[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.09,0:00:04.86,Default,,0000,0000,0000,,There's an invisible force shaping our lives,\Naffecting the weather, climate, land, economy,
Dialogue: 0,0:00:04.86,0:00:10.71,Default,,0000,0000,0000,,and whether a flag looks majestic or just\Nkind of... sits there. I'm talking, of course, about the wind.
Dialogue: 0,0:00:10.71,0:00:14.25,Default,,0000,0000,0000,,Large parts of the globe are brought warmth\Nand water thanks to wind. In Europe, wind
Dialogue: 0,0:00:14.25,0:00:18.86,Default,,0000,0000,0000,,energy is one of the most popular renewable\Nenergies, thanks to wind turbines that harness its power.
Dialogue: 0,0:00:18.86,0:00:22.17,Default,,0000,0000,0000,,Ships with sails have followed the path of\Nthe wind for centuries, bringing trade and
Dialogue: 0,0:00:22.17,0:00:24.01,Default,,0000,0000,0000,,entire empires along with them.
Dialogue: 0,0:00:24.01,0:00:27.75,Default,,0000,0000,0000,,Fierce winds can also bring destruction, stripping\Nsoil away from the ground or even ripping
Dialogue: 0,0:00:27.75,0:00:28.86,Default,,0000,0000,0000,,apart buildings.
Dialogue: 0,0:00:28.86,0:00:32.40,Default,,0000,0000,0000,,Trying to protect ourselves from the wind\Nmight feel like we're battling an imaginary foe.
Dialogue: 0,0:00:32.40,0:00:36.97,Default,,0000,0000,0000,,But wind is definitely not imaginary -- geographers\Nhave defined it and have tools to measure
Dialogue: 0,0:00:36.97,0:00:42.06,Default,,0000,0000,0000,,it! Whether it's a gentle sea breeze or gale-force\Ngusts, wind is any horizontal movement of
Dialogue: 0,0:00:42.06,0:00:46.83,Default,,0000,0000,0000,,air. And air is a mixture of nitrogen, oxygen,\Nand other gases that blend together so well,
Dialogue: 0,0:00:46.83,0:00:48.33,Default,,0000,0000,0000,,they tend to act as one.
Dialogue: 0,0:00:48.33,0:00:51.83,Default,,0000,0000,0000,,Winds are named based on what direction they\Ncome from, and some people are even named
Dialogue: 0,0:00:51.83,0:00:57.28,Default,,0000,0000,0000,,after winds! My name, Alizé, means the northeasterly\Ntrade winds in French -- or les vents Alizés,
Dialogue: 0,0:00:57.28,0:01:01.26,Default,,0000,0000,0000,,the Alizé winds. With a French sailor for\Na father who used to love sailing the warm
Dialogue: 0,0:01:01.26,0:01:04.31,Default,,0000,0000,0000,,northeasterly trade winds, it’s no surprise\Nwhere this came from!
Dialogue: 0,0:01:04.31,0:01:08.67,Default,,0000,0000,0000,,So let's get deeper into the science of where\Nwind comes from -- it’ll be a whirlwind
Dialogue: 0,0:01:08.67,0:01:09.67,Default,,0000,0000,0000,,of an adventure.
Dialogue: 0,0:01:09.67,0:01:12.27,Default,,0000,0000,0000,,I’m Alizé Carrère and this is Crash Course\NGeography.
Dialogue: 0,0:01:12.27,0:01:19.98,Default,,0000,0000,0000,,INTRO
Dialogue: 0,0:01:19.98,0:01:23.51,Default,,0000,0000,0000,,If we zoom out to look at the globe as a whole,\Nwe can see that there are global wind patterns
Dialogue: 0,0:01:23.51,0:01:26.98,Default,,0000,0000,0000,,just like there are global air temperature\Npatterns. And these are intimately linked.
Dialogue: 0,0:01:26.98,0:01:30.85,Default,,0000,0000,0000,,We know that insolation from the Sun doesn’t\Nget distributed evenly and ends up heating
Dialogue: 0,0:01:30.85,0:01:35.06,Default,,0000,0000,0000,,places differently. The temperature of a place\Nis tied to several key factors like latitude,
Dialogue: 0,0:01:35.06,0:01:39.47,Default,,0000,0000,0000,,elevation, how far it is from the ocean or\Nsea, and even what type of surface it is and
Dialogue: 0,0:01:39.47,0:01:41.30,Default,,0000,0000,0000,,how much of the Sun’s energy it absorbs.
