겨울철 북서태평양인 캄차카 부근 해역에 영향을 주는 저기압의 특성을 종합,분석하고 그 발달기구를 규명하기 위하여 기상월보(1966~1974년) 9닌분과 일본 기상철 발행의 인쇄기일도(1970~1974년)5년분을 사용 분석한 결과를 요약하면 다음과 같다. 1) 겨울철 우리나라 부근에서 발현하는 저기압의 총수는 157개 였다. 이것을 월별로 보면 12월 1월에 각각 48개였고,2월에는 61개 발생했으며 경로별로는 BD경로, 즉 중국에서 발생하여 한국을 통과한 뒤 일본의 북해도로 진입하는 저기압은 총 53개로 전체의 36%로 가장 많았으며, CD경로 즉 대만 부근에서 발생하여 동해를 통과하는 저기압은 총 15개로 전체의 13%로 가장 적었다. 2)저기압 강하도는 A경로 일때가 제일 적었고, CD경로 일때가 가장 컸다. 또한 풍속변화량은 C,CD경로일 대가 최대였고, A경로 일때가 최소였다. 3)저기압이 통과하는 상층에 Jet류가 전일에 비해서 하강, 남하할 경우에는 한기중의 막대한 양이 저기압 후면으로 강하하면, 이에 따르는 위치 에너지의 감량이 저기압을 발달시킨다. 반면에 Jet류가 본래의 상태로 정체하고 있는 경우에는 위치에너지의 변화가 거의 없으므로 저기압은 별로 발달하지 않으며,만일 발달한다고 해도 해면 증발등과 같은 지상조건에 따를 뿐이다. 4)700mb면 등온선의 상층골과 기온극대축(혹은 극소축)의 상관위치 관걔는 저기압 발달에 많은 영향을 준다.

이 글에서는 T. S. 엘리엇(Eliot)의 ｢리틀 기딩｣(“Little Gidding”)에 구 현되어 있는 시적 ‘논리’의 윤곽을 파악하고자 한다. 니콜라스 페라 (Nicholas Ferrar)의 종교적 공동체가 있었던 리틀 기딩에는 엘리엇이 자 의식을 가지고서 구축한, 고전주의자, 왕당파, 그리고 국교도로서의 정 체성이 새겨져 있다. 나아가서 그곳은 시간 속에 그리고 그와 동시에 시간 밖에 존재하며 성육신(the Incarnation)에서 인간의 속성과 신의 속 성이 만나듯 역사적이면서 동시에 초월적이라고 상상된다. ｢리틀 기딩｣ 은 계절의 기적적인 교차(“한겨울의 봄”)를 앞세우며 시작하는데 이는 시 전체를 특징짓는 역설이며 수사와 주제의 차원에서 동시에 기능한 다. 제2차 세계대전의 시로서 ｢리틀 기딩｣은 4원소의 죽음을 통하여 상 징적으로 묘사되는 인류문명의 몰락을 목도하지 않을 수 없지만 노리치 의 줄리안(Julian of Norwich)이 피력하는 기독교적 비전(“모두가 평안하 고 / 만물이 평안하리”)을 받아들이고 있다. 이 비전이 구현되는 것은 불과 장미의 상징이 하나가 될 때인데, 연옥의 시라고 할 수 있는 ｢리 틀 기딩｣의 논지를 따르자면 이러한 하나됨은 극단적으로 철저한 자기 성찰과 정화를 통해서이다.

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 (22nd December, 2020 and 29th January, and 25th 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.

This paper has presented not only the spatial coverage change of climate extreme events in summer and winter seasons during the period of 2000-2017, but also their future projections in 2021-2100, South Korea through analysis of a Combined Climate Extreme Index (CCEI). The CCEI quantifies the spatial coverage of climate extreme events based on a set of five indicators. MK (Modified Korean)-PRISM (Parameter-elevation Regression on Independent Slopes Model)v1.2 (1×1km) and RCP scenario data (1×1km) were applied to CCEI. Results indicated that in average, 21.7% of the areas in the summer and 23.6% in the winter experienced climate extremes from 2000 to 2017 regardless of types of climate extreme events in South Korea. The summer of 2003 and 2009 was relatively cool and humid, while the summer of 2014 and 2015 was cool and dry and the summer of 2016 was warm and dry. The extreme events with much above normal maximum and minimum temperature during the study period were detected but not much below normal maximum and minimum temperature after 2015. For RCP2.6 and RCP8.5 scenarios, there were statistically significant trends with spatial coverage expansion of climate extreme events in the future. It might be concluded that climate extreme events in the summer and winter seasons were affected simultaneously by two or more indicators than a single indicator in South Korea.

Extreme low temperature has various effects on society. It has negative impacts on health, industry, agriculture, and transportation during winter season. Therefore, extreme low temperature is recognized as main factor that causing traffic accidents. This study analyzed the relationship between low temperature and traffic accidents from 2012 to 2018. This study also compared the differences in vulnerability to low temperature between urban and rural areas. Generalized Additive Model (GAM) and Poisson regression model are used to estimate the thresholds and the level of traffic accidents. The results show that the thresholds tend to be decreased gradually, but the level of traffic accidents are more likely to increase in both urban and rural areas Comparatively, rural areas are more vulnerable to traffic accident caused by drop in temperature than urban areas.

The Korean Peninsula has experienced regime shift (RS) in winter temperature since the mid-1980s. After the RS, monthly mean temperature significantly increased by 1.05°C in December with 95% confidence level, 1.36°C in January with 99% confidence level, and 1.60°C in February with 99% confidence level, respectively. Interestingly there is no RS in warm winter with 95% confidence level while there is a clear RS in cold winter with 99% confidence level, especially in December and January (DJ), indicating that the RS of winter temperature is mainly due to an abrupt temperature shift in December and January after the RS. Composite analysis suggests that abrupt shift in January after the RS is related to the reduction in sea level pressure (SLP) between Siberian high and Aleutian low, leading to anomalous southerly. However, abrupt shift in December is closely related to the propagation of Rossby wave spanning from the weakening of Ural high to negative anomaly over the North Pacific via high pressure anomaly over the Korean Peninsula, leading to adiabatic heating. Wave activity flux analysis suggests that the abrupt shift of DJ and the associated high pressure anomaly over the Korean Peninsula is induced by the propagation of Rossby wave spanning from North Atlantic Ocean to the Korean Peninsula via the Arctic, especially in cold winter.

Ensemble verification and prediction of low-level wind shear (LLWS) are an important matter for airplane landing and management. In this study, we compared the prediction performance of LLWS forecasts of ensemble mean, multiple regression model and long short-term memory (LSTM), which belong to the family of recurrent neural network based on the grid points over the Jeju area. The prediction skills of methods were compared by mean absolute error. We found that the prediction skills of forecasts of LSTM were better than the bias-corrected forecasts in terms of deterministic prediction.

In this study examined the strength of wall concrete using insulated molds and non-insulated forms by monitoring the strength of the structure using a wireless sensor network by maturity method. It was confirmed that the temperature and compressive strength of the structures are monitored in real time, along with effective strength control.

In this study, the purpose of the study is to determine the depth of damage caused by early frost damage in concrete slab structures under the conditions of external temperature during winter. In other words, we intend to analyze the depth variation of the early frost damage as the thickness of the concrete slab member changes under the condition of the 3-component binder frequently used in practice. As a result, the thinner the component, the significantly reduced the overall temperature of the concrete. In addition, the thinner the component thickness, the higher the delay in increasing the brightness of the core collected from the concrete member, and the greater the effect on the depth of the early frost damage was on the thinner the component thickness.

Persistent Extreme Temperature Events (PETEs) are defined in two steps; first, to define extreme temperature events, the 80th and 20th percentiles of daily maximum and minimum temperature were chosen. Then individual PETE was defined as an event which lasted three or longer consecutive extreme temperature days. In this study, we examined characteristics and changes of PETEs in Republic of Korea (ROK) using 14 weather stations with a relatively long-term period of data, 1954-2016. In ROK, PETEs lasted four-five days on average and occurred two-three times a year. PETEs lasted longer in summer than in winter and in maximum temperature than in minimum temperature. PETEs which lasted greater than seven days account for a greater proportion in summer than in winter. However, intensities of PETEs were greater in winter because of a larger temperature fluctuation. In both summer and winter, durations and intensities of persistent extreme high temperature events increased while those of persistent extreme low temperature events decreased. Changes of PETEs were closely related with both global warming and diverse large-scale climate variabilities such as AO, NAO and Nino 3.4.

Freezing rain is a phenomenon when precipitation falls as a liquid rain drop, but freezes when it comes into contact with surfaces or objects. In this study, we investigated the predictability of freezing rain and its characteristics, which are strongly related with the occurrence of black ice using synoptic scale meteorological observation data. Two different cases occurred at 2012 were analyzed and in the presented cases, freezing rain often occurs in the low-level low pressure with the warm front. The warm front due to the lower cyclone make suitable environment in which snow falling from the upper layer can change into supercooled water. The 0℃ temperature line to generate supercooling water is located at an altitude of 850 hPa in the vertical temperature distribution. And the ground temperature remained below zero, as is commonly known as a condition for black ice formation. It is confirmed that the formation rate of freezing rain is higher when the thickness after 1000-850 hPa is 1290-1310 m and the thickness of 850-700 hPa layer is larger than 1540 m in both cases. It can also be used to predict and estimate the generation of freezing rain by detecting and analyzing bright bands in radar observation.

This study was carried out to elucidate the chemical compositions of water-soluble inorganic ions in PM10 and PM2.5 aerosols collected during summer and winter in downtown Jejusi city. The ratios of NO3 - to the total mass of ionic species in PM10 and PM2.5 aerosols largely increase in winter compared to summer, while SO4 2- ratios in both aerosols appear to follow the opposite trend. Moreover, concentrations of Na+, Mg2+, Ca2+ and Cl- in PM10 and PM2.5-10 aerosols are higher in winter than in summer. The nitrate concentrations in PM10 and PM2.5 aerosols increase with an identical increase in excess ammonium during winter, however, nitrate formation during summer is not important owing to ammonium-poor conditions.

Chemical properties of aerosols were investigated by analyzing the inorganic water-soluble content in PM2.5 collected in the downtown area of Jeju City in Jeju Island. Due to an increase in both the number of visiting tourists and the size of local population, the number of cars in this area is increasing, causing an increase in PM2.5. Eight PM2.5-bound major inorganic ions were analyzed during the summer and winter periods. The water-soluble inorganic component represents a significant fraction of PM2.5. In particular, secondary inorganic aerosols contribute 36.2% and 47.5% of PM2.5 mass in summer and winter, respectively. Nitrate concentrations increase for [NH4 +]/[SO4 2-]>1.5, and excess ammonium, which is necessary for ammonium nitrate formation, is linearly correlated with nitrate. These results are clearly observed during the winter because conditions are more conducive to the formation of ammonium nitrate. A significant negative correlation between Nitrogen Oxidation Ratio (NOR) and temperature was observed. The obtained results can be useful for a better understanding of the aerosol dynamics in the downtown area in Jeju City.

In this paper, for selected station of 8 clusters in East Asia (Park, 2017) more (less) warming periods than the wintertime mean warming of intra-seasonal fluctuation curves were taken and their means were computed. Long term trends and synoptic features of the mean temperature changes were examined. In most clusters, around the third of January there were less warming periods (LWP) than the mean wintertime warming. On the contrary, in February and the first and second of January there were more warming periods (MWP) than the winter mean or LWPs having a warming trend with statistical signicance. Time series of the daily Siberian High indices showed they had been weakening in February and being stagnant around late January. In most stations, the mean temperatures of MWP or LWP had large negative correlation coecients with the Siberian high intensity. is result explains the occurrences of MWPs in most clusters in February and LWPs in late January. In cluster B there were LWPs in early February due to the influence of the Aleutian Low which were strengthening in that periods. Cluster E showed different features without LWPs in late January. The cluster is considered to be affected by its plateau environment of West Yúnnán and the Tibet Plateau which prevent cold air of the lower atmosphere in Northern Asia flowing southward, and by the regional atmospheric circulation of 500hPa surface centered in this region.

