Observational characteristics and dynamic mechanism of low-salinity water lens for the offshore detachment of the Changjiang River diluted water in August 2006

Zhenyu Liu; Wenjing Zhang; Xuejun Xiong; Shouxian Zhu

doi:10.1007/s13131-021-1710-9

Volume 40 Issue 3

Apr. 2021

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Zhenyu Liu, Wenjing Zhang, Xuejun Xiong, Shouxian Zhu. Observational characteristics and dynamic mechanism of low-salinity water lens for the offshore detachment of the Changjiang River diluted water in August 2006[J]. Acta Oceanologica Sinica, 2021, 40(3): 34-45. doi: 10.1007/s13131-021-1710-9

Citation:

Zhenyu Liu, Wenjing Zhang, Xuejun Xiong, Shouxian Zhu. Observational characteristics and dynamic mechanism of low-salinity water lens for the offshore detachment of the Changjiang River diluted water in August 2006[J]. Acta Oceanologica Sinica, 2021, 40(3): 34-45. doi: 10.1007/s13131-021-1710-9

Citation:

Zhenyu Liu, Wenjing Zhang, Xuejun Xiong, Shouxian Zhu. Observational characteristics and dynamic mechanism of low-salinity water lens for the offshore detachment of the Changjiang River diluted water in August 2006[J]. Acta Oceanologica Sinica, 2021, 40(3): 34-45. doi: 10.1007/s13131-021-1710-9

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Observational characteristics and dynamic mechanism of low-salinity water lens for the offshore detachment of the Changjiang River diluted water in August 2006

doi: 10.1007/s13131-021-1710-9

1.
College of Meteorology and Oceanography, National University of Defense Technology, Nanjing 211101, China
2.
First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
3.
College of Oceanography, Hohai University, Nanjing 211101, China

Funds: The National Natural Science Foundation of China under contract No. 41376012.

More Information

Corresponding author: E-mail: zhangwj-lgd@sohu.com
Received Date: 2020-04-13
Accepted Date: 2020-06-22

Available Online: 2021-04-30

Publish Date: 2021-04-30

Abstract

Abstract

The Changjiang River diluted water (CDW) spreads into the East China Sea (ECS) primarily in a plume pattern, although in some years, low-salinity water lenses (LSWLs) detach from the main body of the CDW. In-situ observations indicate that in August 2006, a LSWL detached from the main body of the CDW near the river mouth. In this paper, the effects of winds, tides, baroclinity and upwelling on LSWLs are explored with a three-dimensional model. The results show that: (1) winds play a crucial role in these detachment events because wind-induced northerly Eulerian residual currents impose an uneven force on the CDW and cut it off, thus forming a LSWL; (2) upwelling carries high-salinity water from the lower layer to the upper layer, truncating the low-salinity water tongue vertically, which is conducive to the detachment and maintenance of LSWLs; and (3) upwelling during the evolution of a LSWL is caused by the combined effects of winds and tides. The influences of wind-induced upwelling are mainly near the shore, whereas the upwelling along the 30 m isobath is predominantly affected by tides, with the effect increasing from neap tide to spring tide.
- Changjiang River diluted water,
- low-salinity water lens,
- numerical simulation,
- observational characteristics,
- dynamic mechanism,
- upwelling

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References(26)

