• 제목/요약/키워드: Sea level observation

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Status of Observation Data at Ieodo Ocean Research Station for Sea Level Study

  • Han, MyeongHee
    • 한국지구과학회지
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    • 제41권4호
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    • pp.323-343
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    • 2020
  • Observation data measured at Ieodo Ocean Research Station (IORS) have been utilized in oceanographic and atmospheric studies since 2003. Sea level data observed at the IORS have not been paid attention as compared with many other variables such as aerosol, radiation, turbulent flux, wind, wave, fog, temperature, and salinity. Total sea level rises at the IORS (5.6 mm yr-1) from both satellite and tide-gauge observations were higher than those in the northeast Asian marginal seas (5.4 mm yr-1) and the world (4.6 mm yr-1) from satellite observation from 2009 to 2018. The rates of thermosteric, halosteric, and steric sea level rises were 2.7-4.8, -0.7-2.6, 2.3-7.4 mm yr-1 from four different calculating methods using observations. The rising rate of the steric sea level was higher than that of the total sea level in the case with additional data quality control. Calculating the non-steric sea level was not found to yield meaningful results, despite the ability to calculate non-steric sea level by simply subtracting the steric sea level from total sea level. This uncertainty did not arise from the data analysis but from a lack of good data, even though tide, temperature, and salinity data were quality controlled two times by Korea Hydrographic and Oceanography Agency. The status of the IORS data suggests that the maintenance management of observation systems, equipment, and data quality control should be improved to facilitate data use from the IORS.

회귀모형에 의한 서해안 평균해면의 연시계열자료의 평가 (The Evaluation of the Annual Time Series Data for the Mean Sea Level of the West Coast by Regression Model)

  • 조기태;박영기;이장춘
    • 한국환경과학회지
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    • 제9권1호
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    • pp.19-25
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    • 2000
  • As the tideland reclamation is done on a large scale these days, construction work is active in the coastal areas. Facilities in the coastal areas must be built with the tide characteristics taken into consideration. Thus the tide characteristics affect the overall reclamation plan. The analysis of the tide data boils down to a harmonic analysis of the hourly changes of long-term tide data and extraction of unharmonic coefficients from the results. Since considerable amount of tide data of the West Coast are available, the existing data can be collected and can be used to obtain the temporal changes of the tide by being fitted into the tide prediction model. The goal of this thesis lies in assessing whether the mean sea level used in the field agrees with the analysis results from the long-term observation data obtained with their homogeneity guaranteed. To achieve this goal, the research was conducted as follows. First the present conditions of the observation stations, the land level standard, and the sea level standard were analyzed to set up a time series model formula for representing them. To secure the homogeneity of the time series, each component was separated. Lastly the mean sea level used in the field was assessed based on the results obtained form the analysis of the time series.

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미역과 다시마 가루를 첨가한 케이크의 물리화학적 및 관능적 특성 (Physico-chemical and Sensory Characteristics of Cakes Added Sea Mustard and Sea Tangle Powder)

  • 송영선;안정미
    • 한국식품영양과학회지
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    • 제28권3호
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    • pp.534-541
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    • 1999
  • This study was undertaken to examine the effect of sea tangle and sea mustard on physiochemical and sensory characteristics of cakes and the possibility commercialization of these functional cakes. The moisture contents of cakes prepared with sea tangle and sea mustard were higher than those of control, and a positive correlation between water holding capacity(WHC) and moisture contents was observed(r=0.836). As addition level of sea tangle and sea mustard was increased, volume of cakes were decreased, whereas hardness was increased slightly and color became deep. Hardness was strongly correlated to the volume of cakes(r= 0.914). Visual observation by photomicrography showed that, as addition level of sea mustard and sea tangle was increased, formation of air cells were prohibited and thus volume of cakes was decreased. The microstructural observation by scanning electron microscopy(SEM) showed that air cells of cakes were well developed up to 5% addition of sea tangle powder. As a result of the sensory evaluation for the cakes prepared with sea tangle and sea mustard, no significant difference was observed between control and those addition levels up to 5%. Flavor was proved to be the most important factor in determining overall acceptability and hedonic hardness score was inversely correlated to the objective hardness value(r= 0.853).

