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.

In this study, we analyzed the intraseasonal variability and change of winter temperature over South Korea using long-term observations. The lowest temperature in the wintertime, using daily mean, maximum, and minimum temperature data occurred on January 7th in the period of 2003~2012, while on January 22~25th in the past 30 years(1973~1982, 1983~1992, 1993~2002). Representative seven stations in South Korea also showed consistent result. The strengthening of Siberian High and weakening of Aleutian Low in recent 10 years are found to be closely related with the recent intraseasonal temperature change over South Korea. The baroclinic structure of upper-level low and lower-level high system near Korean peninsula provided good condition for vertical cold-air advection, which resulted in minimum temperature on late January in 1973~1982 and early January in 2003~2012 with strengthened low-level northerly flow.

In this study, the variations of the carbon dioxide fluxes were investigated with soil temperatures in the grassplot and seasonal variations of carbon dioxide concentrations and fluxes were analysed. Soil temperatures, carbon dioxide concentrations and fluxes were measured on the grassplot in Pukyong National University. Field measurements were carried out 25 times from March in 2010 to March in 2011 with nine points on the grassplot. Seasonal variations of carbon dioxide concentrations and fluxes showed an inverse relation. In summer, carbon dioxide concentrations are lower and carbon dioxide fluxes are higher. In winter, carbon dioxide concentrations are higher and carbon dioxide fluxes are lower. On the grassplot, carbon dioxide emission rate increase when the soil temperature is more than 20℃ and the emission rate decrease when the soil temperatures are less than 10℃. When the accumulated rainfall for five days before measurement day is 20~100 mm, it is showed that the more rainfall, the more carbon dioxide emissions. Carbon dioxide emission rate from the grassplot to the upper atmosphere was increased or decreased by the factors such as soil temperature, growth and wither of grass and rainfall. The results of this study showed that the emission of carbon dioxide in the grassplot is dominantly controlled by seasonal factors (especially soil temperature and rainfall).

The seasonal variations of ozone (O3) concentrations were investigated with regard to the relationship between O3 and wind distributions at two different sites (Jung Ang (JA): a semi-closed topography and Seo Chang (SC): a closed topography) within a valley city (Yangsan) and their comparison between these sites (JA and SC) and two non-valley sites (Dae Jeo (DJ) and Sang Nam (SN)) located downwind from coastal cities (Busan and Ulsan). This analysis was performed using the data sets of hourly O3 concentrations, meteorological factors (especially, wind speed and direction), and those on high O3 days exceeding the 8-h standard (60 ppb) during 2008-2009. In summer and fall (especially in June and October), the monthly mean values of the daily maximum O3 concentrations and the number of high O3 days at JA (and SC) were relatively higher than those at DJ (and SN). The increase in daytime O3 concentrations at JA in June was likely to be primarily impacted by the transport of O3 and its precursors from the coastal emission sources in Busan along the dominant southwesterly winds (about 5 m/s) under the penetration of sea breeze condition, compared to other months and sites. Such a phenomenon at SC in October was likely to be mainly caused by the accumulation of O3 and its precursors due to the relatively weak winds under the localized stagnant weather condition rather than the contribution of regional transport from the emission sources in Busan and Ulsan.

에 분포하는 기후변화 취약식물종인 목본식물 20종, 초본식물 18종 총 38종을 대상으로 2009년 5월부터 2010년 11월까지 식물계절 변화 모니터링을 실시하였다. 조사식물은 개엽, 개화, 낙화, 단풍, 낙엽 등 5개의 특성으로 구분하여 기후변화에 따른 아고산지대내 기후변화 취약종의 식물계절 변화를 분석하였다. 기상 자료는 2009년 11월 말부터 2010년 12월 초까지 측정되었으며 조사 결과, 기온은 향적봉-중봉 지역에서 최대가 30.4℃, 최소가 -20.3℃로 조사되었으며, 상대습도는 최고 100%, 최소 3.4%로 조사되었다. 덕유산 향적봉과 중봉지역의 개엽시기를 조사한 결과 박새, 산오풀 등을 제외한 대부분의 종들은 비슷하거나 전년도에 비해 6~20일 정도 늦게 나타났다. 개화시기는 식물계절 변화 중 가장 큰 차이를 보였으며, 이른 봄에 개화하는 처녀치마, 산철쭉, 노랑제비꽃은 2차년도에 13일~20일 빠른 것으로 관찰되었으며, 늦은 봄과 여름에 개화하는 백당나무, 풀솜대, 개시호 등은 2차년도에 6일~10일 늦은 것으로 나타났다. 낙화시기와 단풍시기는 전년도에 비해 10일~18일 늦은 것으로 나타났고, 낙엽시기는 전년도와 유사한 경향성을 보였다. 본 연구결과 기후변화의 영향이 한반도 아고산지대에 분포하는 기후변화 취약종들에게 상당히 미치고 있는 것으로 나타났다.

