• 한국환경농학회지
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• 제40권4호
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• pp.330-334
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• 2021

BACKGROUND: More recently, it has been shown that atmospheric ammonia (NH₃) plays a primary role in the formation of secondary particulate matter by reacting with the acidic species, e.g. SO₂, NOx, to form PM2.5 aerosols in the atmosphere. The Jeonbuk region is an area with high concentration of particulate matter. Due to environmental changes in the Saemangeum reclaimed land with an area of 219 km², it is necessary to evaluate the impact of the particulate matter and atmospheric ammonia in the Jeonbuk region. METHODS AND RESULTS: Atmospheric ammonia concentrations were measured from June 2020 to May 2021 using a passive sampler and CRDS analyzer. Seasonal and annual atmospheric ammonia concentration measured using passive sampler was significantly lower in Jangjado (background concentration), and the concentration ranged from 11.4 ㎍/m³ to 18.2 ㎍/m³. Atmospheric ammonia concentrations in Buan, Gimje, Gunsan, and Wanju regions did not show a significant difference, although there was a slight seasonal difference. The maximum atmospheric ammonia concentration measured using the CRDS analyzer installed in the IAMS near the Saemangeum reclaimed land was 51.5 ㎍/m³ in autumn, 48.0 ㎍/m³ in summer, 37.6 ㎍/m³ in winter, and 32.7 ㎍/m³ in spring. The minimum concentration was 4.9 ㎍/m³ in spring, 4.2 ㎍/m³ in summer, and 3.5 ㎍/m³ in autumn and winter. The annual average concentration was 14.6 ㎍/m³. CONCLUSION(S): Long term monitoring of atmospheric ammonia in agricultural areas is required to evaluate the formation of fine particulate matter and its impact on the environment. In addition, continuous technology development is needed to reduce ammonia emitted from farmland.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권3호
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• pp.24-35
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• 2019

It is known that ${\delta}^{13}C_{DIC}$ (carbon-13 isotope of dissolved inorganic carbonate (DIC) ions) of water increases when dissolved $CO_2$ degases. However, ${\delta}^{13}C_{DIC}$ could decrease when the pH of water is lower than 5.5 at the early stage of degassing. Laboratory experiments were performed to observe the changes of ${\delta}^{13}C_{DIC}$ as $CO_2$ degassed from three different artificial $CO_2$-rich waters (ACWs) in which the initial pH was 4.9, 5.4, and 6.4, respectively. The pH, alkalinity and ${\delta}^{13}C_{DIC}$ were measured until 240 hours after degassing began and those data were compared with kinetic isotope fractionation calculations. Furthermore, same experiment was conducted with the natural $CO_2$-rich water (pH 4.9) from Daepyeong, Sejong City. As a result of experiments, we could observe the decrease of DIC and increase of pH as the degassing progressed. ACW with an initial pH of 6.4, ${\delta}^{13}C_{DIC}$ kept increasing but, in cases where the initial pH was lower than 5.5, ${\delta}^{13}C_{DIC}$ decreased until 6 hours. After 6 hours ${\delta}^{13}C_{DIC}$ increased within all cases because the $CO_2$ degassing caused pH increase and subsequently the ratio of $HCO_3{^-}$ in solution. In the early stage of $CO_2$ degassing, the laboratory measurements were well matched with the calculations, but after about 48 hours, the experiment results were deviated from the calculations, probably due to the equilibrium interaction with the atmosphere and precipitation of carbonates. The result of this study may be not applicable to all natural environments because the pressure and $CO_2$ concentration in headspace of reaction vessels was not maintained constant as well as the temperature. Nevertheless, this study provides fundamental knowledge on the ${\delta}^{13}C_{DIC}$ evolution during $CO_2$ degassing, and therefore it can be utilized in the studies about carbonated water with low pH and the monitoring of geologic carbon sequestration.

