scholarly journals A Modeling Study of the Initial Formation of Polar Lows in the Vicinity of the Arctic Front

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Igor Mingalev ◽  
Konstantin Orlov ◽  
Victor Mingalev
Keyword(s):  
Mathematical Model ◽  
Three Dimensional ◽  
Lower Atmosphere ◽  
The Arctic ◽  
Height Range ◽  
Limited Region ◽  
Polar Lows ◽  
Initial Stage ◽  
Polar Low ◽  
Arctic Front

A regional mathematical model of the wind system of the lower atmosphere, developed recently in the Polar Geophysical Institute, is applied to investigate the initial stage of the formation of polar lows at latitudes of the European Arctic. The mathematical model is based on numerical solving of nonsimplified gas dynamic equations and produces three-dimensional distributions of the atmospheric parameters in the height range from 0 to 15 km over a limited region of the Earth’s surface. Simulation results indicated that the origin of a convexity in the configuration of the arctic front can lead to the formation of a polar low during the period of about one day.

scholarly journals A Simulation Study of the Formation of Large-Scale Cyclonic and Anticyclonic Vortices in the Vicinity of the Intertropical Convergence Zone

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Igor V. Mingalev ◽  
Natalia M. Astafieva ◽  
Konstantin G. Orlov ◽  
Victor S. Mingalev ◽  
Oleg V. Mingalev ◽  
...  
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Intertropical Convergence Zone ◽  
Lower Atmosphere ◽  
Horizontal Wind ◽  
Initial Moment ◽  
Convergence Zone ◽  
Height Range ◽  
Limited Region ◽  
Surface Time

A regional nonhydrostatic mathematical model of the wind system of the lower atmosphere, developed recently in the Polar Geophysical Institute, is utilized to investigate the initial stage of the origin of large-scale vortices at tropical latitudes. The model produces three-dimensional distributions of the atmospheric parameters in the height range from 0 to 15 km over a limited region of the Earth’s surface. Time-dependent modeling is performed for the cases when, at the initial moment, the simulation domain is intersected by the intertropical convergence zone (ITCZ). Calculations are made for various cases in which the initial forms of the intertropical convergence zone are different and contained convexities with distinct shapes, which are consistent with the results of satellite microwave monitoring of the Earth’s atmosphere. The results of modeling indicate that the origin of convexities in the form of the intertropical convergence zone, having distinct configurations, can lead to the formation of different large-scale vortices, in particular, a cyclonic vortex, a pair of cyclonic-anticyclonic vortices, and a pair of cyclonic vortices, during a period not longer than three days. The radii of these large-scale vortices are about 400–600 km. The horizontal wind velocity in these vortices can achieve values of 15–20 m/s in the course of time.

Polar Lows and Their Implications on Marine Operations: Survivability Criteria

2013 ◽  
Author(s):  
Meric Pakkan ◽  
David Heng ◽  
Ove Tobias Gudmestad
Keyword(s):  
Weather Forecast ◽  
Weather Conditions ◽  
The Arctic ◽  
Return Periods ◽  
Polar Lows ◽  
Wind Speeds ◽  
The North ◽  
Arctic Regions ◽  
Short Period ◽  
Polar Low

The oil resource potential in the Arctic/sub-Arctic regions is estimated to be as high as that 25% of the world’s yet-to-be-found. Nevertheless, operating in above-mentioned regions is more complicated and expensive than the ones in the North Sea. One of the most important aspects to consider in operating in these Arctic regions is the presence of polar lows and arctic fronts and storms. These extreme events and implications of them on the marine operations were the main focus of this study. While the maximum polar low-sourced wind speeds for 10-, 20- and 100-year return periods are estimated to be 55.37, 60.93 and 73.52 knots, the maximum polar low-sourced wave heights for 10-, 20- and 100-year return periods are calculated as 5.71, 6.66 and 8.82 meters, respectively. It is found out that polar lows weather conditions do not normally represent design values (survival conditions); however, they represent operational limitations. • We conclude that operations lasting longer than 72 hours shall be designed for a rougher weather than the polar lows lead to (survival mode). • For operations of duration less than 72 hours, the weather forecast is crucial and it must also be possible to abort the operation within a short period if one is close to a polar weather front as a polar low may appear very quickly.

