The Atmosphere

Summary

This environmental science video delves into the atmosphere's critical role, emphasizing the ozone layer's protection against UV radiation and the historical impact of CFCs. It outlines the successful Montreal Protocol in addressing the ozone depletion. The script further explains atmospheric layers, weather, climate, and the significance of convection cells and the Coriolis effect on global weather patterns. It concludes with the El Niño-Southern Oscillation (ENSO) and its influence on climate, highlighting humanity's interaction with Earth's systems.

Takeaways

• 🌍 The atmosphere is a gaseous layer surrounding Earth, and human activities are impacting it and pushing against planetary boundaries.
• 🛡️ The ozone layer, composed of three oxygen atoms, protects us from harmful UV radiation but was damaged by CFCs produced in the 1960s and 1970s.
• 🕳️ The 'hole in the ozone' over Antarctica is a significant environmental issue, leading to increased cancer rates and crop damage.
• 🏭 The industry initially resisted the cost of addressing the ozone depletion but eventually governments took action, leading to the Montreal Protocol in 1987, which banned CFCs.
• ♻️ The Montreal Protocol has been successful, leading to a decrease in CFCs and a gradual recovery of the ozone layer, expected to return to original levels by 2050.
• 🌡️ The atmosphere is divided into different layers: troposphere, stratosphere, mesosphere, thermosphere, and exosphere, with weather and climate being influenced by these layers.
• 🌪️ Atmospheric circulation, influenced by the Earth's tilt and orbit, creates weather patterns and seasons, with convection currents forming cells like the Hadley, Ferrel, and polar cells.
• 🌀 The Coriolis effect, due to Earth's rotation, influences weather patterns, causing winds to move in different directions in the northern and southern hemispheres.
• 🌊 Ocean currents, driven by atmospheric movements and influenced by temperature and salinity, play a significant role in shaping the climate.
• 🌊🔄 El Niño and La Niña are part of the ENSO (El Niño-Southern Oscillation) phenomenon, representing oscillations in Pacific Ocean temperatures that affect global weather patterns.
• 🌳🏜️ Biomes distribution on Earth, such as tropical rainforests, deserts, and boreal forests, is influenced by latitude, tilt of the Earth, and climate patterns.

Q & A

What is the atmosphere and why is it important?

The atmosphere is the layer of gases surrounding the Earth, which we live in. It is important because it provides us with air to breathe and protects us from harmful solar radiation, such as ultraviolet (UV) rays.

What is the role of ozone in the atmosphere?

Ozone plays a crucial role in the atmosphere by protecting us from harmful UV radiation. The 'good' ozone, composed of three oxygen atoms, is found in the stratosphere and shields the Earth's surface from these damaging rays.

What were CFCs and how did they affect the ozone layer?

CFCs, or chlorofluorocarbons, were chemicals used in the past for refrigeration and aerosol propellants. They contributed to the depletion of the ozone layer by releasing chlorine atoms when exposed to UV radiation, which then reacted with and destroyed ozone molecules.

What is the 'ozone hole' and what are its consequences?

The 'ozone hole' refers to the significant depletion of the ozone layer over Antarctica. The consequences of this depletion include an increased risk of skin cancer in humans, damage to crops, and harm to the overall ecosystem.

What is the Montreal Protocol and why was it established?

The Montreal Protocol is an international treaty signed in 1987 to phase out the production of substances responsible for ozone depletion, including CFCs. It was established as a global response to the problem of ozone depletion and has been successful in reducing the use of these harmful substances.

What are the different layers of the Earth's atmosphere?

The Earth's atmosphere is divided into several layers: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Each layer has distinct characteristics and plays a different role in the overall atmospheric system.

How does the tilt of the Earth's axis affect our climate?

The tilt of the Earth's axis causes seasonal changes due to the variation in the amount of sunlight received at different latitudes throughout the year. This tilt, combined with the Earth's orbit around the Sun, leads to the distinct seasons we experience.

What are convection cells and how do they influence weather patterns?

Convection cells are large-scale circulation patterns in the atmosphere caused by uneven heating of the Earth's surface. They include the Hadley cell, Ferrel cell, and polar cell, and they play a significant role in distributing heat and moisture around the planet, influencing weather patterns.

