Quantifying the Impact of Severe Weather Conditions on Online Learning During the COVID-19 Pandemic

Author(s):  
Ezekiel Adriel Lagmay ◽  
Ma. Mercedes T. Rodrigo
2019 ◽  
Vol 12 (1) ◽  
pp. 30 ◽  
Author(s):  
Hugues Brenot ◽  
Witold Rohm ◽  
Michal Kačmařík ◽  
Gregor Möller ◽  
André Sá ◽  
...  

GPS tomography has been investigated since 2000 as an attractive tool for retrieving the 3D field of water vapour and wet refractivity. However, this observational technique still remains a challenging task that requires improvement of its methodology. This was the purpose of this study, and for this, GPS data from the Australian Continuously Operating Research Station (CORS) network during a severe weather event were used. Sensitivity tests and statistical cross-comparisons of tomography retrievals with independent observations from radiosonde and radio-occultation profiles showed improved results using the presented methodology. The initial conditions, which were associated with different time-convergence of tomography inversion, play a critical role in GPS tomography. The best strategy can reduce the normalised root mean square (RMS) of the tomography solution by more than 3 with respect to radiosonde estimates. Data stacking and pseudo-slant observations can also significantly improve tomography retrievals with respect to non-stacked solutions. A normalised RMS improvement up to 17% in the 0–8 km layer was found by using 30 min data stacking, and RMS values were divided by 5 for all the layers by using pseudo-observations. This result was due to a better geometrical distribution of mid- and low-tropospheric parts (a 30% coverage improvement). Our study of the impact of the uncertainty of GPS observations shows that there is an interest in evaluating tomography retrievals in comparison to independent external measurements and in estimating simultaneously the quality of weather forecasts. Finally, a comparison of multi-model tomography with numerical weather prediction shows the relevant use of tomography retrievals to improving the understanding of such severe weather conditions.


1997 ◽  
Vol 78 (3) ◽  
pp. 499-506
Author(s):  
D. R. Smith ◽  
M. A. Rosenthal ◽  
J. P. Mulvany ◽  
W. Sanford ◽  
W. R. Krayer ◽  
...  

For the third consecutive year mid-Atlantic Atmospheric Education Resource Agents (AERAs) conducted a regional workshop for educators on hazardous weather. This workshop attracted teachers from New York to Georgia for sessions by Project ATMOSPHERE AERAs, meteorologists from the National Weather Service, universities, the media, and private industry, who addressed a variety of topics pertaining to the impact of severe weather. As has been the case with the previous workshops, this event represents a partnership of individuals from schools, government agencies, and the private sector that enhances science education and increases public awareness of hazardous weather conditions.


2018 ◽  
Author(s):  
Hugues Brenot ◽  
Witold Rohm ◽  
Michal Kačmařík ◽  
Gregor Möller ◽  
André Sá ◽  
...  

Abstract. Using data from the Continuously Operating Reference Stations (CORS), recorded in March 2010 during severe weather in the Victoria State, in southern Australia, sensitivity and statistical results of GPS tomography retrievals (water vapour density and wet refractivity) from 5 models have been tested and verified – considering independent observations from radiosonde and radio occultation profiles. The impact of initial conditions, associated with different time-convergence of tomography inversion, can reduce the normalised RMS of the tomography solution with respect to radiosonde estimates by a multiple (up to more than 3). Thereby it is illustrated that the quality of the apriori data in combination with iterative processing is critical, independently of the choice of the tomography model. However, the use of data stacking and pseudo-slant observations can significantly improve the quality of the retrievals, due to a better geometrical distribution and a better coverage of mid- and low-tropospheric parts. Besides, the impact of the uncertainty of GPS observations has been investigated, showing the interest of using several sets of data input to evaluate tomography retrievals in comparison to independent external measurements, and to estimate simultaneously the quality of NWP outputs. Finally, a comparison of our multi-model tomography with numerical weather prediction from ACCESS-A model shows the relevant use of tomography retrieval to improve the understanding of such severe weather conditions, especially about the initiation of the deep convection.


