Heavy Snow Research Articles

内蒙古中北部大(暴)雪的分布及其与东亚冬季风关系

内蒙古中北部大(暴)雪的分布及其与东亚冬季风关系

Mechanical Reliability Calculations for the Thin Specialty Glass PV Solar Panels

This study provides important design guidance to the Photovoltaic (PV) solar panel development efforts using the finite element based computations of the PV module under the mechanical loadings. We consider specialty thin glass (Corning Eagle XG®) as superstrate of the PV module, while a standard tempered Soda-Lime-Silica Glass (SLG) is considered as bottom support. The reliability calculations for the module were performed based on the stress magnitudes obtained from the FEA computations. The PV solar panel considered in this study are supported by C-chanel rails that run along the longitudinal direction. The optimum values for the C-chanel rail support location and height were determined using FEA driven reliability calculations. A methodology involving back calculation of the limiting stresses from the reliability constraints is briefly discussed, that can save the time consuming FEA iterations and tedious post processing of FEA results thereafter to calculate reliability. Analysis shows that the best rail position is between 17% to 20% of the module width (L) from the edge. The channel located at close to L/5 from the free edges was found to give mechanical reliability of 99%. Rail height greater than or equal to 23.5 mm can be used to achieve 95% reliability for the heavy snow load test. Lower modulus encapsulants such as silicone decrease the stress on top glass Eagle EG (EXG) and increase the stress on SLG (bottom glass) to a bit over the temper stress level. The butyl perimeter seal has a minimal impact on glass stress levels.

Measurement of Snow Density According to Regional Snow Depth in South Korea

As a result of abnormal weather conditions, such as climate change, the amount of snow damage has increased rapidly; hence, the need for countermeasures against heavy snow damage has increased. The most severe snow damage in South Korea has occurred in greenhouses. The snow damage caused in greenhouses is 76.7 billion KRW per year, and the cumulative damage area is 20,279 hectares. Snow density varies depending on snow depth, air temperature, and humidity. Depending on the weather conditions, snow density varies up to 7 times. Therefore, in this study, snow density was measured using snow depth field data. Based on weather data from the Korea Meteorological Administration and a disaster report, an area in Gangwon Province was selected as the target area. In Gangwon Province, five administrative districts were selected for field data sampling. The results showed that the density of snow increased as snow depth increased. Based on the results of this study, it was judged that the design of buildings and greenhouses could be more appropriate if snow load or snow density are used as variables. Keywords: Snow Damage, Snow Load, Sampling, Snow Density

High Morphological Differentiation in Crown Architecture Contrasts with Low Population Genetic Structure of German Norway Spruce Stands

High elevation sites in the low mountain ranges in Germany are naturally covered by Norway spruce (Picea abies (Karst.) L.) stands. Historically, large scale anthropogenic range expansion starting in the mid to late 18th century had a huge impact on the forest composition throughout Germany. Utilisation and exploitation often led to artificial regeneration, mostly carried out using seeds from allochthonous provenances. Usually, autochthonous (natural) high elevation Norway spruce trees have narrow crown phenotypes, whereas lowland trees have broader crowns. Narrow crown phenotypes are likely the result of adaptation to heavy snow loads combined with high wind speeds. In the present study, neighbouring stand pairs of putative autochthonous and allochthonous origin with contrasting phenotypes in high elevation sites were investigated with 200 samples each. These stands are located in the Ore Mountains, the Thuringian Forest, and the Harz Mountains. Additionally, a relict population with the typical narrow high elevation phenotypes was sampled in Thuringia, known as “Schlossbergfichte”. The objective of the study was to quantify supposedly adaptive phenotypic differences in crown architecture and the genetic differentiation of 11 putatively neutral nuclear microsatellite markers (i.e., simple sequence repeats (nSSRs)). The high differentiation of morphological traits (PST = 0.952–0.989) between the neighbouring autochthonous and allochthonous stands of similar age contrasts with the very low neutral genetic differentiation (FST = 0.002–0.007; G″ST = 0.002–0.030), suggesting that directional selection at adaptive gene loci was involved in phenotypic differentiation. Comparing the regions, a small isolation by distance effect for the Harz Mountains was detected, suggesting landscape resistance restricting gene flow. Finally, the differentiation of the very old autochthonous (up to 250 years) stand “Schlossbergfichte” with typical high elevation phenotypes could cohere with the sampling of a relict genepool.

