Climatological mean features and interannual to decadal variability of ring formations in the Kuroshio Extension region
Climatological mean features and interannual to decadal variability of ring formations in the Kuroshio Extension region
复制标题
DOI：
10.1007/s10872-014-0270-4
复制
发表时间：
2015-10-01
影响因子：
2.3
通讯作者：
Minobe, Shoshiro
中科院分区：
文献类型：
--
作者：
Sasaki, Yoshi N.;Minobe, Shoshiro
利用1992年10月至2010年12月的卫星高度计观测资料，分析了黑潮延伸区（KE）急流所形成的海洋环的气候平均特征及其年际和年代际变化。为了客观地捕捉环脱落从KE射流，一种新的方法，包括检测的射流长度的变化和跟踪的一个环。在KE区域的环形成的空间分布表明，气旋（冷芯）环最频繁地形成在上游区域之间的143 A度和147 A度E周围的KE射流稳定的曲折。相反，大多数反气旋（暖心）环形成在下游地区西部的沙茨基隆起。这些夹断环在上游和下游区域一般向西传播，但约三分之二的环被喷流重新吸收。然而，在KE纬度的纬向涡旋热传输的约四分之一是由环，而不是重吸收的射流。环形成的数量表现出很大的年际至十年变化。在上游和下游KE区，年代际和年际变化分别占主导地位。这些环的形成波动与KE喷流的强度呈负相关。环的形成变化对KE急流以北的海表温度变化起着重要的作用。
This study examines the climatological mean features of oceanic rings shed from the Kuroshio Extension (KE) jet and their interannual to decadal variability using satellite altimeter observations from October 1992 to December 2010. To objectively capture ring shedding from the KE jet, a new method that consists of the detection of the jet length changes and the tracking of a ring is proposed. Spatial distribution of the ring formations in the KE region indicates that cyclonic (cold-core) rings were most frequently formed in the upstream region between 143A degrees and 147A degrees E around the steady meander of the KE jet. In contrast, most of anticyclonic (warm-core) rings were formed in the downstream region west of the Shatsky Rise. These pinched-off rings in both the upstream and downstream regions generally propagated westward, but about two-thirds of the rings were reabsorbed by the jet. Nevertheless, about one-fourth of the meridional eddy heat transport at the latitude of the KE resulted from the rings that are not reabsorbed by the jet. The number of ring formations showed substantial interannual to decadal variability. In the upstream and downstream KE region, decadal and interannual variability was dominant, respectively. These ring formation fluctuations were negatively correlated with the strength of the KE jet. It is also revealed that the ring formation variations play an important role in sea surface temperature changes north of the KE jet.