What is the Indonesian Throughflow?

The Indonesian Throughflow is an ocean current that carries warm, relatively fresh water from the western Pacific into the Indian Ocean through the straits between Indonesia's islands. On average about 15 million cubic metres pass every second. It is the only way for water to pass from one ocean to the other in the tropics, and it runs straight through the Coral Triangle.

What route does the water take through Indonesia?

Most of the water enters from the north, carried past the Philippines by the Mindanao Current. The main path runs south through the Makassar Strait between Borneo and Sulawesi, then east through the Flores Sea to the Banda Sea, one of the deepest basins in the world, where it mixes with a smaller, deep inflow of South Pacific water from the Lifamatola Passage. From there it leaves through three exits: the Lombok Strait, the Ombai Strait north of Timor, and the Timor Passage south of it.

Does the throughflow change with the seasons and El Niño?

Yes. It is generally strongest during the southeast monsoon, roughly June to August, when steady southeasterly winds push surface water away from the coasts of Java and the Lesser Sunda Islands. It weakens during the northwest monsoon from December to February, and drops to its lowest, around 9 Sv, at the monsoon change in April, when Kelvin waves from the Indian Ocean raise sea level on that side and reduce the height difference that drives the flow.

Why does it matter for the world's climate?

The Indonesian Throughflow is the main upper branch of the global ocean circulation that moves heat and salt between the oceans. It warms the southern Indian Ocean and helps set the position of its warm pools, which influence regional climate. The water is then carried west towards Africa and south in the Agulhas Current, and around South Africa some of it spills into the Atlantic. Pacific heat that passed Nusa Penida can end up some 10,000 kilometres away.

What is upwelling, and where does it happen in Indonesia?

Upwelling is cold, nutrient-rich water rising from the deep towards the surface. In Indonesia it happens mainly during the southeast monsoon, when winds push surface water offshore along the south coasts of Java, Bali and the Lesser Sunda Islands, and deep water rises to replace it. Near the Nusa Penida sill, tidal currents also force water over a ridge and break into large internal waves, which divers may feel as sudden temperature changes and shifting currents.

Why is the water so cold at Nusa Penida?

Because Nusa Penida sits at the exit of the Lombok Strait, where tidal mixing and seasonal upwelling bring deep water to reef depth. From about July to October, divers regularly meet water of 16 to 22 °C, sometimes after crossing a sharp thermocline from 26 °C to around 20 °C within a few metres.

Why are the currents so strong at Komodo and Alor?

Komodo National Park sits between the warmer Flores Sea and the cooler Sumba Strait, connected by narrow channels between Komodo, Padar, Rinca and Flores. Tides push water through these gaps, so a site can change character from one hour to the next. The north tends to be warmer and clearer, with schools of fish and reef sharks at Castle Rock and Batu Bolong; the south is colder and greener with plankton, which brings manta rays. Our Komodo dive guide →

How do you dive safely in throughflow currents?

Dive with local guides who plan around the tides, because the same site can be gentle at one hour and dangerous the next. Carry a surface marker buoy on every drift dive and know how to deploy it from depth. Build up your current experience on easier sites first; Toyapakeh and Blue Corner off Nusa Penida are for experienced divers with a local guide. Expect sudden temperature drops and down-currents: if you are pulled down, move away from the wall towards open water or the shallows, as your guide briefed, and turn a dive if conditions look wrong.

How was the throughflow measured?

Between 2004 and 2006, the international INSTANT programme anchored 11 moorings with current meters in the main inflow and outflow channels, measuring all of them over the same three years.

A million cubic metres of water per second. The throughflow's 15 Sv would fill an Olympic swimming pool about 6,000 times every second.

Does the throughflow make the Coral Triangle richer?

It is one of several reasons. It carries larvae and nutrients between reefs, and its upwellings support productive feeding grounds; warm water, thousands of islands and many habitats do the rest.

印度尼西亚贯穿流详解（地图）：为什么佩尼达岛、科莫多和阿洛岛水流强劲

每一秒，约有 1500 万立方米的太平洋海水挤过印度尼西亚群岛，奔向印度洋。海洋学家称之为印尼贯穿流（Indonesian Throughflow）。潜水员则知道，冷水、急流和大型动物都拜它所赐。下面介绍它如何运作、科学家如何测量它，以及当您从船上翻身入水时它意味着什么。

印度尼西亚贯穿流（Indonesian Throughflow），输送量由 INSTANT 计划（2004–2006）测得。1 斯维尔德鲁普（Sv）= 每秒 100 万 m³ 海水。 — 印尼贯穿流，输送量由 INSTANT 计划（2004–2006）测得。1 斯韦德鲁普（Sv）= 每秒 100 万立方米海水。查看大图 ↗