What is the Coriolis effect and how does it affect atmospheric circulation?

The Coriolis effect is the apparent deflection of the path of an object moving in a rotating system, such as the Earth. It influences atmospheric circulation by causing winds to turn right in the Northern Hemisphere and left in the Southern Hemisphere, affecting weather patterns and ocean currents.

What is El Niño and how does it impact global climate?

El Niño is a climate pattern characterized by unusually warm ocean temperatures in the equatorial Pacific Ocean. It impacts global climate by altering weather patterns, often causing drought in some areas and heavy rainfall in others, and is part of the larger ENSO (El Niño-Southern Oscillation) cycle.

How do ocean currents relate to atmospheric circulation and climate?

Ocean currents, which are influenced by atmospheric circulation, play a significant role in climate by redistributing heat across the planet. They can moderate the climate of coastal regions and influence weather patterns by interacting with the atmosphere.

Outlines

00:00

🌍 Atmosphere and Ozone Layer Protection

Mr. Andersen introduces the environmental science video focusing on the atmosphere, our planet's gaseous envelope. He discusses the impact of society and economy on planetary boundaries and uses the stratospheric ozone layer, or 'good ozone', as an example. The ozone layer, composed of three oxygen atoms, shields us from harmful UV radiation. However, the production of CFCs in the 1960s and 1970s led to ozone depletion, causing a 'hole' over Antarctica and posing threats like increased cancer rates and crop damage. The solution was the Montreal Protocol of 1987, which banned CFCs, leading to a decrease in their levels and a recovery of the ozone layer expected by 2050. The video also covers the different layers of the atmosphere, weather versus climate, the role of the Earth's tilt and orbit in creating seasons, and atmospheric circulation influenced by convection currents and the Coriolis effect.

05:01

🌤️ Atmospheric Cells and Climate Patterns

This paragraph delves into the atmospheric circulation and its effects on climate. It explains how the Earth's tilt and orbit around the sun lead to unequal heating, forming convection cells such as the Hadley, Ferrel, and Polar cells. These cells, along with the Coriolis effect due to Earth's rotation, create weather patterns. The paragraph also discusses how ocean currents are influenced by atmospheric movements, affecting climate further. The El Niño-Southern Oscillation (ENSO) is introduced as a key phenomenon where oscillations between El Niño and La Niña occur, impacting global weather and climate. The summary emphasizes the importance of understanding these natural systems in predicting and adapting to climate changes.

10:02

🌊 Oceanic Currents and ENSO Dynamics

The final paragraph examines the oscillation between El Niño and La Niña within the ENSO system. It presents a historical graph showing the fluctuations from 1880 to 2010. The causes of these oscillations are explored through the Walker circulation in the Pacific Ocean, affected by the trade winds. During La Niña, stronger trade winds push warm water towards Australia, leading to cooler weather in Central America. Conversely, during El Niño, the trade winds weaken, and warm water moves eastward, affecting global weather patterns. The paragraph concludes by encouraging viewers to fill in a concept map to consolidate their understanding of the atmospheric levels, the ozone's role, climate influences, and the dynamics of ENSO.

Keywords

💡Atmosphere

The atmosphere is the layer of gases surrounding the Earth, which plays a crucial role in protecting life by absorbing ultraviolet solar radiation, warming the planet, and allowing for the existence of water in liquid form. In the video, the atmosphere is discussed as a series of spheres that surround the Earth, with different layers having distinct characteristics and functions. The video emphasizes the importance of the atmosphere in maintaining the Earth's climate and weather patterns.

💡Stratospheric Ozone

Stratospheric ozone, often referred to as 'good ozone,' is a trio of oxygen atoms (O3) that forms a protective layer in the Earth's atmosphere, primarily in the stratosphere. It is essential for life as it absorbs the majority of the Sun's harmful ultraviolet (UV) radiation. The video discusses how human-produced chlorofluorocarbons (CFCs) have historically depleted this ozone layer, leading to the infamous 'ozone hole,' and the subsequent international efforts to mitigate this through the Montreal Protocol.

