scholarly journals Models to predict the parameters of ship voyages in the Arctic: existing approaches and possible ways of development

2021 ◽  
Vol 11 (3) ◽  
pp. 422-435
Author(s):  
O.V. Tarovik ◽  
Keyword(s):  
Information Support ◽  
The Arctic ◽  
Regression Equations ◽  
Propulsion Performance ◽  
Networks Analysis ◽  
Transit Model ◽  
Vessel Resistance ◽  
Semi Empirical ◽  
Ice Resistance ◽  
Ship Speed

Any information support system for Arctic shipping requires a ship transit model as one of the key elements that allows for strategic analysis, operational planning of vessel voyages, and ice routing of a ship. At the same time, there is no single recognized approach to develop such a model, due to the complexity of ice cover in terms of its impact on shipping. In this article, we have identified and analyzed three principal approaches to predict the parameters of vessel voyages in the Arctic. They are (1) semi-empirical models to estimate the vessel resistance in ice and then calculate propulsion performance, (2) numerical methods to model ship-ice interaction and calculate ice resistance, (3) statistical models to assess the ship speed based on regression equations or neural networks. Analysis of the strengths and weaknesses of each approach allowed us to propose a concept to develop the ship transit model for practical application.

scholarly journals Atmospheric Circulation Effects on Wind Speed Variability at Turbine Height

2007 ◽  
Vol 46 (4) ◽  
pp. 445-456 ◽  
Author(s):  
Katherine Klink
Keyword(s):  
Wind Speed ◽  
Pressure Gradient ◽  
Large Scale ◽  
Ground Level ◽  
The Arctic ◽  
Circulation Index ◽  
Regression Equations ◽  
Change Models ◽  
Wind Speeds ◽  
The North

Abstract Mean monthly wind speed at 70 m above ground level is investigated for 11 sites in Minnesota for the period 1995–2003. Wind speeds at these sites show significant spatial and temporal coherence, with prolonged periods of above- and below-normal values that can persist for as long as 12 months. Monthly variation in wind speed primarily is determined by the north–south pressure gradient, which captures between 22% and 47% of the variability (depending on the site). Regression on wind speed residuals (pressure gradient effects removed) shows that an additional 6%–15% of the variation can be related to the Arctic Oscillation (AO) and Niño-3.4 sea surface temperature (SST) anomalies. Wind speeds showed little correspondence with variation in the Pacific–North American (PNA) circulation index. The effect of the strong El Niño of 1997/98 on the wind speed time series was investigated by recomputing the regression equations with this period excluded. The north–south pressure gradient remains the primary determinant of mean monthly 70-m wind speeds, but with 1997/98 removed the influence of the AO increases at nearly all stations while the importance of the Niño-3.4 SSTs generally decreases. Relationships with the PNA remain small. These results suggest that long-term patterns of low-frequency wind speed (and thus wind power) variability can be estimated using large-scale circulation features as represented by large-scale climatic datasets and by climate-change models.

A Theoretical Model for Ship–Wave Impact Generated Sea Spray

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Shafiul Mintu ◽  
David Molyneux ◽  
Bruce Colbourne
Keyword(s):  
Theoretical Model ◽  
Field Measurements ◽  
Operating Conditions ◽  
Ship Motions ◽  
Wave Impact ◽  
Fishing Vessels ◽  
Semi Empirical ◽  
Wave Induced ◽  
Analytical Expressions ◽  
Ship Speed

Abstract Spray generated by ships traveling in cold oceans often leads to topside icing, which can be dangerous to vessels. Estimation of the spray flux is a first step in predicting icing accumulation. The amount of spray water, the duration of exposure to the spray, and the frequency at which the spray is generated are all important parameters in estimating the spray flux. Most existing spray flux formulae are based on field observations from small fishing vessels. They consider meteorological and oceanographic parameters but neglect the vessel behavior. Ship heave and pitch motions, together with ship speed, determine the frequency of spray events. Thus, the existing formulae are not generally applicable to different sizes and types of vessels. This paper develops simple methods to quantify spray properties in terms that can be applied to vessels of any size or type. Formulae to estimate water content and spray duration are derived based on principles of energy conservation and dimensional analysis. To estimate spray frequency considering ship motions, a theoretical model is proposed. The model inputs are restricted to ship’s principal particulars, operating conditions, and environmental conditions. Wave-induced motions are estimated using semi-empirical analytical expressions. A novel spray threshold is developed to separate deck wetness frequency from spray frequency. Spray flux estimates are validated against full-scale field measurements available in the open literature with reasonable agreement.

