• Journal of the Korean association of regional geographers
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• v.12 no.4
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• pp.461-474
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• 2006

This paper aims to analyze regional characteristics of unusual temperature events on summer and winter. The major data used in this study are the daily mean temperature of summer (June-August) and winter (December-February) and wind field on 850 hPa height. Regions of unusual temperature are divided into five regions by the monthly frequency of unusual temperature occurrence. The divided regions are following as: the middle east coastal region (I) where the summer unusual high temperature occurrence frequency is highest; the Gyunggi west coastal and northern middle inland region (II) where winter unusual low temperature occurrence frequency is highest and winter unusual high temperature occurrence frequency is low; the western middle and south region (III) where unusual temperature occurrence ratio is not concentrated on specific season; the forest and southern east region (IV) where unusual high temperature is low; and the south coastal and Jeju island region (V) where winter unusual high temperature is highest.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5877-5884
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• 2014

Recently, abnormally cold weather has been reported more frequently in winter due to the climate change and abnormal weather changes. On the other hand, the heating capacity of a railcar may be not enough to warm the cabin under severe cold climatic conditions, which is one of the reasons for the passengers' complaints about heating. In this study, the effects of ambient temperature and heater power on the cabin temperature was investigated to obtain the minimum ambient temperature for the tested railcar. The test railcar was placed in a large-climatic chamber, and various ambient temperature conditions were simulated. The effects of the heater output were investigated by monitoring the cabin temperature under a range of heater output conditions. The mean cabin temperature was $14.0^{\circ}C$, which was far lower than the required minimum temperature of $18^{\circ}C$, under a $-10^{\circ}C$ ambient temperature condition with the maximum heat power. When the ambient temperature was set to $0^{\circ}C$ and $10^{\circ}C$, the maximum achievable cabin temperature was $26.1^{\circ}C$ and $34.0^{\circ}C$. Through calculations using the interpolation method, the minimum ambient temperature to maintain an $18^{\circ}C$ cabin temperature was $-6.7^{\circ}C$ for this car. The vertical temperature difference was higher with a higher power output and higher ambient temperature. The maximum vertical temperature difference was higher than $10^{\circ}C$ in some cases. However, the horizontal temperature difference vs. low temperature (< $2^{\circ}C$) was independent of the power output and ambient temperature. As a result, it is very important to reduce the vertical temperature difference to achieve good heating performance.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.2
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• pp.85-92
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• 2015

This study was conducted to analyze the relationship among climatic factors and radial growth of Pinus koraiensis in South Korea. To determine climate-growth relationships, cluster analysis was applied to group climatically similar surveyed regions, and dendroclimatological model was developed to predict radial growth for each climate group under the RCP 4.5 and RCP 8.5 scenarios for greenhouse gases. The dendroclimatological models were developed through climatic variables and standardized residual chronology for each climatic cluster of P. koraiensis. 2 to 4 climatic variables were used in the models ($R^2$ values between 0.35~0.49). For each of the climatic clusters for Pinus koraiensis, the growth simulations obtained from two RCP climate-change scenarios were used for growth prediction. The radial growth of the Clusters 2 and 3, which grow at high elevation, tend to increase. In contrast, Cluster 1, which grows at low elevation, tends to decrease with a large difference. Thus, the growth of Pinus koraiensis, which is a boreal species, could increase along with increasing temperature up to a certain point.

• International Journal of Industrial Entomology and Biomaterials
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• v.12 no.2
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• pp.51-56
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• 2006

