Current Events: Crash Course Kids #34.1 - By Crash Course Kids
Transcript
| 00:09 | you know what I've been thinking about lately , hanging | |
| 00:11 | out on a tropical beach with sand between my toes | |
| 00:14 | and a cool breeze blowing through my hair . I | |
| 00:17 | mean strictly in the interests of science , because the | |
| 00:20 | breeze in my hair and the wind and even the | |
| 00:22 | big cycles going on out there in the ocean are | |
| 00:25 | all great ways of understanding currents . A few episodes | |
| 00:28 | ago , we learned that the uneven heating of land | |
| 00:31 | and water creates wind by forming different pressures owns the | |
| 00:34 | air above the land is warmer and less dense , | |
| 00:36 | so it rises in the air over the water is | |
| 00:39 | cooler and heavier . The cool air rushes in towards | |
| 00:41 | the low pressure zone over the land , forming a | |
| 00:44 | lovely sea breeze . But you may have noticed you | |
| 00:46 | don't need a beach to feel a breeze . Nope | |
| 00:49 | wind is everywhere . Air is constantly moving all around | |
| 00:53 | the world in cycles or currents . Sometimes they're small | |
| 00:57 | , like a light breeze blowing off the sea and | |
| 00:59 | sometimes their massive , mighty rivers of wind . Let's | |
| 01:03 | see how currents move around the world . Yeah . | |
| 01:07 | You know the Earth is a sphere so the sun's | |
| 01:11 | rays hit the middle of the Earth straight on this | |
| 01:14 | part of the Earth receives direct sunlight . Meanwhile , | |
| 01:17 | Earth's poles receive indirect sunlight or sunlight coming in at | |
| 01:20 | an angle here , the light is spread out over | |
| 01:23 | a larger area and is less intense . This means | |
| 01:26 | the Earth's equator is much warmer than the polls . | |
| 01:28 | I mean you wouldn't pack a swimsuit for a trip | |
| 01:30 | to the arctic . And you know that when we | |
| 01:32 | have different temperatures , we're going to have different pressure | |
| 01:34 | zones . The area around the equator is a low | |
| 01:37 | pressure zone here . The warm air rises and starts | |
| 01:40 | to slowly move towards the poles . Now if the | |
| 01:43 | Earth weren't spinning on an axis and if it didn't | |
| 01:45 | tilt and if it wasn't covered in water , then | |
| 01:48 | the warm air at the equator would just rise toward | |
| 01:50 | the poles and the cool air would move in at | |
| 01:52 | the equator where the warm air just left . This | |
| 01:54 | would create two giant air currents called cells . But | |
| 01:58 | of course things on earth are much more interesting . | |
| 02:01 | The sun hits the equator , causing warm air to | |
| 02:03 | rise in . The air moves away from the equator | |
| 02:06 | , but it doesn't have time to get all the | |
| 02:08 | way to the polls . About a third of the | |
| 02:10 | way the air cools falls and moves toward the equator | |
| 02:13 | again , creating a smaller cell . Another cell is | |
| 02:15 | created in the mid latitudes and another at the polls | |
| 02:18 | . In each cell , cold air sinks and warm | |
| 02:21 | air rises . There are six of these cells circling | |
| 02:24 | in the Earth's atmosphere and at the boundaries of these | |
| 02:26 | cells , something really weird starts to happen . We | |
| 02:29 | get jet streams walk erin these cells is trying extra | |
| 02:34 | hard to get from one pressure zone to another , | |
| 02:36 | since there's a big temperature difference between the air over | |
| 02:38 | the poles and the air over the mid latitudes . | |
| 02:41 | But the Earth is spinning faster at the equator than | |
| 02:43 | at the poles . If you were to stand at | |
| 02:45 | the Earth's axis on the north pole , you would | |
| 02:47 | spin around more slowly than if you're standing on the | |
| 02:50 | equator . So as air rises over the equator and | |
| 02:52 | makes its way toward the poles , it keeps moving | |
| 02:54 | eastward at the same rate , even though the higher | |
| 02:56 | it goes , the slower the Earth is spinning . | |
| 02:58 | This creates ribbons of very fast moving air called jet | |
| 03:02 | streams , jet streams moving wiggly patterns across Earth , | |
| 03:05 | caused by the interaction with other high and low pressure | |
| 03:08 | systems . And also with seasonal changes to these streams | |
| 03:11 | are usually between 6 to 14 kilometers off the ground | |
| 03:14 | and can reach speeds of 442 kilometers per hour , | |
| 03:18 | simple enough . But of course there's more we know | |
| 03:21 | from our little trip to the beach that there are | |
| 03:23 | other factors here remember are nice sea breeze , those | |
| 03:26 | small differences between high and low pressure caused by the | |
| 03:29 | heating of the land and water taking place on all | |
| 03:32 | the coastlines around the world . This makes air patterns | |
| 03:35 | even more complicated and jet streams and wind patterns aren't | |
| 03:39 | the only currents flowing around the world . Water actually | |
| 03:42 | moves a lot like air , warm light water rises | |
| 03:45 | and cold , salty heavy water sinks and just like | |
| 03:48 | with air , the sun heats the water that's at | |
| 03:50 | the equator and that warm water then spreads out toward | |
| 03:53 | the poles . Cold water slowly moving back down toward | |
| 03:55 | the equator where it'll warm again in an endless cycle | |
| 03:58 | . This massive movement of water called ocean currents helps | |
| 04:02 | regulate global temperatures just as much as air circulation . | |
| 04:05 | All of this interaction between the land air and water | |
| 04:08 | creates some pretty complicated wind weather and climate patterns . | |
| 04:12 | These currents make large parts of earth livable without them | |
| 04:15 | . The polls would be far too cold and the | |
| 04:17 | equator scorching hot . So currents are a little complicated | |
| 04:25 | and messy and they're always on the move there caused | |
| 04:28 | by uneven heating of the Earth's surface , whether that's | |
| 04:30 | between land and water or between the poles and the | |
| 04:33 | equator , and they're all driven by energy from the | |
| 04:35 | sun . Without that energy , our air and water | |
| 04:38 | would be still . And all of these complex currents | |
| 04:41 | blowing and flowing around all over the place makes it | |
| 04:44 | really hard to predict where the wind will blow and | |
| 04:46 | therefore what kind of whether you're going to have next | |
| 04:49 | week . But that's a problem we'll explore in another | |
| 04:51 | episode , and until then , I'm gonna keep planning | |
| 04:53 | my beach vacation |
Summarizer
DESCRIPTION:
OVERVIEW:
Current Events: Crash Course Kids #34.1 is a free educational video by Crash Course Kids.
This page not only allows students and teachers view Current Events: Crash Course Kids #34.1 videos but also find engaging Sample Questions, Apps, Pins, Worksheets, Books related to the following topics.
GRADES:
STANDARDS:
