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Color composite images of polar region obtained by AMSR-E developed by JAXA onboard NASA Earth observing satellite, Aqua. Images are made from the horizontal polarization of 6.925GHz and both the vertical and horizontal polarizations of 10.65GHz. White area on ocean region indicates the sea covered with ice. The upper images show the three days average of June 2-4. The lower ones are the two days average of July 21-22.

In this period, Sea ice in Arctic region is decreasing and that in Antarctic region is growing. In the 50 days from early June, obvious change in the sea ice distribution is observed. The tendency inverses in August or September to the decrease in Arctic and to the increase in Antarctic. Annual change of sea ice region size exceeds about 15 million square kilometers, which means that ice of about 40 times larger area of Japan repeats growing and disappearing every year. Such change in sea ice distribution is regarded to influence the balance of global heat and radiation and to reflect the symptom of global warming and thus continuous monitoring are highly required.

In these images, land is painted in gray and the white circles (not very clear) at around the North Pole are the regions where AMSR-E does not observe.