scholarly journals CloudSat Observes a Labrador Sea Polar Low

2015 ◽  
Vol 96 (8) ◽  
pp. 1229-1231 ◽  
Author(s):  
John M. Forsythe ◽  
John M. Haynes
Keyword(s):  
Wide Band ◽  
Weather Conditions ◽  
Radar Reflectivity ◽  
The Arctic ◽  
Labrador Sea ◽  
Cloud Band ◽  
Polar Lows ◽  
Cloud Radar ◽  
Polar Low ◽  
First Time

Abstract Polar lows generate hazardous weather conditions in the Arctic, and satellites have played a key role in understanding their genesis and dynamics. For the first time, an overpass of the CloudSat 94-GHz cloud radar over a polar low has been recorded. The case occurred in November 2013 in the Labrador Sea between Canada and Greenland, and had a striking convective appearance with an eyelike feature. A deep cloud band was observed by the radar, with radar reflectivity up to 5-km in altitude in a 50-km-wide band. It is likely that more such matchups exist in the CloudSat mission data.

Methods of modeling the polar low development 

2021 ◽  
Author(s):  
Alexandra Kuznetsova ◽  
Alexander Dosaev ◽  
Nikita Rusakov ◽  
Evgeny Poplavsky ◽  
Yuliya Troitskaya
Keyword(s):  
Barents Sea ◽  
Model Simulation ◽  
Wrf Model ◽  
Heat Fluxes ◽  
The Arctic ◽  
Polar Lows ◽  
Wind Speeds ◽  
The Past ◽  
The Barents Sea ◽  
Polar Low

<p>The ice cover decrease in the Arctic in the past decade has led to polar hurricanes (polar lows) occurring along the entire Northern Sea Route. Wind speeds of these hurricanes reach 35-40 m / s. Over the past 20 years, significant progress in predicting storm trajectories has been achieved, while the quality of forecasting their intensity is still poor. This is due to the fact that the intensity (maximum wind speed and minimum pressure) is determined by the interaction of the atmosphere and the ocean, and at high wind speeds it has significant uncertainty, especially for the smallest-scale processes: splashes, wave collapses and foam bubbles [1].</p><p>Numerical modeling of the polar low development was carried out within the framework of the WRF model [2] in order to develop methods for modeling such extreme events. The water area of the Barents Sea was considered, where a large number of polar hurricanes were observed. Among the identified polar hurricanes [3], a hurricane that took place on 02/05/2009 and was observed at coordinates 69º N, 40º E was chosen. Several approaches were considered to simulate the weather conditions in the studied area of the Barents Sea in the presence of a polar hurricane. The WRF model simulation with the CFSR reanalysis was carried out. The configuration of the model consisted in using, first, the well-proven technique of Large Eddy Simulation (LES) modeling of the planetary boundary layer (PBL). Secondly, the simulation was performed using the WRF add-in for the polar region, Polar WRF [4]. The comparison of the approaches is made. The mechanism of intensification of the atmospheric vortex is considered whether it is baroclinic shear, heat fluxes on the surface or outcome of latent heat during condensation.</p><p>This work was supported by a RFBR grant № 18-05-60299.</p><p><strong>References</strong></p><p>1. Troitskaya, Yu, et al. "Bag-breakup fragmentation as the dominant mechanism of sea-spray production in high winds." Scientific reports7.1 (2017): 1-4.<br>2. A Description of the Advanced Research WRF Version 3 / W. C. Skamarock, J. B. Klemp, J. Dudhia, D. O. Gill, D. M. Barker, M. G. Duda, X.-Y. Huang, W. Wang, J. G. Powers // NCAR TECHNICAL NOTE. - 2008. - №NCAR/TN–475+STR. - С. 113 pp.<br>3. Noer, G., & Lien, T. (2010). Dates and Positions of Polar lows over the Nordic Seas between 2000 and 2010. Norwegian Meteorological Institute Rep.<br>4. Hines, Keith M., et al. "Development and testing of Polar WRF. Part III: Arctic land." Journal of Climate24.1 (2011): 26-48.</p>

