Large-scale currents are found throughout Earth's atmosphere and oceans. In the atmosphere, air currents are caused by the uneven heating of Earth's surface. In the ocean, water currents are caused by winds or differences in density. Created by Khan Academy.
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- here's a question that popped up in my mind: how are waves formed in the ocean?(15 votes)
- What. I need some help i dont get it(2 votes)
- A current is the steady flow of a fluid (such as air or water) within a larger body of that fluid. Large-scale currents are found throughout Earth's atmosphere and oceans. In the atmosphere, air currents are caused by the uneven heating of Earth's surface. In the ocean, water currents are caused by winds or differences in density.(7 votes)
- 2:15explains why a whirlpool in the Southern Hemisphere always spins in the opposite direction as whirlpools in the Northern Hemisphere.(3 votes)
- so i know that our planet has a gravity core but, since earth is round why doesnt the water fall ot of earth? And if the water ( oceans, lakes, and rivers ) dries up, wouldnt the water cycle start again so the water would never dry up? And since space is cold, wouldnt it make water into a solid (ice)?(3 votes)
- How are earth quakes created?(3 votes)
- The tectonic plates crash against each other when the Earth’s core is active. That’s what causes earthquakes to occur.(2 votes)
- Why does water even exist and why do people say the water is blue when it is technically clear(2 votes)
- Hello! There are a couple theories about this but the most favoured of them is that it was acquired from water-rich objects (planetesimals) that made up a few percent of its building blocks. These water-rich planetesimals would have been either comets or asteroids.(2 votes)
- why dosent water stop being salty after water cycle(2 votes)
- Hi there!
The water that the oceans contain still remains salty even after the water cycle, because the water leaves the ocean when it evaporates, and the salt gets left behind. Then the water goes through the rest of the water cycle, and returns to the ocean through rain. The rain comes into contact with the salty water, and is rejuvenated with those minerals. And hence, the water is salty again. Hope this helped!(2 votes)
- how are hurricanes made?(2 votes)
- Hurricanes will form over warm waters. There will typically also need to be a relatively high amount of humidity, and also low air pressure, as low pressure can usually be linked to warmer weather and also rainy weather.
If all of these are present the water starts to be released by the water. This creates clouds and eventually rotation. By then, you will at least have a tropical storm. If it gets stronger, it could upgrade into a hurricane.(2 votes)
- How do tsunamis happen?(1 vote)
- It is caused by earthquakes that are in deep seas
The energy from an earthquake makes the wave get bigger and bigger until it is a tsunami
But not all waves are tsunamis.
Rouge waves are waves that have made ships sink, and that is because rouge waves are bigger than usual waves.
Basically, energy fuels the wave to get bigger
energy makes the waves
If it is not understandable, I read this from a book and remembered it
So, the more energy = higher wave(4 votes)
- So if i live in Texas, then I’m living near the northern pole right? Is that far away from the equator?(2 votes)
- The equator is halfway down the globe/world. If you find a globe and look at it, there should be a line about halfway down. That's the equator. And Texas is pretty close to the equator.(1 vote)
- [Instructor] One of my favorite things to do is go camping. For me, there's nothing better than getting outside, breathing in some fresh air and taking a swim in my favorite river. Have you ever jumped into a river and felt that the deeper, cooler water closer to your feet was moving faster than the shallow, warmer water at your knees? That's a current, which is the a word we use to describe how water or even air flows within a larger body of water or air, but what causes a current? Well, let's start with the Sun. The Sun actually heats Earth unevenly. We know that it's hotter near the equator and it gets colder as you go towards the poles. Near the equator, the Sun's rays hit Earth surface more directly, while near the poles, the Sun's rays hit Earth surface less directly. In both regions, the same amount of solar energy is heading Earth, but near the equator, this energy is concentrated into a smaller area and near the poles it's spread out over a larger area. So the regions near the equator get more solar energy, which makes them warmer and the regions near the poles get less solar energy, which makes them cooler. This uneven heating at Earth also affects air pressure, where it's cooler near the poles, cool air will sink making the air pressure high, but where it's warmer near the equator, warm air will rise resulting in low pressure. This is where the terms low-pressure cells and high-pressure cells come from. The low-pressure warmer air at the equator rises into the upper atmosphere where it cools and flows away towards higher latitudes away from the equator. Because the air is now cooler, it starts to sink again and creates a high-pressure band near these latitudes. This process repeats and creates a pattern of high and low-pressure bands from the equator to the poles. We know that air flows from areas of high pressure to areas of low pressure. This creates air occurrence or winds. Now you might think that these winds would blow in straight lines from high to low-pressure areas. But the global wind patterns, which we call prevailing winds, look like they curved the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This curving has to do with the rotation of Earth and is called the Coriolis effect. As these prevailing winds blow across the surface of the land and water, they also pushed against the surface of the ocean and produce wind-driven surface currents, which helped to move ocean water. Here's what the global pattern of ocean surface currents looks like. Like wind currents, ocean surface currents are also curved due to the Coriolis effect. We can see that in these currents that are traveling north and south, which curved to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. Together as these surface currents of the ocean connect, they formed giant rotating systems of ocean currents called gyres. The currents that drive these gyres extend from the surface to about one kilometer down into the ocean and helped move water all around the globe. But these gyres aren't just moving water, they're moving heat energy as well. Water is pretty good at holding onto heat it absorbs from the Sun. So as the water in our oceans moves around the world through this gyre circulation, the water also carries heat. Here, warm water generally moves from the equator to the poles and cold water moves from the poles to the equator. But the ocean has other deeper currents that are affected by differences in temperature and density. Remember how we talked about areas heated directly and less directly by the Sun? And how that results in low and high-pressure areas? Same thing with water, except that water density is affected by both temperature and salinity, which is a measure of how salty the ocean is. Cooler and saltier water is more dense, so it tends to sink, just like cool air. Whereas warmer and less salty water is less dense and tends to rise, just like warm air. So with these deeper ocean currents, water actually moves vertically or up and down. For example, water near the poles gets very cold. It also gets very salty, because when sea ice is formed, the salt can't go into the ice. Instead, the salt stays behind in the water and so the water gets saltier or more saline. Together, the coldness and salinity makes the water very dense causing it to sink deep into the ocean. And other parts of the ocean, wind drags deep water up to the surface and a process called upwelling. These vertical currents are connected by horizontal currents at the surface and in the deep ocean. Collectively, this system of currents is known as the overturning circulation. You might also hear it called the global ocean conveyor belts. So here's a map showing the overturning circulation. This map might look a little bit strange, but here we're looking at Earth from the South Pole. So Australia and the southern tips of Africa and South America are closes to the center of the map, while Europe, most of Asia and North America are at the edges. Now, if you follow the currents in the overturning circulation, you can see that they flow all over the world's oceans. From the southern ocean around the South Pole, to the Pacific, the Indian and all the way into the North Atlantic. Like the currents in the gyre circulation, the currents in the overturning circulation also carry and disperse heat energy all around the world. Here I am, back in my favorite river, waiting around and enjoying currents of cool water flowing around my feet. And even though this river is small, the currents that flow through it are similar to the global wind and ocean currents that flow all around the world. So these currents connect in our atmosphere and oceans, which means that we are all connected. So currents connect us all.