Impacts of freshwater originating from the Changjiang discharge flowing from the East China Sea on the thermohaline circulation in the Japan Sea

东海长江泄洪淡水对日本海温盐环流的影响

• 批准号: 15540422
• 负责人: SENJYU Tomoharu
• 金额: $ 1.98万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15540422/
• 关键词: Tsusuma Strait; low salinity water; Changjiang discharge; interannual variability; Japan Sea; Japan Sea Proper Water; deep circulation; 長江; 塩分変動; 淡水輸送; 熱塩循環; 日本海中層水

1.Salinity variation in the Tsushima Strait(1)Interannual salinity variations in the Tsushima Strait were investigated based on the historical observation data. The EOF analysis revealed that the most dominant mode is the in-phase variation between the eastern and western channels. This mode correlates with the Changjiang discharge variation, and salinity in the strait tends to decrease over summer related to a large discharge of the Changjiang. The multi-regression model to estimate the Changjiang discharge from precipitation anomalies was developed.(2)An observation of surface temperature and salinity was carried out by a TS-meter moored at Futaoi Island in the Tsushima Strait in 2004-2005. Salinity shows a clear seasonal variation with a rapid decrease in mid-July and a minimum in mid-August in each year. However, salinity in 2005 decreased faster than that in 2004 by about 20 days and the minimum in 2005 was lower than that in 2004 by 1-2 psu. The TS-meter records suggest a periodic passage of water masses with a higher temperature and lower salinity in the strait in June-July.2.Thermohaline circulation in the Japan Sea(1)The abyssal circulation in the Japan Sea was investigated based on the direct current measurements. The distribution of mean flow vectors indicates relatively strong cyclonic circulations along the basin periphery. In contrast, sluggish mean flows are found in the interior region because of eddy motions dominancy.(2)The Yamato Basin Bottom Water (YBBW) exhibits higher temperature and lower dissolved oxygen than those in the Japan Basin Bottom Water (JBBW). Both bottom waters meet around the boundary between the Yamato and Japan Basins, forming a clear benthic front. The YBBW is the modified JBBW flowing into the Yamato Basin. A box-model estimated the turnover time and vertical diffusivity for the YBBW as 9.1 years and 3.4×10^<-3> m^<-3>s^<-1>, respectively.

1.对马海峡盐度变化 (1)根据历史观测资料，研究了对马海峡盐度年际变化。 EOF 分析表明最主要的模式是东部和西部通道之间的同相变化。这种模式与长江流量的变化有关，夏季海峡的盐度趋于下降，这与长江流量较大有关。建立了估算降水异常长江流量的多元回归模型。(2)2004-2005年利用停泊在对马海峡扶桃井岛的TS仪进行了地表温度和盐度观测。盐度有明显的季节变化，每年7月中旬急剧下降，8月中旬最低。然而，2005年盐度下降速度比2004年快约20天，2005年盐度最小值比2004年低1-2 psu。 TS-meter记录显示6-7月海峡内有周期性的高温、低盐度水团通过。2.日本海温盐环流(1)基于直流测量对日本海深海环流进行了研究。平均流量矢量的分布表明盆地外围有相对较强的气旋性环流。相比之下，由于涡运动占主导地位，内部区域平均流量缓慢。(2)大和盆地底水(YBBW)比日本盆地底水(JBBW)表现出更高的温度和更低的溶解氧。两种底层水在大和盆地和日本盆地之间的边界附近交汇，形成清晰的底栖锋。 YBBW 是流入大和盆地的改进型 JBBW。盒模型估计 YBBW 的周转时间和垂直扩散率分别为 9.1 年和 3.4×10^<-3> m^<-3>s^<-1>。

项目成果

Estimation of Chlorophyll Vertical Profiles from Satellite Data and the Implication to Primary Production in Kuroshio Front of the East China Sea.

东海黑潮前缘卫星数据叶绿素垂直剖面估算及其对初级生产的影响。

• 发表时间: 2004
• 期刊: Proc.the 2^<nd> International Symposium on PEACE
• 作者: Enomoto;H.;T.Senjyu;T.Matsuno
• 通讯作者: T.Matsuno

Interannual salinity variations in the Tsushima Strait and its relation to the Changjiang discharge

• DOI: 10.1007/s10872-006-0086-y
• 发表时间: 2006-10
• 期刊: Journal of Oceanography
• 影响因子: 2.3
• 作者: T. Senjyu;Hirofumi Enomoto;T. Matsuno;Sigeaki Matsui

2004年初冬季に対馬海峡東水道で観測された低気圧性渦

2004年初冬在对马海峡东航道观测到的气旋涡

• 发表时间: 2006
• 期刊: 水産大学校研究報告 54
• 作者: A.Yoshiasa;A.Nakatsuka他;鬼塚 剛
• 通讯作者: 鬼塚 剛

Interannual salinity variation in the Tsushima Strait in summer and its relation to the Changjiang river discharge

对马海峡夏季盐度年际变化及其与长江流量的关系

• 发表时间: 2005
• 期刊: Proc.of the Indonesia Ocean Forum 2005 and the 13^<th> PAMS/JECSS Workshop CD-ROM
• 作者: O.Ohtaka;H.Arima;A.Yoshiasa他;Tomoharu Senjyu 他
• 通讯作者: Tomoharu Senjyu 他

Deep flow field in the Japan/East Sea as deduced from direct current measurements

• DOI: 10.1016/j.dsr2.2003.10.013
• 发表时间: 2005-06
• 期刊: Deep-sea Research Part Ii-topical Studies in Oceanography
• 影响因子: 3
• 作者: T. Senjyu;Hong‐Ryeol Shin;J. Yoon;Z. Nagano;H. An;Sang-Kyung Byun;Chin Kee Lee