An Analysis on the Change of Ship Speed According to Ice Load Signal in Continuous Icebreaking and Ramming

2018 ◽  
Author(s):  
Se-Jin Ahn ◽  
Woo-Seong An ◽  
Tak-Kee Lee ◽  
Kyungsik Choi
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
The Arctic ◽  
Time Duration ◽  
Amundsen Sea ◽  
Ice Load ◽  
Research Activities ◽  
The Arctic Ocean ◽  
The Antarctic ◽  
Ship Speed

Recently, the research activities by domestic and overseas researchers using the Korean ice-breaking research vessel, ARAON have been actively conducted. The ARAON regularly operates for research activities in the Antarctic and the Arctic Ocean every year. She conducts many scientific and engineering tasks including ice load measurement, investigation of the properties of material strength for sea ice, and icebreaking performance test during her voyages. Such tests provide important data for studying icebreaker. Ice-breaking mode is determined by conditions of sea ice and ice field, and it is divided into ramming and continuous icebreaking. When the icebreaker meets thick ice or icebergs, the ramming is conducted. At that time, the ship speed is generally slower than that of the continuous icebreaking. The ARAON conducted icebreaking performance tests at the Amundsen Sea in Antarctica in 2012. Many strain data were measured in the ramming and the continuous icebreaking. This study was based on the strain gauge signals measured by the ARAON during the research voyage in 2012 in the Antarctic and 2010 in the Arctic. The signals measured from repetitive ramming under the heavy ice condition in 2012 in the Antarctic Ocean were classified into the five profiles. And the classified ice load signals were analyzed with a focus on raising time, half-decaying time and total time duration. Also, the signals measured from continuous icebreaking in 2010 in the Arctic Ocean were analyzed in the same way as the ramming data. Finally, the time histories of ice load signals were summarized from the viewpoint of speed change at the time of ice load, and two data sets were compared.

Daily monitoring of retrogressive thaw slumps in the Fosheim Peninsula, Ellesmere Island, Canada

2020 ◽  
Author(s):  
Melissa Ward Jones ◽  
Benjamin Jones ◽  
Wayne Pollard
Keyword(s):  
Time Scales ◽  
Air Temperature ◽  
Polynomial Regression ◽  
Pearson Correlation ◽  
Daily Basis ◽  
The Arctic ◽  
Regression Equations ◽  
Daily Monitoring ◽  
Sediment Redistribution ◽  
Short Time