A comprehensive mathematical model of heat and moisture transfer for wood convective drying

Holzforschung ◽  
2017 ◽  
Vol 71 (5) ◽  
pp. 425-435 ◽  
Author(s):  
Jingyao Zhao ◽  
Yingchun Cai
Keyword(s):  
Mathematical Model ◽  
Fluid Flow ◽  
Moisture Transfer ◽  
Three Dimensional ◽  
Convective Drying ◽  
Heat And Moisture Transfer ◽  
Initial Stage ◽  
Heat And Moisture ◽  
Velocity Pressure ◽  
Current Circulation

Abstract The focus of this study is the development of a specific drying model for the design and operation of drying systems for stacked lumber in drying chambers. Namely, a comprehensive three-dimensional (3D) mathematical model of heat and moisture transfer in stacked wood has been developed, where the wood was subjected to convective drying that accounts for the effect of the surrounding fluid flow. In developing the model, the characteristics of wood and fluid flow, i.e. velocity, pressure, temperature, relative humidity (RH) and moisture content (MC) are described by the conservation equations of mass, momentum and energy as well as thermodynamic relations. The model presented was solved numerically by means of the commercial software COMSOL Multiphysics. The simulation results were validated against experimental data under laboratory conditions. Air current circulation was found to be non-uniform during drying, which accounts for the different rates of temperature and MC in wood. At the initial stage of drying, this difference was relatively large but reduced gradually with the drying process. Meanwhile, the transient gathered phenomenon related to humidity around the stacked wood in the chamber was observed in response to air current circulation and evaporation rate of moisture. Finally, sources of error incurred in numerical calculations and actual detection were identified and discussed.

POLAR LOW DETECTION USING SOLAB SIOWS ARCTIC PORTAL

2017 ◽  
Author(s):  
Olga Mashtaler ◽  
Olga Mashtaler ◽  
Alexander Myasoedov ◽  
Alexander Myasoedov ◽  
Elizaveta Zabolotskikh ◽  
...  
Keyword(s):  
Model Development ◽  
Sharp Decrease ◽  
Open Water ◽  
The Arctic ◽  
Wind Fields ◽  
Polar Lows ◽  
Statistical Regularities ◽  
Meteorological Observations ◽  
Strong Winds ◽  
Synthetic Aperture Radars

The relevance of the polar lows (PLs) research is justified by their great destructive power and creation of threat to the safety of navigation in the high latitudes and along the Northern Sea Route. The most dangerous effects on maritime activities are strong winds, waves and icing. In addition, the study of the PLs acquires relevance due to the sharp decrease of the sea ice area in the Arctic in recent years and the emergence of areas of open water, suitable for the appearance and development of PLs. However, despite the importance of PLs, they are apparently not sufficiently studied. As there are no meteorological observations in the areas of their appearance, the main source of information about them are satellite observations. By using images on the SOLab SIOWS Arctic Portal from multiple satellites operating in the IR and visible ranges (e.g., MODIS and AVHRR), and using near-water wind fields from high resolution synthetic aperture radars (Sentine-1, ASAR) and low resolution scatterometers (ASCAT), we identify polar lows in various parts of the Arctic, revealing statistical regularities in the appearance of PLs, their distribution and intensity. Collected database of Pls and their characteristics will be used for further PLs forecasting model development.