15 Sv流入印度洋的平均流量

11.6 Sv经望加锡海峡（Makassar Strait）

11INSTANT 使用的锚系，2004–2006

什么是印尼贯穿流？

印尼贯穿流（Indonesian Throughflow）是一股洋流，它把温暖、盐度相对较低的海水从西太平洋经印度尼西亚岛屿之间的海峡输送到印度洋。平均每秒约有 1500 万立方米海水通过。这是热带地区海水从一个大洋流向另一个大洋的唯一通道，而它正好穿过珊瑚大三角。

它之所以流动，是因为西太平洋最西端的海面比相邻的印度洋略高。高差虽小，却形成了压力差，推动海水穿过岛屿之间的缝隙“顺坡而下”。来自两大洋的风、季风和海洋波动再使其加速或减速。大部分海水在温跃层之上的温暖上层流动，而这一层对珊瑚礁和潜水者最为重要。

海水穿越印度尼西亚走的是哪条路线？

大部分海水从北面进入，由棉兰老海流（Mindanao Current）沿菲律宾输送而来。主通道向南穿过婆罗洲与苏拉威西之间的望加锡海峡（Makassar Strait），再向东经弗洛勒斯海（Flores Sea）流向世界上最深的海盆之一班达海，在那里与经 Lifamatola 海峡流入、规模较小的南太平洋深层海水混合。海水从那里经三个出口流出：龙目海峡、帝汶岛以北的翁拜海峡（Ombai Strait），以及帝汶岛以南的帝汶通道（Timor Passage）。

通道	位置	平均流量
1 · 望加锡海峡	位于婆罗洲与苏拉威西之间。主要的入流通道。	11.6 Sv
2 · 龙目海峡	位于巴厘岛与龙目岛之间，途经佩尼达岛。最短的出口。	2.6 Sv
3 · 利法马托拉水道	位于苏拉威西以东。南太平洋深层水由此流入班达海。	约 1.1 至 2.5 Sv
4 · 翁拜海峡	位于帝汶岛以北，途经阿洛岛（Alor）。	4.9 Sv
5 · 帝汶通道	位于帝汶岛以南。最宽的出口。	7.5 Sv

约 15% 的出流取最短路线，经龙目海峡流出。海峡南口宽约 20 公里，佩尼达岛（Nusa Penida）附近一道约 350 米深的海槛控制着水流。其余经翁拜海峡和帝汶通道流出；帝汶通道是最宽的出口，宽约 160 公里。各出口合计输送约 15 Sv，不过在三年间，总量在约 10.7 至 18.7 Sv 之间波动。

贯穿流会随季节和厄尔尼诺变化吗？

会。它通常在东南季风期间最强，大约是 6 月至 8 月，此时稳定的东南风将表层海水推离爪哇和小巽他群岛沿岸。在 12 月至 2 月的西北季风期间，它会减弱，并在 4 月季风转换时降至最低，约 9 Sv，此时来自印度洋的开尔文波抬高了印度洋一侧的海平面，缩小了驱动水流的高差。

厄尔尼诺也往往会削弱它，因为它会降低太平洋一侧的海面；约 3 Sv 的年际波动就与这些变化有关。潜水者能直接感受到季节变化：水流最强的月份，也正是巴厘岛、龙目岛和小巽他群岛以南冷水上涌的月份。厄尔尼诺年还可能给珊瑚礁带来热应激。了解 2024 年热浪如何影响珊瑚三角区 →

它为何对全球气候至关重要？

印度尼西亚贯穿流是全球海洋环流在大洋之间输送热量和盐分的主要上层分支。它使南印度洋升温，并参与决定其暖池的位置，进而影响区域气候。随后海水向西流往非洲，再随厄加勒斯海流南下，在南非附近，一部分海水溢入大西洋。曾流经佩尼达岛的太平洋热量，最终可能抵达约 10,000 公里之外。

什么是上升流？印度尼西亚哪里会出现上升流？

上升流是指寒冷、富含营养盐的深层海水向海面上涌。在印度尼西亚，它主要出现在东南季风期间：风将爪哇、巴厘岛和小巽他群岛南岸的表层海水推向外海，深层海水随即上涌补充。在佩尼达岛海槛附近，潮流还会迫使海水翻越海脊，并碎裂成巨大的内波，潜水者可能会以水温骤变和水流变向的形式感受到它。