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해풍 효과에 의한 저층대기구조 변화의 측정 (Observation on Structural Change of Low Level Atmosphere due to Effect of Sea Breeze)

  • 전병일;김유근
    • 한국환경과학회지
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    • 제5권4호
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    • pp.441-451
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    • 1996
  • The surface meteorological and upper layer meteorological observation carried out to investigate influences of sea breeze effect on lower layer atmosphere at Gori nuclear power plant for 29∼30 July, 1996. According to surface meteorological data, the inflow of sea breeze was occurred 11:30 on 29 July, 10:30-on 30 July, respectively, at observation site. And the meteorological tower data showed that wind direction of sea breeze was identified as south-westerly, and wind speed of 58 m was 2 times stronger than that of 10 m. It is notworthy that surface inversion layer which built from the night time to daybreak of next day was not broken off by seab reeze's inflow for daytime, and strong inversion layer observed at 47∼243 m with moderately stable class (F) by URC. It was found that strong stable layer of potential temperature appeared at that layer, maximum relative humidity observed at the bottom of inversion layer and maximum mixing ratio observed in the low of inversion layer.

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한국연안해역에서의 해면수위의 변동에 관한 연구 (A Study on the Sea Level Variations in Korean Coastal Area)

  • 이경연;김동수;손창배;김창제
    • 해양환경안전학회지
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    • 제5권1호
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    • pp.19-27
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    • 1999
  • This paper is to estimate the long and short term variations of mean sea level in Korean coastal waters by identifying interrelations among the mean sea level, atmospheric pressure and air temperature along the coast. For this, long-term tidal data observed at tidal and weather observation stations were brought into a statistical analysis. It was noted that, in a general sense, an inverse relationship exists between the sea level and the atmospheric pressure and a positive relationship between the sea level and air temperature, respectively. The maximum difference of monthly mean sea level was in the range of 21 to 25 cm at the eastern and southeastern coasts, meanwhile more than 30 cm being in both in southern and western coasts. It was also noted that mean sea level continues to rise in a long-term basis. Long-term variation of mean sea level trends to rise 0.10 ∼ 0.44 cm per year for each region. However, the long-term variation of mean sea level in the isolated islands shows a different trend, Ullngdo being 0.41 cm fall per year and Chejudo being 0.44 cm rise per year.

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VULNERABILITY OF KOREAN COAST TO THE SEA-LEVEL RISE DUE TO $21^{ST}$ GLOBAL WARMING

  • 조광우;맹준호;윤종휘
    • 해양환경안전학회:학술대회논문집
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    • 해양환경안전학회 2003년도 추계학술발표회
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    • pp.219-225
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    • 2003
  • The present study intends to assess the long-term steric sea-level change and its prediction, and potential impacts to the sea-level rise due to the 21st global warming in the coastal zone of the Korea in which much socioeconomic activities have been occurred. The analysis of the 23 tide-gauge data near Korea reveals the overall mean sea-level trend of 2.31 mm/yr.In the satellite altimeter data (Topex/Poseidon and ERS), the sea-level trend in the East Sea is 4.6mm/yr. Both are larger than those of the global average value. However, it is quite questionable that the sea-level trends with the tide-gauge data on the neighboring seas of Korea relate to global warming because of the relatively short observation period and large spatial variability. It is also not clear whether the high trend of altimeter data in the East Sea is related to the acceleration of sea level rise in the Sea, short response time of the Sea, natural variability such as decadal variability, short duration of the altimeter. The coastal zone of Korea appears to be quite vulnerable to the 21st sea level rise such that for the I-m sea level rise with high tide and storm surge, the inundation area is 2,643 km2, which is about $1.2\%$ of total area and the population in the risk areas of inundation is 1.255 million, about $2.6\%$ of total population. The coastal zone west of Korea is appeared to be the most vulnerable area compared to the east and south. In the west of the Korea, the North Korea appears to be more vulnerable than South Korea. In order to cope with the future possible impact of sea-level rise to the coastal zone of Korea effectively, it is essential to improve scientific information in the sea-level rise trend, regional prediction, and vulnerability assessment near Korean coast.

