基于Argo浮标和历史资料的热带西太平洋次表层与中层水年代变化分析
Decadal variations of the subsurface and intermediate waters in the western tropical Pacific derived from Argo and historic data
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摘要: 利用20世纪80年代和90年代WOD01(World Ocean Database2001)中的CTD温盐剖面资料和2000年以后Argo资料,对比分析了热带西太平洋次表层和中层水团分布的年代变化特征。分析结果表明,在这两个时期,起源于南北太平洋中高纬度海域的各次表层水和中层水,在热带西太平洋分布特征和交织在一起的总体态势基本一致,水团性质的年代变化不大。这与上述两个时段全球海洋-大气耦合系统趋于正常状态相吻合。通过辨识和跟踪表征次表层水性质的盐度极大值,发现南太平洋热带水沿西边界向北扩散程度有所加大,由前一时期的5°N,进一步扩散到6°~7°N;北太平洋热带水在西边界附近的向南扩散程度有所削弱,在2002-2005年间只向南扩散到4°N,而前一个时期则可向南扩散到2°N。通过辨识表征中层水性质的盐度极小值,南极中层水在西边界附近向北扩散程度有所加大,在2002-2005年到达13°N附近,而前一个时期只到达11°N;同期,北太平洋中层水在西边界附近的向南扩散程度有所削弱。上述年代变化与全球水循环强度的变化之间有何关系有待进一步研究。Abstract: The decadal variations of the subsurface and intermediate water masses in the western tropical Pacific Ocean are analyzed with the CTD data of World Ocean Database 2001 (WOD01) in 1980s-1990s and the Argo data after 2000.The results show that the general distributions and water properties of the subsurface water masses and the interm ediate water masses in the western tropical Pacific Ocean during periods of 1985-1994 and 2002-2005 are basically consistent.The slight decadal variation corresponds to the normal status of the global atmosphere-ocean coupling system during the two periods.By tracking the salinity maximum representing the character of the subsurface water masses, the northward diffusion of South Pacific Tropical Water is found to enhance with its edge moving from 5°N during 1985-1994 to 6°~7°N during 2002-2005, while the southward diffusion of North Pacific Tropical Water weakened with its edge moving from 2°N during 1985-1994 to 4°N during 2002-2005.The salinity minimum representing the character of the intermediate water masses show that the northward diffusion of Antarctic Intermediate Water streng thened with its edge moving from 11°N during 1985-1994 to 13°N during 2002-2005; simult aneously, the southward diffusion of North Pacific Intermediate Water weaken.The relationship between the foregoing decadal variations and the strength of global water cycle is worth studying in the future.
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Key words:
- western tropical Pacific /
- subsurface waters /
- intermediate waters /
- decadal variations
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