• Title/Summary/Keyword: climate environments

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Potential Influence of Climate Change on Shellfish Aquaculture System in the Temperate Region

  • Jo, Qtae;Hur, Young Baek;Cho, Kee Chae;Jeon, Chang Young;Lee, Deok Chan
    • The Korean Journal of Malacology
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    • v.28 no.3
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    • pp.277-291
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    • 2012
  • Aquaculture is challenged by a number of constraints with future efforts towards sustainable production. Global climate change has a potential damage to the sustainability by changing environmental surroundings unfavorably. The damaging parameters identified are water temperature, sea level, surface physical energy, precipitation, solar radiation, ocean acidification, and so on. Of them, temperature, mostly temperature elevation, occupies significant concern among marine ecologists and aquaculturists. Ocean acidification particularly draws shellfish aquaculturists' attention as it alters the marine chemistry, shifting the equilibrium towards more dissolved CO2 and hydrogen ions ($H^+$) and thus influencing signaling pathways on shell formation, immune system, and other biological processes. Temperature elevation by climate change is of double-sidedness: it can be an opportunistic parameter besides being a generally known damaging parameter in aquaculture. It can provide better environments for faster and longer growth for aquaculture species. It is also somehow advantageous for alleviation of aquaculture expansion pressure in a given location by opening a gate for new species and aquaculture zone expansion northward in the northern hemisphere, otherwise unavailable due to temperature limit. But in the science of climate change, the ways of influence on aquaculture are complex and ambiguous, and hence are still hard to identify and quantify. At the same time considerable parts of our knowledge on climate change effects on aquaculture are from the estimates from data of fisheries and agriculture. The consequences may be different from what they really are, particularly in the temperature region. In reality, bivalves and tunicates hung or caged in the longline system are often exposed to temperatures higher than those they encounter in nature, locally driving the farmed shellfish into an upper tolerable temperature extreme. We review recent climate change and following environment changes which can be factors or potential factors affecting shellfish aquaculture production in the temperate region.

Analysis of Radio Environments Allocated to HF Ocean Surface Radar in Korea (고주파(HF) 해양레이더 운용에 분배된 국내 주파수 전파 환경 분석)

  • Song, Kyu-Min
    • Ocean and Polar Research
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    • v.38 no.4
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    • pp.325-330
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    • 2016
  • Partial high frequency bands were allocated to the operation of ocean surface radars that monitor the sea surface currents and waves in WRC-12. On that basis, government-related organizations revised the table of domestic frequency allocation. In order to study radio environments in the allocated bands for ocean radar, tests of the radio signal spectrum were carried at 7-sites using the receiver of the ocean surface radar system operated with a shutdown of the transmitter for 10-60 min. The results showed that no serious radio noises occur at 25 and 43 MHz bands, indicating a good radio environment for the ocean surface radar operation. However, at 13 MHz band, it was difficult to generate stable and confidential data from the ocean surface radar because serious radio noises occurred continuously.

Linking Leaf Functional Traits with Plant Resource Utilization Strategy in an Evergreen Scrub Species Rhododendron caucasicum Pall. along Longitudinal Gradient in Georgia (The South Caucasus)

  • Ekhvaia, Jana;Bakhia, Arsena;Asanidze, Zezva;Beltadze, Tornike;Abdaladze, Otar
    • Journal of Forest and Environmental Science
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    • v.38 no.2
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    • pp.110-121
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    • 2022
  • Leaf functional traits widely have been used to understand the environmental controls of resource utilization strategy of plants along the environmental gradients. By using key leaf functional traits, we quantified the relationships between leaf traits and local climate throughout the distributional range of Rhododendron caucasicum Pall. in eastern and western Georgian mountains (the South Caucasus). Our results revealed, that all traits showed high levels of intraspecific variability across study locations and confirmed a strong phenotypic differentiation of leaf functional variation along the east-west longitudinal gradient in response to the local climate; out of the explored climatic variables, the moisture factors related to precipitation and number of precipitation and dry days for winter and growth seasons were more strongly related to leaf trait variation than the elevation and air temperature. Among studied leaf traits, the leaf specific area (SLA) showed the highest level of variability indicating the different resource utilization strategies of eastern and western-central Rh. caucasicum individuals. High SLA leaves for western-central Caucasian individuals work in relatively resource-rich environments (more humid in terms of precipitation amount and the number of precipitation days in winter) and could be explained by preferential allocation to photosynthesis and growth, while eastern Caucasian samples work in resource-poor environments (less humid in terms of precipitation amount and the number of precipitation days in winter) and the retention of captured resources is a higher priority appearing in a low SLA leaves. However, more evidence from a broader study of the species throughout its distribution range by including additional environmental factors and molecular markers are needed for firmer conclusions of intraspecific variability of Rh. caucasicum.