A Real-Time Mathematical Model for Three-Dimensional Tidal Flow and Water Quality

1991 ◽  
Vol 24 (6) ◽  
pp. 171-177 ◽  
Author(s):  
Zeng Fantang ◽  
Xu Zhencheng ◽  
Chen Xiancheng
Keyword(s):  
Mathematical Model ◽  
Water Quality ◽  
Real Time ◽  
Control Volume ◽  
Tidal Flow ◽  
Three Dimensional ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Practical Application ◽  
The Pearl River

A real-time mathematical model for three-dimensional tidal flow and water quality is presented in this paper. A control-volume-based difference method and a “power interpolation distribution” advocated by Patankar (1984) have been employed, and a concept of “separating the top-layer water” has been developed to solve the movable boundary problem. The model is unconditionally stable and convergent. Practical application of the model is illustrated by an example for the Pearl River Estuary.

Research on cargo-loading optimization based on genetic and fuzzy integration

2021 ◽  
Vol 40 (4) ◽  
pp. 8493-8500
Author(s):  
Yanwei Du ◽  
Feng Chen ◽  
Xiaoyi Fan ◽  
Lei Zhang ◽  
Henggang Liang
Keyword(s):  
Genetic Algorithm ◽  
Mathematical Model ◽  
Three Dimensional ◽  
Distribution Center ◽  
Long Time ◽  
Low Efficiency ◽  
Decision Making Model ◽  
The Mathematical Model ◽  
Loading Scheme

With the increase of the number of loaded goods, the number of optional loading schemes will increase exponentially. It is a long time and low efficiency to determine the loading scheme with experience. Genetic algorithm is a search heuristic algorithm used to solve optimization in the field of computer science artificial intelligence. Genetic algorithm can effectively select the optimal loading scheme but unable to utilize weight and volume capacity of cargo and truck. In this paper, we propose hybrid Genetic and fuzzy logic based cargo-loading decision making model that focus on achieving maximum profit with maximum utilization of weight and volume capacity of cargo and truck. In this paper, first of all, the components of the problem of goods stowage in the distribution center are analyzed systematically, which lays the foundation for the reasonable classification of the problem of goods stowage and the establishment of the mathematical model of the problem of goods stowage. Secondly, the paper abstracts and defines the problem of goods loading in distribution center, establishes the mathematical model for the optimization of single car three-dimensional goods loading, and designs the genetic algorithm for solving the model. Finally, Matlab is used to solve the optimization model of cargo loading, and the good performance of the algorithm is verified by an example. From the performance evaluation analysis, proposed the hybrid system achieve better outcomes than the standard SA model, GA method, and TS strategy.

scholarly journals Air Ventilation Performance of School Classrooms with Respect to the Installation Positions of Return Duct

2021 ◽  
Vol 13 (11) ◽  
pp. 6188
Author(s):  
Sungwan Son ◽  
Choon-Man Jang
Keyword(s):  
Air Quality ◽  
Numerical Analysis ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Three Dimensional ◽  
Cross Infection ◽  
School Students ◽  
Height Range ◽  
Air Ventilation ◽  
Ventilation Performance

For students, who spend most of their time in school classrooms, it is important to maintain indoor air quality (IAQ) to ensure a comfortable and healthy life. Recently, the ventilation performance for indoor air quality in elementary schools has emerged as an important social issue due to the increase in the number of days of continuous high concentrations of particulate matter. Three-dimensional numerical analysis has been introduced to evaluate the indoor airflow according to the installation location of return diffusers. Considering the possibility of the cross-infection of infectious diseases between students due to the direction of airflow in the classroom, the airflow angles of the average respiratory height range of elementary school students, between 1.0 and 1.5 m, are analyzed. Throughout the numerical analysis inside the classroom, it is found that the floor return system reduces the indoor horizontal airflow that causes cross-infection among students by 20% compared to the upper return systems. Air ventilation performance is also analyzed in detail using the results of numerical simulation, including streamlines, temperature and the age of air.

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