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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? 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://expstudies.tor.ec.gc.ca/e/ozone/ozonecanada.htm 4
Caribou Photo courtesy of Pierre Fogal Many animals including caribou, polar bears, Arctic wolves, Arctic hares, whales and seals live in Nunavut. Polar bear photos courtesy of Andrea Moss Arctic hare Photo courtesy of Pierre Fogal. Wolf photos courtesy of Emily McCullough 5
http://exp-studies.tor.ec.gc.ca/e/ozone/ozonecanada.htm Eureka is located on Ellesmere Island in the High Arctic. It is the secondnorthernmost 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. 6
Photo courtesy of Pierre Fogal 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 7
CANDAC International Polar Year Legacy Project: Educational Resources 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 8
Earth s Atmosphere 9
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 10
Structure of the Atmosphere http://www.astronoo.com/articles/globalwarming-en.html 11
What is in the air? nitrogen 78% trace gases 1% oxygen 21% Trace Gases include: - Argon - Water vapour - Carbon dioxide - Methane - Nitrous oxide - Ozone - Many many more 12
The Ozone Layer 13
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.cfm 14
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 15 300 Dobson Units (DU).
http://jwocky.gsfc.nasa.gov/dobson.html 16
Ozone Maps Ozone concentrations over the Arctic in July 2000 and January 2010. http://exp-studies.tor.ec.gc.ca/e/ozone/curr_allmap_g.htm 17
Ozone Chemistry in the Atmosphere UV-B radiation O3 O2 O 18
Why is there less ozone? Human activity is damaging our ozone layer. 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. Cl Cl C Cl 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. 20
Ozone Chemistry http://www.theozonehole.com/o zonedestruction.htm 21
Ozone Hole in Antarctic http://exp-studies.tor.ec.gc.ca/cgibin/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 22
http://www.theozonehole.com/polarozone.htm 23
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.asccsa.gc.ca/eng/satellites/scisat/scisat_061213.asp). 24
How do we measure ozone? Ozonesondes launched on balloons Ground-based instruments such as a spectrometer Photo by: Rodica Lindenmaier Photo courtesy of Rodica Lindenmaier Photo by: Rodica Lindenmaier 25
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 26
Spectrometers are a common way to measure greenhouse gases and other gases in the atmosphere. Spectrometers Photo courtesy of Tobias Kerzenmacher Photo courtesy of Tobias Kerzenmacher 27
The Electromagnetic Spectrum http://www.yorku.ca/eye/spectru.htm 28
Inside a UV-Visible Spectrometer Shutter Diffraction grating Mirror #2 To CCD Mirror #1 29 Photo courtesy of Paul Loewen
Inside a UV-Visible Spectrometer Incoming Sunlight Diffraction grating Mirror #2 CCD Camera Mirror #1 Diagram courtesy of Cristen Adams 30
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 31
http://www.asc-csa.gc.ca/images/edu_scisat_grade9-spectra-trans_spectrum_type1.jpg 32
A Simple Spectroscope Entrance Slit Your eye Diffraction Grating 33
For instructions visit: http://jchemed.chem.wisc.edu/hs/journal/issu es/2006/jan/clicsubscriber/v83n01/p56.pdf 34