💡CFCs (Chlorofluorocarbons)

CFCs are synthetic compounds containing carbon, chlorine, and fluorine atoms. They were once widely used in refrigeration, air conditioning, and aerosol propellants. The video explains how CFCs, when released into the atmosphere, can destroy stratospheric ozone by releasing chlorine atoms that react with ozone molecules. This process was a significant environmental concern highlighted in the 1960s and 1970s, leading to the creation of the Montreal Protocol to phase out CFCs.

💡Montreal Protocol

The Montreal Protocol is an international treaty adopted in 1987 to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. The video uses the Montreal Protocol as a successful example of global cooperation to address environmental issues, noting that it led to a decrease in CFCs and a subsequent recovery of the ozone layer.

💡Troposphere

The troposphere is the lowest layer of Earth's atmosphere, extending from the surface to about 8-15 kilometers above the Earth, depending on the latitude. It is the layer where weather occurs and where humans live. The video mentions that the troposphere contains the protective ozone layer at its boundary with the stratosphere and is also the region where 'bad' ozone, or smog, forms, which can be harmful to human health.

💡Climate

Climate refers to the long-term average of weather patterns in a particular region, including elements such as temperature, precipitation, and wind patterns. The video explains that climate is influenced by factors such as the Earth's tilt, its orbit around the Sun, and the distribution of land and water. Climate is a central theme in the video, as it is affected by atmospheric conditions and has significant implications for human life and the environment.

💡Hadley Cell

The Hadley cell is a circulation pattern in the Earth's atmosphere that moves air from the equator towards the poles. It is one of the key components of atmospheric circulation and plays a significant role in distributing heat around the planet. The video describes the Hadley cell as part of the convection currents that arise due to the unequal heating of the Earth's surface, with warm air rising near the equator and sinking at around 30 degrees latitude.

💡Coriolis Effect

The Coriolis effect is the apparent deflection of the path of an object moving in a rotating system, such as the Earth. It causes winds and ocean currents to turn to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The video explains how the Coriolis effect influences weather patterns and ocean currents, contributing to the overall circulation of the atmosphere.

💡ENSO (El Niño-Southern Oscillation)

ENSO is a climate pattern that describes the fluctuations in temperature between the ocean and the atmosphere in the eastern equatorial Pacific. It consists of two main states: El Niño, which is characterized by warmer-than-average ocean temperatures, and La Niña, which is characterized by cooler-than-average temperatures. The video discusses how ENSO affects global weather patterns and can lead to significant climate-related events, such as droughts and floods.

💡Albedo

Albedo is the measure of the reflectivity of a surface, indicating the proportion of the incident light or radiation that is reflected by that surface. In the context of the video, albedo is discussed as a factor that influences the Earth's climate by affecting how much solar radiation is absorbed or reflected by different surfaces, such as snow, vegetation, or water. The video explains that higher albedo results in less solar energy being absorbed, which can contribute to cooler temperatures.

Highlights

The atmosphere is the gas covering on our planet, crucial for life and affected by human activities.

Economic growth can push against planetary boundaries, necessitating a balance between industry and environmental protection.

Stratospheric ozone, or 'good ozone', protects the Earth from harmful UV radiation and is composed of three oxygen atoms.

CFCs, used in the 1960s and 1970s, damaged the ozone layer by releasing chlorine atoms that bind to oxygen, creating the ozone hole.

The ozone hole over Antarctica leads to increased cancer rates and damage to crops, highlighting the importance of the ozone layer.

The Montreal Protocol of 1987 was a successful international treaty that banned CFCs, leading to a decrease in their production and recovery of the ozone layer.

The atmosphere is divided into different layers, including the troposphere where we live, and the stratosphere where the protective ozone is found.

Weather represents the current state of the atmosphere, while climate is the long-term pattern influenced by Earth's tilt and orbit around the sun.

Seasons are a result of the Earth's tilt and its position in orbit, causing unequal heating and distinct weather patterns.

Convection currents and the Coriolis effect due to Earth's spin lead to atmospheric circulation, shaping weather patterns.

Ocean currents, influenced by atmospheric movements, play a significant role in shaping our climate.

