News from the polar regions in October included further analysis of the summer Arctic sea ice melt, genetic discoveries in remarkable Antarctic fish, and preparations for a challenging Antarctic expedition. Missed these stories the first time? Read on!

In September, we reported that the Arctic sea ice extent during the 2008 summer melt season dropped to the second lowest level since satellite measurements began in 1979. While the minimum extent did not surpass the 2007 low, sea ice melted faster in August 2008 than any August before. Preliminary data also suggest that the Arctic sea ice hit the lowest volume ever recorded, due to the increased presence of thin annual ice. In March 2008, this thin, first-year ice covered a record high 73% of the Arctic Ocean. Thin ice is much more susceptible to melting in the summer. Arctic sea ice is now in its annual freeze-up period, closing the Northeast and Northwest passages. Both passages were open at the same time for the first time since satellite measurements began. The German research vessel Polarstern recently returned from an expedition through both passages, effectively circling the North Pole. Researchers on the expedition studied the geology of the Arctic area and the distribution of many marine species. 

Summer 2008 also meant extreme melting and a record number of melting days along the northern portion of Greenland’s ice sheet. Scientists hypothesize that high surface temperatures and possibly other factors such as solar radiation played a role in the increased melting. The northern region is typically colder than the southern portion of the ice sheet, which experienced record melting in 2007.

A new book published by the US geological survey shows that more than 99% of glaciers in Alaska are experiencing significant retreat, thinning, or stagnation. Alaskan glaciers are currently found in 11 mountain ranges, one large island, one island chain, and one archipelago.

Two studies are providing insight into Arctic ice of the past. Mapping of beach ridges on the north coast of Greenland suggests that the Arctic Ocean may have had significantly less ice cover 6000 to 7000 years ago and may have been periodically ice free. A second study attributes the sudden 1997 thinning of the Jakobshavn Isbrae glacier to changes in the atmospheric circulation in the north Atlantic.

A warming climate (and warmer ocean waters) means more frequent, higher intensity Arctic storms, and in turn, a higher rate of sea ice drift. A new NASA study confirms the link between climate and storminess and connected the trend to sea ice movement. Moving sea ice forces mixing of ocean water, and increased mixing may greatly increase the ocean’s ability to absorb carbon dioxide - a negative feedback to climate change.

Much attention has been paid to climate change’s impact on polar bear populations, but the polar regions’ other iconic species is threatened as well. A new World Wildlife Federation report shows that half to three quarters of Antarctica’s major penguin colonies (Emperor and Adelie) are threatened with decline or disappearance if global temperatures rise by more than 2°C. Such a climb (which could be a reality in less than 40 years) would reduce the Southern Ocean’s ice cover, an essential nesting and feeding ground. Decreased sea ice would also negatively impact the krill population, which is an important food source for the penguins.

Scientists have long been amazed by the nototheniods, a type of fish that live in the icy waters off Antarctica. Nototheniods make their own “anti-freeze proteins” that bind to ice crystals in the blood to prevent the fish from freezing. Geneticists analyzed the fishes’ DNA and found that the Antarctic dwelling fish had three to 300 times the number of genes that code for the anti-freeze proteins as compared to other nototheniods that live in warmer waters. More copies of these genes lead to greater amounts of anti-freeze proteins, allowing the fish to live in these cold waters.

The ozone hole - actually a thinning in the ozone layer over Antarctica - is larger now than in 2007, but smaller than in 2006. Weather conditions cause the size of the hole to vary from year to year, making detection of signs of ozone recovery difficult. 

As Antarctic tourism grows, concerns over the effects of this increase with respect to safety, the environment, and the lack of financial resources for monitoring and enforcement grow as well. One possible solution proposed is marketable visitor rights - a concept used in climate change policy. If accepted, a number of visitor days would be set and sold to the highest bidder, who could then trade the rights among other companies. Marketable visitor rights would limit the scale of tourism while also providing a source of revenue for monitoring and enforcement. Tourism in Antarctica is a difficult issue since Antarctica is not a sovereign state. 

Finally, an international team of scientists are preparing for an exciting and challenging new expedition: a study of the Gamburtsev subglacial mountains, buried by up to 4 km of ice. The researchers will work from remote field camps at high altitude and temperatures of -40°C. They will use state-of-the-art technology to map this mysterious landscape.

Know of another significant news story from October that you’d like to share? Reactions to one of the stories discussed here?  Post a comment-we’d love to hear from you!