A fresh look at the deepwater overflow in the Luzon Strait
-
摘要: 基于最新的GDEM3.0月平均和WOA13季节平均资料,我们将水力学理论应用到吕宋海峡,得到了对吕宋深水瀑布规律的新认识。结果表明:(1)吕宋海峡两侧的密度差是维持常年深水瀑布的动力,(2)深水瀑布的季节性变化不仅受吕宋海峡两侧密度差的影响,还受深水瀑布上游厚度变化的影响,(3)吕宋海峡深水瀑布呈弱半年周期性变化,(4)南海深层平均环流结构不会对吕宋海峡深水瀑布的变化作季节内响应。此外,根据GDEM3.0月平均资料和WOA13季节平均资料,深水瀑布流量分别是12月达到最大和秋季(10-12月)达到最大,同时伴随吕宋海峡北太平洋侧的季节性最低温度。本文所得的深水瀑布季节性变化与在吕宋海峡3.5年现场观测结果的季节性一致。Abstract: On the basis of the latest version of a U.S. Navy generalized digital environment model (GDEM-V3.0) and World Ocean Atlas (WOA13), the hydraulic theory is revisited and applied to the Luzon Strait, providing a fresh look at the deepwater overflow there. The result reveals that:(1) the persistent density difference between two sides of the Luzon Strait sustains an all year round deepwater overflow from the western Pacific to the South China Sea (SCS); (2) the seasonal variability of the deepwater overflow is influenced not only by changes in the density difference between two sides of the Luzon Strait, but also by changes in its upstream layer thickness; (3) the deepwater overflow in the Luzon Strait shows a weak semiannual variability; (4) the seasonal mean circulation pattern in the SCS deep basin does not synchronously respond to the seasonality of the deepwater overflow in the Luzon Strait. Moreover, the deepwater overflow reaches its seasonal maximum in December (based on GDEM-V3.0) or in fall (October-December, based on the WOA13), accompanied by the lowest temperature of the year on the Pacific side of the Luzon Strait. The seasonal variability of the deepwater overflow is consistent with the existing longest (3.5 a) continuous observation along the major deepwater passage of the Luzon Strait.
-
Key words:
- Luzon Strait /
- deepwater overflow /
- seasonal variability /
- South China Sea
-
Boyer T P, Garcia H E, Locarnini R A, et al. 2014. 2013 world ocean atlas aids high-resolution climate studies. Eos, 95(41):369-370 Carnes M R. 2009. Description and Evaluation of GDEM-V3.0, Tech Rep NRL/MR/7330-09-9165. Washington, D C. Nav Res Lab, 21. Fang Guohong, Wang Yonggang, Wei Zexun, et al. 2009. Interocean circulation and heat and freshwater budgets of the South China Sea based on a numerical model. Dyn Atmos Oceans, 47(1-3):55-72 Lan Jian, Wang Yu, Cui Fengjuan, et al. 2015. Seasonal variation in the South China Sea deep circulation. J Geophys Res:Oceans, 120(3):1682-1690, doi: 10.1002/2014JC010413[DOI:10.1002/2014JC010413] Nitani H. 1972. Beginning of the Kuroshio. In:Stommel H, Yashida K, eds. Kuroshio:Physical Aspects of the Japan Current. Seattle:University of Washington Press, 129-163 Qu Tangdong, Girton J B, Whitehead J A. 2006. Deepwater overflow through Luzon Strait. J Geophys Res, 111(C1):C01002, doi: 10.1029/2005JC003139 Qu Tangdong, Mitsudera H, Yamagata T. 1998. On the western boundary currents in the Philippine Sea. J Geophys Res, 103(C4):7537-7548 Qu Tangdong, Mitsudera H, Yamagata T. 2000. Intrusion of the North Pacific waters into the South China Sea. J Geophys Res, 105(C3):6415-6424 Qu Tangdong, Song Y T, Yamagata T. 2009. An introduction to the South China Sea throughflow:its dynamics, variability, and application