• 환경분석과 독성보건
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• 제21권4호
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• pp.281-291
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• 2018

Recently, long-range atmospheric transport (LRAT) from China is regarded as a major reason for elevated levels of particulate matter (PM) in Korea. However, local emissions also play an important role in PM pollution, especially in large-scale industrial cities. In this study, PM samples were collected at suburban, residential, and industrial sites in Ulsan, Korea. Polycyclic aromatic hydrocarbons (PAHs) and heavy metals were analyzed, and a potential human health risk assessment was conducted. The concentrations of PAHs and heavy metals in total suspended particles (TSP) increased during high $PM_{10}$ episodes, and backward trajectory analysis verified the influence of LRAT from China during the high episodes. Furthermore, the concentrations of PAHs and heavy metals in $PM_{2.5}$ and $PM_{10}$ at the industrial site were higher than those at the residential site. The risk assessment of PAHs and heavy metals in $PM_{2.5}$ suggested no significant health effects. The highest levels of PAHs were measured in the particle size of $0.32{\sim}0.56{\mu}m$ at the residential site, and those of heavy metals were detected in the particle size of 1.8~5.6 and $>18{\mu}m$, reflecting different major emissions sources for both groups. On the basis of this preliminary study, we are planning long-term monitoring and modeling studies to quantitatively evaluate the influence of industrial activities on the PM pollution in Ulsan.

• 환경분석과 독성보건
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• 제21권4호
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• pp.264-280
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• 2018

In this study, volatile organic compounds (VOCs) were measured using a proton transfer reaction-time of flight-mass spectrometer (PTR-ToF-MS) at the Seoul Metropolitan Area Intensive Monitoring Station (SIMS) in Korea during the summer season of 2018. The results revealed that oxygenated VOCs (OVOCs) contributed a large fraction (83.6%) of the total VOCs, with methanol being the most abundant constituent (38.6%). The VOCs measured at SIMS were strongly influenced by local conditions. Non-volatile organic compounds (NVOCs), such as pinene, increased due to northeasterly wind direction in the morning, and OVOCs and anthropogenic VOCS (AVOCs) increased with northwesterly wind direction during the daytime. This was the result of the eastward location of Bukhansan National Park and the westward location of urban area from the SIMS location. The VOCs included abundant oxidized forms of VOCs, which can affect the generation of fine dust through various response pathways in the atmosphere. The real-time measurement technique using PTR-ToF-MS suggested in this study is expected to contribute to an improved scientific understanding of high-concentration fine dust events because the high temporal resolution makes it possible to analyze the variations of VOCs reflected in dynamic events.

• 대한원격탐사학회지
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• 제36권6_2호
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• pp.1523-1535
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• 2020

원격탐사를 이용한 작황정보 생산은 작물의 생물계절을 이용하여 작물 분류, 생육 모니터링, 생산량 추정 분석이 선행되어야 한다. 생물계절에 추정을 위한 시계열 영상 자료가 필요하지만 KOMPSAT(Korea Multi-Purpose Satellite)만으로 획득하는 것은 물리적 제한이 있으므로 타 지구관측위성과의 융합 활용이 필요하다. 위성자료의 융합 활용을 위해서는 각 위성이 가지는 고유의 방사학적 센서 특성 차이를 극복해야 한다. 본 연구는 위성자료의 융·복합 활용을 위한 첫 단계로서 KOMPSAT-3와 Landsat-8 위성의 교차검보정을 수행하였다. Libya-4 PICS(Pseudo Invariant Calibration Sites)에서 2년간 수집된 위성자료에 대해 초분광위성을 이용하여 산정된 SBAF(Spectral Band Adjustment Factor)를 적용하여 대기상단 반사도를 비교하였다. 교차검보정 결과 KOMPSAT-3와 Landsat-8 위성은 Blue, Green, Red 밴드에서 약 4%, NIR밴드에서 6%의 반사율 차이를 보였다. 온보드 켈리브레이터가 없는 KOMPSAT-3는 Ladnsat-8에 비해 Radiometric Stability가 낮은 것으로 나타났다. 향후 교차검보정의 정확도를 높이기 위해 BRDF(Bidirectional reflectance distribution function) 보정 및 지형보정을 통하여 정규화 된 반사율 자료를 생산하기 위한 노력이 필요하다.

