scholarly journals Modelling of Snow Cover Thickness Influence on the Railway Construction Temperature Regime under Variable Weather Conditions

2017 ◽  
Vol 187 ◽  
pp. 124-134 ◽  
Author(s):  
Deividas Navikas ◽  
Henrikas Sivilevičius
Keyword(s):  
Snow Cover ◽  
Temperature Regime ◽  
Weather Conditions ◽  
Railway Construction ◽  
Cover Thickness ◽  
Variable Weather

The Influence of Date of Oviposition and Climatic Conditions on Hatching of Camnula pellucida (Scudder) (Orthoptera: Acrididae)

1966 ◽  
Vol 98 (11) ◽  
pp. 1145-1159 ◽  
Author(s):  
R. Pickford
Keyword(s):  
Embryonic Development ◽  
Snow Cover ◽  
Temperature Regime ◽  
Low Temperatures ◽  
Extended Period ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Soil Conditions ◽  
Soil Temperatures ◽  
Dry Soil

AbstractField and laboratory hatching experiments were conducted from 1960 through 1963 with eggs of Camnula pellucida (Scudder) laid in field cages and collected at fortnightly intervals. Before freeze-up, embryonic development usually reached prediapause level in all eggs laid before the middle of August; these eggs were the first to hatch when incubated in the laboratory or when left in the soil outdoors. Eggs laid later than mid-August showed progressively less embryonic development and consequently hatched later. Viability was highest in eggs laid during the latter half of August; those laid early in the season often suffered from desiccation because of their long exposure to dry soil conditions; those laid towards the end of the season showed declining viability caused, apparently, by low temperatures. The percentage hatch was relatively high in eggs laid before the end of August but declined progressively thereafter; those laid in October rarely hatched. Seasonal hatching patterns were largely dependent upon weather conditions; such patterns were rapidly completed when an extended period of hot, dry weather continued through the hatching period, but often extended intermittently over a month or more when weather was unsettled. The typical diurnal hatching pattern, which also closely followed the temperature regime, commenced in the morning at 0900–1000 hours as soil temperatures exceeded 65°F., rising to a peak about 1100–1200 hours when temperatures reached 85°F., and then generally declined during the afternoon. However, during rapidly changing weather conditions hatching frequently started and stopped as skies cleared and again clouded over. Winter kill occasionally may be an important factor in reducing populations, especially when snow cover is removed by a mid-winter thaw and sub-zero temperatures follow.

scholarly journals VISIBILITY MONITORING USING MOBILE APPLICATION

2018 ◽  
Vol XLII-5 ◽  
pp. 883-891
Author(s):  
S. Purohit ◽  
P. Chauhan
Keyword(s):  
Mobile Application ◽  
Smart Phone ◽  
Quantitative Measure ◽  
Weather Conditions ◽  
Optical Instruments ◽  
Important Concern ◽  
Transport Safety ◽  
Continuous Power ◽  
Variable Weather ◽  
Solar Position

<p><strong>Abstract.</strong> Visibility is clarity with which the distant objects are perceived in the atmosphere with the naked eye. Visibility monitoring is an important concern in health, environment and transport safety context. Quantitative measures of visibility are increasingly becoming important in various areas as they are representative of the particles present in the environment that causes degradation of the visibility. Existing techniques of visibility estimation employ human observers, optical instruments, chemical sensors or combination of some of them. These techniques suffer from poor spatial and temporal resolution, high cost of installation and maintenance, need of specialized personnel, continuous power supply requirement and difficulty in portability. We propose a smart phone-based visibility monitoring system which estimates air visibility/quality in terms of a quantitative measure: Turbidity. In principle, the application calculates turbidity as difference of intensity of captured sky image and analytical value of sky luminance obtained by implementing Perez model. The estimated turbidity tagged with date, time, location, solar position and luminance is sent to the backend server generating consolidated database for mapping of turbidity and generating various analytical reports. The application can easily be deployed to be used by large number of people facilitating citizen science. The results from application were validated against the observations from SAFAR INDIA application at different stations in Ahmedabad, dates and under variable weather conditions.</p>

scholarly journals Specifics of boglands freezing in the north and northwest of the European part of Russia under climate change

2019 ◽  
Vol 59 (2) ◽  
pp. 233-244
Author(s):  
V. I. Batuev ◽  
I. L. Kalyuzhny
Keyword(s):  
Ambient Temperature ◽  
Snow Cover ◽  
Spatial And Temporal Variability ◽  
North West ◽  
The North ◽  
Climatic Period ◽  
European Part Of Russia ◽  
Freezing Depth ◽  
Main Factors ◽  
Cover Thickness