Evaluating Power Loss and Performance Ratio of Hot-Spotted Photovoltaic Modules

The impact of photovoltaic (PV) hot-spots is assessed through the analysis of 2580 polycrystalline silicon PV modules distributed across the U.K. PV hot-spots were categorized into eight different groups using the percentage of power loss. All hot-spots groups were modeled using the cumulative density function, state-of-the-art geographical mapping, and performance ratio (PR) analysis. Significantly, it was found that 92.15% of the PV modules affected by hot-spotted PV string are located in northern U.K., where the effect of low-temperature levels, heavy snow, and hoarfrost are more significant. Finally, it was found that the distribution of PV modules affected by only one hot-spotted solar cell are likely (82.41%) located in coastal locations. Hence, coastal locations expect to have lower risks for causing multiple hot-spotted solar cells in PV modules, compared to central and colder locations. The PR of all examined PV modules was analyzed. It was evident that the mean PR is significantly reduced due to the existence of hot-spots in the PV modules. The least difference in the PR between healthy and hot-spotted PV modules is equal to −0.83%, whereas the most difference is calculated at −15.47%.

Climate Change Vulnerability of Roads to Heavy Snow: Establishing New Assessment Criteria on VESTAP

Climate Change Vulnerability of Roads to Heavy Snow: Establishing New Assessment Criteria on VESTAP

Climate specific accelerated ageing tests and evaluation of ageing induced electrical, physical, and chemical changes

AbstractAs the PV market shows enormous potential with huge growth rates especially in climatic‐sensible regions, specific artificial ageing test procedures are a key point for an efficient and fast product development of new PV modules/materials optimized for the use in specific climatic regions. Based on the definition of four climate profiles (dry and hot—arid, moderate, humid, and hot—tropical and high irradiation—alpine), a program was worked out with 14 climate specific test conditions for accelerated ageing tests. The big challenge in this respect was the adaption/advancement of existing standard procedures for PV modules/components testing in a way that reliable testing for certain climatic conditions optimized PV modules is possible. The time‐dependent repeated application of combined climatic and environmental stresses (temperature, temperature cycles, humidity, irradiation, mechanical load, salt mist) was used to induce performance losses, material degradation, and failures in test modules which resemble those effects occurring in real‐life PV installations under comparable climatic and environmental conditions. For this demanding task, a large number of identical test modules with respect to composition and module design was manufactured. A detailed nondestructive analysis/characterization of all modules was performed: (1) before; (2) during (six intermediate stages); and (3) after the accelerated ageing test. The nondestructive characterization methods used to follow the module's ageing processes throughout the whole accelerated ageing procedure were current‐voltage characteristics measurements and electroluminiscence images for the electrical performance evaluation and ultraviolet fluorescence (spectroscopic and imaging) measurements, Fourier transform infrared spectroscopy as well as colour measurements of the backsheets outer layer for recording of chemical changes of the encapsulant and backsheet. The electrical and material characterization data were incorporated in an optimized database. As stated above, a set of three identical modules was exposed together in the respective climate specific ageing tests and subsequently characterized in order to increase statistical reliability of the measuring results. The analysis of the data and first approaches of advanced data treatment have already clearly shown that the electrical and material degradation of the test modules is dependent on (1) the type and combination, (2) duration, and (3) mode (sequential versus constant) of the stresses applied. On the one hand, the simulation of environmental stresses like heavy snow and wind load and enhanced frequency of temperature cycling resulting in cell cracks and cell connector breakage could be demonstrated. Additional treatment in salty atmosphere, on the other hand, did not show an accelerating effect on degradation on the electrical or material side. The accelerating effect of enhanced temperature, humidity, or additional irradiation on the degradation of power and materials could be shown very well. Direct evidence for the formation of acetic acid and lead‐acetate in the encapsulant ethylene vinyl acetate after prolonged damp‐heat exposure could be found and directly related to cell corrosion effects paralleled by power losses.

