Form 3

Annual Report
LaMer, Ehime University

Date (24 , 2 , 2018)
To Director of LaMer

Principle Investigator:
Affiliation Ocean University of China, OUC
Positionmaster candidate

Name in print

Mengqi Zhu

Include the report on the result of the project/meeting in a separate sheet.
1. Project / Meeting title
The seasonal and inter-annual variations of the influences of the water masses
structures along the Tsushima Strait Section on the temperature and salinity
distributions along the Japan Sea Section
2. Members of project / meeting
NamePI
Mengqi Zhu
Members
Jie ShiHuiwang GaoXinyu Guo

Affiliation

PositionContribution part

Ocean University
China, OUC

of master candidate Data
processing;Paper writing

Ocean UniversityChina, OUC
Ocean University
China, OUC
Ehime Universityof Associate
Professorof Professor

Beneficial discussion

Professor

Beneficial discussion

Beneficial discussion

TitleThe seasonal and inter-annual variations of the influences of the water masses
structures along the Tsushima Strait Section on the temperature and salinity
distributions along the Japan Sea Section

Members’ names and affiliations
NameJie Shi
Huiwang Gao

Institutionand Employment position
Department
Ocean University Associate Professorof China, OUC
Ocean University Professor

E-mailshijie@ouc.edu.cn
hwgao@ouc.edu.cnof China, OUC
Xinyu Guo

Faculty member of Professor

guoxinyu@sci.ehime-u.ac.jp

LaMer

Aim
This project aims to carry out cooperative research with Prof. Guo Xinyu ofEhime University on the seasonal and inter-annual variations of the influences of thewater masses structures along the Tsushima Strait Section on the temperature andsalinity distributions along the Japan Sea Section.

Procedure
The principal investigator (PI) has first made an oral presentation “The seasonal andinter-annual variations of the influences of the water masses structures along the Tsushima
Strait Section on the temperature and salinity distributions along the Japan Sea Section.”and showed the recent studies including:
1. The temperature and salinity’s seasonal variations on section of the Japan Sea andsection of the Tsushima Strait.

2.The seasonal variations of the influences of the water masses structures from thesection of the Tsushima Strait Section to the Japan Sea Section.
3. The seasonal and inter-annual variations of mixing ratios of the different Tsushima
Strait water masses to the Japan Sea Section.
4. The analysis on the mixing ratios’ variations between the two sections.

Results
Based on the observed water temperatures and salinities along the Tsushima Strait
Section and the Japan Sea Section from WOD13 (Fig. 1), the seasonal and inter-annual
variations of the influences of the water masses structures along the Tsushima Strait
Section on the temperature and salinity distributions along the Japan Sea Section wereanalyzed. The water masses structures along the Tsushima Strait Section showed obvious
seasonal variations (Fig. 2). In winter, the whole water column was occupied by the highsalinity water. In summer, the surface water at Tsushima Strait Section was characterizedby high temperature and low salinity; the deeper water was of high salinity and thesubsurface water was the mixture of the surface water and the deeper water. Compared
the seasonal variations of temperatures and salinities along the two sections, it wassuggested that the distributions of temperature and salinity at the Japan Sea Section wereinfluenced by the structures of water masses at the Tsushima Strait Section. At the Japan
Sea Section, the distributions of temperature and salinity in autumn were mostcomplicated. The surface water was of low salinity, which was influenced by theTsushima Strait Surface and Subsurface water. The Japan Sea Subsurface water was ofhigh salinity, which was determined by the Tsushima Strait Deeper Water. The deeper
water was of low temperature and high density, which was named as the Japan Sea Local

Water. The water masses composition along the Tsushima Strait Section caused the interannual variations of the temperature and salinity distribution along the Japan Sea Section(Fig. 3). The larger Changjiang runoff made the core salinity of summer Tsushima Strait
Surface and Subsurface water lower, and therefore the mixing ratios was higher. Themixing ratios of the Tsushima Strait high salinity water to the Japan Sea Section wasdetermined by the current structure and the temperature and salinity distribution in thesubsurface layer.

Fig. 1. The study area(a) and the stations at the two observational sections(b).

Fig. 2. Climatological T-S diagrams at Tsushima Strait Section and Japan Sea Section fromJanuary to December. Red and black dots represent T-S dots at Tsushima Strait Section and Japan

Sea Section, and the black lines are the isopycnals.

Fig. 3. The distribution of water mixing ratios along the Japan Sea Section (a: SummerTsushima Strait Surface Water; b: Summer Tsushima Strait Subsurface Water; c: Tsushima Strait
High Salinity Water; d: Japan Sea Local Water)

References:
1. Guo X Y, Miyazawa Y, Yamagata T. The Kuroshio Onshore Intrusion along theShelf Break of the East China Sea: The Origin of the Tsushima Warm
Current[J]. Journal of Physical Oceanography, 2006, 36(12): 2205-2231.
2. Mao H L, Ren Y W, Wan G M. Quantitative analysis of water masses inshallow water with T-S relationship[J]. Oceanologia ET Limnologia Sinica,
1964, 6(1): 145-160.

Publication/conference presentation
Conference:
Poster: The seasonal and inter-annual variations of the influences of the water masses
structures along the Tsushima Strait Section on the temperature and salinity distributions
along the Japan Sea Section.
Oral presentation:
Title: The seasonal and inter-annual variations of the influences of the water masses

structures along the Tsushima Strait Section on the temperature and salinity distributions
along the Japan Sea Section.
Lecturer: Mengqi Zhu.
Time: November 14, 2017.
Location: Ehime University.

Perspectives in future
We will investigate the seasonal and inter-annual variations of the influences of theecological effects from the nutrients concentration from the Tsushima Strait Section tothe Japan Sea Section. We are planning to publish our joint research on an international
journals.