1 of 45

The Atmosphere from Space: Ozone

2 of 45

3 of 45

Introduction to Earth Observation

4 of 45

[Optional: slide introducing presenters]

5 of 45

[insert 2-3 sentence summary of what you do]

What do I use satellite data for?

Intro to EO

[Pic to illustrate what you do]

[Pic of you]

6 of 45

What is the Atmosphere?

    • The atmosphere is a layer of gases surrounding our planet
    • It is made up of Nitrogen, Oxygen, Argon, Carbon Dioxide and small amounts of other gases
    • The atmosphere has 5 different layers
    • Troposphere lowest layer of the atmosphere

Image: http://ete.cet.edu/

7 of 45

What is a satellite?

    • Definition: something in orbit around the Earth (or another planet!)
    • Fun Fact! The Earth itself is a natural satellite, orbiting the Sun
    • Thousands of man made satellites orbit the earth
    • Gives a bird's eye view of the Earth

8 of 45

What do you think satellites can measure in our atmosphere?

9 of 45

Weather

    • Ozone
    • Carbon Dioxide
    • Methane

What can we measure from space?

​

    • Temperature
    • Clouds
    • Wind Speed

​

The Atmosphere from Space

Atmospheric Composition

Methane

10 of 45

What on Earth?

11 of 45

A swath of dust 100s of kms across is sweeping over the Atlantic, partially obscuring the islands of Cabo Verde near the top center of the image.

Excessive amounts of dust have decimated some species of Caribbean corals, but dust is also an important source of nutrients for life in the oceans

Dust Storm off West Africa

March 12, 2006

12 of 45

What on Earth?

13 of 45

Fog over

North India

This fog was associated

with a cold spell which

resulted in the coldest

temperature ever

recorded in Delhi.

Temperatures

dropped to 9.4°C

under thick fog

mixed with air

pollution.

14 of 45

What on

Earth?

15 of 45

Wildfire Smoke over West USA

in 2020 - lots of lightning strikes and a heatwave resulted in over 41,000 square kilometres of land across the West Coast burning

16 of 45

What on Earth?

17 of 45

Aurora Borealis North of Iceland

The NOAA-20 VIIRS instrument detects wavelengths of light from green to near-infrared which allows city lights, roads and oil platforms visible to be seen clearly in addition to the Northern Lights

​

18 of 45

What on Earth?

19 of 45

Volcanic plume from Raikoke Volcano Eruption

This photograph taken by astronauts aboard the International Space Station shows the plume of hot gases that rose up high into the atmosphere after the 2019 eruption of the Raikoke Volcano on the Kuril Islands in the West Pacific

20 of 45

Volcanic plume from Raikoke Volcano Eruption

This is a composite image of the same plume taken from the MODIS instrument aboard NASA’s Terra satellite on the morning of the 22nd June 2019

21 of 45

What on Earth?

22 of 45

Methane plumes from oil and gas infrastructure over Turkmenistan

NASA’s EMIT mission was designed to study the composition of dust but it’s spectrometers can also be used to detect methane, an important greenhouse gas. This can help us monitor where methane is being released, spot leaks and hold those responsible to account

23 of 45

The Atmosphere from Space

Layers of the Atmosphere

24 of 45

The Atmosphere from Space

Upper Stratosphere & Mesosphere

Lower Stratosphere

Troposphere

Surface

Image Credit: NASA Astronaut photograph ISS023-E-57948 - acquired on May 25 2010 - provided by ISS Crew Earth Observations experiment Science & Analysis Laboratory, Johnson Space Center

25 of 45

The Atmosphere from Space

Most of the ozone is found in the stratosphere and it protects us from UV radiation

Good Ozone

Bad Ozone

Ozone in the troposphere can cause causing breathing problems in humans and damage vegetation

26 of 45

The Atmosphere from Space

https://www.nationalgeographic.org/encyclopedia/smog/, Accessed 1/2/2022

An example of smog in Shanghai

Ozone is a key component of smog

27 of 45

The Atmosphere from Space

What is ozone?

    • Three oxygen atoms bonded together
    • Formed when UV light breaks down an oxygen molecule into two oxygen radicals
    • These oxygen radicals then react with another oxygen molecule to form ozone
    • Ozone is an unstable molecule, UV light can break it back down into oxygen molecules
    • The amount of ozone in the atmosphere is affected by the balance of these two reactions - if one reaction becomes more frequent then the balance shifts towards what that reaction produces

28 of 45

The Atmosphere from Space

Why is ozone important?

    • UV light breaks down ozone molecules - what else does UV light do?

29 of 45

The Atmosphere from Space

Why is ozone important?

    • UV light breaks down ozone molecules - what else does UV light do?

30 of 45

The Atmosphere from Space

Why is ozone important?