The studies on community structure of benthic macroinvertebrates and environmental survey in selected four sites were performed on wetland Upo from 2008 to 2009. The lowest water temperature was measured at Upo and Mokpo showing 7℃ in February of 2008 and 2009 respectively. The highest water temperature was measured at Upo showing 32℃ in August of 2009. The lowest pH was measured at Topyeong with 5.3 in August of 2009, and the highest pH was measured at Mokpo with 10.1 in August of 2008. Generally the levels pH of 2008 were higher than those of 2009. The range of electric conductivity to the sites was big. Overall, the higher electric conductivity was seen at Sajipo and the lower one was seen at Mokpo. The level of Dissolved oxygen was lowest at Upo with 5.53㎎/ℓ in August 2008, and it was highest at Upo with 14.76㎎/ℓ in February of 2008. The investigation was performed with both quantitative and qualitative collecting methods from four surveying sites, Upo, Mokpo, Sajipo and Topyeong. Through the eight times of seasonal survey, 6 classes, 17 orders, 59 families, 131 species and 5460 individuals of benthic macroinvertebrates were collected. 6 classes, 17 orders, 53 families 106 species and 2439 individuals were identified in 2008, and 6 classes, 16 orders, 44 families, 93 species and 3021 individuals were collected in 2009. The number of species was decreased in 2009 comparing that of 2008, however, the number of individuals were increased in 2009. The dominant species and the subdominant species was Plea (Paraplea) indistinguenda and Diplonychus esakii with 20.16% and 11.90% of dominant indices respectively. From the community analysis, both the species diversity index and the species richness index were highest in Topyeong showing 4.743 and 9.054 respectively. The similarity evaluation to the investigation sites with the species in there showed very high similarity among Upo, Mokpo and Sajipo showing 5 or lower levels of distance cluster combine.

Cool island intensity urban green space was investigated based in Dalsung Park, that is one of the largest parks in Daegu. Cool island intensity(CII), which is defined as the temperature difference between the green space and its surrounding built-up areas, shows time variations. A through-year measurement(2008-2009) of ground level air temperature revealed seasonal variation and relationship to the atmospheric condition of CII. The temperature variation in the park and the reference downtown Daegu was as same order as CII. The noontime CII is larger in summer than that in winter due to the leaf fall of the park trees. On the other hand, seasonal variation of nighttime CII is not so clear. The nighttime CII was larger under the stable atmosphere.

To examine the trend on the flowering time in some weather flora including Prunus serrulata var. spontanea, Cosmos bipinnatus, and Robinia pseudo-acacia in Busan, the changes in time series and rate of flowering time of plants were analyzed using the method of time series analysis. According to the correlation between the flowering time and the temperature, changing pattern of flowering time was very similar to the pattern of the temperature, and change rate was gradually risen up as time goes on. Especially, the change rate of flowering time in C. bipinnatus was 0.487 day/year and showed the highest value. In flowering date in 2007, the difference was one day between measurement value and prediction value in C. bipinnatus and R. pseudo-acacia, whereas the difference was 8 days in P. mume showing great difference compared to other plants. Flowering time was highly related with temperature of February and March in the weather flora except for P. mume, R. pseudo-acacia and C. bipinnatus. In most plants, flowering time was highly related with a daily average temperature. However, the correlation between flowering time and a daily minimum temperature was the highest in Rhododendron mucronulatum and P. persica, otherwise the correlaton between flowering time and a daily maximum temperature was the highest in Pyrus sp.

본 연구에서는 우리나라의 자연 계절의 분포와 변화 경향을 분석하고자 하였다. 1975~2004년의 기간에 대해 국내 68개의 기상청 지상 관측소의 일 평균 기온 자료를 분석한 결과, 대체로 남부 지방으로 갈수록 봄ㆍ가을ㆍ여름 기간은 길어지고, 겨울의 기간은 짧아지나 지리적 특성에 따라 지역적으로 비교적 큰 차이를 보인다. 내륙과 해안을 비교했을 때 해안에 비해 내륙은 겨울의 지속 기간이 길다. 산간 지방의 경우에는 해발고도의 영향으로 여름 기간이 짧고 겨울 기간이 더 길다. 계절의 시기는 대체적으로 여름의 시작은 일러지고 끝은 늦어지며, 그 결과로 전반적으로 여름 기간이 증가하는 경향이다. 겨울은 시작이 늦어지며 끝이 급격히 일러져 겨울 기간이 감소하는 경향이다.

