• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.3
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• pp.233-241
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• 2020

We examined long-term variations in sea surface temperature (SST) and annual amplitudes of SST around the Korean Peninsula. Two SST data sets with data periods of approximately 51 years and longer than 100 years, respectively, were obtained from the National Institute of Fisheries Science and Japan Meteorological Agency. SST of Korean waters clearly increased during last 51 years (1968-2018), which was 2.5 times higher than the global trend. This significant increasing trend was caused by the dominant increasing SST trend during winter. However, a negative and positive SST anomaly frequently appeared during winter and summer, respectively, in a recent decade. These features of seasonal SST variation have changed the annual amplitude of SST, and resulted in a drastically increasing trend after 2009. Using the longer SST data set, it was revealed that the decreasing SST trend in winter began in the 2000s and the increasing SST trend in summer bagan in the 1990s. During a recent decade, there was a distinctive SST increase in summer, whereas a clear decrease in winter. In summary, the annual amplitude of SST around the Korean Peninsula significantly changed from a decreasing trend to an increasing trend during a recent decade.

• 한국해양학회지
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• v.20 no.1
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• pp.22-30
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• 1985

The mean sea level(MSL) along the coast of Korea is high in summer and low in winter, mainly due to the inverse barometric effect and the steric departure. The MSL associated with the inverse barometric effect is spatially uniform and has an amplitude of 8.5$\pm$0.8cm. The thermal departure, with amplitude of 4~8cm, is most dominant in the Yellow Sea. The MSL in the South Sea of Korea is strongly affected by the haline departure, which has an amplitude up to 5cm. The annual range of MSL along the western and eastern coasts of Korea are about 40 and 20cm, respectively. The spatial inhomogeneity of the annual range of MSL arises mainly due to the influence of the Asian monsoon, which amplifies (weakens) the annual MSL along the western (eastern) coast of Korea.

• 한국해양학회지
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• v.19 no.2
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• pp.105-110
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• 1984

We study the annual variation of salinity at the sea surface and at 30m depth in the neighbouring seas of korea by the harmonic method. The analysis based on the monthly salinity data at 182 stations collected regularly by the Fisheries Research and Development Agency during 15 years (1961∼1975). The annual mean salinity in the West Sea is lower than that in the East Sea. In the amplitude of annual salinity variation decreases and the phase delays with the downstream distance of the Tsushima Current. The salinity at 30m has a higher mean, a smaller amplitude and a delayed phase than the corresponding ones at the surface. The annual variations of salinity in the South and East Seas are caused mainly by the annual variations of the local precipitation and that of the fresh water discharge from the Yangtze River.

• Fisheries and Aquatic Sciences
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• v.10 no.3
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• pp.159-169
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• 2007

The complex 2-dimensional movements of fish during an annual migration circuit were generated and simulated by a chaotic model of fish movement, which was expanded from a small-scale movement model. Fish migration was modeled as a neural network including stimuli, central decision-making, and output responses as variables. The input stimuli included physical stimuli (temperature, salinity, turbidity, flow), biotic factors (prey, predators, life cycle) and landmarks or navigational aids (sun, moon, weather), values of which were all normalized as ratios. By varying the amplitude and period coefficients of the klinokinesis index using chaotic equations, model results (i.e., spatial orientation patterns of migration through time) were represented as fish feeding, spawning, overwintering, and sheltering. Simulations using this model generated 2-dimesional annual movements of sea bream migration in the southern and western seas of the Korean Peninsula. This model of object-oriented and large-scale fish migration produced complicated and sensitive migratory movements by varying both the klinokinesis coefficients (e.g., the amplitude and period of the physiological month) and the angular variables within chaotic equations.

• Journal of the Korean Geographical Society
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• v.48 no.4
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• pp.497-508
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• 2013

The objective of this study is to determine the spatiotemporal influences of climatic factors and atmospheric aerosol on phenological cycles of the Korea Peninsular on a regional scale. High temporal-resolution satellite data can overcome limitations of ground-based phenological studies with reasonable spatial resolution. Study results showed that phenological characteristics were similar among evergreen forest, deciduous forest, and grassland, while the inter-annual vegetation index amplitude of mixed forest was differentiated from the other forest types. Forest types with high VI amplitude reached their maximum VI values earlier, but this relationship was not observed within the same forest type. The phase of VI, or the peak time of greenness, was significantly influenced by air temperature. Aerosol optical thickness (AOT) time-series showed strong seasonal and inter-annual variations. Generally, aerosol concentrations were peaked during late spring and early summer. However, inter-annual AOT variations did not have significant relationships with those of VIs. Weak relationships between AOT amplitude and EVI amplitude only indicates that there would be potential impacts of aerosols on vegetation growth in the long run.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2818-2826
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• 2010

