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International Dissemination of Technical Lessons Learned from Ieodo Ocean Research Station Field Trip Program

  • Date

    2021.07.18.

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- Precious Observation Data Obtained from a Harsh Oceanic and Atmospheric Environment, Published in an Internationally Renowned Journal –

 

The Korea Hydrographic and Oceanographic Agency (KHOA, Director General Mr. Lae Hyung HONG), in affiliation with the Ministry of Oceans and Fisheries, has announced the July 2021 publication in internationally renowned journal Frontiers in Marine Science* of a paper sharing observational data gathering lessons from the ‘Ieodo Ocean Research Station Field Trip Program’ 2016 to 2020.

 

* Frontiers is one of the world's top five publishers, producing leading open-access periodicals. Their prestigious journal Frontiers in Marine Science has an impact factor (IF) of 4.912.

** Title of the paper: Ocean and atmospheric observations at the remote Ieodo Ocean Research Station in the northern East China Sea

 

Ieodo Ocean Research Station (Ieodo ORS) is located southwest of the Korean Peninsula, 149 km from Marado at the southernmost tip of Jejudo (commonly referred to in scientific literature as Jeju Island or previously as Cheju Island). It was built near the submarine rock named “Ieodo” in the northern East China Sea in 2003 and is currently operated by the Korea Hydrographic and Oceanographic Agency (KHOA). Now 19 different types of 31 oceanic and atmospheric observation equipments are operated in Ieodo ORS.

 

Ieodo ORS is highly unusual in international terms since it is both a remote platform and concurrently monitors oceanic and atmospheric environments. It is located where the ‘Sargassum horneri’ and Changjiang (Yangtz River) Diluted Water flow together, in a zone from which typhoons approach Korea. The station is also ideally located for measuring background levels of air pollutants, owing to its remote distance away from atmospheric emission sources in East Asia.

 

Six research teams, consisting of participants from KHOA, Gangneung-Wonju National University, Inha University, the Korea Institute of Ocean Science and Technology, Pohang University of Science and Technology, and Seoul National University, have stayed at the station for week-long field trips to conduct oceanic and atmospheric observation research (vertical temperature and salinity data collection, plankton sampling, and installation-operation inspections of equipment).

 

Previously, the researchers experienced difficulties accessing Ieodo ORS due to a lack of routine public transport from the mainland or Jeju Island. However, since 2014 KHOA has provided a dedicated vessel, the Haeyang Nuri, for Ieodo ORS maintenance and to support researcher visits.

 

< Key research highlights>

 

○ (Surface temperature) A thermal imaging camera installed on the roof of Ieodo ORS has measured sea surface temperatures through a remote sensing technique, reducing the risk of equipment loss due to strong waves. Comparisons between summertime sea surface temperatures measured with this thermal imaging camera and direct measurements in the ocean surface layer showed close agreement with an error of only 0.4℃. It is thus expected that the characteristics of long-term sea surface temperature variations can be usefully analyzed using the thermal instrument records.

 

○ (Salinity) During spring to autumn periods with their high levels of biological productivity, biofouling on the salinity sensor can significantly reduce sensor performance. For salinity sensors without anti-fouling devices, it was found that measurement errors occurred as soon as after one week’s deployment. Salinity errors as high as >5pus were found to occur within a month of summer deployment. In contrast, long-term salinity sensor deployment with UV light generators to manage biofouling were successful in producing appropriate salinity records. As such, Ieodo ORS is expected to play a key role in summertime monitoring the Changjiang (Yangtze River) Diluted Water.

 

○ (Ocean Acidification) Waters around Ieodo ORS have received increasing inputs of anthropogenic nutrients via the Changjiang Diluted Water. This has, in turn, led to increasing phytoplankton biomass production and enhanced surface CO₂ removal with eventual decomposition and sinking of the organic matter produced. The enhancement of organic carbon (C) transfers from surface to bottom waters and its subsequent potential increased burial in bottom sediments has likely made the waters surrounding Ieodo ORS a stronger C sink. The high biological activity and subsequent removal of organic matter to bottom layers has meant that the pCO₂ values of waters surrounding Ieodo ORS have often remained at levels below 250 ppm (versus the current global atmospheric pCO₂ of 410 ppm). Research reveals that this air-sea CO₂ disequilibrium is largest at Ieodo ORS and decreases towards Jeju Island. The persistence of this pronounced air-sea CO₂ disequilibrium throughout the year has made the area a strong anthropogenic C sink.

 

○ (Solar radiation) Ieodo ORS could be considered an ideal site for radiation measurement since it is surrounded by sea with no significant change in the surface albedo throughout the year. However, a radiation observation environmental analysis using a 360° view camera found that various equipment mounts on the station frame hindered the pyranometer from producing optimal radiation measurements. This study was able to suggest better deployment sites for pyranometer installation on Ieodo ORS to ensure ideal radiation record quality.

 

The research teams visiting Ieodo ORS developed observational tools to measure surface temperature, salinity, ocean acidification, and solar radiation. In particular, they focused on developing optimal stable observation technologies that can reduce errors in oceanic and atmospheric observations in order to produce continuous accurate measurements.


For this paper, researchers worked together to share the valuable technical experiences accumulated through ‘trial and error’ lessons on improving the stability and accuracy of observations made in a harsh and remote oceanic and atmospheric environment for the benefit of researchers internationally.


These observation experiences are expected to greatly help encourage similar research projects, including ones focused on how best to operate observation equipment to produce continuously stable oceanic and atmospheric observation records in remote environments.


Mr. Lae Hyung HONG, General Director of KHOA, said “We will continue to support the Ieodo ORS field trip program, and to widely distribute quality controlled observation data through international observation networks such as OceanSITES and GOA-ON. As such Ieodo ORS is expected to provide a continental shelf observation base for international, interdisciplinary studies of the ocean and atmospheric processes operating in northeast Asia’s marginal seas”.

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