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 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 20 th 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: 1 st to navigate Northwest Passage from 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 Today2050 © 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

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