Structural failures due to snow in Japan

About half the area of Japan is subject to annual continuous heavy snow. Approximately 15% of the population lives in the area. In this paper, snow-induced failure and structural design of building roofs in Japan are reviewed. First, an overview of the characteristics of snowfall and structural design for snow load in Japan is given. Then, the snowstorm of 2014 is reported, which hit a region without snow zone designation in the design standard and caused many structural failures along with 26 deaths. The snow load for flat roofs for a general area where heavy snow is not expected was increased following this event. Investigation of the roof failure of a power plant due to compacted snow in 2015 is also reported. Compaction of snow due to melting in earlier winter caused excessive snow density compared to what had been expected, while judgement of snow-removal operation was based on a visual evaluation of snow depth. After these events, real-time estimation of snow load has been developed and implemented for a wide area using meteorological observation. Also, a simple snow-load-estimation method based on snow depth measurement is developed to assist judgement of a specific plant.

Changes in vegetation, climate and snowfall regime since the late Pleistocene in a snowy mountainous region of central Japan

Although the most crucial factor shaping vegetation history is temperature, snowfall regime is also important in regions of heavy snow. Pollen analysis in a mire in a snowy mountainous region of central Japan revealed histories of vegetation and precipitation regimes since the latest Pleistocene. The abundance of pinaceous pollen during the latest Pleistocene indicates a subalpine regional coniferous forest and cooler conditions; moreover, sandy sediment and significant occurrence of pollen from Artemisia along with several alpine elements suggest local plant communities of poor vegetation cover in an erosive environment. The increase in Betula and Quercus subgen. Lepidobalanus pollen and the decline in pinaceous pollen in 13,550 cal. yr BP indicates climatic amelioration favourable to temperate trees, and the invasion of sedges and Reynoutria to the small basin and the onset of peat deposition suggest an increase in summer rain. The increase in Fagus crenata pollen after 11,130 cal. yr BP and onwards indicates that the present heavy snowfall regime induced by inflow of the Tsushima Current has been established since that age. The climatic amelioration delayed establishment of the heavy snowfall regime for more than 2400 years. In addition, the retreat of sedges and subsequent invasion of several species of drier habitat after 11,130 cal. yr BP indicate a drier mire condition caused by increased summer temperatures. The recovery of sedges after 3740 cal. yr BP indicates the wettest mire conditions induced by climatic deterioration. A general increasing tendency of conifers in this period supports this interpretation.

Influence of Lake Erie on a Lake Ontario Lake-Effect Snowstorm

AbstractAnnual lake-effect snowstorms, which develop through surface buoyant instability and upward moisture transport from the Laurentian Great Lakes, lead to important local increases in snowfall to the south and east. Surface wind patterns during cold-air outbreaks often result in areas where the air is modified by more than one Great Lake. While it is known that boundary layer air that has crossed multiple lakes can produce particularly intense snow, few observations are available on the process by which this occurs. This study examines unique observations taken during the Ontario Winter Lake-effect Systems (OWLeS) field project to document the process by which Lake Erie influenced snowfall that was produced over Lake Ontario on 28 January 2014. During the event, lake-effect clouds and snow that developed over Lake Erie extended northeastward toward Lake Ontario. OWLeS and operational observations showed that the clouds from Lake Erie disappeared (and snow greatly decreased) as they approached the Lake Ontario shoreline. This clear-air zone was due to mesoscale subsidence, apparently due to the divergence of winds moving from land to the smoother lake surface. However, the influence of Lake Erie in producing a deeper lake-effect boundary layer, thicker clouds, increased turbulence magnitudes, and heavier snow was identified farther downwind over Lake Ontario. It is hypothesized that the combination of a low-stability, high-moisture boundary layer as well as convective eddies and limited snow particles crossing the mesoscale subsidence region locally enhanced the lake-effect system over Lake Ontario within the plume of air originating over Lake Erie.

