Joon-Soo Lee

Study on the Climate Change and the Urbanization Effect in Busan

Abstract This study examines the climatological variability of urban area and the increase of temperature by urbanization using the observed data of Busan and Mokpo during the last 100 years (1910 ∼ 2010). The results are as follows. First, the maximum temperature in Busan during the last 100 years has increased by 1.5 ℃ while average temperature and the minimum temperature have increased by 1.6 ℃ and 2 ℃ . In Mokpo, the maximum temperature and average temperature have increased by 1 ℃ and the minimum temperature has increased by 0.8 ℃ . The increase of urban temperature appeared to be higher in Busan than in Mokpo by 0.5 ℃∼ 1.2 ℃ . Second, as for the change in temperature before and after urbanization, the maximum temperature, average temperature and the minimum temperature during last 50 years compared to the previous 50 years have increased about 1.5 ℃ , 1.6 ℃ and 2.1 ℃ , however, the predicted temperature after removing urbanization effect was estimated to be increased by 1 ℃ . The proportion that urbanization takes on the overall increase of temperature appeared to be 33% at the maximum temperature, 37.5% at average temperature and 52.3% at the minimum temperature, thus the proportion of urbanization appeared to be maximized at the minimum temperature.

A study on the Characteristics of Urban Dryness in Busan

It is well known that urban relative humidity has continuous decreasing trend owing to the influence of urbanization. The change of relative humidity is directly influenced by two factors, namely, temperature effect and water vapor effect in various urban effects. In this study, the temperature and tile water vapor effects on the relative humidity change were analyzed by using monthly mean relative humidities for a long period() in Daegu and Chupungnung. The major results obtained in this study can be summarized as follows. Firstly, the urban dryness was caused mainly by water vapor effect in summer. But, for the other seasons, the urban dryness is mainly due to the temperature effect. Secondly, the relative humidity in Daegu is on the decrease until now. This phenomenon is similar to another Korean huge cities such as Seoul, Daejeon and Incheon. But, it is different compared with Japanese huge cities such as Tokyo, Osaka and Nagoya, indicating a standstill in relative humidity change after 1980s.

A Study on the Thermal Characteristics of Midsummer in Daegu Metropolitan Area

This study aims to examine the actual status of the urban heat island in Daegu by analyzing the data of 17 automatic weather stations installed in the Daegu area. And the results can be summarized as follows: First, regarding the temperature distribution in Daegu by summer time zones, for the 31 days(August 1st till 31st), 18 days showed daily maximum temperature over 30 , and 11 days indicated daily minimum temperature over 25 . The day that showed the highest daily maximum temperature was August 5th, which indicated 36 . Second, about the spatial distribution of time ratio exceeding 30 and 25 , the area with the highest time ratio exceeding 30 is mostly the downtown(central area), eastern area, and northern area. Meanwhile, regarding the time ratio exceeding 25 , the downtown area centering around the central area were high as over 70 , and the outskirts were low as under 65 . Third, considering the temporal distribution of daily maximum temperature and daily minimum temperature, daily maximum temperature was shown around 14:00 to 15:00 while the daily minimum temperature was indicated around 17:00 to 18:00. Daily maximum and minimum temperature were appeared at northeast and downtown, respectively. Fourth, regarding the spatial distribution of tropical days and tropical night days, tropical days showed 77 and tropical night days indicated 42% before and after the 24th and also the 13th each. Tropical days were occurred up to 24 days at northeastern area. And the southwestern area of Daegu showed under 22 days. The downtown showed the 14 days of the tropical night. However, the outskirts indicated relatively few days as under 10 days. Fifth, about the spatial distribution of the average daily temperature range (the difference between the highest temperature and lowest temperature), the central area, the central part of the city, showed the smallest as 7.2 , and as it was closer to the northern area, it became larger, so in the eastern and northern area, it was over 8.8 or so.

