion of sharp interfaces between immiscible fluids is a description of the transition that occurs when the interfaces merge and reconnect. It is well known that classical methods involving sharp interfaces fail to describe this type of phenomena. Following some previous work in this area, we suggest a physically motivated regularization of the Euler equations which allows topological transitions to occur smoothly. In this model, the sharp interface is replaced by a narrow transition layer across which the fluids may mix. The model describes a flow of a binary mixture, and the internal structure of the interface is determined by both diffusion and motion. An advantage of our regularization is that it automatically yields a continuous description of surface tension, which can play an important role in topological transitions. An additional scalar field is introduced to describe the concentration of one of the fluid components and the resulting system of equations couples the Euler (or Navier–Stokes) and the Cahn–Hilliard equations. The model takes into account weak non–locality (dispersion) associated with an internal length scale and localized dissipation due to mixing. The non–locality introduces a dimensional surface energy; dissipation is added to handle the loss of regularity of solutions to the sharp interface equations and to provide a mechanism for topological changes. In particular, we study a non–trivial limit when both components are incompressible, the pressure is kinematic but the velocity field is non–solenoidal (quasi–incompressibility). To demonstrate the effects of quasi–incompressibility, we analyse the linear stage of spinodal decomposition in one dimension. We show that when the densities of the fluids are not perfectly matched, the evolution of the concentration field causes fluid motion even if the fluids are inviscid. In the limit of infinitely thin and well–separated interfacial layers, an appropriately scaled quasi–incompressible Euler–Cahn–Hilliard system converges to the classical sharp interface model. In order to investigate the behaviour of the model outside the range of parameters where the sharp interface approximation is sufficient, we consider a simple example of a change of topology and show that the model permits the transition to occur without an associated singularity.

Ice fracture and spalling in ice-structure interaction : Bin Zou, Jing Xiao & I. J. Jordan, Cold Regions Science & Technology, 24(2), 1996, pp 213–220

Ice fracture and spalling in ice-structure interaction : Bin Zou, Jing Xiao & I. J. Jordan, Cold Regions Science & Technology, 24(2), 1996, pp 213–220

Elasto-delayed-elastic simulation of short-term deflection of fresh-water ice covers : N. K. Sinha & Baolin Cai, Cold Regions Science & Technology, 24(2), 1996, pp 221–235

Elasto-delayed-elastic simulation of short-term deflection of fresh-water ice covers : N. K. Sinha & Baolin Cai, Cold Regions Science & Technology, 24(2), 1996, pp 221–235

The effects of localized deformation on melting processes in ice : C. J. L. Wilson, Y. Zhang & K. Stuwe, Cold Regions Science & Technology, 24(2), 1996, pp 177–189

The effects of localized deformation on melting processes in ice : C. J. L. Wilson, Y. Zhang & K. Stuwe, Cold Regions Science & Technology, 24(2), 1996, pp 177–189

Viscosity of fluidized snow : K. Nishimura, Cold Regions Science & Technology, 24(2), 1996, pp 117–127

Viscosity of fluidized snow : K. Nishimura, Cold Regions Science & Technology, 24(2), 1996, pp 117–127