Dialogue: 0,0:01:41.30,0:01:45.33,Default,,0000,0000,0000,,No matter where we are though, air that’s\Nwarm is lighter, less dense, and tends to
Dialogue: 0,0:01:45.33,0:01:49.70,Default,,0000,0000,0000,,rise. Cool air, on the other hand, is heavier,\Nmore dense, and tends to sink.
Dialogue: 0,0:01:49.70,0:01:53.51,Default,,0000,0000,0000,,And you did hear me correctly -- there's lighter\Nair and heavier air because air molecules
Dialogue: 0,0:01:53.51,0:01:58.20,Default,,0000,0000,0000,,all have weight. Not a lot, but still weight.\NThe weight of air then leads to atmospheric
Dialogue: 0,0:01:58.20,0:02:03.09,Default,,0000,0000,0000,,pressure, which comes from all the air above\Nthat's pressing down on whatever air there is below.
Dialogue: 0,0:02:03.09,0:02:06.24,Default,,0000,0000,0000,,So the pressure is much higher where I’m\Nstanding in Miami than if we were filming
Dialogue: 0,0:02:06.24,0:02:11.40,Default,,0000,0000,0000,,this close to outer space. Down here, there’s\Nall 480 kilometers of atmosphere squishing
Dialogue: 0,0:02:11.40,0:02:15.60,Default,,0000,0000,0000,,down on us. In fact, it’s likely close to\Nstandard sea level pressure -- which is exactly
Dialogue: 0,0:02:15.60,0:02:18.59,Default,,0000,0000,0000,,what it sounds like: the average atmospheric\Npressure at sea level.
Dialogue: 0,0:02:18.59,0:02:22.27,Default,,0000,0000,0000,,We don’t crumple like aluminum cans under\Nthis enormous pressure because the air and
Dialogue: 0,0:02:22.27,0:02:26.66,Default,,0000,0000,0000,,water inside us exert an equal amount of pressure\Noutwards. And the exact atmospheric pressure
Dialogue: 0,0:02:26.66,0:02:31.16,Default,,0000,0000,0000,,in other places will be different depending\Non where we are, the season, or even the time of day.
Dialogue: 0,0:02:31.16,0:02:34.63,Default,,0000,0000,0000,,Wind is actually the atmosphere’s way of\Nsmoothing out pressure differences, which
Dialogue: 0,0:02:34.63,0:02:38.71,Default,,0000,0000,0000,,can be created by the daily and seasonal air\Ntemperature patterns across Earth’s surface.
Dialogue: 0,0:02:38.71,0:02:42.46,Default,,0000,0000,0000,,Meteorologists, who study the atmosphere,\Nuse air pressure measurements to forecast
Dialogue: 0,0:02:42.46,0:02:46.63,Default,,0000,0000,0000,,the weather. Like, a weather report on TV\Nmight show a map full of H’s and L’s,
Dialogue: 0,0:02:46.63,0:02:48.43,Default,,0000,0000,0000,,which is actually a map tracking air pressure.
Dialogue: 0,0:02:48.43,0:02:53.66,Default,,0000,0000,0000,,A giant L stands for low pressure, or a low.\NOn a global scale, a low is an area where
Dialogue: 0,0:02:53.66,0:02:57.38,Default,,0000,0000,0000,,the pressure near the surface is less than\Nstandard sea level pressure. But on a local
Dialogue: 0,0:02:57.38,0:03:01.06,Default,,0000,0000,0000,,scale like on your local weather report, a\Nlow can also be an area where the pressure
Dialogue: 0,0:03:01.06,0:03:04.70,Default,,0000,0000,0000,,is less than in the surrounding area because\Nthere’s actually slightly less air pressing
Dialogue: 0,0:03:04.70,0:03:06.51,Default,,0000,0000,0000,,down on that part of the Earth.
Dialogue: 0,0:03:06.51,0:03:10.27,Default,,0000,0000,0000,,Lows go by lots of names. Like you might hear\Nit called a depression or even a cyclone.
Dialogue: 0,0:03:10.27,0:03:13.96,Default,,0000,0000,0000,,Though it’s not the giant spinning vortex\Nof air we might think of -- that’s a specific
Dialogue: 0,0:03:13.96,0:03:17.75,Default,,0000,0000,0000,,weather event that only forms in tropical\Noceans. But we’ll come back to that in upcoming
Dialogue: 0,0:03:17.75,0:03:18.75,Default,,0000,0000,0000,,episodes.