Assessing the resilience of urban water management to climate change

  • James A. Griffiths
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.32-32
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    • 2023
  • Incidences of urban flood and extreme heat waves (due to the urban heat island effect) are expected to increase in New Zealand under future climate change (IPCC 2022; MfE 2020). Increasingly, the mitigation of such events will depend on the resilience of a range Nature-Based Solutions (NBS) used in Sustainable Urban Drainage Schemes (SUDS), or Water Sensitive Urban Design (WSUD) (Jamei and Tapper 2019; Johnson et al 2021). Understanding the impact of changing precipitation and temperature regimes due climate change is therefore critical to the long-term resilience of such urban infrastructure and design. Cuthbert et al (2022) have assessed the trade-offs between the water retention and cooling benefits of different urban greening methods (such as WSUD) relative to global location and climate. Using the Budyko water-energy balance framework (Budyko 1974), they demonstrated that the potential for water infiltration and storage (thus flood mitigation) was greater where potential evaporation is high relative to precipitation. Similarly, they found that the potential for mitigation of drought conditions was greater in cooler environments. Subsequently, Jaramillo et al. (2022) have illustrated the locations worldwide that will deviate from their current Budyko curve characteristic under climate change scenarios, as the relationship between actual evapotranspiration (AET) and potential evapotranspiration (PET) changes relative to precipitation. Using the above approach we assess the impact of future climate change on the urban water-energy balance in three contrasting New Zealand cities (Auckland, Wellington, Christchurch and Invercargill). The variation in Budyko curve characteristics is then used to describe expected changes in water storage and cooling potential in each urban area as a result of climate change. The implications of the results are then considered with respect to existing WSUD guidelines according to both the current and future climate in each location. It was concluded that calculation of Budyko curve deviation due to climate change could be calculated for any location and land-use type combination in New Zealand and could therefore be used to advance the general understanding of climate change impacts. Moreover, the approach could be used to better define the concept of urban infrastructure resilience and contribute to a better understanding of Budyko curve dynamics under climate change (questions raised by Berghuijs et al 2020)). Whilst this knowledge will assist in implementation of national climate change adaptation (MfE, 2022; UNEP, 2022) and improve climate resilience in urban areas in New Zealand, the approach could be repeated for any global location for which present and future mean precipitation and temperature conditions are known.

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Analysis of Temperature Rise History Considering Construction Environments in Mass Concrete Structural Element (매스콘크리트 구조체의 주변환경을 고려한 온도이력 해석)

  • 이장화;변근주
    • Magazine of the Korea Concrete Institute
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    • v.8 no.4
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    • pp.191-199
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    • 1996
  • Cracks occur in mass concrete structures during construction if temperature of the concrete due to heat of hydration is suddenly changed. The temperature is also changed after placement of mass concrete by construction environments on structures. However, methods which can analyze the temperature history of mass concrete considering the construction environments have not been developed yet. In this research, an algorithm and finite element analysis program is developed for the analysis of temperature rise history of mass concrete considering quantitatively heat transfer coefficient and construction environmental conditions such as climate conditions, curing conditions, forms and form removal, and additive curing. By comparing analysis results of the program with experimental data, other research data, and analysis results by a finite element program ADINAT, validity and accuracy of the program is verified.

The Effects of Working Environments and Psychological Empowerment of the Employed People with Mental Illness on Job Satisfaction (취업정신장애인의 작업환경과 심리적 임파워먼트가 직무만족에 미치는 영향)

  • Choi, Hee-Chul
    • Korean Journal of Social Welfare Studies
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    • v.40 no.3
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    • pp.267-297
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    • 2009
  • The purpose of this study is to examine how working environments and psychological empowerment of the employed people with mental illness influencing their job satisfaction. This research was conducted with 326 the employed people with mental illness working for the competitive employment. The result of study appeared their job satisfaction was estimated in order of psychological empowerment, supervisor's support, participative climate, and compensation system. This research has its meaning in that it dealt with psychological work environments taking into consideration characteristics of the people with mental illness for the first time. And this research was significant in demonstrating that the concept of psychological empowerment is the most important notion to explain job satisfaction of the people with mental illness as well as general workers.

Soil Microbial Communities Associated with Three Arctic Plants in Different Local Environments in Ny-Ålesund, Svalbard