El Niño and La Niña are part of the ENSO (El Niño-Southern Oscillation) phenomenon, impacting global weather and climate.

The troposphere contains the Earth's surface, mountains, and weather phenomena, including bad ozone or smog.

The stratosphere above the troposphere contains the protective ozone layer, crucial for blocking harmful UV radiation.

The mesosphere, thermosphere, and exosphere are higher layers of the atmosphere, with the exosphere bordering space.

Air density in the atmosphere increases closer to Earth due to higher gravitational pull.

Climate patterns, such as the distribution of rainforests and deserts, are influenced by Earth's tilt and orbit.

The Hadley cell, Ferrel cell, and polar cell are convection cells that contribute to atmospheric circulation and climate patterns.

The Coriolis effect influences weather patterns, causing winds to move in different directions in the northern and southern hemispheres.

ENSO's oscillation between El Niño and La Niña affects global weather, with the Walker circulation playing a key role in this process.

Transcripts

Hi.

It’s Mr. Andersen.

And this is environmental science video 4.

It is on the atmosphere, which is the gas covering on our planet.

Remember we live in the atmosphere and as society gets larger we are pushing against

these planetary boundaries.

And since the economy is pushing us towards that the economy is going to have to bring

us back.

A story that relates to this is the story of stratospheric ozone.

We call that good ozone.

It is made of three oxygen atoms.

And it surrounds the planet.

And it protects us from harmful UV radiation.

But in the 1960s and 1970s we were producing huge amount of CFCs.

The CFC, this is an example, it is a carbon fluorine, 3 chlorine molecules.

It would also go into the atmosphere, get hit by UV radiation, kicks off a chlorine,

binds to an oxygen atom, and now we have destroyed the ozone.

And so you probably heard of this hole in the ozone.

This one is right here over Antartica.

What is going to happen if we do not have that protective ozone, increase in cancer,

damage to crops.

And so this is a really big deal.

And so how do we solve that problem?

Industry is going to say, rightly so, we should not have to bare the cost of all of this.

It is going to cost us, you know, millions if not billions of dollars.

We are going to lose jobs.

But eventually the consensus came around and governments said we are going to have to solve

this problem.

And in 1987 they signed on to what is called the Montreal Protocol, where they banned CFCs.

That has lead to a decrease in CFCs, increase now of ozone.

It will probably return to its original levels 2050.

And so this is a great example of how governments can find together like form a treaty that

is incredibly successful.

And so the atmosphere surrounds the earth.

Scientists break it into a number of different spheres.

We have the tropo, stato, meso, thermo and exo sphere.

Now we live in the troposphere and that protective ozone is going to be found right at this boundary

between the two.

Weather is going to be the current state of our atmosphere.

And over a long period of time we call that climate, which is due to the tilt of our axis

and where we are in the orbit around the sun.

And so due to our location we get seasons.

We are pointed towards the sun in the summer and away from the sun in the winter.

But also since we are sphere we are starting to get unequal heating of the planet.

And those convection currents lead to cells in the atmosphere.

We have things like the hadley cell, the ferrel cell.

And what those are doing is moving the atmosphere around on our planet.

Now we also have a spinning planet and that creates something call the coriolis effect.

And so it spins in a characteristic way.

And so the combination of these two lead to atmospheric circulation.

It is moving the weather around on our planet.

Now the oceans also affect our climate.

And as the atmosphere moves around it starts to move the oceans.

And so we get these ocean currents, which are shaping our climate.

And an example of all of these things coming together in el Nino or Enso, the el Nino oscillation

which we will talk about in a little bit.

And so the atmosphere is a series of spheres that surround our planet.

This is not to scale but the lowest one is going to be the troposphere.

That is where our mountains are.

That is where we are.

When you are on a jet you are still within the troposphere.

About that we are going to have the stratosphere.

So weather balloons will move into that area.

If we look at ozone right, so this is going to be ozone right at the surface of the planet,

we are going to have some bad ozone.

We call that tropospheric or smog ozone that can be damaging to us.

We will talk about that later.

But as we move up in the troposphere into the stratosphere we are going to have a huge

increase in that ozone layer.