Use of products containing phytoecdysteroid (PE) as active principle has become popular in prominent sericultural areas of India for hastening larval maturation events and synchronizing cocoon spinning activities as an obvious advantage is assured. At times, the present recommendation of administering PE at the onset of spinning results in peak labour requirement at odd hrs. To enable making recommendation for the use of PE on $multi{\times}bivoltine$ silkworm hybrids based on the climatic conditions prevailing in different areas especially with regard to temperature, the experiment was taken up to determine proper treatment times so that the induced spinning will be more orderly and the labour can be leveraged more efficiently. Different brackets of low ($18-22^{\circ}C$), medium ($24-28^{\circ}C$) and high ($29-32^{\circ}C$) temperature were simulated during the latter half of V larval instar and cocoon spinning. PE was administered to $multi{\times}bivoltine$ silkworm ($BL67{\times}CSR101$) hybrid batches as per the recommended dose at three different times viz., 10 am, 4 pm and 10 pm. Three replicates of 100 larvae were maintained for each treatment. Absolute controls were also maintained in each temperature range to compare the results. Cumulative maturation percentage was recorded at 6 hrs interval to ascertain peak mounting span. The influence of the treatment on the cocoon traits also was studied. Based on the peak mounting span, it was evident that in low temperature 10 pm treatment would be better. In medium and high temperature, treatment at 4 pm proved to be a better option. The influence of the treatment times at different temperature range on labour management is discussed.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• v.26 no.1
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• pp.31-41
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• 1998

The climatic characteristics of summer in 1998 are analyzed with the weather observational data and the upper air observational data. The temperature of that period is lower than that of normal years and the precipitation is larger. Due to the heavy rainfall which started at July 31, rain pured down compared to normal years and the maximum precipitation recorded at the many observational stations, particularly in Seoul, Kyunggi-Do region and mountanious districts like Taegwallyong, Mt. Sokri and Mt. Chiri. The patterns of general circulations in 1982/98 and 1997/98 are compared each other and are analyzed. The anomaly patterns of stream functions on winter in two El Nio years are simialr. The counterclockwise circulation occurred near the date line and the clockwise circulation was appeared near the Hwanam region and Alaska. These patterns are opposite to those of La Nia year, 1988/89. And the anomaly patterns of 500hPa geopotential height in summer are similar, too. The low temperature and much rain were dominated in summer of 1997/98. These phenomena is similar to the existing results of research, that temperature is low and precipitation is large in summer of El Nio years.

• Journal of Environmental Science International
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• v.24 no.4
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• pp.383-391
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• 2015

As occurrence of gradually increasing extreme temperature events in Jeju Island, a hybrid downscaling technique that simultaneously applies by dynamical method and statistical method has implemented on design rainfall in order to reduce flood damages from severe storms and typhoons.As a result of computation, Case 1 shows a strong tendency to excessively compute rainfall, which is continuously increasing. While Case 2 showed similar trend as Case 1, low design rainfall has computed by rainfall in A1B scenario. Based on the design rainfall computation method mainly used in Preventive Disaster System through Pre-disaster Effect Examination System and Basic Plan for River of Jeju Island which are considering climatic change for selecting 50-year and 100-year frequencies. Case 3 selecting for Jeju rain gage station and Case 1 for Seogwipo rain gage station. The results were different for each rain gage station because of difference in rainfall characteristics according to recent climatic change, and the risk of currently known design rainfall can be increased in near future.

• Journal of the Korean Geographical Society
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• v.40 no.6 s.111
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• pp.730-747
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• 2005

This study examines relationships between climatic factors and spatial-temporal patterns and recent changes of tropical night phenomenon(TN) occurring through nighttime stages in South Korea. Frequencies of daily TN at different times of night are extracted from long term(1973-2004) 6 hourly nighttime(9PM and 3AM) temperature and daily minimum temperature data at 61 weather stations. Temporally, the occurrences of TN are more pronounced in the evening(9PM) and during the Changma Break period(late July - early August). Spatially, the TNs in the evening frequently occur in the urbanized inland cities at low latitudes due to urban heat islands, whereas the TNs in the middle of night(3AM) or at dawn frequently appeared along the coastal areas within 30km from ocean due to the thermal inertia of ocean. By contrast, the evening(dawn) TN is not seen in the highlands whose elevation is greater than 800m(300m) along the Taebaek and Sobaek mountain ridges due to temperature lapse rates with height Correlation and multivariate regression analyses reveal that the impacts of human or physical climatic factors, such as latitude, elevation, proximity to ocean, and population density, are diverse on the frequencies of TN according to nighttime stages. Recent temporal changes of the late Changma period and intensified urbanization during the 1990s have increased the occurances of TN in urban areas. Therefore, strategies to mitigate the increasing urban TN should be prepared in the near future.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.229-235
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• 2012

