• Atmosphere
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• v.27 no.4
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• pp.411-422
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• 2017

The aim of this research is to review recent trends in weather and climate research in North Korea. We selected North Korean journal 'Weather and Hydrology' for the last 10 years (2007-2016), and identified trends in research subject, researchers, and affiliations. Furthermore, we analyzed the major achievements and trends by research sector. Our main results are same as follows. The largest number of researches on 'modernization and informatization on prediction' have been carried out in North Korea's recent meteorological and climatological research. This could be implicated that the scope of national science policy directly affected the promotion of specific research field. Especially, North Korea was evaluated to be concentrating its efforts on numerical model research and development. The numerical model which enables very short-term (6 hours) rainfall forecast which using ensemble Kalman filter data assimilation method (4D EnKF) was developed. In addition, development of automatic weather system and improvement of the data transfer system were promoted. However, the result reveals that the automated real-time data transfer system was not fully equipped yet. These results could be used as a basic data for meteorological cooperation between South and North Korea.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.1
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• pp.1-8
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• 2019

Developing reliable soil moisture prediction techniques at agricultural regions is a pivotal issue for sustaining stable crop productions. In this study, a physically-based SWAP(Soil-Water-Atmosphere-Plant) model was suggested to estimate soil moisture dynamics at the study sites. ROSETTA was also integrated to derive the soil hydraulic properties(${\alpha}$, n, ${\Theta}_r$, ${\Theta}_s$, $K_s$) as the input variables to SWAP based on the soil information(Sand, Silt and Clay-SSC, %). In order to predict the soil moisture dynamics in future, the mid-term TIGGIE(THORPEX Interactive Grand Global Ensemble) and long-term S2S(Subseasonal to Seasonal) weather forecasts were used, respectively. Our proposed approach was tested at the six study sites of RDA(Rural Development Administration). The estimated soil moisture values based on the SWAP model matched the measured data with the statistics of Root Mean Square Error(RMSE: 0.034~0.069) and Temporal Correlation Coefficient(TCC: 0.735~0.869) for validation. When we predicted the mid-/long-term soil moisture values using the TIGGE(0~15 days)/S2S(16~46 days) weather forecasts, the soil moisture estimates showed less variations during the TIGGE period while uncertainties were increased for the S2S period. Although uncertainties were relatively increased based on the increased leading time of S2S compared to those of TIGGE, these results supported the potential use of TIGGE/S2S forecasts in evaluating agricultural drought. Our proposed approach can be useful for efficient water resources management plans in hydrology, agriculture, etc.

• Atmosphere
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• v.31 no.5
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• pp.525-537
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• 2021

Black ices on road surfaces in winter tend to cause severe and terrible accidents. It is very difficult to detect black ice events in advance due to their localities as well as sensitivities to surface and upper meteorological variables. This study develops a methodology to detect the road sections vulnerable to black ice with the use of road surface temperature data obtained from a mobile road weather observation vehicle. The 7 experiments were conducted on the route from Nam-Wonju IC to Nam-Andong IC (132.5 km) on the Jungang Expressway during the period from December 2020 to February 2021. Firstly, temporal road surface temperature data were converted to the spatial data with a 50 m resolution. Then, the spatial road surface temperature was normalized with zero mean and one standard deviation using a simple normalization, a linear de-trend and normalization, and a low-pass filter and normalization. The resulting road thermal map was calculated in terms of road surface temperature differences. A road ice index was suggested using the normalized road temperatures and their horizontal differences. Road sections vulnerable to black ice were derived from road ice indices and verified with respect to road geometry and sky view, etc. It was found that black ice could occur not only over bridges, but also roads with a low sky view factor. These results are expected to be applicable to the alarm service for black ice to drivers.

