Increase Your Albedo! Exploring the Fate of Arctic Sea Ice

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