• Atmosphere
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• v.19 no.2
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• pp.155-168
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• 2009

Characteristics of seasonal mean diurnal temperature range (DTR) and their causes over South Korea are investigated using the 60 stations data of Korea Meteorological Administration from 1976 to 2005. In general, the seasonal mean DTR is greatest during spring (in inland area) and least during summer (urban and coastal area). The spatial and seasonal variations of DTR are closely linked with the land surface conditions (especially vegetation activity and soil moisture) and atmospheric conditions (cloud amount, precipitation, local circulation). The seasonal mean DTR shows a decreasing trend at the major urban areas and at the north-eastern part of South Korea. Whereas, it shows an increasing trend at the central area of the southern part. Decreasing and increasing trends of DTR are more significant during summer and fall, and during spring and winter. The decrease (increase) of DTR is mainly caused by the stronger increase of daily minimum (maximum) temperature than daily maximum (minimum) temperature. The negative effects of precipitation and cloud amount on the DTR are greater during spring and at the inland area than during winter and at the coastal area. And the effect of daytime precipitation on the DTR is greater than that of nighttime precipitation.

• Journal of agricultural medicine and community health
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• v.26 no.1
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• pp.115-119
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• 2001

The effect of seasonal variation on social statistic data is important. But in health subcenter in rural areas the effect has not been well known. To determine the seasonal index of medical needs in rural communities, the monthly number of patients were analyzed from Jan. 1994 to Dec. 2000. Seasonal index were calculated using 12 months moving averages and median value of each data. The number of patients excluding common cold were analyzed by same method. The seasonal index from Jan. to Dec. were 0.96, 1.08, 1.23, 0.83, 0.82, 0.75, 1.01, 0.99, 1.02, 1.05, 1.13, 1.13. The seasonal index of patients excluding those with common cold were 0.94, 0.90, 1.42, 0.94, 0.91, 0.77, 1.13, 0.92, 0.84, 1.07, 1.10, 1.16. In a rural area, medical needs are decreased on spring and early summer and increase in winter, and that are the influence of rural area.

• Ocean and Polar Research
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• v.29 no.2
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• pp.113-121
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• 2007

The sound wave in the sea propagates under the effect of water depth, sound speed structure, sea surface roughness, bottom roughness, and acoustic properties of bottom sediment. In shallow water, the bottom sediments are distributed very variously with place and the sound speed structure varying with time and space. In order to investigate the seasonal propagation characteristics of low-frequency sound wave in the Yellow Sea, propagation experiments were conducted along a track in the middle part of the Yellow Sea in spring, summer, and autumn. In this paper we consider seasonal variations of the sound speed profile and propagation loss based on the measurement results. Also we quantitatively investigate variation of bottom loss by dividing the propagation loss into three components: spreading loss, absorption loss, and bottom loss. As a result, the propagation losses measured in summer were larger than the losses in spring and autumn, and the propagation losses measured in autumn were smaller than the losses in spring. The spreading loss and the absorption loss did not show seasonal variations, but the bottom loss showed seasonal variations. So it was thought that the seasonal variation of the propagation loss was due to the seasonal change of the bottom loss and the seasonal variation of the bottom loss was due to the change of the sound speed profile by season.

• Fisheries and Aquatic Sciences
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• v.4 no.3
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• pp.101-111
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• 2001

In an attempt to demonstrate the seasonal variation of the Ulleung Warm Eddy (UWE), in which the UWE changes its shape from a warm core ring in early spring to a warm lens in late summer under the effect of surrounding East Korean Warm Current (EKWC) Water, a simple geostrophic adjustment model is considered. Model results indicate that the buoyancy increase of the EKWC Water and the strengthening of the EKWC towards summer, both of which are typical of this region, are the major factors governing the seasonal variation of the UWE.

• Environmental and Resource Economics Review
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• v.31 no.3
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• pp.343-365
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• 2022

This paper tries to identify the effect of reducing PM2.5 concentration of the First Seasonal Management Policy implemented by Korean government by using statistical method. In particular, this paper tests the hypothesis that this policy effect may differ by region (west-coast, south-coast, and east-coast). To this end, this paper analyzed only pure policy effects by removing temporal abnormalities such as COVID-19, warm winter temperature during the policy implementation period (December 2019 to March 2020) by using the difference-in-difference method (DID). As a result of the analysis, this policy had the effect of reducing PM2.5, but the effect is not homogenous by region. In particular, PM2.5 reducing effect is the largest in west-coast region and south-coast region folllows, but its effect is not statistically significant in the east-cost region. In conclusion, this paper drew implications that the current Seasonal mamangement policy which is implemented regardless of the regional difference needs to be changed.

