• Journal of Forest and Environmental Science
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• v.40 no.2
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• pp.99-110
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• 2024

According to the REDD+ program, it is necessary to monitor, quantify, and report forest conditions in protected land areas. The objectives of this work were to quantify the average monthly aerial net primary productivity (ANPP_MONTH) of semi-arid Chaco Forest at Copo National Park (CNP), Santiago del Estero, Argentina, during the period 2000-2023, as well as its spatial distribution and relationship, and its use efficiency (RUE) of average monthly rainfall (AMR). The ANPP_MONTH model accounted for 90% of the seasonal variability from October to May, the average seasonal ANPP_MONTH was 145 tons of dry matter per hectare (t dm/ha), being the maximum in January with 192 t dm/ha and the minimum in May with 91 t dm/ha. The surface area covered by ANPP_MONTH exhibited a consistent positive trend from October to May (t test=15.65, p<0.01). Strong and significant direct relationships were found between ANPP_MONTH and AMRs, linear models explaining 90% and 96% of the variability, respectively. The results obtained become reference values for assessing the capacity of the forest systems to stock carbon for global warming mitigation and for monitoring and controlling their response to extreme climatic adversities. The average ANPP_MONTH reduces uncertainty when defining the thresholds to monitor and quantify ANPP and forest area, thus facilitating the detection of negative changes in land use in CNP. Such results evidence the National Parks Administration's high effectiveness for the maintenance of protected area and for the high ANPP of the FCHS of CNP in the period 2000-2023.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.30 no.1
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• pp.73-83
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• 2024

In this study, environmental evaluation of high barrier coated paper (coating layer/paper) packaging is conducted in comparison with conventional aluminum laminated (PET/VMPET/LLDPE) plastic packaging. The target product for this packaging is a KF94 mask, which requires a high barrier of water and oxygen to maintain the filtration ability of the mask filter. The functional unit of this study is 10,000 mask packaging materials based on a material capable of blocking oxygen (<1 g/m²day) and moisture (<3 g/m²day) for the preservation of KF94 masks. In order to understand the results easily, paper-based mask packaging system divided into 6 stages (pulp, pulping & paper making, calendaring & coating, printing, packing and waste management), while plastic-based mask packaging consists of 5 stages (material production, processing, printing, packing, waste management) In case of paper-based mask packaging, most contributing stage is calendaring & coating, resulting from heat and electricity production. On the other hand, plastic-based mask packaging is contributed more than 30% by material production, specifically due to linear low density polyethylene and purified terephthalic acid production. The comparison results show that global warming potential of paper-based mask packaging has 32% lower than that of plastic-based mask packaging. Most of other impact indicators revealed in similar trend.

• Journal of the Korean Geographical Society
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• v.40 no.5 s.110
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• pp.584-593
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• 2005

The spatial and temporal variations of heating degree-days (HDDs) and cooling degree-days (CDDs) are closely related with the temperature field. The spatial distribution of 30-year mean HDDs shows that the higher values locates in the northern part of South Korea while the lower values locates in the southern part. The 30-year mean CDDs shows a more randomized distribution than the HDDs. The changing trends of HDDs and CDDs show a different feature: HDDs have a distinct decreasing trend while CDDs have an insignificant change. The decreasing trends of HDDs are consistent over South Korea and most of stations have experienced the statistically significant change. As significant changing areas of HDDs are much broader than those of annual mean temperature, HDDs can be more useful than annual mean temperature to detect the climate change impact on a regional level. In other words, an insignificant change on the mean temperature field can induce the significant change of thermal climatology in a region. The temporal pattern of climatic departure index (CDI) for South Korea HDDs series shows a general decreasing, but a sharp increase during recent years. The drastic decrease of HDDs induces higher CDI indicating larger variability among stations. However, the decrease of South Korea HDDs series cannot totally attribute to the global warming due to urban effects. By the early 1980s, there were no big differences of HDDs between urban and rural series, but later the differences are getting larger. This was expected to be with the intensification of urbanization in South Korea. However, still there is a decreasing trend of HDDs for rural stations.