Dialogue: 0,0:03:18.75,0:03:22.26,Default,,0000,0000,0000,,To keep it simple, we’ll just call it a\Nlow. Lows exist either because air is being
Dialogue: 0,0:03:22.26,0:03:26.78,Default,,0000,0000,0000,,heated and expands up and out, or air higher\Nup in the atmosphere is spreading out, so
Dialogue: 0,0:03:26.78,0:03:29.03,Default,,0000,0000,0000,,there’s less air pressing down on Earth’s\Nsurface.
Dialogue: 0,0:03:29.03,0:03:32.86,Default,,0000,0000,0000,,Down on the ground, we might even be able\Nto tell we’re in a low. As air expands and
Dialogue: 0,0:03:32.86,0:03:36.47,Default,,0000,0000,0000,,rises, winds are drawn towards the center.\NThe rising air cools, and moisture in the
Dialogue: 0,0:03:36.47,0:03:40.21,Default,,0000,0000,0000,,air condenses into droplets. So if we happen\Nto be in the center of a low, the weather
Dialogue: 0,0:03:40.21,0:03:41.93,Default,,0000,0000,0000,,would often be pretty cloudy and rainy.
Dialogue: 0,0:03:41.93,0:03:45.89,Default,,0000,0000,0000,,The giant H’s on the map mark high pressure\Nareas, which we call a high or anticyclone.
Dialogue: 0,0:03:45.89,0:03:50.56,Default,,0000,0000,0000,,In a high pressure cell, either the air is\Ncooling and becoming denser, so it sinks,
Dialogue: 0,0:03:50.56,0:03:54.10,Default,,0000,0000,0000,,or the atmosphere high above is piling up,\Npushing the air below it downward.
Dialogue: 0,0:03:54.10,0:03:57.97,Default,,0000,0000,0000,,Sinking compresses air molecules together\Nand makes them warm. So any water vapor in
Dialogue: 0,0:03:57.97,0:04:02.08,Default,,0000,0000,0000,,the air won’t cool to condense into liquid\Nwater. That means high pressure systems bring
Dialogue: 0,0:04:02.08,0:04:03.60,Default,,0000,0000,0000,,weather that’s clear and sunny, which
Dialogue: 0,0:04:03.60,0:04:05.52,Default,,0000,0000,0000,,I remember as H stands for “happy”.
Dialogue: 0,0:04:05.52,0:04:10.26,Default,,0000,0000,0000,,High and low pressure cells are usually large\N-- like they can be 1000 kilometers across.
Dialogue: 0,0:04:10.26,0:04:13.90,Default,,0000,0000,0000,,And air moving between these vast areas to\Nbalance out energy in the atmosphere helps
Dialogue: 0,0:04:13.90,0:04:17.93,Default,,0000,0000,0000,,us understand and identify the winds. The\Nkey is the difference or change in pressure
Dialogue: 0,0:04:17.93,0:04:22.59,Default,,0000,0000,0000,,between highs and lows, which is called a \Npressure gradient. Like any fluid, air wants
Dialogue: 0,0:04:22.59,0:04:24.11,Default,,0000,0000,0000,,to flow from high to low pressure.
Dialogue: 0,0:04:24.11,0:04:27.50,Default,,0000,0000,0000,,Let’s start on a small scale, and look at\Nan island. When the beaches and land warm
Dialogue: 0,0:04:27.50,0:04:32.17,Default,,0000,0000,0000,,up faster during the day than the surrounding\Nsea, the air over the island expands, rises,
Dialogue: 0,0:04:32.17,0:04:35.54,Default,,0000,0000,0000,,and lowers the pressure at the surface. \NThat leaves room for air from the sea to rush
Dialogue: 0,0:04:35.54,0:04:39.52,Default,,0000,0000,0000,,onto the land, and voilà -- any windsurfer\Nor sun tanner will get a cool sea breeze in
Dialogue: 0,0:04:39.52,0:04:40.52,Default,,0000,0000,0000,,the afternoon.