  • Son, Deokjoo;Lee, Eun Ju
    • Journal of Microbiology and Biotechnology
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    • v.32 no.10
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    • pp.1275-1283
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    • 2022
  • Understanding soil microbial community structure in the Arctic is essential for predicting the impact of climate change on interactions between organisms living in polar environments. The hypothesis of the present study was that soil microbial communities and soil chemical characteristics would vary depending on their associated plant species and local environments in Arctic mature soils. We analyzed soil bacterial communities and soil chemical characteristics from soil without vegetation (bare soil) and rhizosphere soil of three Arctic plants (Cassiope tetragona [L.] D. Don, Dryas octopetala L. and Silene acaulis [L.] Jacq.) in different local environments (coal-mined site and seashore-adjacent site). We did not observe any clear differences in microbial community structure in samples belonging to different plant rhizospheres; however, samples from different environmental sites had distinct microbial community structure. The samples from coal-mined site had a relatively higher abundance of Bacteroidetes and Firmicutes. On the other hand, Acidobacteria was more prevalent in seashore-adjacent samples. The relative abundance of Proteobacteria and Acidobacteria decreased toward higher soil pH, whereas that of Bacteroidetes and Firmicutes was positively correlated with soil pH. Our results suggest that soil bacterial community dissimilarity can be driven by spatial heterogeneity in deglaciated mature soil. Furthermore, these results indicate that soil microbial composition and relative abundance are more affected by soil pH, an abiotic factor, than plant species, a biotic factor.

Relationships between Climate and Tree-Rings of Pinus densiflora in the Ridges of the Baekdudaegan, Korea (백두대간 마루금일대 소나무의 연륜생장과 기후와의 관계)

  • Park, Sang-Gon;Joo, Sung-Hyun;Lee, Kwang-Hee;Park, Won-Kyu
    • Journal of agriculture & life science
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    • v.44 no.5
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    • pp.35-43
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    • 2010
  • To examine the relationship between climate and tree-ring growth of Pinus densiflora S. et Z. growing in the ridges of the Baekdudaegan, it was analyzed the sample cores of 48 trees were collected from 21 sites. After the pattern of tree rings of all Pinus densiflora were cross-dating each other, it was recognized the growth of Pinus densiflora was affected by climate largely when tree-ring chronologies were standardized to remove the age-related growth. As a cluster analysis was conducted to examine the similarity of chronologies, three clusters were classified, the tree-ring growths of Pinus densiflora was not by regional or elevational gradients but by the growth tree-ring width amplitude as micro-site growth environments. Correlation coefficients between the chronologies of three clusters and monthly climate (temperature and precipitation) factors were obtained. As a result, tree-ring growth of Pinus densiflora was more affected by temperature than precipitation and the trees of high-growth cluster possessed less climatic influences.

Effectiveness of droplet protective screens and portable air purifiers against droplet and airborne transmission during conversation (비말 가림막과 휴대형 공기청정기 사용에 의한 대화 중 비말 및 공기전파 저감 효과)

  • Jieun, Heo;Dongho, Shin;Hee-Joo, Cho;Hyun-Seol, Park;Yun-Haeng, Joe
    • Particle and aerosol research
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    • v.18 no.4
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    • pp.87-95
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    • 2022
  • Currently, droplet protective screens (DPSs) are used to prevent the spread of respiratory diseases. As virus particles can maintain their infective in indoor environments, recent studies have investigated the risk of airborne transmission. However, the ability of DPSs to block airborne transmission has not been verified yet. In this study, the preventive ability of DPSs against droplet and airborne transmission was evaluated. Moreover, the effectiveness of a Portable air purifier (PAP) was investigated. According to results, in a simulated room where an infectious person spoke, the DPS blocked more than 90% of the micron-sized droplets (with a diameter larger than 1 ㎛) transmitted to the front of the infectious person. However, sub-micron droplets (with a diameter smaller than 1 ㎛) passed through the DPS and spread in a room. However, the PAP reduced the amount of both micron and sub-micron droplets transmitted to the front of the infectious person. When the PAP airflow direction was set from the DPS surface to the free space near the infectious person, improved prevention against droplet and airborne transmission was recorded. However, airborne transmission was accelerated when the PAP airflow direction was set from the free space to the DPS surface.

Study on the Long-term Change of Urban Climate in Daegu (대구의 장기적 도시기후 변동에 관한 연구)

  • 김해동
    • Journal of Environmental Science International
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    • v.12 no.7
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    • pp.697-704
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    • 2003
  • Through data analysis using the meteorological data during 40 years(1961∼2000) for 2 stations(Daegu and Chupungnyong), we studied the present condition and long-term trends in urban climatic environments of Daegu. It was found that there was about 1.5$^{\circ}C$ rise in annual mean temperature of Daegu from 1961 to 2000. On the other hand, that of Chupungnyung was not more than 0.4$^{\circ}C$ for the same period. The regional disparity in temperature changes has been caused by the difference of urban effects on climate between two regions. In particular, the urban warming appears more significant in winter season. There was about 3$^{\circ}C$ rise in annual mean daily minimum temperature of winter season(Dec.∼Feb.) in Daegu. As the result, the number of winter days continuously decreased from 115 days(1961) to 75 days(2000). The long-term trends of relative humidity were also studied to exame the effects of urbanization on climate in Daegu. It was found that there was about 7% decrease in relative humidity of Daegu during past 40 years(1961∼2000). On the other side, the decrease of Chupungnyung was not more than 2% for the same period. The long-term trends of the other climatic factors(fog days, tropical night days, etc) were also studied in this study.