• 한국환경보건학회지
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• 제49권2호
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• pp.108-117
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• 2023

Background: When particles are absorbed into the human body, they penetrate deep into the lungs and interact with the tissues of the body. Heavy metals in PM_2.5 can cause various diseases. The main source of PM_2.5 emissions in South Korea's atmosphere has been surveyed to be places of business. Objectives: The concentration of heavy metals in PM_2.5 near the Ulsan Industrial Complex was measured and a health risk assessment was performed for residents near the industrial complex for exposure to heavy metals in PM_2.5. Methods: Concentrations of heavy metals in PM_2.5 were measured at four measurement sites (Ulsan, Mipo, Onsan, Maegok) near the industrial complexes. Heavy metals were analyzed according to the Air Pollution Monitoring Network Installation and Operation Guidelines presented by the National Institute of Environmental Research. Among them, only five substances (Mn, Ni, As, Cd, Cr⁶⁺) were targeted. The risk assessment was conducted on inhalation exposure for five age groups, and the excess cancer risk and hazard quotient were calculated. Results: In the risk assessment of exposure to heavy metals in PM_2.5, As, Cd, and Cr⁶⁺ exceeded the risk tolerance standard of 10^-6 for carcinogenic hazards. The highest hazard levels were observed in Onsan and Mipo industrial complexes. In the case of non-carcinogenic hazards, Mn was identified as exceeding the hazard tolerance of 1, and it showed the highest hazard in the Ulsan Industrial Complex. Conclusions: This study presented a detailed health risk from exposure to heavy metals in PM_2.5 by industrial complexes located in Ulsan among five age groups. It is expected to be utilized as the basis for preparing damage control and industrial emission reduction measures against PM_2.5 exposure at the Ulsan Industrial Complex.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.169-169
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• 2022

Over the past 100 years, the global average temperature has risen by 0.75 ℃. The Korean Peninsula has risen by 1.8 ℃, more than twice the global average. According to the RCP 8.5 scenario, the CO₂ concentration in 2100 will be 940 ppm, about twice as high as current. The National Institute of Crop Science(NICS) is using the SPAR (Soil-Plant Atmosphere Research) facility that can precisely control the environment, such as temperature, humidity, and CO₂. A Python-based colony photosynthesis algorithm has been developed, and the carbon and nitrogen absorption rate of rice is evaluated by setting climate change conditions. In this experiment, Oryza Sativa cv. Shindongjin were planted at the SPAR facility on June 10 and cultivated according to the standard cultivation method. The temperature and CO₂ settings are high temperature and high CO₂ (current temperature+4.7℃ temperature+4.7℃·CO₂ 800ppm), high temperature single condition (current temperature+4.7℃·CO₂ 400ppm) according to the RCP8.5 scenario, Current climate is set as (current temperature·CO₂400ppm). For colony photosynthesis measurement, a LI-820 CO₂ sensor was installed in each chamber for setting the CO₂ concentration and for measuring photosynthesis, respectively. The colony photosynthetic rate in the booting stage was greatest in a high temperature and CO₂ environment, and the higher the nitrogen fertilization level, the higher the colony photosynthetic rate tends to be. The amount of photosynthesis tended to decrease under high temperature. In the high temperature and high CO₂ environment, seed yields, the number of an ear, and 1000 seed weights tended to decrease compared to the current climate. The number of an ear also decreased under the high temperature. But yield tended to increase a little bit under the high temperature and high CO₂ condition than under the high temperature. In addition, In addition to this study, it seems necessary to comprehensively consider the relationship between colony photosynthetic ability, metabolite reaction, and rice yield according to climate change.

• 대기
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• 제33권5호
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• pp.477-492
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• 2023

