Formation of Central Mode Water based on two zonal hydrographic sections in spring 2013 and 2016
Formation of Central Mode Water based on two zonal hydrographic sections in spring 2013 and 2016
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DOI：
10.1007/s10872-020-00551-9
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发表时间：
2020-05
影响因子：
2.3
通讯作者：
E. Oka;S. Kouketsu;D. Yanagimoto;Daiki Ito;Y. Kawai;S. Sugimoto;B. Qiu
中科院分区：
文献类型：
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作者：
E. Oka;S. Kouketsu;D. Yanagimoto;Daiki Ito;Y. Kawai;S. Sugimoto;B. Qiu
2013年4月和2016年6月，在日本以东沿着41° N和37.5° N的两个纬向高密度水文剖面被占用，以研究与锋面和涡旋相关的中央模态水（CMW）和过渡区模态水（TRMW）的形成。在41° N断面上，除了黑潮分叉锋以南的断面上形成了较轻的CMW（L-CMW）和D-CMW外，CMW（D-CMW）和TRMW的密集型在锋的两侧连续形成。L-CMW和D-CMW也在黑潮延伸锋和黑潮分叉锋之间的37.5° N断面的东部形成，但在两个锋分叉点以西断面的西部几乎没有形成。2013年4月在41° N断面西部观测到的D-CMW和TRMW密集区倾向于表现出多个核心（垂直最小位涡），这可能是由深冬混合层破坏形成的。2016年6月，在黑潮分叉锋以南的两个断面东部的L-CMW和D-CMW密集区也观察到了这种多核结构，特别是在三个反气旋涡旋中。它可能是由低位涡水在涡与涡之间的相互作用中与周围区域交换而形成的，这表明了一种新的模式水俯冲机制。
Two zonal high-density hydrographic sections along 41° N and 37.5° N east of Japan were occupied in April 2013 and June 2016 to examine the formation of Central Mode Water (CMW) and Transition Region Mode Water (TRMW) in relation to fronts and eddies. In the 41° N section traversing the meandering subarctic front, the denser variety of CMW (D-CMW) and TRMW was formed continuously on both sides of the front, except for the part of the section located south of the Kuroshio bifurcation front where the lighter variety of CMW (L-CMW) and D-CMW was formed instead. L-CMW and D-CMW were also formed in the eastern part of the 37.5° N section between the Kuroshio Extension front and the Kuroshio bifurcation front, but were hardly formed in the western part of the section west of the bifurcation point of the two fronts. D-CMW and TRMW pycnostads in the western part of the 41° N section observed in April 2013 tended to exhibit more than one core (vertical minimum of potential vorticity), which might be formed by destruction of deep winter mixed layers. Such multiple-core structure was also observed in L-CMW and D-CMW pycnostads in the eastern part of both the sections south of the Kuroshio bifurcation front in June 2016, being particularly abundant in three anticyclonic eddies. It was likely to be formed by the exchange of low-potential vorticity water among the eddies and the ambient region in association with eddy-to-eddy interaction, suggesting a new mechanism of mode water subduction.