Dialogue: 0,0:04:40.52,0:04:44.67,Default,,0000,0000,0000,,And similar things happen at a bigger scale\Nacross the globe! Air at the equator is consistently
Dialogue: 0,0:04:44.67,0:04:48.64,Default,,0000,0000,0000,,warmed by the Sun and tends to expand and\Nrise, so we get a belt of low pressure around
Dialogue: 0,0:04:48.64,0:04:52.74,Default,,0000,0000,0000,,the Earth called the equatorial trough. And\Nwe’d expect the poles to experience high
Dialogue: 0,0:04:52.74,0:04:54.82,Default,,0000,0000,0000,,pressure, because the air there is cold and\Nsinking.
Dialogue: 0,0:04:54.82,0:04:59.15,Default,,0000,0000,0000,,But winds don’t just blow north and south.\NThis is because the Earth rotates. To see
Dialogue: 0,0:04:59.15,0:05:02.51,Default,,0000,0000,0000,,what really happens to these winds, let’s\Nimagine we’re flying an airplane from the
Dialogue: 0,0:05:02.51,0:05:07.40,Default,,0000,0000,0000,,North Pole to the South Pole, with a layover\Nin Ecuador on the equator. Let’s go to the Thought Bubble.
Dialogue: 0,0:05:07.40,0:05:08.98,Default,,0000,0000,0000,,Hello this is Captain Carrère speaking.
Dialogue: 0,0:05:08.98,0:05:13.48,Default,,0000,0000,0000,,If you look out the windows, you’ll see\Nthe surface of the Earth slowly rotating eastwards.
Dialogue: 0,0:05:13.48,0:05:17.58,Default,,0000,0000,0000,,So in order to stay on a “straight” path,\Nwe have to constantly make little turns.
Dialogue: 0,0:05:17.58,0:05:21.87,Default,,0000,0000,0000,,This phenomenon that causes moving objects\N-- like our plane or air or water -- to
Dialogue: 0,0:05:21.87,0:05:26.11,Default,,0000,0000,0000,,seem like they curve as they travel over the\Nrotating Earth is known as the Coriolis effect.
Dialogue: 0,0:05:26.11,0:05:30.55,Default,,0000,0000,0000,,The Earth is rotating beneath our plane, but\Nalso as we travel towards the equator, the
Dialogue: 0,0:05:30.55,0:05:34.40,Default,,0000,0000,0000,,Earth actually rotates faster because the\NEarth is bigger at the equator and it has
Dialogue: 0,0:05:34.40,0:05:35.57,Default,,0000,0000,0000,,to move faster to keep up.
Dialogue: 0,0:05:35.57,0:05:39.57,Default,,0000,0000,0000,,It’s like a marching band turning a corner\N-- if they want to stay together in a straight
Dialogue: 0,0:05:39.57,0:05:43.54,Default,,0000,0000,0000,,line, the marchers on the inside of the circle\Ntake much smaller steps and move slower than
Dialogue: 0,0:05:43.54,0:05:44.69,Default,,0000,0000,0000,,the marchers on the outside.
Dialogue: 0,0:05:44.69,0:05:47.77,Default,,0000,0000,0000,,So if we’re at the poles, we’d just kind\Nof spin in place.
Dialogue: 0,0:05:47.77,0:05:51.84,Default,,0000,0000,0000,,But as latitude decreases, our rotational\Nspeed increases until we get to the equator
Dialogue: 0,0:05:51.84,0:05:57.00,Default,,0000,0000,0000,,and the Earth’s surface practically zooms\Nby at 1600 kilometers per hour -- which is
Dialogue: 0,0:05:57.00,0:05:59.54,Default,,0000,0000,0000,,about twice as fast as our plane.
Dialogue: 0,0:05:59.54,0:06:03.48,Default,,0000,0000,0000,,Then as our plane gets closer and closer to\NEcuador and the equator, our rotational momentum
Dialogue: 0,0:06:03.48,0:06:07.04,Default,,0000,0000,0000,,comes from the slow speeds at the North Pole,\Nnot the rapidly rotating equator.
Dialogue: 0,0:06:07.04,0:06:11.04,Default,,0000,0000,0000,,Which means we end up getting deflected to\Nthe right into the Pacific Ocean and have
Dialogue: 0,0:06:11.04,0:06:12.76,Default,,0000,0000,0000,,to make little left turns to get to Ecuador.
Dialogue: 0,0:06:12.76,0:06:16.33,Default,,0000,0000,0000,,Something similar happens on our second flight\Ntoward the South Pole.
Dialogue: 0,0:06:16.33,0:06:19.64,Default,,0000,0000,0000,,But this time we started out rotating faster\Nthan our final destination.