<p>Retrogressive thaw slumps (RTS) occur from the mass wasting of ice-rich permafrost. These horseshoe-shaped features have an ablating or retreating ice-rich headwall with fluidized sediment that is transported along the RTS floor. RTS can remain active for up to decades and enlarge as the headwall retreats. With observed increases in RTS number, rates and sizes in recent decades, there is a need to understand these highly dynamic landforms, however there is a general lack of detailed field observations of RTSs. We monitored 3 RTS for over half of the 2017 thaw period by setting up and tracking survey transects on a near daily basis. We correlated mean daily and cumulative retreat to mean daily air temperature (MDAT), total daily precipitation (TDP) and thawing degree days (TDD) using various polynomial regressions and Pearson correlation techniques. Our results show that July retreat was highly variable and periods of increased RTS retreat did not always align with periods of increased air temperature. Also, multiple periods of increased retreat could occur within a single period of increased air temperature. These retreat trends were observed to be largely driven by sediment redistribution in the RTS floor. Retreat rates decreased suddenly in early August, indicating a threshold of either air temperature, solar radiation or a combination of both must be reached for increased retreat rates. There was a statistically significant correlation between daily mean and mean cumulative retreat with MDAT (p < 0.001) and TDD (p < 0.001 and < 0.0001) but not with TDP. Correlating mean cumulative retreat and cumulative TDD using polynomial regression (quadratic and cubic) generated R<sup>2 </sup>values greater than 0.99 for all 3 sites as these variables account for past and current conditions within the monitoring period, as well as lag responses of retreat. This suggests the potential of accurately modelling RTS retreat with minimal field data (air temperature and headwall position), however this is currently restricted to individual RTSs and only within short time scales. We tested this idea by modelling 2 weeks of cumulative retreat in 2018 for 2 of our sites we monitored using the 2017 regression equations. Percent prediction error was 8% at one site and 16% at the other. Monitoring RTS on a daily scale allows RTS behaviour and trends to be identified that may be obscured at annual time scales. With the widespread increased numbers of RTSs being observed around the Arctic, understanding their dynamics is critical as these landforms impact surrounding ecosystems and infrastructure which will be exacerbated with climate change.  </p>

Influence of Sea Temperature upon the Numbers of Grilse and Multi-Sea-Winter Atlantic Salmon (Salmo salar) Caught in the Vicinity of the River Dee (Aberdeenshire)

1985 ◽  
Vol 42 (9) ◽  
pp. 1513-1521 ◽  
Author(s):  
J. H. A. Martin ◽  
K. A. Mitchell
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
The Arctic ◽  
Average Weight ◽  
Regression Equations ◽  
Catch Per Unit Effort ◽  
Data Set ◽  
Sea Temperature ◽  
Atlantic Salmon Salmo Salar ◽  
High Seas

The possible influence of sea temperature upon the age of return of Atlantic salmon (Salmo salar) was examined using the catch and weight data of grilse and multi-sea-winter (MSW) salmon of the Aberdeen Harbour Board caught either within or adjacent to the River Dee (Aberdeenshire). This data set, apart from a 10-yr period of commercial confidentiality, is very suitable because uniformity of effort allowed catch per unit effort to be calculated. Only in the last few years was external pressure (high seas fishing) applied to the system. Various temperature series were examined but the known loci of high seas fishing and the temperature ranges involved suggested that the most relevant series is from the subarctic. Increase in temperature is shown to be associated with larger numbers of fish returning as MSW salmon and fewer as grilse. The average weight of grilse increases with grilse catch numbers. Regression equations for grilse and MSW salmon catch numbers are produced for the period 1877–1972. There is a marked 4-yr periodicity in the grilse catch data. A hypothesis is proposed that the temperature of the subarctic influences the migratory pattern, that fish travel further north into the Arctic/subarctic only during those years when the minimum temperature remains above 2 °C.

scholarly journals Increasing the probability of recognizing a target using a two-dimensional image from the sensor of the visible range of the onboard complex of information support for search and rescue operations in the Arctic

2020 ◽  
Vol 30 (3) ◽  
pp. 21-27
Author(s):  
A. S. Zhdanov ◽  
S. A. Matveev ◽  
Yu. V. Petrov ◽  
S. A. Rudyka ◽  
S. Yu. Strakhov ◽  
...  
Keyword(s):  
Object Recognition ◽  
Target Recognition ◽  
Recognition Performance ◽  
Search And Rescue ◽  
Information Support ◽  
The Arctic ◽  
Visible Range ◽  
Image Brightness ◽  
Television Camera ◽  
Constant Color

The article addresses the task of improving target recognition in onboard information support system for search and rescue operations in the Arctic region. One of the tasks performed by the complex is recognition of objects in twodimensional camera images, which suffer from the loss of the image brightness, being formed by constant brightness principle, with its direct impact on the probability of target recognition. To preserve the brightness of the image, the authors propose to process the primary signals of the camera according to the principle of constant color brightness. The proposed processing can increase the probability of correct target recognition. The paper analyzes the principles of encoding the primary signals of the television camera. For the object recognition problem, the cascades were trained based on the cascade classifier using the principles of constant brightness and constant color brightness. The output of the trained cascades has confirmed that the processing of the primary signals of a television camera based on the principle of constant brightness improves target recognition and therefore will increase the object recognition performance of the complex under development.

scholarly journals On Assessment of Climatic Risks and Vulnerability of Natural and Economic Systems in the Sea Zone of the Russian Arctic

2018 ◽  
Vol 64 (1) ◽  
pp. 55-70 ◽  
Author(s):  
S. A. Soldatenko ◽  
G. V. Alekseev ◽  
N. E. Ivanov ◽  
A. E. Vyazilova ◽  
N. E. Kharlanenkova
Keyword(s):  
Climate Change ◽  
Information Support ◽  
The Arctic ◽  
Economic Systems ◽  
Russian Arctic ◽  
Sea Ice Extent ◽  
Impact Of Climate Change ◽  
Arctic Sea ◽  
Climatic Risks ◽  
The Impact

The article presents an analysis of the impacts of climate change on the natural and economic systems of theArcticand the existing methods for assessing climatic risks. Based on the analysis of the impact of climate change on natural and economic systems and the Arctic population, a register of risks due to climate change has been formed. A conceptual model for assessing the impact of climate change on various systems is proposed. The main problems in the identification of climatic risks in theArcticare identified. Indicators of climate change were selected: the surface air temperature; sea ice extent and the frequency of dangerous hydrometeorological phenomena that affect economic activity in the Arctic sea zone and its individual regions. The assessment methodology of natural and economic systems vulnerabilities in the Russian Arctic sea zone, including susceptibility to impacts, sensitivity and adaptive potential, is considered. These are the key factors on the basis of which the systems vulnerability to climate change is determined, as well as the information support of the processes of assessment and reduction of the consequences of climate threats. The algorithm of the developed methodology for vulnerability determining includes a sequence of 7 steps.

scholarly journals Quantum chemical approach to calculating the enthalpies of the formation of alkali metal xanthates

2020 ◽  
Vol 15 (2) ◽  
pp. 30-37
Author(s):  
Yu. V. Popov ◽  
A. S. Dolgachev ◽  
E. V. Shishkin ◽  
Yu. L. Zotov ◽  
V. E. Shishkin
Keyword(s):  
Experimental Data ◽  
Alkali Metal ◽  
Quantum Chemical ◽  
Linear Regression Analysis ◽  
Biologically Active ◽  
Enthalpies Of Formation ◽  
Regression Equations ◽  
Flotation Reagents ◽  
Organic Part ◽  
Semi Empirical

Objectives. The aim of this work is to study the possibility of the joint use of quantum chemical methods and correlation analysis to determine the formation enthalpies of metal-containing organic substances using the example of alkali metal xanthates, which are of interest as biologically active substances and effective flotation reagents. Methods. Semi-empirical methods of quantum chemical calculating (Modified Neglect of Diatomic Overlap, Austin Model 1, Recife model 1 methods) and linear regression analysis were used. Results. Using the semi-empirical Modified Neglect of Diatomic Overlap, Austin Model 1, and Recife model 1 methods, the enthalpies of formation of 16 potassium and sodium alkyl xanthates were calculated, and the obtained results were compared with experimental data. It was found that the best correlation for potassium and sodium salts of dithiocarbonic acid esters could be observed using the Austin Model 1 method. Using the obtained regression equations, the enthalpies of formation were calculated for 30 xanthates, the organic part of which contained alkyl, cyclic non-aromatic structures, and one or two heteroatoms such as nitrogen, oxygen, and fluorine, and for which there are no experimental data. Conclusions. As a result of the study, an excellent correlation was established between the experimental and the calculated (by the Austin Model 1 method) values of the enthalpies of formation of potassium and sodium alkyl xanthates. The data obtained can be used to calculate the thermal effect of the xanthogenation reactions of alcohols and to design the production of the corresponding xanthates. 

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