Abstract

Deep-sea moorings in the equatorial Indian Ocean were first deployed by India in the year 2000, and currents were measured at three locations (\(77^\circ \hbox {E}\), \(83^\circ \hbox {E}\), and \(93^\circ \hbox {E}\)) on the equator. In this paper, we present two decades of current observations from these moorings and discuss how the moorings have evolved with time. The observations show that the 180-day (90-day) period dominates the surface and mid-depth (bottom) circulation. Though the Wyrtki Jets are strong, the near-surface currents do not show any clear semi-annual reversals. The reversals become evident only below 100 m.

Research Highlights

1. 1.

   Twenty years of ocean current data collected at the equatorial Indian Ocean

2. 2.

   Bottom current data show strong intraseasonal variability

3. 3.

   Upward phase propagation associated with the semi-annual cycle more prominent for the mid-depth currents

4. 4.

   The semi-annual reversals not evident every year near the surface

中文翻译：

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赤道印度洋的近二十年来的观测

摘要

印度于2000年首次在赤道印度洋部署深海系泊设备，并在三个位置测量了洋流（\（77 ^ \ circ \ hbox {E} \），\（83 ^ \ circ \ hbox { E} \）和赤道上的\（93 ^ \ circ \ hbox {E} \））。在本文中，我们将介绍来自这些系泊设备的最新二十年观测结果，并讨论系泊设备如何随着时间演变。观测结果表明，在180天（90天）的周期内，地表和中深度（底部）环流占主导地位。尽管Wyrtki射流很强，但近地表电流并没有显示任何明显的半年度反转。逆转仅在100 m以下才变得明显。

研究重点

1. 1。

   在赤道印度洋收集的二十年洋流数据

2. 2。

   底部当前数据显示强烈的季节内变异性

3. 3。

   与半年周期相关的向上相位传播在中深度海流中更为突出

4. 4，

   半年一次的逆转每年在地表附近都不明显