In this study, the intra-seasonal fluctuation (ISF) of wintertime temperature change in East Asia was classified by a cluster analysis of complete linkage. A ISF of temperature change was defined as a difference of synthesized harmonics (1 to 36 harmonic) of daily temperature averaged for 30 years (1951~1980, 1981~2010). Eight clusters were gained from the ISF curves of 96 stations in East Asia. Regions of the cluster C, G and A1 seem to be affected by the Siberian High (SH) center, whereas the cluster A1, A2, D, B and F by the SH main pathways. Regions of the cluster E are apart from the SH main pathways and appear to be in the area of influence of other factors. Wintertime temperatures in Northwest China (clusters C, G) and Northeast China (cluster A1) were increased very largely. In most clusters, around late January there were less warming periods than the winter mean of the mean ISF of the clusters, before and after this time there were more warming periods than the winter mean.

The purpose of this study is to characterize long-term (1973~2012) changes in intra-seasonal temperature and extreme low temperature events in winter observed at 61 weather stations in the Republic of Korea and their associations with changes in atmospheric circulation patterns around East Asia. Maps of long-term linear trends clearly show that both temperature means and extreme events in Korea have asymmetrically changed between early winter and late winter. In early winter, changes with statistical significance are less observable, while in late winter reductions in low extreme temperature events as well as increases in temperatures, particularly after mid-1980s, are obviously observed across the study region. Comparisons of tropospheric synoptic climatic fields before and after the mid-1980s demonstrate that in early winter of recent decades, active meridional circulation from the Arctic appeared in western Eurasia and Bering sea, while in late winter, zonal circulation around East Asia associated with positive Arctic Oscillation-like patterns prevailed. These results indicate that asymmetric changes between early and late winter temperatures in Korea are associated with intra-seasonally inconsistent atmospheric circulation patterns around East Asia.

This study was conducted to measure the effect of PE film mulching and irrigation methods on the growth, yield and antioxidant activity of potatoes tubers, in order to examine the possibility of cultivating potatoes in winter season in vinyl greenhouse on the reclaimed tidal land with weak ground inside the sea wall currently completed. The test was conducted on the sandy loam soil (Munpo series), and its salt concentration was 0.42% at the time of planting. The emergence speed per kind of PE film mulching was in the order of black > coloration > transparent > green color, with the black color showing the fastest speed. The temperature change during a day per kind of PE film mulching was in the order of transparent > coloration > green > black color. As for the salt concentration in the soil for each different way of water management, the salt concentration in the treatment of drip irrigation with 1 week interval was lower than that drip irrigation with 2 weeks interval. As for the growth of above-aerial part, plant length was higher, number of tiller and leaves were more and dry weight of above-aerial part was larger in the treatment of drip irrigaton with 1 week interval than drip irrigation with 2 weeks interval. As for the yield of potatoes depending on were higher with pear color vinyl treatment. each way of water management, the yield in the treatment of drip irrigation with 1 week interval was more than drip irrigation with 2 weeks interval. The yield for each different kind of PE film mulching in the weekly drip-irrigation management section was in the order of transparent ≥ black ≥ coloration ≥ green color. In both of total phenol content and DPPH free radical activity experiments, the content and activity

This study investigates the direct and indirect effects of anthropogenic aerosols emission on East Asian climate during the winter (December-February) for the period of 1961-1990. Using a globally coupled climate model, HadGEM2-AO, we compare ensemble means between historical runs with and without aerosol emissions. During the 20th century the major contributions to the total Aerosol Optical Depth (AOD) over the East Asian region came more from anthropogenic aerosols than from natural aerosols. The increasing total AOD induces the negative radiative in a clear-sky condition, leading to cooling the surface. Indirect effect contributes to the increase in the total cloud fraction, resulting from the increased low-level stratus and stratocumulus clouds. Consequently, the net surface radiative flux becomes negative due to the direct and indirect effects of aerosols. Land surface cooling seems to enhance the landsea pressure gradient in the East Asian wintertime climate, and the associated wind anomalies induce the regional wintertime precipitation amount changes over South China.