Author(s):  
Juan J. Marti ◽  
Alvaro Saenz ◽  
Javier Martínez ◽  
Jose L. Salamanca ◽  
Salvador Salamanca

One of the main requirements for the Walterdale Bridge Replacement in Edmonton was to minimize the impact on the river during the construction. This was a big challenge, as the use of ordinary construction methods such as falseworks and cranes was almost impossible. Furthermore, the river was not navigable. Consequently, all water equipment used, such us barges, had to be modularized, land transported and assembled directly on site, limiting the capacity. Then, it was decided to split the construction of the arch in different stages, performing several special heavylifting activities. Firstly, a partial arch (the central part), weighing 1,000 metric ton was manufactured on a riverbank. After that, it was skidded and loaded-out onto two modular barges, which moved the segment to the area between the abutments. By means of two towers specifically assembled, which included four strand jacks, the arch was then partially lifted and connected to additional sections of the arch, creating a new 1,800 T and 146-m long arch. Following this, the new arch was also lifted to its final position, in a similar way. This paper describes all the special heavylifting operations and the equipment used to assemble the arch of the bridge, facing with severe weather conditions, such as temperatures down to-20ºC and a river partially frozen.


Author(s):  
W. Rosenthal ◽  
S. Lehner

Safety of shipping is an ever growing concern. In a summary, Faulkner investigated the causes of shipping casualties (2002, “Shipping Safety: A Matter of Concern,” Ingenia, The Royal Academy of Engineering, Marine Matters, pp. 13–20) and concluded that the numbers of unexplained accidents are far too high in comparison to other means of transport. From various sources, including insurers data over 30% of the casualties are due to bad weather (a fact that ships should be able to cope with) and a further 25% remain completely unexplained. The European project MaxWave aimed at investigating ship and platform accidents due to severe weather conditions using different radars and in situ sensors and at suggesting improved design and new safety measures. Heavy sea states and severe weather conditions have caused the loss of more than 200 large cargo vessels within the 20years between 1981 and 2000 (Table 1 in Faulkner). In many cases, single “rogue waves” of abnormal height as well as groups of extreme waves have been reported by crew members of such ships. The European Project MaxWave deals with both theoretical aspects of extreme waves and new techniques to observe these waves using different remote sensing techniques. The final goal is to improve the understanding of the physical processes responsible for the generation of extreme waves and to identify geophysical conditions in which such waves are most likely to occur. Two-dimensional sea surface elevation fields are derived from marine radar and space borne synthetic aperture radar data. Individual wave parameters such as maximum to significant wave height ratios and wave steepness, are derived from the sea surface topography. Several ship and offshore platform accidents are analyzed and the impact on ship and offshore design is discussed. Tank experiments are performed to test the impact of designed extreme waves on ships and offshore structures. This article gives an overview of the different work packages on observation of rogue waves, explanations, and consequences for design.


2021 ◽  
pp. 1-46
Author(s):  
Yunpeng Cai ◽  
Jihui Ma ◽  
Xu Tuanwei ◽  
Wenfa Yan

With the rapid development of the high-speed railway industry, train detection and identification play a vital role in capacity improvement and safe operation in railway systems. Conventional detection methods such as track circuit and axle counting tend to be interfered with by severe weather conditions and irrelevant conductive objects, leading to false detections. Fiber-optic distributed acoustic sensing (DAS) technology is a prevailing sensing method in geophysics research, petroleum exploration, and structure inspection. Compared to traditional detection techniques, DAS is suitable for long-distance detection and is resistant to severe weather conditions and electrical interference. We have developed a train detection and classification system using DAS technology and have explored an effective classification method for train identification. Specifically, we conduct a field experiment by the side of a railroad over viaducts and the data are collected with the DAS detection system. To eliminate the impact of background noise, DC noise, and motor vehicle signals from the original data, we adopt a wavelet denoising method and Chebyshev filter to extract the features of three types of train signals. The vibration signals of these different trains indicate remarkable cyclical variations related to the number of wheelsets in the time domain and have similar narrow-band discrete spectrums with different characteristic peak frequencies. Furthermore, based on the features of the train signals, we select a support vector machine classifier to identify three types of trains, with accuracy greater than 97%.


