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• In 2002, a group of university researchers joined together under

the title of the Canadian Network for the Detection of

Atmospheric Change (CANDAC) with the objective of improving

the state of observational atmosphere research in Canada.

• This group recognized the need for an Arctic laboratory and

identified the Polar Environment Atmospheric Research

Laboratory (PEARL) in Eureka, Nunavut as the ideal station.

• They worked enthusiastically to raise funds to run the facility

and had a fully-functional Arctic lab operating in 2005.

• Since then, researchers have been taking various

measurements to monitor and better understand current

atmospheric conditions. 2

Funding for CANDAC has been provided by:

3

Where do we take measurements?

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Nunavut

• CANDAC

researchers collect

data in Eureka,

Nunavut.

• Nunavut is

geographically the

largest of all

thirteen Canadian

provinces and

territories, but is

the least

populated.

http://exp-

studies.tor.ec.gc.ca/e/ozone/ozonecanada.htm

• Many animals including caribou, polar

bears, Arctic wolves, Arctic hares, whales

and seals live in Nunavut.

Wolf photos courtesy of Emily McCullough

Caribou Photo courtesy of Pierre Fogal

Polar bear photos courtesy of

Andrea Moss Arctic hare Photo courtesy of

Pierre Fogal.

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• Eureka is located on

Ellesmere Island in

the High Arctic.

• It is the second-

northernmost

permanent research

community in the

world.

• Eureka experiences

complete darkness

from mid-October until

late February and

complete Sunlight

from early April to late

August.http://exp-studies.tor.ec.gc.ca/e/ozone/ozonecanada.htm

• Many CANDAC researchers operate

their instruments from the Polar

Environment Atmospheric Research

Laboratory (PEARL) located in

Eureka.

• Researchers typically travel to

PEARL by airplane.

Photo courtesy of Pierre Fogal

Photo courtesy of Pierre Fogal

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• As part of the International Polar Year (IPY) Legacy

Project, CANDAC has created educational resources

aimed at enhancing environmental science education in

classes from kindergarten to grade 12.

• Educational materials can be found at:

http://candac.ca/candac/Outreach/Outreach.php .

• This particular presentation is about:

The Ozone Layer

CANDAC International Polar Year

Legacy Project: Educational Resources

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Earth’s Atmosphere

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• The atmosphere is like a blanket of air that surrounds the Earth.

• It is about 100 km thick, but most of the air is close to the Earth’s surface.

• It provides oxygen for us to breathe and contains ozone to protect us from harmful ultraviolet radiation.

• It allows life to exist on Earth.

Earth

atmosphere

1010

Structure of the Atmosphere

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http://www.astronoo.com/articles/globalWarming-en.html

What is in the air?

oxygen

21%

nitrogen

78%

trace gases

1%

Trace Gases include:

- Argon

- Water vapour

- Carbon dioxide

- Methane

- Nitrous oxide

- Ozone

- Many many more…

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The Ozone Layer

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Ozone in the Atmosphere

• Ozone is a molecule made up of three oxygen atoms.

• The oxygen that we breathe is a molecule made up of two oxygen atoms.

• Ozone protects the Earth by blocking harmful UV light from the Sun. http://www.ec.gc.ca/ozone/DOCS/KIDZO

NE/EN/ozoneupthere.cfm14

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Dobson Unit (DU)

• A Dobson Unit (DU) is the unit measure for total ozone.

• If all of the ozone in a column of air from the surface of Earth to space were brought to standard temperature (0°C) and pressure (1atm), the column would be 0.3cm thick.

• In order to make these measurements easier to work with, a Dobson Unit was defined to be 0.001atm-cm.

• So the 0.3cm ozone column would represent 300 Dobson Units (DU).

16http://jwocky.gsfc.nasa.gov/dobson.html

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Ozone Maps

http://exp-studies.tor.ec.gc.ca/e/ozone/Curr_allmap_g.htm

• Ozone

concentrations

over the Arctic in

July 2000 and

January 2010.

Ozone Chemistry in the Atmosphere

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UV-Bradiation O3

O

O2

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Why is there less ozone?

• Chlorofluorocarbons (CFCs) used to be used in our refrigerators and air conditioners.

• CFCs do not occur naturally – they were made by people.

• The Montreal Protocol was a very successful international treaty designed to protect the ozone layer.

• Human activity is damaging our ozone layer.

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Cl

Cl

Cl

C F

CFCl3

(Fluorotrichloromethane)19

How this happens

• When CFCs reach the ozone layer, the

ultraviolet light breaks them apart to form

atomic chlorine.

• In the cold atmosphere over the poles

chlorine becomes ‘active’ and breaks

down ozone.

• One chlorine atom can destroy thousands

of ozone molecules.

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Ozone Chemistry

http://www.theozonehole.com/o

zonedestruction.htm

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Ozone ‘Hole’ in Antarctic

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http://exp-studies.tor.ec.gc.ca/cgi-

bin/selectMap?lang=e&type1=du&day1=mm&month1=10&year1=2010&howmany1=1&interval1=1&intervalunit1=m&

hem1=s&type2=no&day2=23&month2=02&year2=2010&howmany2=1&interval2=1&intervalunit2=d&hem2=n&mapsi

ze=100

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http://www.theozonehole.com/polarozone.htm

Ozone Measurements in the Arctic

• Right now, ozone is being measured at Eureka

by CANDAC members and across Canada by

Environment Canada scientists.

• They are making measurements of ozone and

other atmospheric molecules using

spectrometers and balloons.

• Satellites over the Arctic also measure ozone.

• In the past two decades, average ozone over the

Arctic has decreased by 6% (http://www.asc-

csa.gc.ca/eng/satellites/scisat/scisat_061213.asp).

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How do we measure ozone?

Ozonesondes launched on balloons

Photo by: Rodica Lindenmaier

Photo by: Rodica Lindenmaier 25

Photo courtesy of Rodica Lindenmaier

Ground-based instruments such as a

spectrometer

SCISAT-1

• Launched in

2003, the

Atmospheric

Chemistry

Experiment (ACE)

is a Canadian

satellite used to

study the Earth’s

atmosphere.

•It studies ozone

over Canada with

focus on the Arctic.

http://www.asc-csa.gc.ca/images/recherche/images/SatBG2.jpg

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Spectrometers

• Spectrometers are a

common way to measure

greenhouse gases and

other gases in the

atmosphere.

27Photo courtesy of Tobias Kerzenmacher Photo courtesy of Tobias Kerzenmacher

The Electromagnetic Spectrum

http://www.yorku.ca/eye/spectru.htm

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Photo courtesy of Paul Loewen

Inside a UV-Visible Spectrometer

Shutter

To CCD

Diffraction gratingShutter

Mirror #2

Mirror #129

Inside a UV-Visible Spectrometer

Diffraction

grating

Mirror #2

Mirror #1

CCD

Camera

Incoming Sunlight

30Diagram courtesy of Cristen Adams

‘Fingerprints’

• Each person has their own set of fingerprints, and so too do gases in the atmosphere.

• A particular gas or molecule absorbs a unique pattern of colours.

• When the light reaches the spectrometer, the spectrum will be missing pieces where the light has been absorbed by the gases in the atmosphere.

Gas

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http://www.asc-csa.gc.ca/images/edu_scisat_grade9-spectra-trans_spectrum_type1.jpg

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A Simple Spectroscope

Diffraction Grating

Entrance SlitYour eye

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For instructions visit:

http://jchemed.chem.wisc.edu/HS/Journal/Issu

es/2006/Jan/clicSubscriber/V83N01/p56.pdf

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