The Effects of Natural Disasters on Social Trust: Evidence from South Korea

In this paper, we examine whether disasters affect social trust levels using South Korean panel data from 2014–2016. We also investigate whether the effects of disasters on social trust differ depending on the type of disaster. We consider four types of disasters: typhoons, heavy rain, heavy snow and strong winds and waves. Our findings show that although all of these disasters influence the level of generalized social trust, each type has separate impacts. In our findings, there is a statistically significant positive relationship between cumulative damage costs per capita and social trust levels for heavy rain, heavy snow and strong winds and waves but we find the opposite result for typhoons. In the disaster recovery process, it is possible for social trust to be strengthened and weakened at the same time. Social trust can develop when victims such as neighbors and firefighters interact with others. Conversely, when a local government responds slowly to a disaster, dissatisfaction and discontent toward it can increase and this could weaken social trust. Moreover, disaster-affected individuals may be more competitive over limited resources, resulting in conflicts among them. Thus, we argue that the net effects of disasters on social trust levels can differ based on the speed of government responses to disasters and on active support for the victims from people such as neighbors.

Early-stage ecological influences of population recovery of large mammals on dung beetle assemblages in heavy snow areas

Past conservation initiatives and rapidly decreasing human populations in modern Japan have contributed to population recoveries of Sika deer (Cervus nippon), wild boar (Sus scrofa), and Japanese macaque (Macaca fuscata) throughout the country. Ironically, however, these recoveries have not always received a favorable reception, because these mammals can also be agricultural pests. To open public debate on the recoveries, based on a thorough understanding of their multifaceted roles in sustaining the local ecosystem, we evaluated the initial stage ripple effects caused by the mammalian population recovery on the community assembly of dung beetles, which are keystone decomposer organisms in terrestrial ecosystems. For the evaluation, we conducted manipulative snapshot experiments, using camera and pitfall traps, for mammal and dung beetle assemblages, respectively, in four different mountain ranges within the heavy snow areas of northern Japan, where the recovery of three mammal populations was at an early stage. The current findings implied that, although the feces of every recovering mammal species could provide valuable resources for most beetles, the ripple effects from the mammal population recoveries were subject to hysteresis of the local ecosystem, i.e., catastrophic shifts in ecosystems originating from the historical background of regional mammal defaunation. In particular, the abundance of tunnelers that could benefit from positive ripple effects decreased with an increase in past disturbances, which resulted in emptier forests, i.e., an ecosystem with fewer large mammals. The findings suggested that recovering populations of large mammals do not always contribute to the restoration of the original dung beetle communities, at least initially.

Design and Calculation Analysis on a New Type of Aircraft Hydraulic Chocks

In order to facilitate the rapid drainage of airport apron in the special weather (such as heavy rain and snow), the apron is usually designed to have a certain slope. However, this slope leads to a difficult problem that chocks are not easy to take out when the airplane leave airport. In order to solve this problem, a hydraulic chocks design scheme is firstly proposed. The aircraft hydraulic chock involves two systems, which are named the slider system and the rod system Taking Boeing 737-800 as an example, this paper firstly makes reasonable assumptions. And then uses a hydraulic chocks to analyze the aircraft’s stress situation. Through the calculation and analysis of the scheme, the feasibility of the scheme is verified, it also completely solve problem that chocks are not easy to take out. At the same time, the use of the hydraulic wheel block also avoids injury to personnel and waste of time.