References

[1]	Blumberg A F, Mellor G L. 1987. A description of a three-dimensional coastal ocean circulation model. In: Heaps N S, ed. Three-dimensional Coastal Ocean Models. Washington: American Geophysical Union, 1–16
[2]	Chen Changsheng, Xue Pengfei, Ding Pingxing, et al. 2008. Physical mechanisms for the offshore detachment of the Changjiang diluted water in the East China Sea. Journal of Geophysical Research, 113(C2): C02002
[3]	Hu Mingna, Zhao Chaofang. 2008. Upwelling in Zhejiang coastal areas during summer detected by satellite observations. Journal of Remote Sensing (in Chinese), 12(2): 297–304
[4]	Kim H C, Yamaguchi H, Yoo S, et al. 2009. Distribution of Changjiang diluted water detected by satellite chlorophyll-a and its interannual variation during 1998–2007. Journal of Oceanography, 65(1): 129–135. doi: 10.1007/s10872-009-0013-0
[5]	Li Li, Cen Jingyi, Cui Lei, et al. 2019. Response of size-fractionated phytoplankton to environmental factors near the Changjiang Estuary. Acta Oceanologica Sinica, 38(1): 151–159. doi: 10.1007/s13131-018-1259-4
[6]	Li Mingming, Xie Lingling, Zong Xiaolong, et al. 2018. The cruise observation of turbulent mixing in the upwelling region east of Hainan Island in the summer of 2012. Acta Oceanologica Sinica, 37(9): 1–12. doi: 10.1007/s13131-018-1260-y
[7]	Li Daoji, Zhang Jing, Huang Daji, et al. 2002. Oxygen depletion off the Changjiang (Yangtze River) Estuary. Science in China Series D: Earth Sciences, 45(12): 1137–1146. doi: 10.1360/02yd9110
[8]	Lie H J, Cho C H, Lee J H, et al. 2003. Structure and eastward extension of the Changjiang River plume in the East China Sea. Journal of Geophysical Research, 108(C3): 3077. doi: 10.1029/2001JC001194
[9]	Lü Xingang, Qiao Fangli, Xia Changshui, et al. 2006. Upwelling off Yangtze River estuary in summer. Journal of Geophysical Research, 111(C11): C11S08
[10]	Lü Xingang, Qiao Fangli, Xia Changshui, et al. 2007. Tidally induced upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer. Science in China Series D: Earth Sciences, 50(3): 462. doi: 10.1007/s11430-007-2050-0
[11]	Moon J H, Hirose N, Yoon J H, et al. 2010. Offshore detachment process of the low-salinity water around Changjiang bank in the east China sea. Journal of Physical Oceanography, 40(5): 1035–1053. doi: 10.1175/2010JPO4167.1
[12]	Ni Tingting, Guan Weibing, Cao Zhenyi, et al. 2014. Numerical study on the upwelling of Zhejiang coast in spring. Journal of Marine Sciences (in Chinese), 32(2): 1–13
[13]	Peng Jian, Zhu Shouxian, Li Xunqiang, et al. 2014. Impact of wind on the low-salinity water lens in the northeast out of the Changjiang Estuary in summer. Journal of East China Normal University (Natural Science) (in Chinese), (3): 105–116
[14]	Pu Yongxiu. 2002. The summer salinity distribution types of the 30°N profile in the East China Sea. Donghai Marine Science (in Chinese), 20(1): 1–13
[15]	Wang Kaimin, Xiong Xuejun, Guo Binghuo, et al. 2012. The extension form and seasonal variation of the Changjiang diluted water during 2006–2007. Coastal Engineering (in Chinese), 31(1): 46–54
[16]	Wu Qiong, Wang Xiaochun, Liang Wenhao, et al. 2020. Validation and application of soil moisture active passive sea surface salinity observation over the Changjiang River Estuary. Acta Oceanologica Sinica, 39(4): 1–8. doi: 10.1007/s13131-020-1542-z
[17]	Wu Hui, Zhu Jianrong, Shen Jian, et al. 2011. Tidal modulation on the Changjiang River plume in summer. Journal of Geophysical Research, 116(C8): C08017
[18]	Xuan Jiliang, Huang Daji, Zhou Feng, et al. 2012. The role of wind on the detachment of low salinity water in the Changjiang Estuary in summer. Journal of Geophysical Research, 117(C10): C10004
[19]	Zhang Tingting, Zhao Feng, Wang Sikai, et al. 2019. Estimating the macrobenthic species richness with an optimized sampling design in the intertidal zone of Changjiang Estuary. Acta Oceanologica Sinica, 38(2): 114–124. doi: 10.1007/s13131-019-1352-3
[20]	Zhang Wenjing, Zhu Shouxian, Dong Lixian, et al. 2011. A new hybrid vertical coordinate ocean model and its application in the simulation of the Changjiang diluted water. China Ocean Engineering, 25(2): 327–338. doi: 10.1007/s13344-011-0027-4
[21]	Zhang Wenjing, Zhu Shouxian, Li Xunqiang, et al. 2014a. Numerical simulation and dynamical analysis for low salinity water lens in the expansion area of the Changjiang diluted water. China Ocean Engineering, 28(6): 777–790. doi: 10.1007/s13344-014-0060-1
[22]	Zhang Wenjing, Zhu Shouxian, Li Xunqiang, et al. 2014b. Impact of tide induced residual current and tidal mixing on the low salinity water lens in the northeast out of the Changjiang Estuary. Haiyang Xuebao (in Chinese), 36(3): 9–18
[23]	Zhao Baoren. 1993. The upwelling off Yangtze River Estuary. Haiyang Xuebao (in Chinese), 15(2): 108–114
[24]	Zhao Baoren, Li Huifei, Yang Yuling. 2003. Numerical simulation of upwelling in the Changjiang River mouth area. Studia Marina Sinica (in Chinese), (45): 64–76
[25]	Zhu Jianrong. 2003. Dynamic mechanism of the upwelling on the west side of the submerged river valley off the Changjiang mouth in summertime. Chinese Science Bulletin, 48(24): 2754–2758. doi: 10.1007/BF02901770
[26]	Zhu Shouxian, Ding Pingxing, Sha Wenyu, et al. 2001. New Eulerian-Lagrangian method for salinity calculation. China Ocean Engineering, 15(4): 553–564