Temporal variations of net Kuroshio transport based on a repeated hydrographic section along 137°E
Temporal variations of net Kuroshio transport based on a repeated hydrographic section along 137°E
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DOI：
10.1007/s00382-021-06061-8
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发表时间：
2021-11-26
期刊：
影响因子：
4.6
通讯作者：
Sugimoto, Shusaku
中科院分区：
文献类型：
--
作者：
Kawakami, Yuma;Kojima, Atsushi;Sugimoto, Shusaku
利用日本气象厅提供的沿沿着137度的重复水文剖面资料，分析了1972-2018年黑潮净输送量的时间变化。由地转流相对于1000 dbar深度的积分得到的黑潮净输送在年际和年代际时间尺度上波动。黑潮净输送量的主导时间尺度随时间变化，年际变化在1972-1990年和2000-2018年较为明显，年代际变化仅在2000年之前出现。结果表明，冬季北太平洋中部风应力旋度的变化，在年际尺度上反映了阿留申低压的纬向移动和北太平洋副热带高压强度的变化，在年代际尺度上反映了阿留申低压强度的变化，引起了黑潮净输送的变化。除年际和年代际变化外，还指出黑潮净输送存在20年尺度的变化及其与阿留申低压强度波动的可能联系。此外，我们的研究结果表明，在大净黑潮输送，黑潮和黑潮延伸区附近的海表温度趋于增加，导致强烈的向上感热和潜热释放。
Temporal variations of net Kuroshio transport are examined for 1972-2018 based on a repeated hydrographic section along 137 degrees E, which is maintained by the Japan Meteorological Agency. The net Kuroshio transport obtained by integration of geostrophic current velocity relative to 1000 dbar depth fluctuates on inter-annual and decadal timescales. The predominant timescale of the net Kuroshio transport changes with time; the inter-annual variation is pronounced in 1972-1990 and 2000-2018, and the decadal variation is detected only before 2000. We find that a winter wind stress curl variation in the central North Pacific which reflects meridional movements of the Aleutian Low and intensity fluctuations of the North Pacific subtropical high on an inter-annual timescale and intensity fluctuations of the Aleutian Low on a decadal timescale, causes the net Kuroshio transport variation. In addition to the inter-annual and decadal variations, we further pointed out a bi-decadal-scale variation of the net Kuroshio transport and its possible link to the Aleutian Low intensity fluctuation. Moreover, our results indicate that during large net Kuroshio transport, sea surface temperature around the Kuroshio and Kuroshio Extension region tends to increase, resulting in vigorous upward sensible and latent heat release.