00:00Los océanos cubren más del 70% de la superficie de la Tierra y nunca están quietos.
00:07Los vientos, la rotación del planeta y fenómenos como la fuerza de Coriolis mantienen sus aguas en constante movimiento.
00:15Para estudiarlos, misiones como SWOT, Sentinel-6 y PACE observan desde el espacio su nivel, temperatura, color y corrientes,
00:24ayudándonos a comprender mejor su dinámica y su influencia en el clima.
00:30The oceans. They are always on the move.
00:34Together, the ocean basins are like a big, interconnected highway that transports nutrients, carbon, and heat around the world.
00:42This mesmerizing data visualization of ocean currents was created using a model called Estimating the Circulation and Climate of the
00:50Ocean, or ECHO for short.
00:52It's built using real-world data from satellites, buoys, and all kinds of other measurements.
00:59All of this movement starts with physics.
01:03Because the Earth is spinning, the water feels something called the Coriolis effect.
01:08This pushes some of the strongest currents, like the Gulf Stream and the East Australian Current,
01:13against the east side of the continents.
01:17Because these currents wind up on the west side of the ocean basins they sit in, scientists call them Western
01:24Boundary Currents.
01:26In this visualization, the currents closer to the surface are white, and the deeper currents are blue,
01:33almost like you're seeing those deep currents through the top layer of water.
01:37But what's causing all this motion?
01:40And what makes some water rise and some water sink?
01:44Let's take a look.
01:46Here, we can see the Pacific Ocean's strongest current, the Kurashio.
01:51It begins in the warm, tropical Philippine Sea, and then flows north past Taiwan.
01:57After it reaches Japan, it turns east and heads across the Pacific Ocean,
02:03spinning off huge eddies where it turns right.
02:06The Kurashio carries over 200 times more water than the world's largest river, the Amazon.
02:15This visualization makes it easy to see how the ocean moves water across the planet.
02:21But what's hard to see are the places where the water moves up or down.
02:25This is called upwelling or downwelling.
02:29When upwelling brings cold, deep nutrients into the sunlight near the surface,
02:34it creates a feeding ground for all sorts of ocean life.
02:40Nutrients, carried in part by the Kurashio current,
02:43help feed the fisheries in Japan and create an important economic zone for the country.
02:49Another major western boundary current is the Agulis current,
02:53which carries water down the east coast of Africa to its southern tip called Cape Agulis.
02:59There, the current makes a sharp turn to the east,
03:03but sometimes it pinches off giant eddies called the Agulis rings,
03:07which drift west into the Atlantic.
03:10These circular currents carry salt and heat into the Atlantic
03:14and form an important part of the overturning circulation,
03:19also known as the global ocean conveyor belt.
03:23This so-called conveyor belt is a system of currents that carries heat northward
03:28across the equator and into the North Atlantic.
03:30It plays a big role in the climates of North America, Europe, and Africa.
03:36Without it, winters in Europe would be much colder
03:39and droughts in Africa more severe.
03:43But the oceans do more than just move heat around.
03:46In some places, they absorb heat from the sun,
03:49and in others, they release it back to the air.
03:53We can see that in the Gulf Stream.
03:56Yet another part of the ocean's conveyor belt,
03:59the Gulf Stream starts in the tropics, where the water is very warm.
04:03As it drags warm water up the east coast of North America,
04:08it acts like a heater for the atmosphere.
04:10By the time this water has wandered across the Atlantic
04:13and wrapped around Europe, Iceland, and Greenland,
04:16it's gotten so cold that it sinks deep into the North Atlantic Ocean.
04:22But temperature isn't the only thing that can make water sink.
04:26So can salt.
04:28Salinity, or the amount of salt in the water, can make it heavy.
04:33The saltier and colder water is, the heavier it gets.
04:37As it gets warm and fresh, water gets lighter.
04:42Changes in the heaviness, or density, of ocean water
04:45are what keep the ocean's conveyor belt turning.
04:48The streaks you see near the surface
04:50show how water is moving from one place to another.
04:53But if you look closely, you can see that deep down,
04:57water is moving in a different direction,
05:00sometimes even the opposite direction,
05:02like it does far below the Gulf Stream.
05:05This cold, deep water headed south beneath the Gulf Stream
05:09is another part of that same ocean conveyor belt
05:12that keeps Europe warm.
05:14Some of that warm Gulf Stream water
05:16that heads north at the surface
05:18eventually winds up there,
05:20moving south again
05:21after losing so much heat to the atmosphere.
05:25Eventually, this cold, deep water
05:28will spread around the globe
05:29and slowly rise toward the surface.
05:33There, it will warm up in the sun
05:35and get ready to start the trip all over again.
