Increase Your Albedo!
Exploring the Fate
of Arctic Sea Ice
What is Albedo?
• Albedo is the fraction of solar radiation incident on a surface that is reflected.
• In plain terms, albedo is the ability of a surface to reflect the sun’s radiation. Your white t-shirt has a higher albedo than your darker ones… that’s why it keeps you cool in the summer!
Pop Quiz!
• Guess which terrestrial surface type has the most albedo… (reflects more sunlight than it absorbs).
• Albedo is expressed as a percentage of reflected radiation (0.1 or 10%)
Pop Quiz
The Big Picture
• The Earth as a whole reflects about 30% of incoming solar radiation back into space
• Clouds and snow/ice each have an albedo of roughly 80%
© NASA
So What?
• Clouds and ice are basically the thermostats of the planet
• They’re regulating the temperature of the Earth by reflecting much of the solar radiation it receives
© CASES
What’s Going On?
• The United Nations Intergovernmental Panel on Climate Change (IPCC) has made some startling observations:
•Arctic sea-ice extent has decreased by 3% per decade between 1978-1996
•Summer sea-ice extent has shrunk by 20% (880,000 sq. km) in the Atlantic part of the Arctic Ocean
•Arctic air temperature has risen by as much as 5˚C during the 20th century with the last decade being the warmest
•There is consistent evidence of later Fall freeze-up and earlier Spring breakup
What’s Next?
• Loss of sea ice (80% albedo) gives way to water (3-5% albedo)!
• This net loss of albedo results in further heat absorption at Earth’s surface, resulting in more sea ice melting, resulting in more warming…
• It’s a positive feedback loop!
© CASES
What’s CASES?
• The Canadian Arctic Shelf Exchange Study• A Canadian-led international research network
made up more than 70 researchers from Canada and 9 other countries
• Goal: Understand and model the response of biogeochemical and ecological cycles to atmospheric, oceanic and continental forcing of sea-ice cover variability on the Mackenzie Shelf
• In simpler terms: Study the effects of changing sea-ice cover on the Arctic environment!
Mackenzie Shelf
The Amundsen
• Inauguration: August 26, 2003 in Québec City• Named after Norwegian explorer Roald Amundsen: 1st to
navigate Northwest Passage from 1903-1906 and to reach the South Pole in 1911
• Only Canadian ship to have full-time dual role of icebreaking and scientific research
The Amundsen
Large-scale density-driven circulation in the oceans, driven by differences in temperature and salinity. Cold salty water sinks and warmer water rises.
Maximum and Minimum Ice
• Minimum in Fall (September)
• Maximum in Spring (March)
• Ice no longer extends as far and now retreats further
• What’s in store for the future?
© CASES
Present and Future Ice Cover
March SeptemberMarch September
Today 2050© CASES
What’s in Store for Nanook?
• Ice freezes later and melts sooner: Less feeding time
• Seals fewer and farther out: Longer distance to feed
• More open water: Fatigue from swimming
© NFB-ONF
The Northwest Passage
© CASES
Passage Pioneers
• Roald Amundsen, August 1905, first successful navigation. Aboard the Gjoa (Oslo-Pacific).
• St-Roch, 1944, Northern Deep-Water Route.
• Sedna IV, August-November 2002, sailed from Magdalen Island to Vancouver.
• What’s next?
© CASES
Oslo to TokyoTotal travel distance for a one-way trip from Norway to Japan:
• Via Panama Canal: 24 000 km• Via Cape Horn: 35 000 km• Via Suez Canal (Asian Route): 21 500 km• Via Northwest Passage: 14 500 km
Activity
We will be drawing the most efficient (and realistic) route between the southern tip of Greenland to the Bering Strait!
1. Groups of 4 (or more).
2. You will need: String, Adhesive, Ruler.
3. Try to draw your own way across the Northwest Passage by navigating the shortest distance.
4. Good Luck!
Discussion