Dialogue: 0,0:06:19.64,0:06:24.41,Default,,0000,0000,0000,,So as we make our final approach to the South\NSandwich Islands we’d get deflected left
Dialogue: 0,0:06:24.41,0:06:27.14,Default,,0000,0000,0000,,and end up east of where we want to be if\Nwe didn’t correct.
Dialogue: 0,0:06:27.14,0:06:31.83,Default,,0000,0000,0000,,Please make sure your seatbelts are fastened\Nand your tray tables are stowed as we prepare for landing!
Dialogue: 0,0:06:31.83,0:06:36.00,Default,,0000,0000,0000,,Thanks, Thought Bubble. In general, the Coriolis\Neffect deflects objects to the right in the
Dialogue: 0,0:06:36.00,0:06:38.56,Default,,0000,0000,0000,,Northern Hemisphere and to the left in the\NSouthern Hemisphere.
Dialogue: 0,0:06:38.56,0:06:42.10,Default,,0000,0000,0000,,Which is how we get those wind spirals around\Nthe low and high pressures areas on our weather
Dialogue: 0,0:06:42.10,0:06:46.76,Default,,0000,0000,0000,,map, and why they’re also called cyclones\Nand anticyclones. The air wants to rush directly
Dialogue: 0,0:06:46.76,0:06:49.95,Default,,0000,0000,0000,,from the center of the high to the center\Nof the low but gets deflected.
Dialogue: 0,0:06:49.95,0:06:54.23,Default,,0000,0000,0000,,So in our model, the heated air at the equator\Nfirst rises upward towards the tropopause,
Dialogue: 0,0:06:54.23,0:06:57.24,Default,,0000,0000,0000,,which is the boundary between the troposphere\Nand the stratosphere, as it tries to move
Dialogue: 0,0:06:57.24,0:06:59.16,Default,,0000,0000,0000,,poleward high up in the atmosphere.
Dialogue: 0,0:06:59.16,0:07:02.93,Default,,0000,0000,0000,,Then as it moves away from the equator, the\NCoriolis effect causes air traveling northwards
Dialogue: 0,0:07:02.93,0:07:07.76,Default,,0000,0000,0000,,to turn right, speeding faster east the further\Nnorth it gets. The air is also cooling, and
Dialogue: 0,0:07:07.76,0:07:11.43,Default,,0000,0000,0000,,by the time it sinks back to the surface,\Nit’s only reached around 30 degrees latitude.
Dialogue: 0,0:07:11.43,0:07:15.51,Default,,0000,0000,0000,,So instead of one big circulation cycle, as\Nproposed by George Hadley, an English lawyer
Dialogue: 0,0:07:15.51,0:07:20.47,Default,,0000,0000,0000,,and amateur meteorologist, who first described\Nit in 1735, we get a more complicated circulation
Dialogue: 0,0:07:20.47,0:07:22.46,Default,,0000,0000,0000,,system containing the Hadley cell.
Dialogue: 0,0:07:22.46,0:07:25.78,Default,,0000,0000,0000,,Hadley wanted to understand why surface winds\Nthat should have blown straight south towards
Dialogue: 0,0:07:25.78,0:07:29.19,Default,,0000,0000,0000,,the equator -- along the pressure gradient\Nfrom high pressure to low pressure -- took
Dialogue: 0,0:07:29.19,0:07:33.45,Default,,0000,0000,0000,,a turn west. Solving that mystery would help\Nensure European trading ships would safely
Dialogue: 0,0:07:33.45,0:07:36.21,Default,,0000,0000,0000,,reach the shores -- and goods -- of the Americas.
Dialogue: 0,0:07:36.21,0:07:39.83,Default,,0000,0000,0000,,This isn’t the first time our understanding\Nof the winds has gone hand in hand with exploration,
Dialogue: 0,0:07:39.83,0:07:43.67,Default,,0000,0000,0000,,and trade, wealth, and power were driven by\Nthe winds. For instance, new technologies
Dialogue: 0,0:07:43.67,0:07:47.95,Default,,0000,0000,0000,,created in the 1400s like the quadrant and\Nthe astrolabe enabled accurate navigation
Dialogue: 0,0:07:47.95,0:07:50.45,Default,,0000,0000,0000,,and mapping of ocean currents, winds, and\Ntrade routes.