That is that protective layer around us.

Above the stratosphere we have the mesosphere.

That is where meteors are burning up.

Above that we have the aurora are.

That is going to be the thermosphere.

And then finally we are bordering space.

This is going to be the exosphere up here.

Now what are some conditions within the whole atmosphere?

We are going to increase density the closer we get to the earth because there is higher

gravitational pull the closer we are.

Now what is the atmosphere like today.

That is weather.

Is it raining?

Is it sunny?

What is the temperature?

And that is important.

But what is more important is climate.

That is going to be weather over a long period of time.

And if we look at this biomap you start to see some patterns.

And so if you can look right here we are going to have a bunch of tropical rainforest.

We will have deserts right here.

And if I put the latitudes over this, the one thing that I am always surprised is how

low the equator is.

So if we put this in at 0 degrees, then 30 and then 60, real patterns start to emerge.

So right here along the equator we going to have all of this precipitation.

Rainforests are going to be found there.

But look right here at 30 degrees, above and below, or northern and southern, we are going

to have these deserts.

And then we are going to have these big boreal forests out here.

And so all of that has to do with where the earth is in orbit and also the tilt of the

earth.

And so we get seasons due to the tilt of the earth as it moves around the sun.

This is obviously not to scale, but as the northern hemisphere is pointed toward the

sun, look here on the north pole, it is going to be 24 hours of daylight.

In the winter it is going to be 24 hours of night.

Right here we would have the equinoxes.

But depending on are we pointed towards the sun, summer or away from the sun, winter,

it is going to affect our weather and therefore our climate.

Remember everything would be reversed if we were in the southern hemisphere.

We also get unequal heating.

So if I, again not to scale, but if I were to put an atmosphere in here, as the suns

rays come in here at this part it is going through a very small amount of the atmosphere.

So we do not lose much heat.

But up here we are going to through more of the atmosphere.

It is going to be colder near the top.

If we remove that and just look at the light itself, right here this amount of sun rays

is all concentrated on this very small surface area.

But up here near the north pole it is spread out over a long surface area, a large surface

area.

So it is going to be cooler near the poles.

Now remember as we move around the sun that axis is going to tilt back and forth and so

that is going to affect us on a equal heating.

And the last thing that affects unequal heating is the albedo of the earth.

It is our reflectiveness.

So as the sunlight hits the snow, for example, it is going to be reflected off.

But if it hits vegetation or water for example, we are going to have a different amount of

albedo.

So it is a combination of all of these things that creates climate.

First one that is most important are going to be the cells on our planet.

What that means is right here at the equator we are heating up the air, most right here

along this point and so what we get are these convection cells.

So we heat up the air and it is moving up.

It becomes less dense and it is moving up.

Now what quickly happens to it is it actually cools down.

And so as it cools down we eventually reach something called the dew point.

That is where it cannot hold water anymore and we are going to have the formation of

clouds.

And then we are going to have precipitation.

Have you ever wondered why the bottoms of all of the clouds line up?

It is because we are cooling the air as it moves up until we hit that due point.

Now what happens eventually is that that atmosphere is going to start to drop down again.

And so we have another cell here and another cell here.

So if we were to look at the equator we are going to have a huge amount of precipitation

here, but remember at around 30 degrees all of that air is moving down, it actually is

being heated up and we are not going to have much precipitation there.

Or at the pole itself.

And so these will be affected by the tilt of the earth as well.

And so cells are important to understand, so I have turned the earth on its side.

So this is now equator, north pole.

So if we move from the equator to the north pole the first thing we see is a huge amount

of convection near the equator and you are going to have a huge amount of weather right

here.

It will eventually move up and then it slides down.

As it moves down it is going to actually heat up and we are not going to have much precipitation

at 30 degrees.

We call this first one the hadley cell.

It is named in honor of the person who proposed it.

Now if we keep moving, so again we are moving down to this next cell right here, we are

also going to have convection current that is moving the air up at 60 degrees north latitude

and south.

And then eventually it is going to be heated as it moves down.

So we are going to have more precipitation here.

We call this the ferrel cell.