2020 ◽  
pp. 28-33
Author(s):  
Valery Genadievich Popov ◽  
Andrey Vladimirovich Panfilov ◽  
Yuriy Vyacheslavovich Bondarenko ◽  
Konstantin Mikhailovich Doronin ◽  
Evgeny Nikolaevih Martynov ◽  
...  

The article analyzes the experience of the impact of the system of forest belts and mineral fertilizers on the yield of spring wheat, including on irrigated lands. Vegetation irrigation is designed to maintain the humidity of the active soil layer from germination to maturation at the lower level of the optimum-70-75%, and in the phases of tubulation-earing - flowering - 75-80% NV. However, due to the large differences in zones and microzones of soil and climate conditions and due to the weather conditions of individual years, wheat irrigation regimes require a clear differentiation. In the Volga region in the dry autumn rainfalls give the norm of 800-1000 m3/ha, and in saline soils – 1000-1300 and 3-4 vegetation irrigation at tillering, phases of booting, earing and grain formation the norm 600-650 m3/ha. the impact of the system of forest belts, mineral fertilizers on the yield of spring wheat is closely tied to the formation of microclimate at different distances from forest edges.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1226
Author(s):  
Beatriz Fraga-De Cal ◽  
Antonio Garrido-Marijuan ◽  
Olaia Eguiarte ◽  
Beñat Arregi ◽  
Ander Romero-Amorrortu ◽  
...  

Prefabricated solutions incorporating thermal insulation are increasingly adopted as an energy conservation measure for building renovation. The InnoWEE European project developed three technologies from Construction and Demolition Waste (CDW) materials through a manufacturing process that supports the circular economy strategy of the European Union. Two of them consisted of geopolymer panels incorporated into an External Thermal Insulation Composite System (ETICS) and a ventilated façade. This study evaluates their thermal performance by means of monitoring data from three pilot case studies in Greece, Italy, and Romania, and calibrated building simulation models enabling the reliable prediction of energy savings in different climates and use scenarios. Results showed a reduction in energy demand for all demo buildings, with annual energy savings up to 25% after placing the novel insulation solutions. However, savings are highly dependent on weather conditions since the panels affect cooling and heating loads differently. Finally, a parametric assessment is performed to assess the impact of insulation thickness through an energy performance prediction and a cash flow analysis.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1241
Author(s):  
Stanko Vršič ◽  
Marko Breznik ◽  
Borut Pulko ◽  
Jesús Rodrigo-Comino

Earthworms are key indicators of soil quality and health in vineyards, but research that considers different soil management systems, especially in Slovenian viticultural areas is scarce. In this investigation, the impact of different soil management practices such as permanent green cover, the use of herbicides in row and inter-row areas, use of straw mulch, and shallow soil tillage compared to meadow control for earthworm abundance, were assessed. The biomass and abundance of earthworms (m2) and distribution in various soil layers were quantified for three years. Monitoring and a survey covering 22 May 2014 to 5 October 2016 in seven different sampling dates, along with a soil profile at the depth from 0 to 60 cm, were carried out. Our results showed that the lowest mean abundance and biomass of earthworms in all sampling periods were registered along the herbicide strip (within the rows). The highest abundance was found in the straw mulch and permanent green cover treatments (higher than in the control). On the plots where the herbicide was applied to the complete inter-row area, the abundance of the earthworm community decreased from the beginning to the end of the monitoring period. In contrast, shallow tillage showed a similar trend of declining earthworm abundance, which could indicate a deterioration of soil biodiversity conditions. We concluded that different soil management practices greatly affect the soil’s environmental conditions (temperature and humidity), especially in the upper soil layer (up to 15 cm deep), which affects the abundance of the earthworm community. Our results demonstrated that these practices need to be adapted to the climate and weather conditions, and also to human impacts.


Sign in / Sign up

Export Citation Format

Share Document