Characteristics of Variation of Sea Surface Temperature in the East Sea with the Passage of Typhoons

In this study, the wind direction and the wind speed of the nearest temperature observations point of the National Weather Service was analyzed in order to investigate the rapid rise and drop of water temperature in the East Coast appeared after passing of the 2015 typhoon No. 9 and 11. Then the figures were simulated and analyzed using the WRF(weather research and forecast) model to investigate in more detailed path of the typhoon as well as the changes in the wind field. The results were as follows. A sudden drop of water temperature was confirmed due to upwelling on the East coast when ninth typhoon Chanhom is transformed from tropical cyclones into extra tropical cyclone, then kept moving eastwards from Pyongyang forming a strong southerly wind after 13th and this phenomenon lasted for two days. The high SST(sea surface temperature) is confirmed due to a strong northerly wind by 11th typhoon Nangka. This strong wind directly affected the east coast for three days causing the Ekman effect which transported high offshore surface waters to the coast. The downwelling occurred causing an accumulation of high temperature surface water. As a results, the SST of 15m and 25m rose to that of 5m.

Analysis of Long-term Oceanic Data for the Prediction of Undaria pinnatifida Aquaculture Production off the Coast of Busan

미역(Undaria pinnatifida)은 갈조식물문 다시마목 미역과에 속하는 해조류로서 동아시아지역의 주요 양식 종으로 활성화 되어 있는 해조류이다. 우리나라에서는 1970년대부터 미역 양 식산업이 활발히 이루어지고 있으며, 총 해조류 양식의 약 48% 정도를 차지하고 있다(Park et al., 2008). 부산연안에서도 해조 류 양식이 활발히 이루어지고 있으며 주요 양식종인 김, 미역, 다시마 양식의 생산량은 국내 총 생산량의 5.9%를 차지하고 있 으며, 품종 별로는 미역 7.1%, 김 6.7%, 다시마 3.1%를 차지하 고 있다(Gijang Gun Office, 2012). 각 해조류 양식종별 생산액 의 국내 비율을 살펴보면, 김은 6.0%, 미역은 18.7%, 다시마는 13.1%를 차지하고 있어, 특히 미역양식은 생산량에 비하여 생 산액이 전국 비율의 2.5배 이상 높아 품질 좋은 미역생산이 이 루어지고 있음을 시사하고 있다. 부산연안에서 이루어지고 있 는 미역생산의 시기를 살펴보면 일반적으로 조기산 미역양식에 서 후기산 건조용 미역까지 주로 9월 중순 이후에서 이듬해 4월 까지 미역양식이 활발히 이루어지고 있으며, 9월 중순-12월까 지는 조기산 물미역을 양성하여 10-12월에 수확을 하며, 11월 에서 이듬해 3월까지는 후기산 물미역 및 건조용 미역을 양성 하여 주로 이듬해 1-3월 사이에 수확을 한다. 또한 12월에서 이 듬해 4월까지 양성하는 후기산 건조용 미역의 경우 수확은 이 듬해 1-4월 사이에 이루어지고 있다(Gijang Gun Office, 2012). 해조류의 성장 및 생육에는 다양한 해양, 기상 요소가 작용 을 하는 것으로 알려져 있으며(Lobban and Harrison, 1994; Dring, 1982, Dawes, 1981), 우리나라의 다양한 연구에서도 수 온, 광도, 파고 등이 중요한 원인으로 알려져 있다(Nam, 1986; Koh et al., 1989; Koh and Sung, 1983; Nam et al., 1996). 특 히, 수온과 해조류 양식과는 밀접한 관련이 있는 것으로 알려져 있으며 김 생산량과 수온 등 환경과의 해역 별 상관성에 관한 연구는 다양하게 수행되어 왔다(Lee, 1988; Hong et al., 1987; Jang et al., 1983). 부산연안에서 미역 생산량과 수온과의 상관

Analysis of Correlation between the Cause of Urbanization and Urbanization Effect of Busan by Using Daily Minimum Temperatures

