• Title/Summary/Keyword: Coastal fog

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A study on the water temperature and salinity guidelines for a military product test & evaluation in the Korean coastal seas (군수품 환경시험을 위한 한반도 해수 온도 및 염분 기준 설정에 관한 연구)

  • Kim, Youngrae;Yun, Jae-Hyeong;Na, Jae-Hyun;Kim, Jang-Eun;Kim, Si-Ok;Kim, DongGil;Hong, YeonWoong
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.4
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    • pp.811-818
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    • 2017
  • Environmental tests are used to verify a equipment that can withstand the rigors of harsh environments. In case of military products for export, the tests have to be based on the climatic data of the world. However, if the climatic data of the world is used for domestic military products, it may cause an increase in manufacture price. There is currently no climatic data that can be used as criteria for the tests in the Korean peninsula and coastal seas. Therefore, this paper suggests a water temperature and a salinity guidelines of salt fog tests for military products used in the area. As a result, we present water temperature and salinity information that is extreme and FOO of the Korean coastal seas.

The Influence of Meteorological Factors on PM10 Concentration in Incheon (기상인자가 미세먼지 농도에 미치는 영향)

  • Shin, Moon-Khee;Lee, Choong-Dae;Ha, Hyun-Sup;Choe, Choon-Suck;Kim, Yong-Hee
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.3
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    • pp.322-331
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    • 2007
  • In this study, we have analyzed $PM_{10}$ concentration measured at Incheon Regional Air Monitoring Network (10 stations) and meteorological data at Incheon Weather Station to investigate factors (i.e. wind direction, wind speed, relative humidity, major meteorological phenomenon, and sea-land breezes existence) influencing $PM_{10}$ concentration in Incheon during 2005. Statistical differences among meteorological factors were assessed by Kruskal-Wallis test or Mann-Whitney U test. The main conditions causing high $PM_{10}$ concentration are summarized below; 1. When westerly wind prevailed (however, $PM_{10}$ decreased when winds were blowing from the east or north). 2. When the winds were calm, owing to accumulation of nearby emissions under stagnant conditions, or when the wind speed is in excess of 6 m/s, which shows the effect of fugitive dust produced by wind erosion. 3. Under the condition of high relative humidity and poor diffusion based on meteorological phenomenon such as fog, mist, and haze. 4. When the Sea-Land breezes existed, which occurred 70 days in Incheon during 2005 and contributed significantly to high $PM_{10}$ concentration in the coastal urban area. In conclusion, we have found that the meteorological factors have influence on $PM_{10}$ concentration in Incheon.

A Study on the Efficient Operation of VTS in Inchon (인천항 VTS의 효율적인 운영방안에 관한 연구)

  • 김상환;박진수
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.10b
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    • pp.11-25
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    • 1998
  • Many Countries have made efforts to assist ships navigate accurately , safely and expeditiously for the safety control against increasing marine traffic , in their coastal waters. However, they are exposed in spite of these efforts,to risks of casulaties and marine polluation caused by traffic congestion when ships are navigating through waterways approaches to ports or harbors and in narrow fairways. Therefore, efficient control of VTS in Port is necessary nowadays to provide ships with necessary service , which interacts with shipping and organize the flow of traffic so as to maximize the efficiency of the port or harbor while minimizing the risk of accident and environmental pollution. Even though the navigation condition of ships is very inferior compared to other ports in Korea, such as the big difference between the ebb and flood tide, the frequent fog, the narrow fairway , the density of navigation traffic in Inchon Port is high and transportation quantity of dangerous cargoe increases gradually. In cosideration of the characteristics of natural circumstance and traffic circumstance the VTS established newly in Inchon port have to operate efficiently. The purpose of this study is to help efficient operation of VTS in Inchon port by accomplishing both the literature research and questionnaire survey. Questionnaire survey was read to the VTS personnel in Inchon Port and customer familiar to Inchon Port such as ship navigators, pilots, shipping companies and so on. Most of ship navigators who occupy half of the respondents are Korean Officer who had responded while they were calling at Inchon port. The conclusions and recommendations includes ; First, the service area should be extended over Designated area to provide the vessel with navigational assistance service regarding the information of traffic congestion area, fishing boat and small ship's activities. Second, the types of information service to be offered are ship's movement and weather condition inthe vicinity of the port and state of fairway in the approaching channel to thte fairway. Third, VTS personnel should be upgraded by the on-the-job training and continuous simulation training as well as supplement of the qualified personnel for VTS operation. Fourth , the Harbor Master System to be introduced for safe navigation and efficient port operation.

