GOING GOING GONE

Although we didn't notice, a new record was set on 14 September this year. At that time, the ice cap at the North Pole was the second smallest it has been since satellites began to measure it in 1979 and it had the smallest volume ever recorded.

Average sea ice extent during September, a benchmark measurement in the scientific study of Arctic sea ice, was 1.8 million square miles. The record monthly low, set in 2007, was 1.65 million square miles.

The 2008 low strongly reinforces the 30-year downward trend in Arctic sea ice extent. The 2008 September low was 34 percent below the long-term average from 1979 to 2000 and only 9 percent greater than the 2007 record. Because the 2008 low was so far below the September average, the negative trend in the September extent has been pulled downward, from a minus 10.7 percent per decade to a minus 11.7 percent per decade, he said.
Conditions last spring played an important role in the outcome of this year's melt, the researchers said. In March 2008, 73 percent of the Arctic basin was covered, not by a thick ice cap but by thin ice that froze last winter for the first time. This is really scary because thin ice is more prone to melting during the summer. The widespread thin ice in spring 2008 set the stage for extensive ice loss during the melt season. In August 2008, the Arctic Ocean lost more ice than any previous August on record.

Preliminary data indicate that 2008 probably represents the lowest volume of Arctic sea ice on record, partly because less multiyear ice is surviving now and the remaining ice is so thin.

The melt season of 2008 reinforces the decline of Arctic sea ice documented over the past 30 years, said CU-Boulder Senior Research Associate Ted Scambos, NSIDC lead scientist. "The trend of decline in the Arctic continues, despite this year's slightly greater extent of sea ice," said Scambos. " The Arctic is more vulnerable than ever.

And not only is the ice disappearing . . .

ON THE MOVE

The Markham Ice Shelf, a massive 19-square-mile platform of ice, broke away from Ellesmere Island in early August and is adrift in the Arctic Ocean. More than half of the nearby Serson Ice Shelf - about 47 square miles - also recently broke away into the sea.

The accelerating sea-ice melt that last summer opened the Northwest Passage through the Canadian Arctic for the first time since satellite records began in 1978 may signal a significant climatic shift that has serious economic and ecological implications for wildlife, natural resources and world politics.

Researchers say that summer ice melting in the Arctic is advancing much faster than any of the climate models predicted. Since the area is, for the most part uninhabited, it's extremely important to understand what's happening there in order to predict the future more accurately.

To better understand the evolving northern polar climate, researchers have begun working on a computer program that will merge a decade of detailed atmospheric, sea, ice and land surface measurements. Compiling these immense data sets will produce descriptions of the changes occurring across this remote region.

An international and interdisciplinary collaboration of scientists, will "reanalyze" Arctic data from the past decade at three-hour intervals, 15-kilometer distances and 70 layers from the surface of the Earth to the top of the atmosphere. The study area encompasses the Arctic Ocean, the surrounding landmasses and the rivers that drain into the ocean - an enormous area of nearly 29 million square miles.

For most of human history, there was virtually no data on what went on in the Arctic. There were virtually no measures of temperatures, wind speeds and snowfall especially in the long six-month Arctic night. But satellites have changed all that. Scientists have been inundated with vast amounts of information. Today, the trick is to figure out how to effectively use all the diverse information sources.

With the help of the Ohio Supercomputer Center, scientists have undertaken a four-year project that will use about 350 terabytes of data to create detailed visualizations.

The National Science Foundation, as part of the International Polar Year observance, funds the Arctic System Reanalysis project, the first comprehensive environmental reanalysis project led by the academic community. IPY is a large scientific program focusing on the Arctic and the Antarctic from March 2007 to March 2009.

The International Polar Year is being undertaken "amidst abundant evidence of changes in snow and ice: reductions in extent and mass of glaciers and ice sheets, reductions in area, timing, and duration of snow cover, and reductions in extent and thickness of sea ice," according to a statement released by IPY scientists. "Changes in snow cover and sea ice have immediate local consequences for terrestrial and marine ecosystems."

Each summer, polar bears are being forced from their seal-hunting grounds on the melting sea ice, endangering their limited populations. Hundreds of thousands of acres of peat moss may decompose and begin to release higher amounts of methane and carbon dioxide, potentially accelerating the accumulation of greenhouse gases in the atmosphere.

But that's not the only consequence of the Arctic meltdown. Countries that border the polar ice cap are already jostling for political control of one of Earth's last remaining frontiers. Russia, Denmark and Canada have claimed the Arctic sea floor in hopes of securing valuable oil, gas and mineral rights. Canada also is claiming political control over shipping lanes that pass by that country's northern islands, and Russia may follow suit, as passages near its shores are nearly clear of ice.

And speaking of those clear passages. . . . .

JOHN CABOT'S DREAM After reaching the second-lowest extent ever recorded in September, sea ice in the Arctic has begun to refreeze in the face of autumn temperatures, closing both the Northeast Passage above Siberia and the Northwest Passage above Canada. This year marked the first time since satellite measurements began in the 1970s that the Northeast Passage, and the Northwest Passage were both open at the same time for a few weeks.

The Northwest Passage, a long-sought shortcut from Europe to Asia through the Canadian Arctic that has been historically impassable, opened up for the second consecutive time this year. The main Northwest Passage opened on 18 August although the indirect, more southerly route - called the Amundsen Northwest Passage - opened up in July.

The Northeast Passage, which extends from the Norwegian Sea, along the Arctic coast of Asia and through the Bering Sea to the Pacific Ocean opened this year for the very first time since satellite data has been collected.

Each year, the Arctic Ocean experiences the formation and then melting of vast amounts of ice that floats on the sea surface, but the rate of overall loss has accelerated. During the last 30 years, satellites that have been observing the Arctic have witnessed reductions in the minimum ice extent at the end of summer from around 8 million km² in the early 1980s to the historic minimum of less than 4.24 million km² in 2007.

So . . . no global warming, eh? When the kids in the Planetarium ask me a question like "What would happen if the Moon exploded?" I always say, "You must postulate me a mechanism for that happening." And when they say "Whut?" I say "You must give me some reason that the Moon would explode before I can answer that question."

So, I say to you, dear reader, if you don't believe in global warming, why do you think the North Pole ice cap is vanishing? Postulate me a mechanism for what's causing the observed data. Why is the ice disappearing? Why is more and more of it disappearing every year?