Transit Information Utilization during an Extreme Weather Event: An Analysis of Smartphone App Data

Extreme weather events such as heavy snow can severely disrupt urban transportation systems. When this occurs, travelers often seek information about the status of transportation services. This study aims to assess information utilization during an extreme weather event by analyzing data from a smartphone application (“app”) called Transit, which provides real-time transit and shared mobility information in many cities. This research focuses on a snowstorm that hit the northeastern United States in January 2016 and severely disrupted transit and shared mobility services. An analysis of Transit app data is conducted in four parts for New York City, Philadelphia, and Washington, D.C. First, hourly app utilization during the snowstorm was compared with mean hourly app utilization prior to the storm. Second, the rate of app usage was calculated by dividing hourly utilization during the storm by the mean hourly volume before the storm. Third, an ordinary least squares regression model of hourly app usage was estimated for each city. Last, a feature within the app used to request Uber vehicles was examined. The results of the first three analyses reveal that overall app usage decreased during the snowstorm in all three cities; after the storm, New York experienced a significant increase in overall app use during the first Monday commuting period. The analysis of Uber data reveals that app users continued to search for ridehailing services during the snowstorm, despite travel bans. These findings are important for transportation operators and app developers to understand how travelers use information during extreme weather events.

Hydrographic And Hydrochemical Characteristics of the Landslide Lake Jazerske (Spišska Magura, Northern Slovakia)

Abstract This article presents the hydrographic and hydrochemical characteristics of this lake. Lake Jazerske is located in the Western Carpathians (Spiš Magura) in northern Slovakia. It occupies a depression that was formed at the foot of the main scarp of a landslide. Below the lake, there are small intercolluvial depressions that have been transformed into wetlands (peat bogs). The studied lake is very small. Its area is 3600 m2 and its length is 85 m. The maximum depth of the lake is 7.2 m and its capacity is 17 000 m3. The lake is supplied by an inflow of groundwater via fractured aquifers. During periods of heavy rainfall and snow melting, the lake is also supplied by the water from surface runoff. On the main slope of the landslides, traces of ephemeral courses were also found. During the periods of increased supply (spring snow melting, summer rainfall), the outflow of water from the lake occurs both on the surface and underground. In terms of its hydrochemistry, the lake water represents the four-ion type - bicarbonate-sulphate-calcium-magnesium. The concentrations of various ions is characteristic of the shallow groundwater of the Carpathian flysch. The predominant cation, the average concentration of which is 52 mg dm-3, is calcium. The dominant anion is carbohydrates with an average concentration of 163 mg dm-3. What is interesting is the very low levels of chlorides, which do not exceed 2 mg dm-3. The electrolytic conductivity of the water flowing out of the lake ranged from 290 to 328 μS cm-1.

Snow damages on trees of an uneven age in mixed broadleaf forests: effects of topographical conditions and tree characteristics

Snow damage on natural stands is an important problem concerning mountainous forest management. In the present research, the frequency and intensity of heavy snow damage on natural stands and the relationship of damages with characteristics of trees, stand and topography were studied in mountainous forests of northern Iran. A systematic sampling design was applied to the study area (140 ha), with 122 circular plots. The grid dimension was 100 m and each plot area was 1000 m2. The four types of snow damage to trees include: crown damage (8.6%), stem breakage (5.4%), uprooting (3.2%), and bending (1.4%). The frequency of crown damage grew with an increase in the diameter at breast height (DBH), while the frequency of stem breakage, uprooting and bending decreased with an increase the DBH. The frequency of crown damage, stem breakage, and total damages was related to tree species (p < 0.01). Not all tree species were equally susceptible to snow damage. The amount of damage grew with increasing elevation and slope angle and decreased with increasing soil depth. Young trees (DBH < 25 cm) were more susceptible to snow damage than other trees. Snow damage decreased by as the trees in the stand became more mixed in age. The susceptibility of trees to snow damage increased by height and slenderness coefficient. With adequate silvicultural operation, snow damage can be reduced to a minimum level in these natural forests.

Factors Affecting Bone Mineral Density Among Snowy Region Residents in Japan: Analysis Using Multiple Linear Regression and Bayesian Network Model.