• Korean Journal of Remote Sensing
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• v.33 no.2
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• pp.249-255
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• 2017

Antarctica isimportant area in order to understand climate change. In addition, this area is complex region where indicate warming and cooling trend according to previous studies. Therefore, it is necessary to understand the long-term variability of Antarctic energy budget. Net radiation, one of energy budget factor, is affected by albedo, and albedo cause negative radiative forcing. It is necessary to analyze a relationship between albedo and net radiation in order to analyze relationship between two factors in Antarctic climate changes and ice-albedo feedback. In thisstudy, we calculated net radiation using satellite data and performed an analysis of long-term variability of net radiation over Antarctica. In addition we analyzed correlation between albedo. As a results, net radiation indicates a negative value in land and positive value in ocean during study periods. As an annual changes, oceanic trend indicates an opposed to albedo. Time series pattern of net radiation is symmetrical with albedo. Correlation between the two factors indicate a negative correlation of -0.73 in the land and -0.32 in the ocean.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.18-18
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• 2011

Climate change is impacting and will increasingly impact both the quantity and quality of the world's water resources in a variety of ways. In some areas warming climate results in increased rainfall, surface runoff, and groundwater recharge while in others there may be declines in all of these. Water quality is described by a number of variables. Some are directly impacted by climate change. Temperature is an obvious example. Notably, increased atmospheric concentrations of $CO_2$ triggering climate change increase the $CO_2$ dissolving into water. This has manifold consequences including decreased pH and increased alkalinity, with resultant increases in dissolved concentrations of the minerals in geologic materials contacted by such water. Climate change is also expected to increase the number and intensity of extreme climate events, with related hydrologic changes. A simple framework has been developed in New Zealand for assessing and predicting climate change impacts on water resources. Assessment is largely based on trend analysis of historic data using the non-parametric Mann-Kendall method. Trend analysis requires long-term, regular monitoring data for both climate and hydrologic variables. Data quality is of primary importance and data gaps must be avoided. Quantitative prediction of climate change impacts on the quantity of water resources can be accomplished by computer modelling. This requires the serial coupling of various models. For example, regional downscaling of results from a world-wide general circulation model (GCM) can be used to forecast temperatures and precipitation for various emissions scenarios in specific catchments. Mechanistic or artificial intelligence modelling can then be used with these inputs to simulate climate change impacts over time, such as changes in streamflow, groundwater-surface water interactions, and changes in groundwater levels. The Waimea Plains catchment in New Zealand was selected for a test application of these assessment and prediction methods. This catchment is predicted to undergo relatively minor impacts due to climate change. All available climate and hydrologic databases were obtained and analyzed. These included climate (temperature, precipitation, solar radiation and sunshine hours, evapotranspiration, humidity, and cloud cover) and hydrologic (streamflow and quality and groundwater levels and quality) records. Results varied but there were indications of atmospheric temperature increasing, rainfall decreasing, streamflow decreasing, and groundwater level decreasing trends. Artificial intelligence modelling was applied to predict water usage, rainfall recharge of groundwater, and upstream flow for two regionally downscaled climate change scenarios (A1B and A2). The AI methods used were multi-layer perceptron (MLP) with extended Kalman filtering (EKF), genetic programming (GP), and a dynamic neuro-fuzzy local modelling system (DNFLMS), respectively. These were then used as inputs to a mechanistic groundwater flow-surface water interaction model (MODFLOW). A DNFLMS was also used to simulate downstream flow and groundwater levels for comparison with MODFLOW outputs. MODFLOW and DNFLMS outputs were consistent. They indicated declines in streamflow on the order of 21 to 23% for MODFLOW and DNFLMS (A1B scenario), respectively, and 27% in both cases for the A2 scenario under severe drought conditions by 2058-2059, with little if any change in groundwater levels.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.3
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• pp.241-253
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• 2009

This study performs the investigation of a long-term variation of annual maximum surge heights(AMSH) and main characteristics of high surge events, and the statistical evaluation of the AMSH using sea level data at Yeosu and Tongyeong tidal stations over more than 30 years. It is found that the long-term uptrends based on the linear regression in the AMSH are 34.5 cm/34 yr at Yeosu and 33.6 cm/31 yr at Tongyeong, which are relatively much higher than those at Sokcho and Mukho in the Eastern Coast. 71% and 68% of the AMSH occur during typhoon's event in Yeosu and Tongyeong tidal stations, respectively, and the highest surge records are mostly produced by the typhoon. The generalized extreme value distribution taking into account of the time variable is applied to detect time trend in annual maximum surge heights. In addition, Gumbel distribution is checked to find which one is best fitted to the data using likelihood ratio test. The return level and its 90% confidence interval are obtained for the statistical prediction of the future trend. The prevention of the growing storm surge damage by the intensified typhoon requires the steady analysis and prediction of the surge events associated with the climate change.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.3
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• pp.99-107
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• 2012