This study examined urbanization effects and the causes of urbanization, urban population growth, increase of the city scale, land cover change, and human cultures and economic activities, using the daily minimum temperatures of the past 50 years (1961-2010) with the subject of Busan and analyzed correlations between urbanization effects and the causes of urbanization. Thereby, this paper drew a conclusion as below: 1) Due to the urbanization effects, the average annual daily minimum temperature increased as about ; however, except for the factor of urbanization, the increase was shown as about . The occupancy of urbanization effects in the total temperature increase was quite high as about 83%. 2) Just like other cities experiencing urbanization, Busan, too, sees population growth and the expansion of city area as well as increased urbanization effects. First of all, correlation between population growth and urbanization effect was high as 0.96 before 1985 while it was lowered as 0.19 after 1985. Also, correlation between the increase of city area and urbanization effect was high as 0.64 and 0.79 before and after 1985. 3) Regarding the correlation between long-term land use change and urbanization effect, urbanization effect was affected greatly by the increase of city area (0.97) and reduction of green area (0.92). 4) Concerning human activities possible to affect the climatic factors of a city, this paper found the following factors: road length, car increase, power use, and the consumer price index, etc. And regarding the correlation between the three factors and urbanization effect, the correlation was higher in the consumer price index (0.97), the number of registered cars (0.89), power use (0.75), and road length (0.58) in order.

An Evaluation of Atmospheric Environmental Capacity in Daegu

This study aims to implement the modeling of selected substances for the evaluation of Atmospheric Environmental Capacity by means of the data of 2006 atmospheric pollution substance emissions. As a result, it turned out that the substance with the concentration higher than Atmospheric Environmental standard concentration was NO2, and 17.6% of the total regions researched turned out to exceed the standard concentration. In addition, set was the targeted amount to be reduced in the areas where the upper limit of emission per unit lattice was exceeded, and the model was adopted accordingly. As a result, it turned out that about 80% of the actual emission should be reduced to meet the 2006 Atmospheric Environmental standard over the Daegu. In reality, it is impossible to reduce 80% of the actual emission. Thus, the same ratio of reduction was applied in all of the Daegu regions, and the modeling was applied. The results are as follows: When 30% was reduced, the level went down to 50 ppb, which is as high as 2006 Atmospheric Environmental standard; when 50% was reduced, the level went down to 30 ppb, which is as high as 2007 Atmospheric Environmental standard.

Development of Real-time Oceanographic Information System for Long Line Hanging Aquaculture Farm and Temperature Variation in the Coastal Area of the East Sea

Abstract Mass mortalities of cultivated organisms have occurred frequently in Korean coastal waters causing enormous losses to cultivating industry. The preventive measures require continuous observation of farm environment and real-time provision of data. However, line hanging aquaculture farm are generally located far from monitoring buoys and has limitations on installation of heavy equipments. Substituting battery pack for solar panels and miniaturizing size of buoy, newly developed system can be attached to long line hanging aquaculture farm. This system could deliver measured data to users in real-time and contribute to damage mitigation and prevention from mass mortalities as well as finding their causes. The system was installed off Gijang and Yeongdeck in Korea, measuring and transmitting seawater temperature at the sea surface every 30 minutes. Short term variation of seawater temperature, less than one day, in Gijang from June to July 2009 corresponded tidal period of about 12 hours and long term variation seemed to be caused by cold water southeast coast of Korea, particularly northeast of Gijang. Seawater temperature differences between Gijang station and the other station that is about 500 m away from Gijang station were 1 ℃ on average. This fact indicates that it is need to be pay attention to use substitute data even if it is close to the station. Daily range of seawater temperature, one of crucial information to aquaculture, can be obtained from this system because temperature were measured every 30 minutes. Averages of daily range of temperature off Gijang and Yeongdeok during each observation periods were about 2.9 ℃ and 4.7 ℃ respectively. Dominant period of seawater temperature variation off Yeongdeok was one day with the lowest peak at 5 a.m. and the highest one at 5 p.m. generally, resulting from solar radiation.Key Words :Long line hanging, Aquaculture farm, Oceanographic information, Real-time, Temperature variation, East Sea