• Atmosphere
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• v.20 no.4
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• pp.437-449
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• 2010

The relocation effect of observation station (REOS) on the homogeneity of seasonal mean of maximum and minimum temperature, diurnal temperature range (DTR) and relative humidity (RH) was investigated using surface observation data and document file. Twelve stations were selected among the 60 stations which have been operated more than 30 years and relocated over one time. The data from Chunpungryeong station were used as a reference to separate the impacts of station relocation from the effects caused by increased green house gases, urbanization, and others. The REOS was calculated as a difference between REOS of relocated station and REOS of reference station. Although the REOS is clearly dependent on season, meteorological elements, and observing stations, statistically significant impacts are found in many stations, especially the environment of observing station after relocation is greatly changed. As a result, homogeneity of seasonal mean of meteorological elements, especially DTR and RH, is greatly reduced. The results showed that the effect of REOS, along with the effect of urbanization, should be eliminated for the proper estimation of climate change from the analysis of long-term observation data.

• Journal of Korean Society of Transportation
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• v.18 no.5
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• pp.7-16
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• 2000

This paper is focused on verifying time-space repetition of the highway accident and finding the their causes and deterrents. We classify all months into several seasonal groups, develop the model for each seasonal group and analyze the results of these models for Joong-bu highway. The existence of seasonal effect is verified by the analysis or self-organizing map and the accident indices. Agglomerative hierarchical cluster analysis which is used to decide the seasonal groups in accordance with accident patterns, winter group, spring-fall group. and summer group. The accident features of winter group are that the accident rate is high but the severity rate is low. while those of summer group are that the accident rate is low but the severity rate is high. Also, the regression model which is developed to identify the accident Pattern or each seasonal group represents that the season-related factors, such as the amount of rainfall, the amount of snowfall, days of rainfall, days of snowfall etc. are strongly related to the accident pattern of evert seasonal group and among these factors the traffic volume, amount of rainfall. the amount of snowfall and days of freezing importantly affect the local accident Pattern. So, seasonal effect should be considered to the identification of high-risk road section. the development of descriptive and Predictive accident model, the resource allocation model of accident in order to make safety management plan efficient.

• Journal of Environmental Science International
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• v.20 no.9
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• pp.1141-1149
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• 2011

The three-dimensional hydrodynamic model was simulated to understand coastal sea front of formation and seasonal variation in the Southern Sea of Korea. In this study, we used to concept of stratification factor, to realize seasonal distribution of stratification coefficient which of seasonal residual flow, considered with, tide, wind and density effect. Tidal current tends to flow westward during the flood and eastward during ebb. The current by the wind stress showed to be much stronger the coastal than the offshore area in the surface layer. And the current by the horizontal gradient of water density showed to be relatively weak in the coastal area, with little seasonal differences. On the other hand, the flow in the offshore area showed results similar to that of the Tsushima Warm Current. The stratification factor (SHv) was calculated by taking into account the total flow of tide, wind and density effect. In summer, the calculated SHv distribution ranged from 2.0 to 2.5, similar to that of the coastal sea front. The horizontal temperature gradient showed to be strong during the winter, when the vertical stratification is weak. On the other hand, the horizontal gradient became weak in summer, during which vertical stratification is strong. Therefore, it is presume that the strength of vertical stratification and the horizontal temperature gradient affect the position of the coastal sea front.

• Korean Journal of Child Studies
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• v.37 no.5
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• pp.101-116
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• 2016

Objective: This study aimed to investigate how the eco-centered early childhood education by seasonal divisions influences the child's nature-friendly attitude and emotional intelligence. Methods: Forty 5-year-olds from 2 preschools in Gyeonggi were selected through convenience sampling and were divided into the experimental group (21) and the comparative group (19). The experimental group received eco-centered childhood education by seasonal divisions 2 or 3 times a week (33 in total). Pre-post data were collected on both groups and analyzed via t-test and ANCOVAs. Results: The key result was as follows: eco-centered childhood education by seasonal divisions influenced positively the nature-friendly attitude and emotional intelligence of children. Conclusion: Based on the result, it is recommended that eco-centered early childhood education be applied in childhood education and that relevant program be developed. Eco-centered education by seasonal divisions is meaningful in early childhood so that children can be harmonious with the nature. Furthermore, the study should be continued for the development of qualified eco-centered education.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.6 no.3
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• pp.309-325
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• 1994

Ocean circulation in the Gulf of Alaska is remarkably constant throughout the year despite of being forced by one of the largest seasonal wind stresses in the world. To explain the small seasonal changes in the transport of Alaska Stream. a set of numerical models is employed. First a diagnostic approach is applied to reproduce circulation from the observed density structure. The results reveals the very small seasonal changes in the Alaska Stream transport. Next a series of the prognostic models is used: a barotropic model. a flat bottom baroclinic model, and baroclinic model with topography. These models reveal the influence of topography and baroclinicity on the ocean's response to the seasonal wind forcing. The intercomparisons of the various model results suggest that the seasonal response of the baroclinic ocean is primary barotropic and the resultant barotropic circulation is weakened by the scattering effect of the bottom topography.