for climate. Dyn Atmos Oceans, 47(1-3):3-14, doi: 10.1016/j.dynatmoce.2008.05.001 Smith W H F, Sandwell D T. 1997. Global sea floor topography from satellite altimetry and ship depth soundings. Science, 277(5334):1956-1962 Stommel H, Arons A B. 1959-1960. On the abyssal circulation of the world ocean-Ⅱ. An idealized model of the circulation pattern and amplitude in oceanic basins. Deep-Sea Res (1953), 6:217-233 Teague W J, Carron M J, Hogan P J. 1990. A comparison between the generalized digital environmental model and Levitus climatologies. J Geophys Res, 95(C5):7167-7183 Tian Jiwei, Yang Qingxuan, Liang Xinfeng, et al. 2006. Observation of Luzon Strait transport. Geophys Res Lett, 33(19):L19607, doi: 10.1029/2006GL026272 Tian Jiwei, Yang Qingxuan, Zhao Wei. 2009. Enhanced diapycnal mixing in the South China Sea. J Phys Oceanogr, 39:3191-3203, doi: 10.1175/2009jpo3899.1 Wang Joe. 1986. Observation of abyssal flows in the northern South China Sea. Acta Oceanogr Taiwan, 16:36-45 Wang Guihua, Xie Shangping, Qu Tangdong, et al. 2011. Deep South China Sea circulation. Geophys Res Lett, 38(5):L05601, doi: 10.1029/2010GL046626 Whitehead J A. 1989. Internal hydraulic control in rotating fluids-applications to oceans. Geophys Astrophys Fluid Dyn, 48(1-3):169-192 Whitehead J A. 1998. Topographic control of oceanic flows in deep passages and straits. Rev Geophys, 36(3):423-440, doi: 10.1029/98RG01014 Wyrtki K. 1961. Physical Oceanography of the Southeast Asian Waters, Naga Rep 2. Scripps Inst of Oceanogr, 195 Xie Qiang, Xiao Jin'gen, Wang Dongxiao, et al. 2013. Analysis of deep-layer and bottom circulations in the South China Sea based on eight quasi-global ocean model outputs. Chin Sci Bull, 58(32):4000-4011, doi: 10.1007/s11434-013-5791-5 Xu Fanghua, Oey L Y. 2014. State analysis using the local ensemble transform Kalman Filter (LETKF) and the three-layer circulation structure of the Luzon Strait and the South China Sea. Ocean Dyn, 64(6):905-923, doi: 10.1007/s10236-014-0720-y Yang Qingxuan, Tian Jiwei, Zhao Wei. 2010. Observation of Luzon Strait transport in summer 2007. Deep-Sea Res:I. Oceanogr Res Pap, 57(5):670-676 Zhang Zhengguang, Zhao Wei, Liu Qinyu. 2010. Sub-seasonal variability of Luzon Strait transport in a high resolution global model. Acta Oceanologica Sinica, 29(3):9-17, doi: 10.1007/s13131-010-0032-0 Zhang Zhiwei, Zhao Wei, Tian Jiwei, et al. 2015. Spatial structure and temporal variability of the zonal flow in the Luzon Strait. J Geophys Res:Oceans, 120(2):759-776, doi: 10.1002/2014JC010308 Zhao Wei, Zhou Chun, Tian Jiwei, et al. 2014. Deep water circulation in the Luzon Strait. J Geophys Res:Oceans, 119(2):790-804, doi: 10.1002/2013JC009587 Zhou Chun, Zhao Wei, Tian Jiwei, et al. 2014. Variability of the deep-water overflow in the Luzon Strait. J Phys Oceanogr, 44(11):2972-2986 Zhu Yaohua, Fang Guohong, Wei Zexun, et al. 2016. Seasonal variability of the meridional overturning circulation in the South China Sea and its connection with inter-ocean transport based on SODA2.2.4. J Geophys Res:Oceans, 121(5):3090-3105, doi: 10.1002/2015JC011443
点击查看大图
计量
- 文章访问数: 2176
- HTML全文浏览量: 55
- PDF下载量: 1097
- 被引次数: 0