Long-term complex observations covering the period of 1949–2018 made possible to determine the average annual characteristics of the depth of freezing of wetlands in the North and Northwest of the European territory of Russia together with main factors of its formation, and spatial and temporal variability. The main factors that determine the depth of freezing of wetlands are ambient temperature, snow cover thickness, and a degree of watering of the micro landscape (water reserves of the micro landscape). At the initial stage of freezing, the major factor is the ambient temperature, when intensity of the freezing reaches 0.5–0.8 cm/day. As snow falls, the freezing rate becomes smaller, and when the snow cover thickness reaches 25–30 cm the depth amounts to 0.2–0.3 cm/day and smaller. It was found that the spatial variability of the freezing depth decreases from large values of the coefficient of variation (0.3–0.4) at the depth of 20–30 cm to less than 0.1 when the depth exceeds 60 cm. The largest values of the depth are recorded in the North of the Kola Peninsula, where sometimes they reach from 84 to 97 cm with the average values of 48–66. In large hummocky bogs, when the seasonal freezing comes down to 63–65 cm it links with the permafrost layer. On average, swamps of these bogs freeze down to a depth of 68 cm. The average climatic depth of freezing of oligotrophic bogs of the NorthWest is 21–24 cm; in some years, freezing of them reaches 32–40 cm. It has been shown that the relative warming of the climate resulted in decreasing in the depth of freezing of wetlands in the North and North-West of the European territory of Russia. Relative to the previous climatic period, the depth of frost penetration in the northern Ilasskoye bog decreased by 32%, and in north-western Lammin-Suo bog – by 31%.

scholarly journals Identification of solar radiation effect on climatic indicators of the territory of Ukraine

2018 ◽  
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Air Temperature ◽  
Temperature Regime ◽  
Atmospheric Pressure ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Practical Significance ◽  
Statistical Dependence ◽  
Physical Processes

Formulation of the problem. Understanding that solar energy is the main source of the majority of biological, chemical and physical processes on Earth, investigation of its influence on different climatic fields allows us to define the features of its space and hour fluctuations. To define radiation and temperature regime of the territory it is necessary to determine climatic features of the spreading surface, which absorbs and will transform solar energy. Considering the fact that modern climatic changes and their consequences cover all components of the system, today there is a problem of their further study for comprehension of atmospheric processes, modeling weather conditions on different territories depending on the properties. The purpose of the article is to determine interrelations between indexes of solar radiation (the Wolf's number) and air temperature, atmospheric pressure on the territory of Ukraine during 1965-2015, their change in space and time. Methods. Correlative method is one of the main methods of a statistical analysis which allows us to receive correlation coefficients of solar radiation variability indexes, air temperature, atmospheric pressure on the territory of the research. This technique estimates the extent of solar radiation influence on temperature regime of the territory and distribution of atmospheric pressure. Results. Coefficients of correlation, which characterize variability of solar radiation indexes, air temperature and atmospheric pressure on the explored territory have been received by means of statistical correlation analysis method. This technique allows us to estimate the degree and nature of solar radiation influence on a temperature regime of the territory and distribution of atmospheric pressure. It has been defined that direct correlative connection between indexes of solar radiation is characteristic of air temperature and atmospheric pressure fields. Significant statistical dependence between incoming solar radiation on the territory of Ukraine and atmospheric pressure has been noted during the spring and autumn periods mainly at the majority of stations. Between indexes of solar radiation and air temperature the inverse correlative connection in winter will be transformed to a direct connection during the spring and summer periods. Scientific novelty and practical significance. Physical processes, which happen in the atmosphere, are characterized by complex interrelations. For further research it is important to define solar radiation value and the extent of influence on climatic conditions.

scholarly journals COMPARATIVE CHARACTERISTICS FOR ANTHROPOGENOUS POLLUTION OF SNOW COVER ON THE TERRITORY OF A MAJOR INDUSTRIAL CENTER UNDER THE INFLUENCE OF POLLUTION’S VARIOUS SOURCES

2019 ◽  
pp. 36-42 ◽  
Author(s):  
O.V. Sazonova ◽  
T.K. Ryazanova ◽  
D.S. Tupikova ◽  
T.V. Sudakova ◽  
N.M. Toropova ◽  
...  
Keyword(s):  
Snow Cover ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Weather Conditions ◽  
Oil Refinery ◽  
Motor Vehicles ◽  
Industrial Enterprises ◽  
Adverse Weather ◽  
Snow Water ◽  
Surrounding Areas