To study the spatial and temporal variations of sea surface temperature(SST) in the Northeast Asia sea during the period of 1985 to 2009. At first, the buoy data from Korea Meteorological Administration(KMA) and the satellite data have been matched up eight points. The root mean square error and the bias were increased towards the coastal shallow region. The study area which is divided 7 regions from Japan Meteorological Agency(JMA). We analyzed NOAA/AVHRR data by harmonic analysis which is comparison and analysis the center of the each regions. The mean SST varied between $8^{\circ}C$ to $26.0^{\circ}C$. The annual amplitude varied between $7^{\circ}C$ to $24^{\circ}C$. And the annual phase varied between end of July to end of August. Cross-correlation coefficients of mean SST, annual amplitude, and annual phase varied 0.57 to 0.85, -0.04 to 0.81 and 0.35 to 0.80 at all study area, respectively.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.13 no.1
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• pp.7-13
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• 2017

In order to use and manage the building energy efficiently, it is necessary to minimize building energy consumptions, and establish operation plans of various equipment. The maximum heating and cooling load calculation is an essential way in various equipment selections, and the annual building load calculation is used in forecasting & evaluating the LCC required for operation plan. In this study, noting that the annual building load changes depending on outside temperature around year, we propose a predicting method of annual building load. By using the $4^{th}$ polynomial function that have two double radix and a feature the $f(x)=a^4$ in x = 0 condition, we can calculate annual building load very easily only with the two result (maximum heating and cooling load) and a minimum parameters.

• Ocean and Polar Research
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• v.28 no.4
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• pp.415-423
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• 2006

Interannual variation and long-term trends of coastal sea surface temperature (SST) in Korea were investigated by analyzing 27 coastal SST time series from 1969 to 2004. Long-term linear increasing trend was remarkable with the rate over $0.02^{\circ}C/year$ at almost all the stations. The slope of long-term linear trend was larger at the stations along the eastern coast than in the western and southern regions. It was also noticeable that there was a common tendency of interannual variability with the period of 3-5 years at most of the stations. SST was lower in the 1970's and early 1980's while it was higher in the 1990's and early 2000's after the increase in the late 1980's. The pattern of the interannual variability of SST was similar to that of air temperature. Increasing trend of minimum SST in winter was obvious at most stations na it was larger along the eastern coast, while the linear trend of maximum SST in summer was less definite. Therefore, the decreasing tendency of annual amplitude was mainly due to the increasing tendency of SST in winter.

• The Korean Journal of Ecology
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• v.17 no.4
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• pp.513-521
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• 1994

Distribution patern of 30 species that are occurring predominantly in the mantle communities (Mantelgesellschaften) in South Korea was studied. The study was arried out by geographic and bioclimatic analysis on 368 releves obtained from the Zurich-Montpellier School's method, which involves direct analysis on the latitude, altitude, annual mean temperature and the lowest temperature of the site. Rosa multiflora and Pueraria thunbergiana which are regarded as repersentative pioneer species to the mantle community has the highest frequency, 70.1% and 60.3%, respectively. Three distribution patterns were recognized, i.e. northern type, central type and southern type, and each type was characterized by horizontal and altitudinal amplitude. Their concetrate distribution ranges on the annual mean temperature were 8~11℃, 9~12℃ and 10~13℃, respectively. It was recognized that tendencies of overlapping and continuous distribution pattern of the types and species exist. Geographically, the souther limit f the northern type is 35.5。N and the northern limit of the southern type 37.0。N. The central type is located at an coincided with the previous study in which cool-temperate forests were synchorologically indentified into northern/altimontane, certral/montane and southern/submontane type. The subsidiary knowledges from this study will provide practical information on the constructuin of the fence plant community for environmental conservation.

• 한국해양학회지
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• v.22 no.2
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• pp.71-79
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• 1987

We studied the annual variation of water temperatures in the upper 200m off southeast coast of Korea by means of harmonic analysis of the temperatures at 10 standard depths of 51 stations. The distributions of the mean temperature in coastal zone are almost parallel to the coast, whereas those in offshore are almost zonal. With an increase of depth, the annual amplitude decreases nearly exponentially and the annual phase increases nearly linearly. The average e-folding depth for the annual amplitudes is 65m, vertical change of the annual phase is 180 per 200m, and the vertical eddy conductivity is $4\textrm{cm}^2/sec$. Annual variations of temperatures in the coastal zone of a few tens miles from the coast are considerably different from those in offshore area. The e-folding depths in coastal zone are shallower than those in offshore region, and the changes of phase with depths in coastal zone are smaller than those in offshore region.