October, 2007 (2)
January, 2008
Figure 1: Comparison of the Arctic sea in 2005 and 2007. Click to see the larger image (200kB).
Figure 1 shows true color images of the Eurasian continent, the North American continent and the sea ice area in the Arctic sea. It also shows the brightness temperature of the sea surface measured at the top of the atmosphere (larger image). This image was derived from data in August 2005 and August 2007 from MODIS (Moderate Resolution Imaging Spectro-radiometer) on NASA's Terra satellite.
JAXA press release reported that the smallest record on September 20, 2005 was broken on August 15, 2007. The new record was made on September 24, 2007. In this image, sea ice shrinks especially at the coast of Siberia and Alaska. Warm seawater (yellow-green) flows into the coastal sea area and reaches to the sea-ice edge at high latitudes.
Figure 2: Open up of the Northwest Passage
Look at the offshore of North America in the 2007 image. Sea ice extinction from Alaska to the Canadian Arctic Archipelago (white arrow) results in an open up of the Northwest Passage, which is the shortest line from Japan to the Atlantic Ocean. This is the first time event since satellite measurements began.
<About Figures>
Satellite: Terra
Sensor: MODIS
Observation date: August 1 - 31, 2005 and August 1 - 31, 2007
Lands and sea ice: True color image using band 1 (620-670nm) as red, band 4 (545-565nm) as green, and band 3 (459-479nm) as blue. ETOPO2 is also used as elevation data. The elevation is amplified by 48 times.
Sea area: Brightness temperature image using band 31 (10780-11280nm).