• Journal of Climate Change Research
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• v.5 no.4
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• pp.367-374
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• 2014

The monthly mean air temperature datasets of 61 stations in South Korea from 1973 to 2012 were collected to calculate trends in the warmth index (WI) and to analyze the potential enlargement of safety cultivation limit for sweet persimmon. The WI averaged over the last 40 years was 104.1 (℃·Month) at 61 stations, with the highest at Seogwipo station (WI=137.9) and the lowest at Daegwallyeong station (WI=60.9). It has increased by 1.8 (℃·Month) per 10 years over the last 40 years, with the highest in the year 1994 (WI=112.0) and the lowest in the year 1976 (WI=94.7). When the possible stations for sweet persimmon cultivation were classified by the basis on WI≥100, 38 out of the 61 weather stations were included in the safety cultivation zone for sweet persimmon for the last 40 years. On the other hand, the number of weather stations within the safety cultivation zones for sweet persimmon for the last 10 years (from 2003 to 2012) were 47 by adding additional 9 stations (Socho, Wonju, Chungju, Seosan, Uljin, Yangpyeong, Icheon, Cheonan, and Geochang stations). A further study of the climate conditions and soil characteristics is required for a better assessment of the safety cultivation zones for sweet persimmon.

• Journal of Environmental Science International
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• v.31 no.4
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• pp.329-339
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• 2022

Better understanding the mechanism of black ice occurrence on the road in winter is necessary to reduce the socio-economic damage it causes. In this study, intensive observations of road weather elements and surface information under the influence of synoptic high-pressure patterns (22^nd December, 2020 and 29^th January, and 25^th February, 2021) were carried out using a mobile observation vehicle. We found that temperature and road surface temperature change is significantly influenced by observation time, altitude and structure of the road, surrounding terrain, and traffic volume, especially in tunnels and bridges. In addition, even if the spatial distribution of temperature and road surface temperature for the entire observation route is similar, there is a difference between air and road surface temperatures due to the influence of current weather conditions. The observed road temperature, air temperature and air pressure in Nongong Bridge were significantly different to other fixed road weather observation points.

• Atmosphere
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• v.25 no.3
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• pp.407-433
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• 2015

First half of my article focused on analyzing the current state of historical materials regarding weather and climate, and established a list of weather-related historical literature collection of Korea with which to make a lexical approach to the situations of all kinds of weather literature. It also put emphasis on gathering information and data of weather logs from journal-type historical records which were contained in 48 weather-related journals of Choseon period. The results of this research are expected to be useful for the activation of study in historical meteorology. The latter half of my research focused on analyzing various meteorological states of sunny, cloudy, rainy, snowy and frosty weather which were recorded in the official Annals of King Kojong (1864~1907). And it re-verified historical rainfall data of preceding researches of Wada Yuji (1917), Jung-Lim (1994), Jhun-Moon (1997). In result, different records were found between data of theirs and mine. It means that we have to analyze and reconstruct newly the meteorological data of the Annals of King Gojong and the Daily Records of Royal Sungjungwon (1623~1910) during the late Choseon period.

• Journal of Climate Change Research
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• v.4 no.4
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• pp.385-395
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• 2013

In this paper, we target to develop weather platform and services to use in smart devices which is in real-time mobility environment. The existing TPEG-based navigation service requires a dedicated terminal, DMB communication method, and service scalability, so there are limits. In this paper, we analyze, processing and storage the real-time weather information suitable for navigation on the end user's smart devices by weather information service platform has been developed that can provide a standardized. In addition, we develop weavigation services and API for the developer to develop weather services easily. And we introduce system for serving information of dangerous district forecast based on natural disaster dangerous district data.

• Journal of Climate Change Research
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• v.6 no.2
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• pp.87-94
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• 2015

To compare changes in winter temperature over South Korea, 30-year average climate data and climate data of recent 10 years (2014~2014) such as mean temperature, daily maximum temperature and daily minimum temperature were analyzed. Also, we set analysis extreme cold waves frequency related to winter such as freezing days, snow days, days with temperature of below -5, and days with temperature of below -10. This process enabled the comparative analysis of winter temperature changes and extreme cold waves frequency related to winter. This study estimated that winter temperature has gradually increased throughout the last five decades, however, the frequency of extreme weather, such as cold waves has also increased.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2015.08a
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• pp.1-17
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• 2015

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.31 no.4
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• pp.16-23
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• 2013