The paper presents the comparative studies’ results of the snow cover quality in the intracity districts of Samara and its surrounding areas at a distance of up to 1000 m from the oil refinery during 2017–2018. We have identified a high extent of pollution on a set of indicators caused by anthropo-technogenic influence (the content of hydrocarbons, suspended solids, difficult-to-oxidize organic matter (by chemical oxygen demand), some metals, etc.). Many important sanitary and hygienic indicators (a significant part of hydrocarbons, benzo[a]pyrene) were not found in filtered snow water, but ones were determined in suspended solids. Comparative analysis for the chemical composition of snow cover on the territory close to the oil refinery and on the streets in Samara revealed no significant differences. In this regard, it is possible to assume a significant contribution of motor vehicles to anthropo-technogenic environmental pollution. It is important to take into account that when snow is melting it can be a source of secondary pollution of soil, waste- and groundwater, therefore it is necessary to periodically monitor the snow cover quality as an integral part of monitoring environment state and take measures to prevent adverse effects of human activities (redistribution of traffic flow of transit heavy vehicle, notification of industrial enterprises in order to reduce noxious emissions for the period of forecasting adverse weather conditions).

scholarly journals Stress-resilient maize for climate-vulnerable ecologies in the Asian tropics

2020 ◽  
pp. 1264-1274
Author(s):  
P.H. Zaidi ◽  
Thanh Nguyen ◽  
Dang N. Ha ◽  
Suriphat Thaitad ◽  
Salahuddin Ahmed ◽  
...  
Keyword(s):  
Climate Change ◽  
Agricultural Research ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Yield Potential ◽  
Specific Situation ◽  
Environment Interaction ◽  
Maize Germplasm ◽  
Growing Conditions ◽  
Variable Weather

Most parts of the Asian tropics are hotspots of climate change effects and associated weather variabilities. One of the major challenges with climate change is the uncertainty and inter-annual variability in weather conditions as crops are frequently exposed to different weather extremes within the same season. Therefore, agricultural research must strive to develop new crop varieties with inbuilt resilience towards variable weather conditions rather than merely tolerance to individual stresses in a specific situation and/or at a specific crop stage. C4 crops are known for their wider adaptation to range of climatic conditions. However, recent climatic trends and associated variabilities seem to be challenging the threshold limit of wider adaptability of even C4 crops like maize. In collaboration with national programs and private sector partners in the region, CIMMYT-Asia maize program initiated research for development (R4D) projects largely focusing on saving achievable yields across range of variable environments by incorporating reasonable levels of tolerance/resistance to major abiotic and biotic stresses without compromising on grain yields under optimal growing conditions. By integrating novel breeding tools like - genomics, double haploid (DH) technology, precision phenotyping and reducing genotype × environment interaction effects, a new generation of maize germplasm with multiple stress tolerance that can grow well across variable weather conditions were developed. The new maize germplasm were targeted for stress-prone environments where maize is invariability exposed to a range of sub-optimal growing conditions, such as drought, heat, waterlogging and various virulent diseases. The overarching goal of the stress-resilient maize program has been to achieve yield potential with a downside risk reduction.

scholarly journals Hybrid Wind–PV Frequency Control Strategy under Variable Weather Conditions in Isolated Power Systems

2020 ◽  
Vol 12 (18) ◽  
pp. 7750 ◽  
Author(s):  
Ana Fernández-Guillamón ◽  
Guillermo Martínez-Lucas ◽  
Ángel Molina-García ◽  
Jose-Ignacio Sarasua
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Control Strategy ◽  
Rotational Speed ◽  
Power Plants ◽  
Mean Squared Error ◽  
Frequency Control ◽  
Weather Conditions ◽  
Squared Error ◽  
Variable Weather

Over the last two decades, variable renewable energy technologies (i.e., variable-speed wind turbines (VSWTs) and photovoltaic (PV) power plants) have gradually replaced conventional generation units. However, these renewable generators are connected to the grid through power converters decoupled from the grid and do not provide any rotational inertia, subsequently decreasing the overall power system’s inertia. Moreover, the variable and stochastic nature of wind speed and solar irradiation may lead to large frequency deviations, especially in isolated power systems. This paper proposes a hybrid wind–PV frequency control strategy for isolated power systems with high renewable energy source integration under variable weather conditions. A new PV controller monitoring the VSWTs’ rotational speed deviation is presented in order to modify the PV-generated power accordingly and improve the rotational speed deviations of VSWTs. The power systems modeled include thermal, hydro-power, VSWT, and PV power plants, with generation mixes in line with future European scenarios. The hybrid wind–PV strategy is compared to three other frequency strategies already presented in the specific literature, and gets better results in terms of frequency deviation (reducing the mean squared error between 20% and 95%). Additionally, the rotational speed deviation of VSWTs is also reduced with the proposed approach, providing the same mean squared error as the case in which VSWTs do not participate in frequency control. However, this hybrid strategy requires up to a 30% reduction in the PV-generated energy. Extensive detailing of results and discussion can be also found in the paper.

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