• Korean Journal of Remote Sensing
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• v.17 no.3
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• pp.219-230
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• 2001

The daytime and nighttime sea surface temperature (SST) differences and their seasonal variabilities in the East Sea were studied using Argos drifters data during 1996~1999. The SST differences for 1,438 data set were derived from 30 Argos drifters related to the NOAA satellite-based location and data collection system. The horizontal variation of SST differences in summer in the East Sea were higher than those in winter. The relationship between the SST differences and the half day moving distances of Argos drifters was studied. Monthly SST difference in the northern and southern part of 38$^{\circ}$N in the East Sea was considered. The SST differences derived from NOAA-14 satellite were compared with those from Argos drifter between daytime and nighttime in the turbulent eddy off Wonsan coast of Korea.

• Proceedings of the KSRS Conference
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• 2000.04a
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• pp.13-18
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• 2000

We observed sea level variation of the long time at Kerguelen island in the South Indian Ocean with ARGOS data and meteorological data during about 1 year(May 1993~March 1994) through using filter, spectral analysis, coherency and phase, and found characteristics for the two oceanic signal levels(detided oceanic signal level, h$_{detided}$ and seasonal oceanic level, h$_{corr.ib}$). The forms of variations are very well agreed to between ARGOS data and meteorological data for atmospheric pressure in the observed periods. The seasonal difference of sea level between Summer and Winter is about 1.6cm. Both the detided oceanic signal level(h$_{detided}$) variation and the inverted barometer level(h$_{ib}$) variation have a strong correlation for T>1day period bands. Characteristics of h$_{detided}$ variation are decided not by the influence of any meteorological distributions (pressure, winds, etc), but the influence of another factors(temperature, salinity, etc.) for T>2days periods bands. h$_{corr.ib}$ plays an very important role of sea level variation of the long time term(especially T>about 180days period bands).

• Korean Journal of Remote Sensing
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• v.16 no.3
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• pp.211-220
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• 2000

Even though recurring eddies at the terminal end of the East Korean Warm Current have been identified in the thermal infrared imagery from the NOAA/AVHRR sensor and ocean color data from Orbview-2/SeaWiFS sensor, it is difficult to make observation in the field regarding recurring eddies located around the Wonsan coastal area in North Korea. But we could get in situ data related to an eddy from an ARGOS satellite tracking drifter trapped in the eddy on January 4th, 1999. An ARGOS drifter, a NOAA satellite tracked buoy was trapped by the eddy during January 4th.March 18, 1999. The ARGOS drifter rotated 10 times per 72 days on the edge of the eddy located at $39^{\circ}N$, $129^{\circ}E$. The diameter of the eddy was about 100 km. The horizontal rotation velocity of the recurring cold-core anti-cyclonic eddy was 1.53 km/h(42 cm/sec). The sea surface temperatures of the eddy varied from $14.7^{\circ}C$ on January 5, 1999 to $9.6^{\circ}C$ on March 18,1999. To study the mechanism of the recurring eddy. we tried to find out the relationship between the vector of the drifter moving in the eddy and the wind vector in Sokcho and Ulleung Island located near the eddy in southern Korea, and the difference in sea level between Ulleung Island and Mukho. We hope the results of this study would be useful for calibration and validation data of simulation and numerical modeling studies of the recurring eddy.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.11
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• pp.61-69
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• 2006

Position determination accuracy is strongly depending on how much precisely and frequently satellite receiver measures transmitted signals from terminals on target animals when Doppler effect is applied for position determination. ARGOS satellite system has shown relatively high position determination accuracy by operating multiple satellites, which enable operator to get more Doppler shift data from terminals. In case of animal tracking mission with single satellite, however, it is difficult for the satellite receiver to receive transmitted signals from terminals frequently during short period that satellite passes over ground terminals. This is one of the main sources to decrease position accuracy on target animals. In this paper, the Doppler rate estimation is implemented to increase the number of Doppler shift data received by single satellite. It is proved that the relatively high position determination accuracy with increased number of estimated data can be obtained. We also suggest that the Doppler rate estimation is applicable for position determination system with single satellite.

• Korean Journal of Remote Sensing
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• v.16 no.2
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• pp.117-133
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• 2000

We studied the sea level variations at Kerguelen island in the South Indian Ocean with ARGOS data and meteorological data during about 1 year(May 1993~April 1994) through using filter, spectral analysis, coherency and phase, and found characteristics for the two oceanic signal levels(detided oceanic signal level, h$_{detided}$ and seasonal oceanic level, h$_{corr.ib}$). The forms of atmospheric pressure variations are good agreed to between ARGOS data and meteorological data in the observed periods. This Kerguelen area shows the inflow of an air temperature(gain of a radiant heat) into the sea water and the stagnation of high atmospheric pressure bands in summer, and the outflow of a sea water temperature(loss of sensible and latent heat) toward the atmosphere and the stagnation of low atmospheric pressure bands in winter. The seasonal difference of sea level between summer and winter is about 1.6cm. Both the detided oceanic signal level(h$_{detided}$) variation and the inverted barometer level(h$_{ib}$) variation have a strong correlation for T>1day period bands. The characteristics of h$_{detided}$ variation are not decided by the influence of any meteorological distributions (atmospheric pressure), but the influence of other factors(bottom water temperature) for T>2days periods bands. h$_{corr.ib}$ plays a very important role of sea level variation in the observed periods (especially T>about 180days period bands).

• Ocean and Polar Research
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• v.33 no.spc3
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• pp.359-369
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• 2011

This study documents KORDI's experience of successfully deploying a deep ocean buoy for monitoring oceanic and atmospheric variabilities in the tropical western Pacific Ocea nsince May 2010. The primary focus of this study was to compare TRITON (big and old type) with m-TRITON (smaller and new type) buoys within the JAMSTEC's buoy management system. The objective of operating a KORDI buoy is to ascertain oceanic variability in the tropical western Pacific. We adopted a slack-line mooring type to observe water temperatures at six layers from surface to 400 m depth. However, we could not acquire satisfactory results due to lack of expertise in buoy management system. A new KORDI buoy has been developing, which has been modified from both buoys, and ARGOS-3 satellite system and a slack-type mooring line.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.4
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• pp.19-26
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• 2002

This is a brief report on the development of a system which provides fishing vessels with a real-time key information that can direct to regions of high fish density. Water temperature and Plankton distribution are the base parameters and various public information have been examined and summarized. The suface water temperature can be obtained from NOAA's high resolution infrared data base and the vertical water temperature can be obtained from TAO/TRITON's buoy near the equator and ARGOS's drifting buoy covering wider Pacific ocean. MODIS's data is also utilized for sea color information. A model data format is proposed and a few examples are demonstrated.

• Fisheries and Aquatic Sciences
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• v.26 no.11
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• pp.669-677
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• 2023

The spotted seal (Phoca largha) in the Yellow Sea has declined due to poaching and habitat destruction. To aid conservation efforts, Argos satellite tracking were used to monitor the movements of a free ranging spotted seal around Baengnyeongdo Island. The satellite-transmitting tag successfully attached to the seal provided 1,556 location data collected during 107 days. The seal mostly moved between two haul-out sites, Yeonbong Rock and Mulbeom Rock. From October 6th to December 12th, the seal stayed within a 7 km radius of Yeonbong Rock. However, as the signal was lost, it was not possible to identify when the seal started to migrate from Baengnyeongdo Island to winter breeding area. This study provide understanding into the habitat preferences and movement patterns of spotted seals around Baengnyeongdo Island, contributing to the conservation and management of this species. Further research with more individuals and different age groups is essential to understand their habitat preference and develop effective conservation measures for the spotted seal population in the Yellow Sea.

• Korean Journal of Remote Sensing
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• v.15 no.2
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• pp.175-181
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• 1999

A recurring eddy which located at the terminal end of the Korean East Warm Current was captured on ocean color and sea surface temperature imagery from satellite in spring and autumn. During late April, 1997 thermal infrared imagery from the NOAA AVHRR sensor and ocean color data from the Japanese ADEOS-I OCTS sensor, revealed this feature. The cold core had elevated chlorophyll concentrations, based on OCTS estimates, of greater than 3 mg/m$^3$ while the warmer surrounding waters had chlorophyll concentrations of 1 mg/m$^3$ or less. The elevated cholophyll accociated with this eddy has not been previously described. The eddy is also evident in SST images from autumn, but the SST in the core is warmer than in spring, and the warm jet flowing to the west of the eddy is also warmer is autumn compared to spring. A reccurring eddy and the high chlorophyll_a concentration area which surround around the eddy show on NOAA and SeaWiFS images in March 2, 1998. The eddy forms at the northern extent of the Korean East Warm Current as those waters collide with the cold, south-flowing Liman Current over a topographic shelf about 1500 m deep. This region of the eddy formation appears to have a strong connection with the dynamics of the western part of the polar front eddy field that dominates surface mesoscale structure in the central East (Japan) Sea. Interaction of the eddy with ARGOW tracked drifters, and evidence for its persistence are discussed.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.70-75
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• 1998

The comparison of Topex/Poseidon sea surface heights and Tide Gauge sea levels was studied in the South Indian Ocean after Topex/Poseidon mission of about 3 years (11- 121 cycles) from January 1993 through December 1995. The user's handbook (AVISO) for sea surface height data process was used in this study Topex/Poseidon sea suface heights ($\zeta$$^{T/P}$), satellite data at the point which is very closed to Tide Gauge station, were chosen in the same latitude of Tide Gauge station. These data were re-sampled by a linear interpolation with the interval of about 10 days, and were filtered by the gaussian filter with a 60 day-window. Tide Gauge sea levels ($\zeta$$^{Argos}$, $\zeta$$^{In-situ}$ and $\zeta$$^{Model}$), were also treated with the same method as satellite data. The main conclusions obtained from the root-mean-square and correlation coefficient were as follows: 1) to Produce Tide Gauge sea levels from bottom pressure, in-situ data of METEO-FRANCE showed very good values against to the model data of ECMWF and 2) to compare Topex/Poseidon sea surface heights of Tide Gauge sea levels, the results of the open sea areas were better than those of the coast and island areas.