营养盐滋养浮游生物，浮游生物又养活小鱼和蝠鲼，整个食物网因此更加丰富。IUCN 的鲨鱼与鳐类专家指出，巴厘岛以南的深层上升流是佩尼达岛周边水域如此高产的原因之一；联合国教科文组织则称科莫多周边海域是世界上生产力最高的海域之一。

为什么佩尼达岛的海水这么冷？

因为佩尼达岛位于龙目海峡出口，潮汐混合和季节性上升流将深层海水带到珊瑚礁所在的深度。大约 7 月至 10 月，潜水者经常遇到 16 至 22 °C 的海水，有时会穿过一道明显的温跃层，在短短几米内从 26 °C 降至约 20 °C。

正是这股冷水把翻车鱼（mola mola）带到清洁站，通常在 20 至 30 米深处。Crystal Bay 是最知名的潜点，即使在旺季，也可能需要在两三天内潜好几次才能见到一条。同样的海水也滋养着 Manta Point 和 Manta Bay 的珊瑚礁蝠鲼；该岛已被认定为鲨鱼与鳐类重要区域。翻车鱼季请带上 5 毫米潜水服和头套。我们的巴厘岛与佩尼达岛潜水指南 →

为什么科莫多和阿洛岛的水流这么强？

科莫多国家公园位于较温暖的弗洛勒斯海与较凉爽的松巴海峡（Sumba Strait）之间，两者由科莫多岛、帕达尔岛（Padar）、林卡岛（Rinca）和弗洛勒斯岛之间的狭窄水道相连。潮汐推动海水穿过这些缝隙，因此同一个潜点的状况可能一小时一个样。北部通常更温暖、更清澈，在 Castle Rock 和 Batu Bolong 可以看到鱼群和礁鲨；南部更冷，海水因浮游生物而偏绿，吸引了蝠鲼。我们的科莫多潜水指南 →

阿洛岛位于翁拜海峡旁，这条海峡向印度洋输送约 4.9 Sv 的海水，带来了冷水上涌、极其清澈的海水和健康的珊瑚礁，同时也带来了强劲的水流。在潘塔尔海峡，海水在一次潜水中就可能明显变冷；海峡中央的尖峰礁只在合适的潮时、由经验丰富的当地潜水商带领下潜。我们的阿洛岛潜水指南 →

如何在贯穿流的水流中安全潜水？

跟随会根据潮汐安排行程的当地向导潜水，因为同一个潜点可能这一小时还很温和，下一小时就变得危险。每次放流潜水都携带水面信号浮标（SMB），并掌握在水下释放它的方法。先在较容易的潜点积累潜流经验；佩尼达岛外的 Toyapakeh 和 Blue Corner 适合有经验的潜水者在当地向导陪同下下潜。要预料到水温骤降和下降流：一旦被往下拉，就按向导简报的那样离开峭壁，游向开阔水域或浅水区；状况不对就中止潜水。

快速问答

贯穿流是如何测量的？

2004 年至 2006 年间，国际 INSTANT 计划在主要的入流和出流通道中布设了 11 套装有海流计的锚系，在同样的三年里对所有通道进行了测量。

什么是斯维尔德鲁普（Sverdrup）？

每秒一百万立方米的水。贯穿流的 15 Sv 每秒可以注满一个奥运标准泳池约 6,000 次。

贯穿流是否让珊瑚三角区更加丰饶？

这是原因之一。它在珊瑚礁之间输送幼体和营养盐，它带来的上升流则维系着高产的觅食场；温暖的海水、数以千计的岛屿和多样的栖息地成就了其余部分。

延伸阅读：全部八张珊瑚三角区地图，以及珊瑚大三角与大堡礁的比较。我们的珊瑚大三角与潜水指南更深入地介绍了行程规划；请查看我们的全部指南。

事实核查于 2026 年 10 月。流量数据为 INSTANT 计划的多年平均值；实际海流会随潮汐、季节和厄尔尼诺而变化，因此当天的海况请务必以当地潜水商的信息为准。

The Indonesian throughflow during 2004–2006 as observed by the INSTANT program (Gordon et al. 2010, Dynamics of Atmospheres and Oceans)
Direct estimates of the Indonesian Throughflow entering the Indian Ocean: 2004–2006 (Sprintall et al. 2009, Journal of Geophysical Research)
Indonesian Throughflow (Wikipedia)
龙目海峡（维基百科）
Komodo National Park（联合国教科文组织世界遗产中心）
Nusa Penida ISRA factsheet (IUCN SSC Shark Specialist Group)
Mola mola in Bali (Nusapenida.org)
地图：地形与海底地形 NOAA ETOPO1；海岸线 Natural Earth；太平洋边界流参照 Qiu et al. 2015 与 Hu et al. 2015