    • UV light breaks down ozone molecules - what else does UV light do?
    • Q: How does ozone protect us from these effects?

31 of 45

The Atmosphere from Space

Why is ozone important?

    • UV light breaks down ozone molecules - what else does UV light do?
    • Q: How does ozone protect us from these effects?
    • A: UV radiation is ‘used up’ by the ozone molecules when they break down

32 of 45

The Atmosphere from Space

Why is ozone important?

    • UV light breaks down ozone molecules - what else does UV light do?
    • Q: How does ozone protect us from these effects?
    • A: UV radiation is ‘used up’ by the ozone molecules when they break down
    • What will be the effect on UV reaching the ground if the ozone layer gets thinner?

33 of 45

How do satellites measure Ozone?

Satellites have instruments on them that are sensitive to UV light

Measures ozone globally each day

Measured in Dobson Units (DU)

100DU = 1mm thick layer of ozone at surface of Earth

Satellite can have two views:

1.Nadir View

2.Limb View

Nadir View: instrument looks straight down and measures total amount of ozone in the atmosphere

Limb View: instrument looks sideways through atmosphere and gives ozone concentrations at different heights

Image: ESA_MultiMediahttps://www.esa.int/ESA_Multimedia/

34 of 45

The Atmosphere from Space

Let's look at some ozone measurements from space

https://cfs.climate.esa.int/index.html

Click ‘Data Layers’ on the top right panel and search for the ‘Ozone’ layer

35 of 45

On your own, in groups or as a class pick a place in each of these images from ESA's Climate from Space Web Application and write down the estimate total ozone in Dobson Units (DU) below

The Atmosphere from Space

Let's look at some ozone measurements from space

36 of 45

The Atmosphere from Space

The ozone hole in Antarctica only exists during some months of the year. Look at the ozone levels over Antarctica during 2019. In which three months do we see the ozone hole form?

Jan-Apr

May-Aug

Sept-Dec

37 of 45

The Atmosphere from Space

Jan-Apr

May-Aug

Sept-Dec

Now look back at the ozone hole over Antarctica in 1998. How does the size of the ozone hole compare to 2019? (i.e. was it bigger or smaller)

38 of 45

The Atmosphere from Space

Discovering The Ozone Hole

    • Chlorofluorocarbons (CFCs) were discovered in the 1930s and used in fridges, aerosol propellants and foam blowing because they are non-toxic and inert (chemically unreactive)
    • CFCs do not react with anything in the troposphere so over time they are transported to the stratosphere and broken down by ultraviolet light to release chlorine which then destroys ozone

Chlorofluorocarbons (CFCs)

39 of 45

The Atmosphere from Space

Discovering The Ozone Hole

Ground Based Observations

https://www.nature.com/articles/d41586-019-02837-5, Accessed 1/2/2022

    • In 1985 ground based observations at the Halley station in Antarctica showed that ozone levels had declined greatly
    • The graph shows ozone levels measured at the Halley station, with ozone declining in the late 1970s
    • The globe shows low ozone over Antarctica in dark blue - this is the Antarctic ozone hole

40 of 45

The Atmosphere from Space

Discovering The Ozone Hole

How did satellites not find the ozone hole?

    • The Nimbus-7 TOMS satellite was launched by NASA in 1978
    • It observed low ozone values but scientists were not very confident in the retrieval algorithm*
    • This image on the right is the first public image of the ozone hole in 1983 which was presented after the ground observations

https://www.nasa.gov/topics/earth/features/bhartia-qa.html, Accessed 2/2/2022

https://eospso.nasa.gov/missions/nimbus-7, Accessed 2/2/2022

*A retrieval algorithm is some maths which turns what the satellite measures into useful data

41 of 45

The Atmosphere from Space

Discovering The Ozone Hole

Montreal Protocol

    • After the initial ground observations and satellite images showed the ozone hole, numerous field campaigns also confirmed the ozone hole
    • This lead to international agreement to control CFCs in 1987 and the agreement was called the Montreal Protocol

​

The Montreal Protocol

1987

    • Regulates the production and use of ozone-depleting substances
    • Said to be one of the most successful environmental agreements
    • The ozone hole is now recovering

42 of 45

The Atmosphere from Space

Discovering The Ozone Hole

https://www.youtube.com/watch?v=yuhEB9YvuQM&t=69s

43 of 45

The Atmosphere from Space

Let's make our own colour map of the ozone hole

44 of 45

Now we will compare your colour maps with your classmates

45 of 45

Summary of the Class

We discovered what a satellite is and how it is used to measure properties of the atmosphere

Lesson Recap 1

We found out what ozone is, how it is measured from space and the ozone hole

Lesson Recap 2

We learned how to create a colour map to show the ozone hole and what colours make a good colour map

Lesson Recap 3

The Atmosphere from Space