関係者各位
沿岸環境科学研究センター
化学汚染・沿岸環境研究拠点（LaMer）
拠点長 岩田 久人
沿岸環境科学研究センター（ＣＭＥＳ）、共同利用・共同研究拠点「化学汚染・沿岸環境研究拠点（ＬａＭｅｒ）」プロジェクトの一環として、下記の要領で第３８回特別講演会を行うこととなりました。
聴講は無料・事前申し込み不要です。多くの皆様のご参加をお待ちしております。
記
【日 時】２０２０年２月４日（火） 午前１０時～１１時３０分
Tuesday, February 4th, 2020 10:00 – 11:30 a.m.
【場 所】愛媛大学理学部 総合研究棟1. ６階 愛媛大学理学部会議室（６７４）
Meeting room #674, Science Research Bldg 1
■Lecturer: Prof. Jing Zhang
Graduate School of Science and Engineering, University of Toyama
■Title: What can we learn from the chemical tracers?
– Material transport between the marginal seas and the Kuroshio –
■Abstract: Marginal seas in the western North Pacific and western boundary
current area are constantly or intermittently exchanging energy
and materials between land and open ocean. A large amount of
nutrients is transported between the boundary area of the East
China Sea (ECS) shelf region and Kuroshio, however, it is
difficult to clarify the various sources solely by estimating
the potential temperature (PT) and salinity. Chemical tracers
e.g. rare earth elements (REEs), Nd and Cs isotopic compositions
(εNd, 137Cs) are suitable and conservative as water mass
indicators, and are excellent tools for classification and
analysis of multiple water masses while coupling with salinity
and temperature, particularly where there is complex water
structure. The estimation of the mixed four water masses is,
Mixed Shelf Water (MSW), Kuroshio Surface Water (KSW), Kuroshio
Tropical Water (KTW), and Kuroshio intermediate Water (KIW),
with KIW and KTW accounting for 39±14% and 49±18%,
respectively, of the central ECS shelf bottom water (Zhang et
al., 2018). Using Nd concentration and εNd. three end-member
models indicate that approximately 10% of the CDW (Changjiang
Diluted Water), 28% of the YSW (Yellow Sea Water), and 62% of
the Kuroshio Water enter the Sea of Japan while approximately
6% of the MSW discharges into the adjacent areas of the
Northwestern Pacific (Che and Zhang, 2018). To clarify the
nutrient transport through the Tsushima Strait from the North
Pacific to the Sea of Japan, 137Cs originated from the Fukushima
Dai-ichi Nuclear Power Plant (FNPP1) accident is used as a direct
indicator. A maximum 137Cs in the Luzon Strait area, ECA and
Tsushima Strait, were observed in the same water mass, with the
similar temperature (15-17C), salinity (34.60-34.75) and density
(sq, 25.2-25.7), which is recognized as Subtropical Mode Water
(STMW). KIW, gradually located at 400m in Luzon Strait and up to
150m water depth at the Tokara and Tsushima Straits, is rich in
nutrients. As a result, KIW (STMW) transports about 10% of
nutrients into the Sea of Japan in total flowing through the
Tsushima Strait.
Keywords:
rare earth elements, εNd, 137Cs, nutrient transport,
Luzon Strait, East China Sea
■Language: English
■No advanced registration, no fee for attending.
以上
ご不明な点は、下記までお問い合わせください。
化学汚染・沿岸環境研究拠点
（Leading Academia in Marine and Environment Pollution Research）
Email: lamer@stu.ehime-u.ac.jp