Dynamic height anomaly from Argo profiles and sea-level anomaly from satellite altimetry: a comparative study in the Indian Ocean
Dynamic height anomaly from Argo profiles and sea-level anomaly from satellite altimetry: a comparative study in the Indian Ocean
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DOI：
10.1080/01431161.2010.494638
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发表时间：
2011-09
影响因子：
3.4
通讯作者：
Smitha George;Rashmi Sharma;N. Agarwal;S. Basu;A. Sarkar
中科院分区：
文献类型：
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作者：
Smitha George;Rashmi Sharma;N. Agarwal;S. Basu;A. Sarkar
在印度洋，高度计反演的海平面异常（SLA）与Argo反演的动力高度异常（DHA）进行了比较。在10°S以上的区域，异常相当一致。当用Argo盐度代替气候盐度时，协议得到改善。还研究了DHA与Argo盐度和SLA相关性的季节变化。相关性差的原因可能是由于SLA中存在正压（非空间）成分，而不是DHA所捕获的，这是一种纯粹的空间效应。在阿拉伯海的某些区域，盐定分量对动力高度的影响很大，这是因为：（1）索马里海流和北赤道海流将南部低盐度海水平流输送到该区域，（ii）在西南季候风期间沿阿拉伯海岸沿着的低盐度涌上来的水;及（iii）降水及河流-在阿拉伯海东部的河流中，海水盐度较高，导致当地形成低盐度水。在孟加拉湾，降水和北方河流入流对盐成分量的影响较大。在印度洋东南部，印度尼西亚洋流是造成这种影响的主导因素。
Altimeter-derived sea-level anomaly (SLA) has been compared with Argo-derived dynamic height anomaly (DHA) in the Indian Ocean. The anomalies have been found to agree quite well in the region above 10°S. The agreement is improved when climatological salinity is replaced by Argo salinity. Seasonal variation of correlation of DHA computed with Argo salinity and SLA has also been studied. The reasons for the poor correlation could be attributed to the fact that there is a barotropic (non-steric) component of the SLA, not captured by DHA, which is a purely steric effect. It has been also found that the impact of halosteric component on dynamic height is quite high in certain regions of the Arabian Sea because of (i) low-salinity water of southern region advected into the region by Somali and North Equatorial Current, (ii) upwelled water of low salinity during south-west monsoon along the Arabian coast and (iii) precipitation and river run-off from rivers in the eastern Arabian sea contributing to the local formation of low-salinity water. In the Bay of Bengal, the factors responsible for the large impact of halosteric component are precipitation and river influx in the northern part. In the south-eastern Indian Ocean, Indonesian Throughflow is the governing factor for this impact.