• Ocean and Polar Research
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• v.38 no.4
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• pp.331-338
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• 2016

Many studies using tracers have been conducted to understand a physical process in a system. Rain-on-snow could accelerate snowmelt processes, which influences the hydrological process in both temperate and polar regions. Hydrological and ecological conditions will be affected by the amount and timing of discharge reaching the bottom of a snowpack. The discharge consists of the rain-on-snow, pore water penetrating into the snowpack and natural meltwater. In this study, after a rain-on-snow experiment, we conducted an isotopic hydrograph separation to distinguish rainwater and pore water from meltwater. Using the isotopic data of snow and meltwater from Lee et al. (2010), two components were separated based on the assumption that rainwater and pore water are new water and natural meltwater is old water. After the second rain-on-snow experiment, the maximum contributions of rainwater and pore water reached up to 69% of the discharge and then decreased. During the study period, the measured total discharge was 4153 L and 40% (based on hydrogen isotope) of rainwater and pore water was calculated in the discharge, which is not consistent with what Lee et al. (2016) calculated using chemical separation (63%). This inconsistency can be explained by how an end-member was defined in both approaches. The contributions of artificial rainonsnow and pore water to melwater discharge range between the two methods. This study will suggest a mixing calculation from isotopic compositions of the Southern Ocean.

• Structural Engineering and Mechanics
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• v.52 no.1
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• pp.35-49
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• 2014

This paper studies the behaviour of deteriorated reinforced concrete (RC) beams attacked by various forms of simulated acid rain. An artificial rainfall simulator was firstly designed and evaluated. Eleven RC beams ($120mm{\times}200mm{\times}1800mm$) were then constructed in the laboratory. Among them, one was acting as a reference beam and the others were subjected to three accelerated corrosion methods, including immersion, wetting-drying, and artificial rainfall methods, to simulate the attack of real acid rain. Acid solutions with pH levels of 1.5 and 2.5 were considered. Next, ultrasonic, scanning electron microscopy (SEM), dynamic, and three-point bending tests were performed to investigate the mechanical properties of concrete and flexural behaviour of the RC beams. It can be concluded that the designed artificial simulator can be effectively used to simulate the real acid rainfall. Both the immersion and wetting-drying methods magnify the effects of the real acid rainfall on the RC beams.

• Journal of the Korean earth science society
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• v.31 no.5
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• pp.465-474
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• 2010

Real-time rainfall monitoring is of great practical importance over the highly populated Indochina area, which is prone to natural disasters, in particular in association with rainfall. With the goal of d etermining near real-time half-hourlyrain estimates from satellite, the three-layer, artificial neural networks (ANN) approach was used to train the brightness temperatures at 6.7, 11, and $12-{\mu}m$ channels of the Japanese geostationary satellite MTSAT against passive microwavebased rain rates from Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and TRMM Precipitation Radar (PR) data for the June-September 2005 period. The developed model was applied to the MTSAT data for the June-September 2006 period. The results demonstrate that the developed algorithm is comparable to the PERSIANN (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks) results and can be used for flood monitoring across the Indochina area on a half-hourly time scale.

• Journal of Korean Society of Steel Construction
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• v.16 no.4 s.71
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• pp.415-423
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• 2004

To investigate the long-term corrosion resistance of an uncoated weathering steel, an important outdoor constructional steel material, skyward surfaces of the weathering steel and a control steel initially exposed to rural and industrial atmospheres for 9 years were electrochemically tested in neutral artificial rain in terms of electrochemical potentials, impedances, and anodic potentiodynamic polarization curves. Their results were then discussed. A quite passive and stable rust layer to the artificial rain was well formed on the skyward surface of the weathering steel exposed to the industrial and rural atmospheres, and its corrosion rate in the artificial rain was measured to be about a low $3{{\mu}m}/y$. Continuous immersion of all the weathered surfaces in the artificial rain revealed the gradual degradation of the weathered corrosion layers on the steel, resulting in a cathodically controlled corrosion of the substrate steel by the electrochemical measurements. Alloy components of the weathering steel were found to retard the degradation of the weathered corrosion layers on the steel in the artificial rain. For better corrosion evaluation of the weathering steel, more electrochemical measurements of surfaces that have been exposed for more than 9 years to more closely simulated atmospheric waters are needed. These measurements are almost non-destructive and can provide online and in situ information on the corrosion rate, the development of corrosion and the conditions of rust layers on any interested surface and at any exposure time of the steel, so they can be effectively applicable to the corrosion evaluation of steel structures such as bridges, towers, and architectures by forming an electrochemical cell on an interested structural surface and by using a portable electrochemical instrument.

