Chinese scientists has made significant breakthrough in the study of the Indonesian Throughflow

发布时间:2018-10-07 文章来源:中国科学院海洋环流与波动重点实验室

 

Chinese scientists has made significant breakthrough in the study of the Indonesian Throughflow

 

Recently, the Journal of Physical Oceanography of the American Meteorological Society, which is one of the most prestigious academic journals in the physical oceanography research of the world, has published an important research paper led by Chinese scientists on the variations of the Indonesian Throughflow under the influence of the western boundary currents (Yuan et al. 2018).  The achievement is made jointly by the scientists from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS), including Professor Yuan Dongliang and his team, from the Research Center for Oceanography of the Indonesian Institute of Sciences (RCO-LIPI), and from the Max-Planck Institute für Meteorology of Germany.

Based on four consecutive years of subsurface moorings observations in the Maluku Channel of the Indonesian Seas, the upper-ocean circulation in the Maluku Sea has been observed for the first time in history, showing a mean northward transport to the Pacific Ocean of about 1.0 Sv, clarifying the ambiguity of the traditional understanding of the upper-ocean circulation in the area.  The observations unravel a significant southward increase of the Indonesian Throughflow during the spring and summer of 2014, with a total transport of 14 Sv, of which 3.5 Sv are the interannual variability.  These variations were significantly different from the response of the local circulation to the wind forcing and were suggested to be induced by the shifting of the Mindanao Current in the Pacific Ocean.  The variations of the Indonesian Throughflow may have an inhibitory effect on the onset and development of the El Ni?o event in 2014.

 

FIG. 1. Schematic of the upper-ocean circulation of the Indonesian Seas.  Solid and empty triangles mark the positions of the 2012–2014 and 2014–2016 mooring positions, respectively.  The solid line across the Maluku Channel indicates the section of the normal transport calculation.

 

FIG. 2. (a) NCEP winds and the (b) zonal and (c) meridional components of the moored ADCP velocity time series at M00 in the Maluku Channel during December 2012–November 2016

 

The observations in this paper suggest that the interactions between the Rossby waves and the western boundary currents could cause the Indonesian Throughflow to vary significantly, providing solid evidence for the nonlinear reflections of the Rossby waves at the Pacific western boundary.  Yuan Dongliang has discovered that the nonlinear reflection of Rossby waves at the western boundary is significantly different from the classic linear theory nearly 15 years ago, but has suffer from no observational data at that time.  They have conducted theoretical analysis of the multiple equilibria and hysteresis dynamics of the western boundary currents flowing across a gap (Yuan and Wang, 2011; Wang and Yuan, 2012), which lays a foundation for analyzing the mooring data in the Maluku Sea.  Their collective research results under the umbrella title of "Dynamics of the exchange between the Pacific western boundary currents and the marginal seas" have been awarded the tier-2 natural science prize of the Shandong province.  The above innovative researches have laid a solid theoretical and observational foundation for the study of nonlinear dynamics of the western boundary currents in the Pacific Ocean.

 

1.        Yuan D., Li Xiang, Wang Zheng, Li Yao, Wang Jing, Yang Ya, Hu Xiaoyue, Tan Shuwen, Zhou Hui, Adhitya Kusuma Wardana, Dewi Surinati, Adi Pureandana, Mochamad Furqon Azis Ismail, Praditya Avianto, Dirham Dirhamsyah, Zainal Arifin, Jin-Song Von Storch, 2018: Observed Transport Variations in the Maluku Channel of the Indonesian Seas Associated with Western Boundary Current Changes, J. Phys. Oceanogr., 48(8), 1803-1813.

2.        Wang, Z., D. Yuan, 2014: Multiple equilibria and hysteresis of two unequal transport western boundary currents colliding at a gap. J. Phys. Oceanogr., 44, 1873-1885, doi: 10.1175/JPO-D-13-0234.1.

3.        Wang, Z., and D. Yuan, 2012: Nonlinear Dynamics of Two Western Boundary Currents Colliding at a Gap. J. Phys. Oceanogr., 42(11), 2030-2040.

4.        Yuan, D., and Z. Wang, 2011: Hysteresis and Dynamics of a Western Boundary Current Flowing by a Gap Forced by Impingement of Meso-scale Eddies. J. Phys. Oceanogr., 41, 878-888, doi: 10.1175/2010JPO4489.1

 

 

 

中国科学家在印尼贯穿流研究领域取得重要突破

 

最近,美国气象学会《物理海洋学报》学术期刊报导了印尼贯穿流受西边界流影响发生变异的重要研究成果(Yuan et al. 2018),该论文为中国科学院海洋研究所袁东亮研究员课题组与印尼科学院海洋研究中心以及德国马普气象研究所科学家的合作研究成果。

通过印尼海马鲁古海峡的连续4年的潜标观测,发现马鲁古海上层环流平均输运向北流向太平洋,澄清了过去对马鲁古海上层环流的模糊认识。并首次估算了输运平均值,约为1.0 Sv。观测显示,2014年春夏季,印尼贯穿流突然向南增强,流量总变化达14 Sv,其中年际变化有3.5 Sv,与风强迫的变化响应不同,这些变异主要是由太平洋西边流——棉兰老流路径发生跃迁引起的,并且该变异可能对2014年的厄尔尼诺的发生、发展过程起了抑制作用。

 

  

1   印尼海上层环流示意图(左)和马鲁古海峡海流时间序列(右)(摘自Yuan et al. 2018 JPO

 

该论文的观测发现,罗斯贝波与西边界流相互作用能够引起印尼贯穿流的变化,从而为Rossby波在太平洋西边界的非线性反射提供了坚实的证据。袁东亮研究员在国际上最早发现,罗斯贝波在西边界的非线性反射与经典的线性理论不符,但是一直没有找到直接的观测证据。团队前期关于西边界流在缺口处的多平衡态和迟滞变异过程动力学理论分析(Yuan and Wang, 2011; Wang and Yuan, 2012),为分析马鲁古海潜标数据提供了理论基础。“太平洋西边界流与边缘海交换的动力机制”的研究成果,获得了山东省自然科学二等奖。这些原创性成果,为太平洋西边界流的非线性动力学研究奠定了坚实的理论和观测基础。

 

1.        Yuan D., Li Xiang, Wang Zheng, Li Yao, Wang Jing, Yang Ya, Hu Xiaoyue, Tan Shuwen, Zhou Hui, Adhitya Kusuma Wardana, Dewi Surinati, Adi Pureandana, Mochamad Furqon Azis Ismail, Praditya Avianto, Dirham Dirhamsyah, Zainal Arifin, Jin-Song Von Storch, 2018: Observed Transport Variations in the Maluku Channel of the Indonesian Seas Associated with Western Boundary Current Changes, J. Phys. Oceanogr., 48(8), 1803-1813.

2.        Wang, Z., D. Yuan, 2014: Multiple equilibria and hysteresis of two unequal transport western boundary currents colliding at a gap. J. Phys. Oceanogr., 44, 1873-1885, doi: 10.1175/JPO-D-13-0234.1.

3.        Wang, Z., and D. Yuan, 2012: Nonlinear Dynamics of Two Western Boundary Currents Colliding at a Gap. J. Phys. Oceanogr., 42(11), 2030-2040.

4.        Yuan, D., and Z. Wang, 2011: Hysteresis and Dynamics of a Western Boundary Current Flowing by a Gap Forced by Impingement of Meso-scale Eddies. J. Phys. Oceanogr., 41, 878-888, doi: 10.1175/2010JPO4489.1

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