Dialogue: 0,0:07:50.45,0:07:54.29,Default,,0000,0000,0000,,Over the years many more scientific minds\Nhave explored the implications of Hadley’s
Dialogue: 0,0:07:54.29,0:07:57.25,Default,,0000,0000,0000,,theory, and we’re still learning more as\Nwe explore the movement of energy between
Dialogue: 0,0:07:57.25,0:07:58.86,Default,,0000,0000,0000,,the atmosphere and biosphere.
Dialogue: 0,0:07:58.86,0:08:03.44,Default,,0000,0000,0000,,We know now that in reality, air in both hemispheres\Nconverges in the narrow band around the equator
Dialogue: 0,0:08:03.44,0:08:06.23,Default,,0000,0000,0000,,called the intertropical convergence zone and rises.
Dialogue: 0,0:08:06.23,0:08:10.09,Default,,0000,0000,0000,,The surface winds, or doldrums, that form\Nhere as the air converges and rises upwards
Dialogue: 0,0:08:10.09,0:08:14.83,Default,,0000,0000,0000,,are light and not super reliable. Sailing\Nships could get stuck in the doldrums for days.
Dialogue: 0,0:08:14.83,0:08:18.44,Default,,0000,0000,0000,,Similarly weak winds are found on the poleward\Nedges of the Hadley cells, where air is being
Dialogue: 0,0:08:18.44,0:08:22.22,Default,,0000,0000,0000,,forced down, creating high pressure zones\Ncentered at about 30 degrees latitude called
Dialogue: 0,0:08:22.22,0:08:24.44,Default,,0000,0000,0000,,the subtropical high pressure belts.
Dialogue: 0,0:08:24.44,0:08:28.67,Default,,0000,0000,0000,,Sailors of yore were often forced to eat their\Nhorses or throw them overboard in these “horse
Dialogue: 0,0:08:28.67,0:08:32.41,Default,,0000,0000,0000,,latitudes” to conserve drinking water and\Nlighten the weight while the sailing ships
Dialogue: 0,0:08:32.41,0:08:37.16,Default,,0000,0000,0000,,waited for the weak winds at the center of\Nthese highs to pick up. [Wow, that’s pretty dark.]
Dialogue: 0,0:08:37.16,0:08:39.73,Default,,0000,0000,0000,,In between these high and low pressure belts,
Dialogue: 0,0:08:39.73,0:08:43.59,Default,,0000,0000,0000,,there are strong and reliable winds spiraling\Noutwards from the subtropical high pressure
Dialogue: 0,0:08:43.59,0:08:49.87,Default,,0000,0000,0000,,belt towards the equator. These are the easterly\NTrade Winds -- and they’re my favorite winds, obviously!
Dialogue: 0,0:08:49.87,0:08:53.32,Default,,0000,0000,0000,,Many ships have depended on the trade winds,\Nlike early Spanish sailing ships as they sought
Dialogue: 0,0:08:53.32,0:08:56.69,Default,,0000,0000,0000,,God, glory, and gold in what we now call Central\Nand South America.
Dialogue: 0,0:08:56.69,0:09:00.38,Default,,0000,0000,0000,,Of course, making the return trip was another\Nmatter. The ancient mariners of the Spanish
Dialogue: 0,0:09:00.38,0:09:04.42,Default,,0000,0000,0000,,galleons going home from the Americas plotted\Na course using the winds blowing poleward
Dialogue: 0,0:09:04.42,0:09:08.90,Default,,0000,0000,0000,,from the subtropical high pressure belt. These\NWesterlies are strongly deflected to the right
Dialogue: 0,0:09:08.90,0:09:10.30,Default,,0000,0000,0000,,and blow from the southwest.
Dialogue: 0,0:09:10.30,0:09:14.25,Default,,0000,0000,0000,,These strong winds blow towards another low\Npressure belt called the subpolar lows where
Dialogue: 0,0:09:14.25,0:09:18.74,Default,,0000,0000,0000,,they clash with the polar Easterlies blowing\Nfrom the frigid, very high pressure poles.
Dialogue: 0,0:09:18.74,0:09:21.82,Default,,0000,0000,0000,,In the Southern Hemisphere, they blow with\Ngreater strength as there’s very little
Dialogue: 0,0:09:21.82,0:09:24.24,Default,,0000,0000,0000,,land in these latitudes to interrupt their\Nflow.
