https://repository.kopri.re.kr/handle/201206/5380 2026-04-17T08:03:07Z 2026-04-17T08:03:07Z Hiroshi Sumata Takashi Kikuchi Cho, Kyoung-Ho Koji Shimada Ursula Schauer Rudiger Gerdes Axel Behrendt Mary-Louise Timmermans Benjamin Rabe Michael Karcher Frank Kauker https://repository.kopri.re.kr/handle/201206/6565 2022-03-24T07:14:01Z 2018-01-01T00:00:00Z

Title: Decorrelation scales for Arctic Ocean hydrography ？ Part I: Amerasian Basin Authors: Hiroshi Sumata; Takashi Kikuchi; Cho, Kyoung-Ho; Koji Shimada; Ursula Schauer; Rudiger Gerdes; Axel Behrendt; Mary-Louise Timmermans; Benjamin Rabe; Michael Karcher; Frank Kauker Abstract: Any use of observational data for data assimilation requires adequate information of their representativeness in space and time. This is particularly important for sparse, non-synoptic data, which comprise the bulk of oceanic in situ observations in the Arctic. To quantify spatial and temporal scales of temperature and salinity variations, we estimate the autocorrelation function and associated decorrelation scales for the Amerasian Basin of the Arctic Ocean. For this purpose, we compile historical measurements from 1980 to 2015. Assuming spatial and temporal homogeneity of the decorrelation scale in the basin interior (abyssal plain area), we calculate autocorrelations as a function of spatial distance and temporal lag. The examination of the functional form of autocorrelation in each depth range reveals that the autocorrelation is well described by a Gaussian function in space and time. We derive decorrelation scales of 150？200？km in space and 100？300 days in time. These scales are directly applicable to quantify the representation error, which is essential for use of ocean in situ measurements in data assimilation. We also describe how the estimated autocorrelation function and decorrelation scale should be applied for cost function calculation in a data assimilation system.

2018-01-01T00:00:00Z Kim, Sun Young Lim, Dhong-il Kang, Sung-Ho Huh, Sik Shin, Hyeon Ho Roh, Youn Ho https://repository.kopri.re.kr/handle/201206/6082 2022-03-24T07:12:30Z 2018-01-01T00:00:00Z

Title: Decadal-scale variations of sedimentary dinoflagellate cyst records from the Yellow Sea over the last 400 years Authors: Kim, Sun Young; Lim, Dhong-il; Kang, Sung-Ho; Huh, Sik; Shin, Hyeon Ho; Roh, Youn Ho Abstract: In recent decades, the Yellow Sea has experienced severe environmental deterioration due to increasing input of anthropogenic pollutants and consequently accelerated eutrophication. Whilst there have been significant advances in documenting historical records of metal pollution in the Yellow Sea region, changes in phytoplankton community structures affected by eutrophication remain understudied. Here, we present a new record of dinoflagellate cyst-based signals in age-dated sediment cores from the Yellow Sea mud deposits to provide better insight into eutrophication history and identification of associated responses of the regional phytoplankton community. It is of note that there were significant variations in abundances and community structures of dinoflagellate cysts in three historical stages in association with increasing anthropogenic activity over the last 400 years. Pervasive effects of human interference altering the Yellow Sea environments are recognized by: 1) an abrupt increase of organic matter, including the diatom-produced biogenic opal concentrations (∼1850);2) a distinct shift in phytoplankton composition towards dinoflagellate dominance (∼1940), and 3) recent acceleration of dinoflagellate cyst accumulation (∼1990). Particularly in the central Yellow Sea shelf, the anomalously high deposition of dinoflagellate cysts (especially Alexandrium species) is suggested to be a potentially important source of inoculum cells serving as a seed population for localized and recurrent blooms in coastal areas around the Yellow Sea.

2018-01-01T00:00:00Z Hahm, Yu-Geun https://repository.kopri.re.kr/handle/201206/9125 2022-03-24T07:13:19Z 2017-06-30T00:00:00Z

Title: Development of data assimilation system to construct an interannual sea-ice prediction system using dynamical sea-ice model Authors: Hahm, Yu-Geun

2017-06-30T00:00:00Z Kim, Seung-Kyu https://repository.kopri.re.kr/handle/201206/9128 2022-03-24T07:14:08Z 2017-06-30T00:00:00Z

Title: Development of analytical methods for anthropogenic pollutants (microplastics) Authors: Kim, Seung-Kyu

2017-06-30T00:00:00Z