Pilot's pics show Arctic ice collapse

The Yomiuri Shimbun

 

OSAKA--Aerial photographs of the Arctic Ocean off Banks Island in Canada taken this summer clearly show sea ice is melting rapidly.

The total area of sea ice in the Arctic Ocean this summer was the smallest seen since satellite observations started in 1978.

Such aerial photographs are extremely rare, and global warming researchers regard the aerial photographs as important evidence of large-scale melting of sea ice.

Japan Airlines pilot Hiroyuki Kobayashi, 61, took the photographs during a flight from Anchorage, Alaska to Frankfurt on Aug. 29, using a single-lens reflex digital camera, at an altitude of between 10,000 and 11,000 meters.

A photograph of the sea northwest of Banks Island, at latitude 77 degrees north and longitude 129 degrees west, shows many melting ice blocks drifting in the sea. The ocean's surface is visible over a large area, indicating the thickness of the sea ice has decreased.

Another photograph shows more earth is exposed than usual in Greenland, near the North Pole. Typically, Greenland is 80 percent covered by an ice sheet.

Kobayashi, who has flown over the area about 20 times in his flying career, said the summertime melting of sea ice in the area near Banks Island has increased year by year since about 2000.

"Greenland had been totally white even in the height of summer until last year, because it was covered by the ice sheet," he said.

"I saw scenes like this for the first time this summer."

Jun Inoue, a researcher with the Japan Agency for Marine-Earth Science and Technology, said the photographs would be useful in exploring the relationship between melting sea ice and global warming.

The agency has performed satellite and ship observations of sea ice in the Arctic Ocean since 1978, and in a Sept. 24 survey observed that sea ice in the Arctic this summer covered a total of 4.25 million square kilometers--a decrease from 2005 of 1.06 million square kilometers, or an area equivalent to three times that of the entire Japanese archipelago.

Before this year, the September 2005 level of 5.31 million square kilometers was the smallest area of sea ice ever recorded in the area.

The agency believes the increase is the result of a climactic phenomenon called the ice-albedo feedback. Ice-albedo feedback occurs when a high pressure system causes ice to melt, which exposes more water on the surface. The ice is then exposed to a greater amount of sunlight: direct sunlight, and that reflected from the exposed water. This in turn causes the ice to melt more quickly, creating an ever expanding cycle.

The air above the Arctic sea this year began to warm around June, earlier than usual.

According to data from the U.S. National Aeronautics and Space Administration's earth observation satellite Aqua, conditions matching the ice-albedo feedback have been confirmed in the Canadian Arctic Archipelago, including Banks Island.

However, Kobayashi's photographs, which were taken at one-seventieth the altitude of a satellite's orbit, are expected to provide a clearer indication than previously available of the serious impact of the changes.

Kobayashi, a captain who works for Japan Airlines' public relations department, takes photographs during flights for use in the firm's publicity activities.