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연직관측자료를 통한 복잡 연안지역의 오존 이류특성 (Characteristics of Ozone Advection in Vertical Observation Analysis Around Complex Coastal Area)

  • 이화운;박순영;이순환;임헌호
    • 한국대기환경학회지
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    • 제25권1호
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    • pp.57-74
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    • 2009
  • In order to clarify the vertical ozone distribution in planetary boundary layer of coastal area with complex terrain, an observation campaign was carried out around Gwangyang Bay with dense pollutant emission sources during two days from June, 4 2007. For this observation are Radiosonde, SODAR(SOnic Detection And Ranging) and Tethered ozone sonde were employed. The surface meteorological and photochemical observation data provided by AWS (Automatic Weather System) and AQMS (Air Quality Monitoring System) were also applied for analysis. Synoptic condition is strongly associated with lower level ozone distribution in complex terrain coastal area. Since mesoscale circulation induced by difference of characteristics of land and sea and orographic forcing is predominant under calm synoptic condition, vertical distribution of ozone is complicate and vertical ozone concentration greatly fluctuated. However in second day when synoptic influence become strong, ozone concentration in lower levels is vertically uniform regardless of observation level. This results in vertical observation indicates that vertical ozone distribution is often determined by synoptic condition and also affects surface ozone concentration.

Steric Sea Level Variability in the East Asian Seas estimated from Ocean Reanalysis Intercomparison Project Data

  • Chang, You-Soon;Kang, Min-Ji
    • 한국지구과학회지
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    • 제40권5호
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    • pp.487-501
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    • 2019
  • In this study, steric height variability in the East Asian Seas (EAS) has been analyzed by using ocean reanalysis intercomparison project (ORA-IP) data. Results show that there are significant correlations between ocean reanalysis and satellite data except the phase of annual cycle and interannual signals of the Yellow Sea. Reanalysis ensemble derived from 15-different assimilation systems depicts higher correlation (0.706) than objective analysis ensemble (0.296) in the EAS. This correlation coefficient is also much higher than that of the global ocean (0.441). For the long-term variability of the thermosteric sea level during 1993-2010, a significant warming trend is found in the East/Japan Sea, while cooling trend is shown around the Kuroshio extension area. For the halosteric sea level, a dominant freshening trend is found in the EAS. However, below 300 m depth around this area, the signal-to-noise ratio of the linear trend is generally less than one, which is related to the low density of observation data.

An Estimation Of Average Current Velocity In The Western Channel Of The Korea Strait From Mean Sea Level Data

  • Lee, Jae Chul;Jung, Chang Hee
    • 한국해양학회지
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    • 제12권2호
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    • pp.67-74
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    • 1977
  • With the serial observation data and the tidal records at Busan and Izuhara from 1966 to 1973, the geostrophic current velocity and its relation to the difference of mean sea level of both sides were studied in order to estimate indirectly the average current velocity from the tidal observations. The results shows that the current velocity is estimated by the relationship V=4.016(H-98.3) with the 95% confidence limits of V 4.2 cm/sec. Ther relationship between the observed current velocity and the simultaneous daily mean sea level difference shows a similar result, V=4.717(H-99.6). The two equations were applied to the evaluation of annual variations of current velocity from the average monthly mean sea level data of both stations.

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Sea Level Response in the Korea Strait to Typhoons

  • Hong, Chul-Hoon
    • Journal of the korean society of oceanography
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    • 제31권3호
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    • pp.107-116
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    • 1996
  • A shallow water numerical model is established to investigate the response of coastal water in the Korea Strait to typhoons that pass nearby the Korea Strait. Atmospheric pressure and wind by Fujita's formula (1952) and Miyazaki et al. (1961), respectively are used in the model. The model results show an agreement fair with the observation partially, but poor with the amplitude of the sea level variation. In particular, the discrepancy is larger in a typhoon passing through right side than that through left side of the Korea Strait. The model showes that the disagreement between the model and the observation can be caused by numerically unrealistic distributions of armospheric pressure and wind around the strait. In the Korea Strait the isostatic effects in the model were underestimated, whereas the wind fields were overestimated.

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