• Journal of the Korean earth science society
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• v.34 no.7
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• pp.645-661
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• 2013

The synoptic, thermodynamic, and dynamic characteristics of a heavy snowfall event that occurred in Seoul metropolitan area on 27 to 28 December 2010 was investigated. During this period there was a distinctive case that was identified as a polar low. We analyzed surface and upper level weather charts, snowfall amount, sea surface temperature, satellite imagery, sounding, and the National Center for Environmental Prediction global $1^{\circ}{\times}1^{\circ}$ reanalysis data. The polar low developed in an area where there was strong baroclinicity in the lower level aided by strong conditional instability due to 925 hPa warm air advection and 700 hPa cold air advection. The development mechanism of polar low is due, in part, to the tropopause folding, which advected stratospheric air increasing potential vorticity in mid-level and inducing cyclonic vorticity and convergence in low-level. Eventually clouds developed and there were snowfall total of 10 cm in Seoul metropolitan area and as much as 20 cm in southern parts of Korea. During the snowfall development, there was a $-45^{\circ}C$ cold core at 500 hPa and shortwave maintained $3-5^{\circ}$ separation with surface trough, which favored the development of polar low located in the warm sector and cyclonic advection area. The height of the dynamical tropopause lowered to 700 hPa during the peak development and increase in potential vorticity allowed strong vertical motion to occur. Overall, there was a close relationship between the development of snowfall and tropopause undulation. The heaviest snowfall occurred east of the tropopause folding where strong cyclonic vorticity, vertical motion, and moisture advection all coincided while the polar low was passing through the Korean peninsula.

• Journal of the Korean earth science society
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• v.41 no.3
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• pp.222-237
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• 2020

A heavy (93 mm hr^-1) rainfall event accompanied by lightning occurred over Gangneung in the Yeongdong region of South Korea on August 6, 2018. This study investigated the underlying mechanism for the heavy rainfall event by using COMS satellite cloud products, surface- and upper-level weather charts, ECMWF reanalysis data, and radiosonde data. The COMS satellite cloud products showed rainfall exceeding 10 mm hr^-1, with the lowest cloud-top temperature of approximately -65℃ and high cloud optical thickness of approximately 20-25. The radiosonde data showed the existence of strong vertical wind shear between the upper and lower cloud layers. Furthermore, a strong inversion in the equivalent potential temperature was observed at a pressure altitude of 700 hPa. In addition, there was a highly developed cloud layer at a height of 13 km, corresponding with the vertical analysis of the ECMWF data. This demonstrated the increased atmospheric instability induced by the vertical differences in equivalent potential temperature in the Yeongdong region. Consequently, cold, dry air was trapped within relatively warm, humid air in the upper atmosphere over the East Sea and adjacent Yeongdong region. This caused unstable atmospheric conditions that led to rapidly developing convective clouds and heavy rainfall over Gangneung.

• Journal of the Korean earth science society
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• v.26 no.5
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• pp.417-428
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• 2005

The seasonal variation and frequency of precipitation phenomenon of the Korean Peninsula in summer show strong local weather phenomena because of its topographical and geographical factors in the northeastern area of Asia. The characteristics of the prevailing weather patterns in summer precipitation in Korea have great influences on the variation patterns and the appearances over a ten-day period during the summer precipitation. The purpose of this paper is to induce variation patterns over a period 10 days during the summer precipitation, clarify the variations of their space scales, and study the subdivision of precipitation regions in Korea according to the combinations of precipitation amounts and variation pattern during the period, using the mean values during the years $1991\~2003$ at 78 stations in Korea. The classified precipitation of a period of 10 days of summer precipitation, and the principal component vector and the amplitude coefficient by the principal component analysis were used for this study. The characteristics of variation pattern over the ten-day period can be chiefly divided into two categories and the accumulated contributory rate of these is $64.3\%$. The variation patterns of summer precipitation during period of 10 days in Korea are classified into 9 types from A to K. In addition, regional divisions of summer precipitation in Korea can be classified into 17 types.

• Journal of the Korean earth science society
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• v.43 no.3
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• pp.386-404
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• 2022

From April 29 to 30, 2011, under the influence of Asian dust originated from Mongolia, a high concentration of Asian dust was observed nationwide for 4 days in Korea. This study investigated the causes and characteristics of and weather conditions associated with Asian dust at high concentrations at its source in Mongolia. For analysis, Asian dust weather data, Asian dust monitoring tower data, satellite data, backward trajectory data, observation data (PM₁₀ and OPC data), and ECMWF reanalysis data were used. In the synoptic analysis, it was observed that the intervals of isobars were densely distributed in the central region of Mongolia and the pressure gradient force was strong. It could be inferenced that Asian dust occurred due to strong winds. The temperature was relatively high, above 10℃, just before the occurrence of Asian dust, and it decreased sharply at the onset of the dust. The relative humidity had a low value of less than approximately 40%. After the occurrence of Asian dust, it increased sharply to over 50% and then showed a tendency to decrease. In the aerosol index shown by the COMS satellite, a high concentration value of over 25 was detected in Inner Mongolia, and it was consistent with the observations made with naked eyes. In the 72-hour backward trajectory, the northwest airflow streamed into Korea, and on May 2, Heuksando showed the highest PM₁₀ concentration of 1,025 ㎍ m^-3(times the average). Especially, in kinematic vertical analysis, it was observed that low pressure on the ground was strengthened by cyclonic relative vorticity developed in the upper layer. Also, the vertical velocity development is considered to have played a major role in the occurrence of high concentration Asian dust.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.3
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• pp.151-171
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• 2023