• Journal of Life Science
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• v.8 no.3
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• pp.299-304
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• 1998

In order to clarify the effects of acid rain on soil microorganisms, the inpact of acid to soil microorganisms was survyed for 14 weeks using soil microcosms from industrial site A and B, Gaejok mountain, and Daechong lake in Taejeon area. The acid tolerant-microorganisms in natural soil, using culturing method were counted to be 5.8 - $8.0{\times}10^6$CFU/g soil. The number of microorganisms using ATP-biomass analysis for natural soil samples were also analyzed and 2.2 - $2.6{\times}10^9$ cell/g soil in industrial site A and B, Gaejok mountain, and Daechong lake were determined. In soil samples, which were treated with artificial acid rain, the number of acid tolerant microorganisms were counted 2.9 - $5.8{\times}10^5$ and 2.8 - $7.5{\times}10^8$, respectively. Therefore, we conformed that the numver of soil microorganisms were influenced by acid rain. Also, long term acid tolerant microorganisms were identified as Rhodotorula sp. and Pseudomonas sp.

• Journal of the Mineralogical Society of Korea
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• v.26 no.4
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• pp.273-283
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• 2013

The artificial rain (pH 4.0, pH 5.6 and pH 6.85) and weathering simulation test are applied in dolomitic marble for the prediction of deterioration of the stone monuments constructed with carbonate rock by acid rain. pH of the applied rain all increase to about neutral pH after reaction of marble. The contents of $Ca^{2+}$ and $Mg^{2+}$ have increased more than twofold in two acid rain and deionized neutral rain after reaction of marble. The weight of marble is expected to decrease $0.00037kg/m^2$ each test cycle by pH 4.0 rain. This weight reduction rate of marble is 1.4 and 3.1 times more in pH 5.6 and pH 6.85 rain respectively, and 3.7 times more in only artificial weathering test. The compressive strength of marble is expected to decrease 0.2468, 0.1791 and $0.1280kg/m^2$ per test cycle with pH 4.0, pH 5.6 and pH 6.85 rain, respectively. These results mean that more acidic rain more enfeeble the strength of marble. Dolomite and small amount of calcite are precipitated in the rains after reaction of marble.

• Journal of the Korean association of regional geographers
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• v.19 no.4
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• pp.764-774
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• 2013

In this study we reviewed how acid rain as the global environmental problems was dealt with geography textbooks from Korea and England. The results are as follows. First, unlike geography textbooks from England, the concept and criteria of acid rain are not explained exactly in Korea geography textbooks. Second, whereas the cause of acid rain was explained with natural and artificial factors in geography textbooks from England, in Korea the artificial factors only were explained. But if the artificial factors only will be introduced to students, they may misunderstand about the acid rain. Third, the results and policies of acid rain were provided in geography textbooks from Korea and England. But whereas they were deal with separately in Korea, in textbooks from England they were provided with their patterns and concrete cases. So it is necessary to provide the exact concept, results and processes of the global environmental problems structurally in geography textbooks. And it is necessary to provide the results and their policies of the global environmental problems with concrete cases for students' understanding and sympathy about them. If the concepts and causes of global environmental problems are not understood previously, it is possible to stimulate only the moral and ethical aspects too much when the results and policies of them is introduced in geography textbooks.

• Journal of Korean Society for Atmospheric Environment
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• v.7 no.3
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• pp.208-218
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• 1991