This study was conducted to investigate the climatic factors affecting bud phenology of Pinus densiflora provenances. Data were collected from Jungseon, Chungju and Jeju plantations which were parts of the 11 provenance trials established by Korea Forest Research Institute in 1996. The 36 provenances were included in this trial ($33^{\circ}30^{\prime}{\sim}38^{\circ}08^{\prime}$ in latitude and $126^{\circ}30^{\prime}{\sim}129^{\circ}20^{\prime}$ in longitude). The bud swelling date and bud burst date of the provenances were investigated from March to May in 2004 in two-day interval. The four geographic factors and fifteen climatic factors of the test sites and provenances were considered in this study. Canonical correlation analysis was conducted to examine the major factors affecting the bud phenology. Our results suggested that the major factors affecting the timing of bud swelling and burst are the differences in latitude, longitude, extremely low temperature (during December-February), extremely high temperature (during November-February) and annual mean growing days between test plantation and provenance. The provenances with lower winter temperature than that of plantation showed the faster bud swelling and bud burst. Based on these results, the implication on the seed transfer of P. densiflora was discussed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.1
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• pp.41-51
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• 1999

This study was conducted to investigate the effects of local climatic conditions on the annual increment of Korean white pine planted in Gapyung and Yaungdong. For this, stand variables such as mean DBH, mean height, basal area per hectare, and volume per hectare by stand age were measured and summarized for each locality. Based on these statistics, annual increments for 8 years from stand age 10 to 18 were calculated for each of stand variables. A topoclimatological technique which makes use of empirical relationships between the topography and the weather in study sites was applied to produce normal estimates of monthly mean, maximum, minimum temperatures, relative humidity, precipitation, and hours of sunshine. Then, the yearly climatic variables from 1990 to 1997 for each study site were derived from the spatial interpolation procedures based on inverse- distance weighting of the observed deviation from the climatic normals at the nearest 11 standard weather stations. From these estimates, 17 weather variables such as warmth index, coldness index, index of aridity etc., which affect the tree growth, were computed on yearly base for each locality. The deviations of measured annual increments from the expected annual increments for 8 years based on yield table of Korean white pine were then correlated with and regressed on the yearly weather variables to examine effects of local climatic conditions on the growth. Gapyung area provides better conditions for the growth of Korean white pine in the early stage than Youngdong area. This indicates that the conditions such as low temperature, high relative humidity, and large amount of precipitation provide favor environment for the early growth of Korean white pine. A ccording to the correlation and regression an analysis using local climatic conditions and annual increments, the growth pattern of Gapyung area corresponds to this tendency. However, it was found that the relationship between annual increments and local climatic conditions in Youngdong area shows different tendency from Gapyung. These results mean that the yearly growth pattern could not sufficiently be explained by climatic conditions with high variance in yearly weather variables. In addition, the poor growth in Youngdong area might not only be affected by climatic conditions, but also by other environmental factors such as site quality.

• Parasites, Hosts and Diseases
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• v.44 no.3
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• pp.259-264
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• 2006

House dust mites play an important role in the pathogenesis of allergic diseases. Many factors may influence mite growth. The presence of mites is related to mean temperature and humidity as well as altitude. The aim of this study was to analyze the mite fauna in 5 regions of western Anatolia, Turkey, that have similar climatic properties with low mean temperature and humidity, but differ in altitude. During the period October-November 2004, house dust was collected from 290 homes in 5 different cities. House dust mites were isolated in 67 (23.1 %) of 290 samples. The family Pyroglyphidae (Astigmata) was present in all positive samples. This study suggests that the selected western Anatolian regions that share similar environmental conditions host similar dust mite populations.