BackgroundAs the onset of osteoporosis leads to reduced activities of daily living and may result in patients being bedridden, efforts to prevent decreased bone density are necessary. Various studies on the relationship between sex, age, nutrients, and exercise habits and bone mineral density have been conducted to date. However, for snowy region residents, the magnitude of influence of various factors affecting bone mineral density and the influence level have not been clarified.ObjectiveThis study aimed to clarify the degree of influence and factors influencing bone mineral density based on survey results on health conditions and lifestyle habits in heavy snow areas.MethodsA total of 354 citizens who visited a drugstore in the target area were included in a study that included using the brief-type self-administered diet history questionnaire on lifestyle and exercise habits. Height, weight, body composition, and bone densitometer values were analyzed using multiple regression to calculate their association with bone mineral density. In addition, a Bayesian network model was used to determine the influence level of each factor as a conditional probability.ResultsMultiple regression analysis revealed that age, sex, fracture, and calcium intake significantly influenced bone mineral density. In addition, the result of Bayesian network analysis suggested that age and sex affected bone mineral density, whereas nutrients and exercise habits might not have a direct impact. However, calcium intake and the T-score were significant factors affecting the presence or absence of fracture experiences, suggesting that adequate calcium intake is essential for preventing fractures.ConclusionsIn the multiple regression analysis, age, sex, fracture, and calcium intake were selected as factors; however, in the Bayesian analysis, only age and sex affected bone mineral density while nutrients did not. In addition, the fact that calcium intake and the T-score were shown to affect bone fracture history suggests that calcium intake is an important measure that can prevent bone fractures. Overall, these results suggest that measures such as ensuring a bone fracture–free environment and providing nutritional advice for calcium intake can be effective in preventing bone loss.

〈大雪〉を描く『枕草子』 ―― 〈雪と中宮と私〉という肖像 ――

〈大雪〉を描く『枕草子』 ―― 〈雪と中宮と私〉という肖像 ――

Assessment of the Progressive Collapse Resistance of Double-Layer Grid Space Structures Using Implicit and Explicit Methods

A double-layer grid space structure is a conventional long span structure used where large column-free areas are required. Due to its’ large indeterminacy and the redundancy of its structural configuration, it is normally considered in design practice, that progressive collapse will not be triggered when the loss of an individual member occurs. However, research and several prior accidents have shown that progressive collapse could occur following the loss of some critical members when the structures are subject to abnormal loading such as heavy snow. To investigate the structural behavior of this type of structure, a 3D finite element model of a double-layer space structure grid was built by the authors, several collapse scenarios have been investigated using an implicit method which follows the alternative path method defined in GSA. In addition, case studies have been made using the explicit method which is to simulate the whole process of the structural collapse. In the analysis, different members failure or support collapses were studied. The response of the structure was investigated and the correspondent potential of progressive collapse was discussed in detail. Methods to mitigate the progressive collapse of this type of space structure have also been recommended.

Global Distribution of Snow Precipitation Features and Their Properties from 3 Years of GPM Observations

Abstract Using a 3-yr Global Precipitation Mission (GPM) Ku-band Precipitation Radar (KuPR) dataset, snow features (SFs) are defined by grouping the contiguous area of nonzero solid precipitation. The near-surface wet bulb temperatures calculated from ERA-Interim reanalysis data are used to verify that SFs are colder than 1°C to omit snowfall that melts before reaching the surface. The properties of SFs are summarized to understand the global distribution and characteristics of snow systems. The seasonal and diurnal variations of SFs and their properties are analyzed over Northern and Southern Hemispheric land and ocean separately. To quantify the amount of snow missed by the GPM KuPR and the amount of snow underestimated by the CloudSat Cloud Profiling (CPR), 3-yr KuPR pixel-level data are compared with 4-yr CloudSat CPR observations. The overall underestimation of snowfall during heavy snow events by CPR is less than 3% compared to the combined CPR and KuPR estimates. KuPR underestimates about 52% of weak snow. Only a small percentage of SFs have sizes greater than 10 000 km2 (0.35%), maximum near-surface reflectivity above 30 dBZ (5.1%), or echo top above 5 km (1.6%); however, they contribute 40%, 49.5%, or 30.4% of the global volumetric snow detected by KuPR. Snow in the Northern Hemisphere has stronger diurnal and seasonal variation compared to the Southern Hemisphere. Most of the SFs over the ocean are found with relatively smaller, less intense, and shallower echo tops than over land.