It is named in honor of the person who proposed it.

And then finally we have a polar cell.

It is named in honor of . . ., no its not.

It is just near the pole.

And so the other things that contributes to atmospheric circulation is coriolis effect.

So again the earth is spinning.

Think of it like a record player spinning around.

If I were to tape something to the record player, like this cone, let’s say it represents

then mountains, as the record player spins the mountains are just going to move around

with the earth.

We are moving on the earth right now.

We are not affected by it because we are connected to the earth.

But let’s say I put something on that record player that is movable.

Let’s say I put a marble on it and now I spin it.

Watch what happens to the marble.

It will be deflected off.

And if I were to trace that path it moves like this.

And so if you think about it, on the north side of the record it is going to be moving

clockwise.

But if you could move underneath the record it would actually be moving counter-clockwise.

And so the earth is like that record player.

It is a sphere, obviously, but in the northern hemisphere it is going to move clockwise.

In the southern hemisphere it is going to move counter-clockwise.

And so the combination of these cells and coriolis effect creates the weather patterns

that we have on our planet.

So you can see here are the three cells, hadley, ferrel and polar cells right here.

But we also have the movement due to the spin of the earth.

And so right here near the equator we are going to have what are called the trade winds.

They are always going to be moving in this direction due to the spin of the earth.

Both in the southern and northern hemisphere they are all moving in this direction.

If we move north or south we are going to start to get what are called the westerly,

because it is going to be moving in this direction.

Now as that atmosphere pushes on the ocean, we get oceanic currents.

We are getting these trade winds and then we are getting the westerlies coming back.

As that blows on the ocean we get this gulf stream that is moving the ocean.

We also start to get deep currents in the ocean due to heat but also due to changes

in salinity.

And so this ocean is moving around, as a consequence of not only salt but also the temperature.

And so tying this all together is something you should be very familiar with is Enso or

the en nino southern oscillation.

And what really is going on is it is just moving back and forth between el nino and

la nina.

And so this is a graph that shows this oscillation from 1880 to 2010.

And so it is in a neutral position, it will then move towards el nino.

And then it will move back to la nina.

And then it will move to el nino.

Sometimes it is not a very big el nino.

Sometimes it is a very big el nino or la nina.

It just moves back and forth.

So it is oscillating.

You can see that in their record.

But you should be asking yourself, what causes it?

And so let’s go look.

So here we are looking at the Pacific Ocean.

So this is the Pacific Ocean right here.

This would be Central America, South America, North America and then all the way on the

other side of the Pacific is going to be Australia over here.

And so what we have is a walker circulation.

Remember the trade winds are blowing the wind in this direction along the equator.

And as they do that what we get is a circulation pattern that moves the ocean water, cold water

here, it is pushing the warm water to the western Pacific.

This is the neutral or the normal position.

Now what can happen, watch what happens to the walker circulation as I move us into a

la nina.

So as I move us into la nina watch what happens to the walker circulation.

We have greater trade winds, an increase in trade winds is pushing more of that warm water

over here towards Australia.

So we are going to get that weather way over here.

It is going to be cooler here around Central America.

Now watch what happens when the walker circulation starts to die off, now we have el nino.

And so we do not have that huge push and so we are going to have warm weather, it actually

starts to move in the opposite direction.

And so this ocean is now going to affect the atmosphere and it is going to affect humanity

as well.

So could you fill in this concept map?

I would encourage you to pause the video and give it a try.

And then I will tell you the answers.

First thing, could you tell me the levels inside the atmosphere?

It is troposphere, stratosphere, mesosphere, thermosphere, so that should be here and exosphere.

My mnemonic for this is try some milk then eggs.

That is a good way to remember the layers.

Right here we would have the important ozone gas which can be bad if we have it way down

here in the troposphere.

Weather over a long period of time is going to be the climate, which is affected by the

tilt of the earth and the sun and the location of the sun.

So we get seasons from that.

We also get unequal heating which creates these convection cells.

Hadley cell, ferrel cell, polar cell.

The spin of the earth creates the coriolis effect and also the ocean can impact that.

So hopefully you got all of those right.

And I hope that was helpful.