To compare the resistance of landscape trees by acid rain, simulated acid rain was treated on the seeds of 6 coniferous species (Pinus densiflora, Pinus thunbergii, Pinus koraiensis, Taxus cuspidata, Cedrus deodara, Thuja occidentalis) and 6 broad-leafed species (Ligustrum obtusifolium, Acer Buergerianum, Acer Ginnala, Styrax obassia, Cornus Kousa, Magnolia obovata). The experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agri-Tech Junior College. The seeds of 12 tree species were planted on the nursery soil in the early spring of 1991. The regime of artificial acid rain, in terms of spray frequency per monthly and spray amount at year records. Simulated acid rain (pH 2.0, pH 4.0, pH 5.6 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (April 8 to August 31) in 1991. Seedling establishment, seedling growth and nutrient contents in needles and leaves were measured and compared among the treatment. The results were summerized as follows; 1. In general, coniferous species were more resistant than broad-leafed species in the resistant comparisons of landscape trees by simulated acid rain. But there were resistant tree species to acid rain among the broad-leafed species. 2. Among 6 coniferous species used in this experiment, Pinus densiflora, Pinus koraiensis, Taxus cuspidata, Cedrus deodara and Pinus thunbergii revealed the resistant tree species to acid rain. But Thuja occidentalis was very susceptible to acid rain, because of no germination in pH 2.0 treatment plot of acid rain. 3. Among 6 broad-leafed species used in this study, Magnolia obovata, Styrax obassia and Ligustrum obtusifolium showed relative resistant tree species to acid rain. But Acer Buergerianum, Acer Ginnala and Cornus Kousa were very susceptible to acid rain, because of no germination in pH 2.0 plot of acid rain treatment.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.334-334
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• 2022

Improvement of old-fashioned rain gauge systems for automatic, timely, continuous, and accurate precipitation observation is highly essential for weather/climate prediction and natural hazards early warning, since the occurrence frequency and intensity of heavy and extreme precipitation events (especially floods) are recently getting more increase and severe worldwide due to climate change. Although rain gauge accuracy of 0.1 mm is recommended by the World Meteorological Organization (WMO), the traditional rain gauges in both weighting and tipping bucket types are often unable to meet that demand due to several existing technical limitations together with higher production and maintenance costs. Therefore, we aim to introduce a newly developed and cost-effective hybrid rain gauge system at 0.1 mm accuracy that combines advantages of weighting and tipping bucket types for continuous, automatic, and accurate precipitation observation, where the errors from long-term load cells and external environmental sources (e.g., winds) can be removed via an automatic drainage system and artificial intelligence-based data quality control procedure. Our rain gauge system consists of an instrument unit for measuring precipitation, a communication unit for transmitting and receiving measured precipitation signals, and a database unit for storing, processing, and analyzing precipitation data. This newly developed rain gauge was designed according to the weather instrument criteria, where precipitation amounts filled into the tipping bucket are measured considering the receiver's diameter, the maximum measurement of precipitation, drainage time, and the conductivity marking. Moreover, it is also designed to transmit the measured precipitation data stored in the PCB through RS232, RS485, and TCP/IP, together with connecting to the data logger to enable data collection and analysis based on user needs. Preliminary results from a comparison with an existing 1.0-mm tipping bucket rain gauge indicated that our developed rain gauge has an excellent performance in continuous precipitation observation with higher measurement accuracy, more correct precipitation days observed (120 days), and a lower error of roughly 27 mm occurred during the measurement period.

• Convergence Security Journal
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• v.12 no.2
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• pp.99-106
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• 2012

March 11, 2010, in Japan located over East Sea of Korea, due to the strong earthquake tsunami, Fukushima Nuclear Power Plant was ceased and exploded resulting in leaking radioactive substances. Even though it was an accident happened in a nation, leaked radioactive substances were spread across the world moving along ocean currents and air current. Our nation also had terror and confusion about radioactive rain after the accident, and even though a year has been passed by after the accident, the problem on the radioactive contamination isn't solved. So to speak, nuclear accident of neighboring country is a threat to our nation but not only Japan but also Chinese ocean across the West Sea has nuclear power plants. Beside threat of nuclear accident of neighboring countries, North Korea in military confrontation is the world 3rd country holding chemical and biological weapons and can spray the biological weapons to South Korea at any time like Yeonpyeong-do bombard provocation in November, 2010. The study is the strategy confronting such threats and grafted artificial rain technology which is weather control technology. Since radioactive substances on radioactive accidents and North Korean biological weapons can differ in the density by the weather condition, only artificial rain technology can remove the threat perfectly but it is worth to try as the method to reduce damage and in the aspect of psychology. To use the artificial rain technology in the aspect of national security to acquire the public safety, research institutes such ADD should fulfill active and symbolic technology research development.