This study analyzed farmer's responses to the pilot project in advance of the nationwide expansion of the farm-customized early warning service for weather risk management by conducting a survey among all farmers who received text messages of this service. We analyzed not only the satisfaction of farmers with the early warning service, but also the effectiveness of the service in preventing agrometeorological disasters through cross-tabulation analysis of survey results. More than 330 farmers participated in the survey, and more than 60% of the respondents said that they had prevented or mitigated crop disasters by using the early warning service. The cross-tabulation analysis showed that farmers who perceived the field-specific weather information of the early warning service to be more accurate than the weather forecast were statistically significantly more likely to prevent crop disasters than those who did not. According to our case study, farmers who grew open field fruit crops were particularly sensitive to weather information and confirmed that early warning services, along with disaster prevention facilities, were effective in preparing for freezing and frost injury that had been occurring frequently under the influence of climate change. This study is significant in that it is the first to systematically analyze the effectiveness of the farm-customized early warning service for weather risk management based on extensive surveys. It is expected to contribute to exploring ways to develop the service ahead of the nationwide expansion of the early warning service in the near future.

• Journal of Korean Home Economics Education Association
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• v.33 no.1
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• pp.169-185
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• 2021

The purpose of this study is to apply the clothing teaching-learning plan from a critical science perspective developed to improve teenager's empowerment, and to examine it's effects. A total of 12 plans of 5 modules(Module A to E) developed from critical science perspective were implemented for four weeks. Second-year students (N 42) of K Middle School located in Y-si, Gyeonggi-do participated in the study in the study, and the survey results were analyzed quantitatively using t-tests. For the quality analysis, The student interview data, action reports and etc. were collected, and qualitative analysis was conducted using empowerment model as the analysis framework. The findings of study are follows. First, two hours each for modules A to D, and four hours for module E were assigned, because module E included an action project. In the action projects by for groups, students were expected to take the lead in conducting the activities such as developing promotional posters, posting opinions online, promoting videos, informing how to make recyclables, and donating to the community. Second, as a result of analyzing the pre-implementation vs post-implementation empowerment scores, a significant difference was found in social-political empowerment (t=-2.06, p<0.05). According to the analysis of student interviews and students project's reports, students were found to become aware of empowerment through the instruction. On the intrapersonal level, positive self-awareness and self-efficacy, and on the interpersonal level, smooth communication and democratic decision-making were confirmed. This study is meaningful in that regular a home economics instruction class from a critical science perspective have made a quantitative and qualitative impact on teenagers' improvement empowerment, providing opportunities to find their roles in the soceity, cooperate with others, and behave responsibly as members of society.

• Journal of Science and Technology Studies
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• v.18 no.2
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• pp.135-179
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• 2018

How do robots interact with the elderly? In this paper, we analyze the contexts of interaction between robots and the elderly and the role of mediators in initiating, facilitating, and maintaining the interaction. We do not attempt to evaluate the robot's performance or measure the impact of robots on the elderly. Instead, we focus on the circumstances and contexts within which a robot is situated as it interacts with the elderly. Our premise is that the success of human-robot interaction does not depend solely on the robot's technical capability, but also on the pre-arranged settings and local contingencies at the site of interaction. We select three television shows that feature robots for the elderly and one "dementia-prevention" robot in a regional healthcare center as our sites for observing robot-elderly interaction: "Grandma's Robot"(tvN), "Co-existence Experiment''(JTBC), "Future Diary"(MBC), and the Silbot class in Suwon. By analyzing verbal and non-verbal interactions between the elderly and the robots in these programs, we point out that in most cases the robots and the elderly do not meet one-to-one; the interaction is usually mediated by an actor who is not an old person. These mediators are not temporary or secondary components in the robot-elderly interaction; they play a key role in the relationship by arranging the first meeting, triggering initial interactions, and carefully observing unfolding interactions. At critical moments, the mediators prevent the interaction from falling apart by intervening verbally or physically. Based on our observation of the robot-elderly interaction, we argue that we can better understand and evaluate the human-robot interaction in general by paying attention to the existence and role of the mediators. We suggest that researchers in human-robot interaction should expand their analytical focus from one-to-one interactions between humans and robots to human-robot-human interactions in diverse real-world situations.