There has been increasing number of patients with asthma, rhinitis, and conjunctivitis due to the atmospheric pollution and global warming. In this study, we investigated daily observed number of pollens to establish a standardized method for the impact analysis of the climate changes on the number of daily pollens in Korea. Daily observed allergenic pollens of trees, weeds, and pine were analyzed during the period of 1998 to 2010 (except 2006) in Seoul, Busan, Daegu, Gwangju, Gangneung, and Jeju. They increased in large cities including Seoul during the last 12 years and the long-term trend may continue in the future. Daily concentration or amount of pollens was highly correlated with weather variables. Positive correlation was found between air temperature and the pollens although different relationships existed for different locations. Chill days were utilized to estimate the length of the flowering or pollen period. The pollen period of trees was shorter in the field when the winter temperature was low. This approach may be utilized to determine the quantitative change in length of the pollen season in the future.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.2
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• pp.122-130
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• 2014

Seasonal variations and long term linear trends of SST (Sea Surface Temperature) at Yeosu Coast ($127^{\circ}37.73^{\prime}E$, $34^{\circ}37.60^{\prime}N$) in Korea were studied performing the harmonic analysis and the regression analysis of the monthly mean SST data of 46 years (1965-2010) collected by the Fisheries Research and Development Institute in Korea. The mean SST and the amplitude of annual SST variation show $15.6^{\circ}C$ and $9.0^{\circ}C$ respectively. The phase of annual SST variation is $236^{\circ}$. The maximum SST at Yeosu Coast occurs around August 26. Climatic changes in annual mean SST have had significant increasing tendency with increase rate $0.0305^{\circ}C/Year$. The warming trend in recent 30 years (1981-2010) is more pronounced than that in the last 30 years (1966-1995) and the increasing tendency of winter SST dominates that of the annual SST. The time series model that could be used to forecast the SST on a monthly basis was developed applying Box-Jenkins methodology. $ARIMA(1,0,0)(2,1,0)_{12}$ was suggested for forecasting the monthly mean SST at Yeosu Coast in Korea. Mean absolute percentage error to measure the accuracy of forecasted values was 8.3%.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.41-51
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• 2023

As abnormal climatic event occur frequently due to global warming, many nations have proclaimed their commitment to achieving carbon neutrality and are actively pursuing a transition toward a hydrogen economy. At this time, ammonia has garnered significant attention not only as a high-capacity hydrogen carrier but also as a promising candidate as a carbon-free fuel. In particular, anion exchange membrane fuel cells offer the advantage of directly supplying ammonia to the fuel cell, eliminating the necessity for separate ammonia decomposition or hydrogen purification. Therefore, in this study, the operation principle and research trend of the anion exchange membrane fuel cell are reviewed, and several research using ammonia as a fuel in anion exchange membrane fuel cell are also investigated.

• Journal of Korea Water Resources Association
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• v.56 no.12
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• pp.883-893
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• 2023

While South Korea's dependence on imported grains is very high, droughts impacts from exporting countries have been overlooked. Using the Evaporative Stress Index (ESI), this study globally analyzed frequency, extent, and long-term trends of agricultural droughts and their relation to natural oscillations and global crop prices. Results showed that global-scale correlations were found between ESI and soil moisture anomalies, and they were particularly strong in crop cultivation areas. The high correlations in crop cultivation areas imply a strong land-atmosphere coupling, which can lead to relatively large yield losses with a minor soil moisture deficits. ESI showed a clear decreasing trend in crop cultivation areas from 1991 to 2022, and this trend may continue due to global warming. The sharp increases in the grain prices in 2012 and 2022 were likely related to increased drought areas in major grain-exporting countries, and they seemed to elevate South Korea's producer price index. This study suggests the need for drought risk management for grain-exporting countries to reduce socioeconomic impacts in South Korea.