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Characteristics of Aerosol and Cloud Condensation Nuclei Concentrations Measured over the Yellow Sea on a Meteorological Research Vessel, GISANG 1 (기상 관측선 기상 1호에서 관측한 황해의 에어로졸과 구름응결핵 수농도 특성 연구)

  • Park, Minsu;Yum, Seong Soo;Kim, Najin;Cha, Joo Wan;Ryoo, Sang Boom
    • Atmosphere
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    • v.26 no.2
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    • pp.243-256
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    • 2016
  • Total number concentration of aerosols larger than 10 nm ($N_{CN10}$), 3 nm ($N_{CN3}$), and cloud condensation nuclei ($N_{CCN}$) were measured during four different ship cruises over the Yellow Sea. Average values of $N_{CN10}$ and $N_{CCN}$ at 0.6% supersaturation were 6914 and $3353cm^{-3}$, respectively, and the minimum value of $N_{CN10}$ was $2000cm^{-3}$, suggesting significant anthropogenic influence even at relatively clean marine environment. Although $N_{CN10}$ and $N_{CN3}$ increased near the coast due to anthropogenic influence, $N_{CCN}$ was relatively constant and therefore $N_{CCN}/N_{CN10}$ ratio tended to decrease, suggesting that coastal aerosols were relatively less hygroscopic. In general $N_{CN10}$, $N_{CN3}$, and $N_{CCN}$ during the cruises seemed to be significantly influenced by wet scavenging effects (e.g. fog) and boundary layer height variation. Only one new particle formation (NPF) event was observed during the measurement period. Interestingly, the NPF event occurred during a dust storm event and spatial scale of the NPF event was estimated to be larger than 100 km. These results demonstrate that aerosol and CCN concentration over the Yellow Sea can vary due to various different factors.

Characteristics of Meteorological Conditions and Air Pollution in a Valley City on Bad Visibility Days of the Cold Half Year (한후기 계곡지형 내 도시 시정악화 발생일의 기상 및 대기오염 특성 분석)

  • Kang, Jae-Eun;Song, Sang-Keun;Kim, Yoo-Keun
    • Journal of Environmental Science International
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    • v.22 no.6
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    • pp.745-759
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    • 2013
  • The characteristics of meteorological conditions and air pollution were investigated in a valley city (Yangsan) on bad visibility days (from 05:00 to 09:00 LST) of the cold half year (November 2008 to April 2009). This analysis was performed using the hourly observed data of meteorological variables (temperature, wind speed and direction, relative humidity, and 2 m and 10 m temperature) and air pollutants ($NO_2$, $SO_2$, $PM_{10}$, and $O_3$). In addition, visibility data based on visual measurements and a visibility meter were used. The bad visibility days were classified into four types: fog, mist, haze, and the mixture (mist+haze). The results showed that the bad visibility days of the four types in the valley city were observed to be more frequently (about 50% of the total study period (99 days except for missing data)) than (27%) those near coastal metropolitan city (Busan). The misty days (39%) in the valley city were the most dominant followed by the hazy (37%), mixture (14%), and foggy days (10%). The visibility degradation on the misty days in Yangsan was closely related to the combined effect of high-level relative humidity due to the accumulation of water vapor from various sources (e.g. river, stream, and vegetation) and strong inversion due to the development of surface radiative cooling within the valley. On the hazy days, the visibility was mainly reduced by the increase in air pollutant (except for $O_3$) concentrations from the dense emission sources under local conditions of weaker winds from the day before and stronger inversion than the misty days. The concentrations of $NO_2$, $PM_{10}$, and $SO_2$ (up to +36 ppb, $+25{\mu}g/m^3$, and +7 ppb) on the hazy days were a factor of 1.4-2.3 higher than those (+25 ppb, $+14{\mu}g/m^3$, and +3 ppb) on the misty days.

Long-term Trends of Visibility and Air Quality in Seoul, Ganghwa, Susan, Gwangju, Jeju (서울, 강화, 서산, 광주, 제주지역에서의 장기간 대기오염 및 시정 변화경향에 대한 연구 : 1990년 1월~2001년 7월)

  • Han, J.S.;Moon, Kwang-Joo;Kong, B.J.;Hong, Y.D.;Lee, S.J.;Shin, J.Y.
    • Journal of Environmental Impact Assessment
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    • v.13 no.4
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    • pp.197-211
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    • 2004
  • Visibility impairment was known as an indicator of the increased air pollution. In many previous studies, it is known that both directly emitted fine particles mainly from vehicles and secondary aerosols from photochemical reactions could contribute to this visibility impairment in addition to the meteorological condition. Furthermore, the visibility showed different change patterns according to the geographical condition. In order to research into the influence of these factors on visibility, this study analyzed the visibility at 15:00, observed from 1990 to 2001 in Seoul, Ganghwa, Susan, Gwangju, Jeju. As a result, the visibility was increased in Seoul except the rainfall period, but in Susan, Gwangju, Jeju, it decreased with the relative humidity (RH). Especially, in Seoul, the number of low visibility days was larger than other sites and variations of the visibility were sensitive to the concentration of air pollutants, such as TSP, $NO_2$, $O_3$. The visibility impairment was mainly observed in meteorological condition of RH<50% and relatively stationary front. Therefore it is inferred that photochemical smog could lead to the low visibility in Seoul. On the other hands, in Ganghwa and Susan, when RH was 60~70%, the low visibility observed under the influence of the transports of air pollutants from nearby cities as well as humid air mass from coastal region. And in Jeju, sea fog and humid air mass caused the visibility impairment when the RH was larger than 80%. Finally, during the observational period, some cases of low visibility phenomena were simultaneously observed in the vast region including Seoul, Susan, Ganghwa. It not only includes the visibility aggravation by Asian Dust, but also could be caused by the movement and diffusion of flying dust or secondary aerosols. Moreover, the result shows that these phenomena could be mainly influenced by meteorological factors covering the wide regions.