Based on the new climate normals (1991~2020), annual mean, maximum and minimum temperature is 12.5℃, 18.2℃, and 7.7℃, respectively while annual precipitation is 1,331.7 mm, the annual mean wind speed is 2.0 m s^-1, and the relative humidity is 67.8% in the Republic of Korea. Compared to 1981~2010 normal, annual mean temperature increased by 0.2℃, maximum and minimum temperatures increased by 0.3℃, while the amount of precipitation (0.7%) and relative humidity (1.1%) decreased. There was no distinct change in annual mean wind speed. The spatial range of the annual mean temperature in the new normals is large from 7.1 to 16.9℃. Annual precipitation showed a high regional variability, ranging from 787.3 to 2,030.0 mm. The annual mean relative humidity decreased at most weather stations due to the rise in temperature, and the annual mean wind speed did not show any distinct difference between the new and old normals. With the addition of a warmer decade (2011~2020), temperatures all increased consistently and in particular, the increase in the maximum temperature, which had not significantly changed in previous decades, was evident. The increasing trend of annual and summer precipitation by the 2010s has disappeared in the new normals. Among extreme climate indices, MxT30 (Daily maximum temperature ≥ 33℃ days), MnT25 (Daily minimum temperature ≥ 25℃ days), and PH30 (1 hour maximum precipitation ≥ 30 mm days) increased while MnT-10 (Daily minimum temperature < -10℃ days) and W13.9 (Daily maximum wind speed ≥ 13.9 m/s days) decreased at a statistically significant level. It is thought that a detailed study on the different trends of climate elements and extreme climate indices by region should be conducted in the future.

• 한국수자원학회논문집
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• 제56권12호
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• pp.883-893
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• 2023

2020년 기준 한국의 곡물자급률은 20.2%에 불과하지만 곡물수출국에서 발생하는 가뭄이 국내에 미치는 영향은 아직 면밀히 분석되지 않았다. 본 연구에서는 증발산 기반 가뭄지수인 Evaporative Stress Index (ESI)를 이용해 세계 주요 곡물생산지역의 농업가뭄의 발생빈도, 장기추세, 자연진동과의 상관성을 분석하였다. 또한 국제 곡물거래가격과 작물생산지역의 가뭄면적을 비교하여 해외에서 발생한 가뭄이 한국 경제에 미치는 영향을 정성적으로 평가하였다. ERA5 기후재분석자료로 산정된 ESI는 전지구적으로 토양수분과 강한 상관성을 보였으며 특히 작물재배 지역에서의 둘의 상관성이 매우 강하게 나타났다. 작물재배지역에서의 높은 상관성은 강한 지면-대기결합을 의미하며, 이 때문에 작은 토양수분 부족이 상대적으로 큰 수확량 손실로 연결될 가능성이 크다. 1991-2022 기간 작물재배지역에서 ESI는 뚜렷한 감소추세를 보였으며 지구온난화와 함께 가뭄면적이 증가할 가능성이 있다. 2012년과 2022년에 급격히 상승한 국제곡물가격은 수출국에서 발생한 대규모 가뭄과 밀접한 관계가 있는 것으로 분석되었으며 한국의 생산자물가지수를 상승시킨 주요 원인 중 하나로 판단된다. 본 연구는 해외지역에서 일어나는 가뭄의 영향을 줄이기 위해 감시와 위험관리 전략이 필요함을 시사한다.

• 한국해양학회지:바다
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• 제29권2호
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• pp.101-115
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• 2024

해양의 고수온 현상은 지구온난화로 인한 주요 문제 중 하나로, 식량 자원의 감소와 해양 탄소 흡수력의 저하 등, 해양 생태계와 인류에게 직접적인 위협으로 부상하고 있다. 따라서, 한반도 주변 해역에서의 고수온 예측은 해양 환경 모니터링 및 관리에 중요하다. 본 연구에서는 역학 모델 기반 한반도 고수온 예측 시스템의 성긴 해양의 수직격자체계로 인한 고수온 예측의 과소모의를 개선하기 위해 LSTM 모델을 개발하였다. 2023년에 대해 수행된 한반도 고수온 예측 시스템의 고수온 예측 결과와 LSTM 모델의 결과를 기반으로 한반도 주변의 동해 해역, 황해 해역 그리고 남해 해역에서의 고수온 예측 성능을 평가했다. 본 연구에서 개발된 LSTM 모델이 세 영역 모두에서 수온이 상승하는 시기에 수온 예측 성능을 크게 개선하는 것으로 나타났으며, 수온 상승이 시작되기 전이나 하강하는 시기에는 예측 성능의 개선 효과가 미미했다. 이는 LSTM 모델이 성층이 강화되는 환경에서 성긴 수직격자로 인해 발생하는 고수온 예측의 과소모의를 개선할 수 있는 가능성을 보여준다. 향후 역학 모델의 예측 성능 개선이나 역학 모델의 대체에 자료기반 인공지능 모델의 활용성이 확대될 것으로 기대한다.