The purpose of this study is to clarify the characteristic of urban heat island intensity in urban area formed at a basin. Thermal environments for basin-type cities are influenced by significant topographic relief winds. In this study, we analyzed the diurnal variations of the heat island intensity according to meteorological condition and season using AWS(Automatic Weather observation System) data in Daegu Metropolitan area for 1 year(3/April, 2003 ～ 2/April, 2004). In this study, we defined the urban heat island intensity as the air temperature difference between two points, the downtown and the suburban area. The suburban area is located at valley mouth around the western tip of Daegu. The results are summarized as follows; 1. The maximum heat island intensity was recorded at early morning under the meteorological conditions, calm and clear 2. The heat island intensity was strong in the order of winter, fall, spring and summer. 3. The heat island intensity came out minus values in the afternoon. This phenomenon is known as a common for basin-type cities. 4. The heat island intensity was twice or more in clear and calm than not so.

The purpose of this study is to analyze seasonal changes in structure and landscape of Gongji stream corridor in Chuncheon, and to suggest some guidelines to contribute to creating a desirable close-to- nature stream. The study seasonally surveyed floodplain and revetment conditions, channel micro-topography, streamflow level and velocity, and vegetational cover. Flooding, water level, and vegetation were major factors of affecting seasonal changes in streambed structure and stream landscape. Small sand bars and islands were considerably disturbed by flooding and water level change. However, large islands and sand bars in the upper and middle section of the study stream remained or reappeared even after flooding. Flooding also tended to repeat channel sedimentation at the same spot. Controlling water volume of the Euiam Lake, which is adjacent to the study stream, caused higher water level downstream in the dry seasons. The majority of vegetation in sand bars and islands was washed away by the floods. Vehicle passing, crop cultivation, and ball game were other elements which disturbed vegetation in the floodplain. Creating a close-to-nature stream should reflect micro-topographical changes of channel by flooding, prevent improper vehicle entry and human use, and remove concrete material in the revetment and floodplain.

새만금간척지역은 동경 와 북위 위치하고 있다. 새만금간척지역은 대조차가 5.6m 이고 최대 조유속은 이다. 조간대 침전물의 대부분은 금강, 만경, 동진강으로부터 유입되고 있다. 이 지역의 저질은 실트질 모래로 구성되어 있다. 동절기의 바람은 북서풍이 우세하다. 새만금간척면적은 40,100ha 이고 방조제의 길이는 33km이다. 본 연구의 목적은 강 진단모델과 예보모델에 의하여 간척전 후의 잔차류의 계절변화를 규명하는 것이다.

The traffic accidents in large cities such as Pusan metropolitan city have been increased every year due to increasing of vehicles numbers as well as the gravitation of the population. In addition to the carelessness of drivers, many meteorological factors have a great influence on the traffic accidents. Especially, the number of traffic accidents is governed by precipitation, visibility, humidity, cloud amounts and temperature, etc. In this study, we have analyzed various data of meteorological factors from 1992 to 1997 and determined the standardized values for contributing to each traffic accident. Using the relationship between meteorological factors(visibility, precipitation, relative humidity and cloud amounts) and the total automobile mishaps, an experimental prediction formula for their traffic accident rates was seasonally obtained at Pusan city in 1997. Therefore, these prediction formulas at each meteorological factor may be used to predict the seasonal traffic accident numbers and contributed to estimate the variation of its value according to the weather condition in Pusan city.

국립수산진흥원의 한국 연안 어장환경 오염조사 결과 보고서를 사용하여, 인천 연안역의 수온 및 염분의 계절변화의 특성을 살펴 보았다. 수온의 연변화는 인천항과 소래에 이르는 조간대 해역이 만의 바깥쪽 해역보다도 수온의 연평균이 높고, 진폭도 크며, 위상도 빨랐다. 염분의 연변화는 인천항과 소래에 이르는 조간대 해역이만의 바깥쪽 해역보다도 연평균은 낮고, 진폭은 크며, 위상은 느리게 나타났다. 이러한 특성은 T-S도를 이용하여 나타낸 수괴의 계절 변화에서도 뚜렷하게 볼 수 있었다. 즉, 인천 연안역의 수괴는 수온과 염분의 연교차가 큰 인천과 소래에 이르는 조간대 해역과 염분 변동에 영향을 주는 강수나 증발, 담수 유입의 계절적 변화에 비교적 영향을 적게 받는 만의 바깥쪽 해역으로 구분할 수 있었다. 또한 얕은 수심과 강한 조류로 인하여 수층이 연중 거의 혼합된 분포를 보이고 있었다.