• Journal of the Korean earth science society
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• v.32 no.4
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• pp.388-401
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• 2011

Asian dust was observed a total of 66 times in the springtime during the period from 2002 to 2010, with 26 cases in March, 23 cases in April and 17 cases in May. This study investigates a Asian dust episode that occurred during the period from 22 to 25 May 2010, based on synoptic weather patterns, wind vector at 850 hPa, relative humidity at 1000 hPa, Jet streams and wind vector at 300 hPa, PM10 concentration in Korea and satellite imagery. In this case, Asian dust originated on 22 May along the rear of a developing low pressure system in Mongolia. The Asian dust was then transported southeastward and bypassed the Korea peninsula from 23 to 24 May, before reaching Japan on 25 May. Jet streams on 24 May bypassed the Korean peninsula and induced the development of a surface low pressure centered over the peninsula. The resulting air flow was critical to the trajectory of the Asian dust, which likewise bypassed the Korean peninsula. 72-hour backward trajectory data reveal that the Shandong Peninsula and the East China Sea were the points of origin for the air flows that swept through the Japanese sites where Asian dust was observable to the naked eay. The Asian dust pathway is ascertained by horizontal distribution of the Asian dust of RGB imagery from MODIS satellites which captured the Asian dust moving over the Shandong Peninsula, the East China Sea, and northwest of the Kyushu region in Japan. Since the synoptic pattern and the transport way of the Asian dust case are far from typical ones, which Asian dust forecasting technique has long been based on, this study can be good example of exceptional Asian dust pattern and it will be used for more accurate Asian dust forecasting.

• Journal of the Korean earth science society
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• v.32 no.3
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• pp.276-293
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• 2011

In this study a modeling system consisting of Weather Research and Forecasting (WRF), Sparse Matrix Operator Kernel Emissions (SMOKE), the Community Multiscale Air Quality (CMAQ) model, and the CMAQ-Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID) model has been applied to estimate enhancements of $PM_{10}$ during Asian dust events in Korea. In particular, 5 experimental formulas were applied to the WRF-SMOKE-CMAQ (MADRID) model to estimate Asian dust emissions from source locations for major Asian dust events in China and Mongolia: the US Environmental Protection Agency (EPA) model, the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model, and the Dust Entrainment and Deposition (DEAD) model, as well as formulas by Park and In (2003), and Wang et al. (2000). According to the weather map, backward trajectory and satellite image analyses, Asian dust is generated by a strong downwind associated with the upper trough from a stagnation wave due to development of the upper jet stream, and transport of Asian dust to Korea shows up behind a surface front related to the cut-off low (known as comma type cloud) in satellite images. In the WRF-SMOKE-CMAQ modeling to estimate the PM10 concentration, Wang et al.'s experimental formula was depicted well in the temporal and spatial distribution of Asian dusts, and the GOCART model was low in mean bias errors and root mean square errors. Also, in the vertical profile analysis of Asian dusts using Wang et al's experimental formula, strong Asian dust with a concentration of more than $800\;{\mu}g/m^3$ for the period of March 31 to April 1, 2007 was transported under the boundary layer (about 1 km high), and weak Asian dust with a concentration of less than $400\;{\mu}g/m^3$ for the period of 16-17 March 2009 was transported above the boundary layer (about 1-3 km high). Furthermore, the difference between the CMAQ model and the CMAQ-MADRID model for the period of March 31 to April 1, 2007, in terms of PM10 concentration, was seen to be large in the East Asia area: the CMAQ-MADRID model showed the concentration to be about $25\;{\mu}g/m^3$ higher than the CMAQ model. In addition, the $PM_{10}$ concentration removed by the cloud liquid phase mechanism within the CMAQ-MADRID model was shown in the maximum $15\;{\mu}g/m^3$ in the Eastern Asia area.

• Atmosphere
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• v.22 no.4
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• pp.489-497
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• 2012

Recently released a top secret document explicitly shows that the early development plan for an earth observation satellite in the USA has a hidden and more important purpose for a concept of 'free space' than the scientific purpose. At that time, the hidden and secret concept imbedded within the early space development plan prevail other national policies of the USA government for purpose of the national security. Under these circumstances, it is quite reasonable to accept a possibility that the meteorological satellites which play a key role in the every area of meteorology and climatology was also born for the hidden purposes. Even it is so, it is quite amazing that the first meteorological satellite is launched in the USA despite of the facts that the major users of the meteorological satellites were not very enthusiastic with the meteorological satellite and the program was not started as a formal meteorological satellite project. This was only possible because of the external socio-political impact caused by the successful launch of the Russian Sputnik satellite and a few key policy developers who favored the meteorological satellite program. It is also interesting to note that the beginning of the first Korean meteorological satellite program was initiated by a similar socio-political influence occurred by the launch of a North Korean satellite.