自2012年秋天以來,在科技部支助下,OKTV及SK-II計畫有系統、持續的探測黑潮,揭露了許多黑潮不為人知的面貌,為海洋學界開創新的研究題材。綜合2012至2014年間海底倒置測深儀(PIES)、都普勒流剖儀(ADCP)、研究船測水文及流速、水下滑翔觀測儀(Seaglider)資料,解析出黑潮由呂宋島東北方到臺灣東方的流速及水文結構增厚,導致流量增加50%,更重要的是量化黑潮主流結構以下大約在2000–4000 m深的反流在呂宋東北方的流量為–10.3±2.3百萬立方公尺每秒(即海洋慣用單位Sv),在臺灣東方KTV1測線為–12.5±1.2 Sv。尤其在臺灣東邊花東海盆反流的產生跟變動,和中尺度反氣旋渦流接近黑潮時,深層反氣旋渦流被宜蘭海脊阻擋造成黑潮下方反向流所致,如隨附示意圖所示。本項臺美合作研究結果由Dr. Magdalena Andres (WHOI associate scientist)、本所物理組4位同仁及3位APL-UW研究人員共同撰寫並於最近出版於Journal of Geophysical Research:
Andres, M., V. Mensah, S. Jan, M.-H. Chang, Y.-J. Yang, C. M. Lee, B. Ma, and T. B. Sanford (2017), Downstream evolution of the Kuroshio’s time-varying transport and velocity structure, J. Geophys. Res. Oceans, 122, doi:10.1002/2016JC012519. (見http://onlinelibrary.wiley.com/doi/10.1002/2016JC012519/abstract)。
本篇論文被選為”JGR Highlights”,是OKTV、SK-II一系列論文中,第二篇被JGR選為研究亮點的論文,JGR編輯評論如下:
“This study of the Kuroshio ocean current looks at its changing characteristics as it flows between Luzon and Taiwan. It is based on in-situ data sets from two companion field programs that measured the current’s strength and velocity structure. The results reveal that the current’s evolution is influenced by factors such as downstream thickening, bathymetric ridges, and eddies from the ocean interior. Given contemporary discussions about the role of Western boundary currents in global observing systems, this is a great example of how boundary observations tie together basin-wide circulation.”
(撰稿:詹森,2017/05/21)