Myung-Hee Park

Evaluation of Mitigation Effect of Upo-Swamp on the Air temperature Variation with Nighttime Cooling Rate

In this study, we investigated the effects of Upo-swamp upon local thermal environment with nighttime cooling rate. To do this, we set up the AWS(Automatic Weather observation System) over the central part of Upo-swamp on the early October 2007. We conducted the study by comparing the AWS data with another weather data observed by several meteorological observations of the Korea Meteorological Administration located at the vicinity of Upo-swamp for one year. The air temperature of Upo-swamp was higher than that of the surrounding in cold-climate season. But it was opposite in warm-climate season. We confirmed that Upo-swamp roles to mitigate the daily and annual air temperature ranges. And the daily air temperature variation of Upo-swamp lagged behind the land one. This phenomenon represent that the heat reservoir capacity of Upo-swamp is much larger than that of the ground.

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.

Sensitivity Analysis of Air Pollutants Dispersion Model in the Road Neighboring Area Due to the Line Source -The Object on ISCST3, CALINE4 Model-

The air pollutant emission is mainly caused by line sources in urban area. For example, the annually totaled air pollutant emission is known to consist of about 80% of line sources in Daegu. Hence, the appropriate assessment on the air pollutants of line sources is very important for the atmospheric environmental management in urban area. In this study, we made a comparative study to evaluate suitable dispersion model for estimating the air pollution from line sources. Two air pollution dispersion models, ISCST3 and CALINE4 were the subject of this study. The results were as follows; In the assessment of air pollution model, ISCST3 was found to have 4 times higher concentration than CALINE4. In addition, actual data obtained by measurement and estimated values by CALINE4 were generally identical. The air pollution assessment based on ISC3 model produced significantly lower values than actual data. The air pollution levels estimated by ISCST3 were very low in comparison with the observational values.

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 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.

An Observational Study of Parked Cars` Effect in the Sunshine on the Increase of Air Temperature

This study investigated the effect of parked cars in the sunshine on the increase of air temperature on a sunny day. Air temperatures were determined both from inside of the parked cars and the top surface of the vehicle at which one car was parked under the sunshine and the other in the shade for the duration of 27 hours. The surface temperatures of asphalt and bare soil were simultaneously measured in both locations, sunshine and shade areas, along with a couple of meteorological factors. The sensible heat fluxes from the surfaces of asphalt, bare soil and two vehicles were estimated by utilizing those observed data. The results are as follows; 1) The surface temperatures of bare soil, asphalt and two vehicles increased with respectively during the day. 2) The sensible heat fluxes were noticeably higher from the top surface of the parked vehicle in the sunshine than from the asphalt or bare soil. The differences of sensible heat fluxes between the vehicle`s roof and the other two surfaces of asphalt and bare soil were 60 (asphalt) and 85 (bare soil) during the daytime.