| 摘要: |
| 利用长时间序列的石垣和基隆两个验潮站的海平面高度记录(18年)计算了台湾以东的黑潮流量，并结合风应力资料(SODA)，探讨了台湾以东黑潮流量的年际变化及其和风应力旋度的关系。台湾以东黑潮流量的峰值出现在1980—1981、1982—1983、1986、1988及1991年，低值出现在1984、1990、1993—1995年。小波分析结果显示，台湾以东黑潮流量具有2—5年的显著周期(峰值在2年和5年)；台湾以东北太平洋区域风应力旋度具有2—7年的显著周期(峰值在3年和6年)。在1980—1991年间，黑潮大弯曲频繁发生，台湾以东黑潮流量偏大，与台湾以东太平洋区域风应力旋度间的关系较好；而在1991—1995年间，没有黑潮大弯曲发生，台湾以东黑潮流量偏低，与台湾以东太平洋区域风应力旋度间的关系较差。 |
| 关键词: 台湾以东黑潮流量,风应力旋度,年际变化 |
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| 基金项目:国家自然科学基金资助项目，40333030号；中国海洋大学引进人才科研启动基金资助项目，2003-2005 |
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| THE INTERANNUAL VARIATION OF THE KUROSHIO TRANSPORT EAST OF TAIWAN |
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JIA Ying-Lai, LIU Qin-Yu, LIU Wei, LIN Xiao-Pei
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physical Oceanography Laboratory＆Ocean-Atmosphere Interaction and Climate Laboratory Ocean University of China
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| Abstract: |
| Based on the regression relationship along the WOCE PCM-1 section between the sea level records and the Kuroshio transport, sea level records are employed to calculate Kuroshio transport between 1980 and 1997 at 1 day s interval which comes from Keelung and Ishigaki in World Ocean Circulation Experiment (WOCE) dataset. The wind stress data involved in this study is available from Simple Ocean Data Assimilation (SODA) which is 1°×1° (resolution from October 1992 to August 2001 at 1 month’s interval.
The Kuroshio transport calculated from sea level records data accordant well with that from the PCM-1 mooring data that the correlation coefficient between the two amounts to as high as 0.72, far above the 95% significant level. The 13-month running averaging of the Kuroshio transport is subtracted to reduce the seasonal and intraseasonal variation of the Kuroshio transport. From the Kuroshio transport anomaly time serial (also called SLDKV in this paper), maximum of the Kuroshio transport occurred at 1980—1983, 1986, 1988 and 1991 (positive ano maly, exceeds 0.5Sv), while minimum of the Kuroshio transport occurred at 1984, 1990, 1993—1995(positive anomaly exceeds -0.5Sv), which indicates a trend of reduction of the Kuroshio transnort east of Taiwan after 1991. The results of wavelet analysis suggest the 2—5 years significant variation in the Kuroshio transport to the east of Taiwan with the peaks at 2 and 5 years. The 2—3 years fluctuation is stronger during 1980 and 1990 and the 5 years fluctuation stronger in the following 8 years.
From the Sverdrup relationship, the interannual variation of Kuroshio east of Taiwan relates to that in the wind stress curl field above the interior gyre. Based on the wind stress data in SODA dataset, the barotropie Sverdrup transport along 24.5°N in the interior gyre of the North Pacific is calculated. The seasonal and intraseasonal variation of the Sverdrup transport (also called WDKV in this paper) is subtracted. The correlation coefficient be & ween the WDKV and SLDKV is 0.67, far above the 95% significant level. In the years(1980—1983, 1986— 1988)when the SLDKV is much larger than normal, the Sverdrup transport reaches to maximum. While in the years (1981, 1990, 1993—1995) when the SLDKV is much lower than normal, the Sverdrup transport did not decrease as the SLDKV. The wavelet analysis shows that the primary period of the WDKV is 2—7years with maximum of 3 and 6 years. Between 1980 and 1994, the 6—7 years period is dominate while the 2—3years period is dominate between 1980—1990. Before 1991, the interannual variation of the Kuroshio transport agrees well with that of the Sverdrup transport. While after 1991, there is great differeace between the variation of the Kuroshio transport and the Sverdrup transport.
During the years when the Kuroshio large meander frequently occurred (such as 1980— 1991), the Kuroshio transport was large and the 2—5 year variation was distinct. Beside, there was close relationship between the Kuroshio transport and the wind strese curl. While in years of no Kuroshio large meander (such as 1991—1995), the Kuroshio transport became small and the close relationship with wind stress curl disappeared. |
| Key words: Kuroshio transport east of Taiwan, Wind stress curl, Interannual variation |