Dialogue: 0,0:09:24.24,0:09:28.30,Default,,0000,0000,0000,,So altogether, on our idealized Earth we’ve\Nseen that there are actually seven pressure
Dialogue: 0,0:09:28.30,0:09:33.99,Default,,0000,0000,0000,,belts: two polar highs, two subpolar lows,\Ntwo subtropical highs and one equatorial low.
Dialogue: 0,0:09:33.99,0:09:36.68,Default,,0000,0000,0000,,And winds flow between these belts of high\Nand low pressure.
Dialogue: 0,0:09:36.68,0:09:41.37,Default,,0000,0000,0000,,On the real Earth, the belts are not so organized.\NThey form cells of pressure and we see more
Dialogue: 0,0:09:41.37,0:09:45.20,Default,,0000,0000,0000,,complex patterns of pressure and wind, as\Nthe cells shift with the seasons and vary
Dialogue: 0,0:09:45.20,0:09:50.03,Default,,0000,0000,0000,,between land and water. So our idealized Earth\Nis kind of like a wind and pressure map. It’s
Dialogue: 0,0:09:50.03,0:09:53.60,Default,,0000,0000,0000,,a simplified model that helps us understand\Nwhat’s happening on the real Earth.
Dialogue: 0,0:09:53.60,0:09:57.54,Default,,0000,0000,0000,,Just like the atmosphere works like a cell\Nmembrane, the winds are like Earth’s circulatory
Dialogue: 0,0:09:57.54,0:10:01.46,Default,,0000,0000,0000,,system. So many things vital to our planet\Nflow through the winds.
Dialogue: 0,0:10:01.46,0:10:05.13,Default,,0000,0000,0000,,During the voyages of discovery in the 15th\Nto 18th centuries -- which we now recognize
Dialogue: 0,0:10:05.13,0:10:08.99,Default,,0000,0000,0000,,weren’t really discoveries at all -- the\Nknowledge of winds, ocean currents, natural
Dialogue: 0,0:10:08.99,0:10:12.98,Default,,0000,0000,0000,,harbors and more was an essential foundation\Nfor circumnavigating the globe.
Dialogue: 0,0:10:12.98,0:10:17.34,Default,,0000,0000,0000,,And we continue to rely on the winds to power\Nour economies. As a renewable energy source,
Dialogue: 0,0:10:17.34,0:10:21.14,Default,,0000,0000,0000,,this silent force will continue to shape our\Nlives in the future. I hope wherever you are
Dialogue: 0,0:10:21.14,0:10:25.22,Default,,0000,0000,0000,,is in the center of a sunny high pressure\Narea which will be perfect weather to go with
Dialogue: 0,0:10:25.22,0:10:28.11,Default,,0000,0000,0000,,the flow in the ocean, which we’ll talk\Nabout next week.
Dialogue: 0,0:10:28.11,0:10:32.40,Default,,0000,0000,0000,,Many maps and borders represent modern geopolitical\Ndivisions that have often been decided without
Dialogue: 0,0:10:32.40,0:10:37.25,Default,,0000,0000,0000,,the consultation, permission, or recognition\Nof the land's original inhabitants. Many geographical
Dialogue: 0,0:10:37.25,0:10:40.97,Default,,0000,0000,0000,,place names also don't reflect the Indigenous\Nor Arboriginal peoples languages.
Dialogue: 0,0:10:40.97,0:10:44.72,Default,,0000,0000,0000,,So we at Crash Course want to acknowledge\Nthese peoples’ traditional and ongoing relationship
Dialogue: 0,0:10:44.72,0:10:47.86,Default,,0000,0000,0000,,with that land and all the physical and human\Ngeographical elements of it.
Dialogue: 0,0:10:47.86,0:10:51.20,Default,,0000,0000,0000,,We encourage you to learn about the history\Nof the place you call home through resources
Dialogue: 0,0:10:51.20,0:10:55.79,Default,,0000,0000,0000,,like native-land.ca and by engaging with your\Nlocal Indigenous and Aboriginal nations through
Dialogue: 0,0:10:55.79,0:10:58.39,Default,,0000,0000,0000,,the websites and resources they provide.
Dialogue: 0,0:10:58.39,0:11:01.55,Default,,0000,0000,0000,,Thanks for watching this episode of Crash\NCourse Geography. If you want to help keep
Dialogue: 0,0:11:01.55,0:11:05.54,Default,,0000,0000,0000,,all Crash Course free for everyone, forever,\Nyou can join our community on Patreon.