Digital Typhoon: Sea Ice Information and "Himawari" Satellite Images
1. Sea Ice (Drift Ice) on Meteorological Satellite 'Himawari'
A meteorological satellite is mainly used for observing atmosphereic phenomena, but can also be used for observing other phenomena. For example, the satellite can observe sea ice (drift ice) by focusing on the difference of reflectivity between sea ice (drift ice) and water surface on visible imagery. To check the sea ice in the past, we provide the archive of sea ice by year. The period of archives is from January 1 to April 30 for each year.
JMA Disaster Information XML
The current sea ice information is announced in "prefectural sea ice forecast" in JMA Disaster Information XML (in Japanese).
An Example of Drift Ice Seen on "Himawari"
March 8, 2008 was a clear day around Hokkaido, and the drift ice is clearly visible on "Himawari" satellite image. The image below was taken on noon, and the drift ice was floating from the Sakhalin Island to the coast of Hokkaido, and although the large amount was blocked by the Shiretoko Peninsula and Kunashir Island, some go through Nemuro Strait to Notsuke Peninsula and Nemuro Peninsula like a band of ice. According to the news, some drift ice even go further to pass around Nosappu Cape to the Pacific Ocean to reach as far as off the coast of Kushiro. It is not so clearly visible on the satellite image, but you can see fluffy white regions along the coast of Pacific Ocean in the eastern part of Hokkaido. Looking at the animation GIF made from satellite images of every hour, the movement of these regions is much slower than that of clouds, so these regions may be not clouds but drift ice.
2. Information Sources on Sea Ice
If the sea ice is hard to recognize, first check the
Sea Ice Distribution in the Sea of Okhotsk Larger Image Page - JAXA EORC page and look at the animation again. Then the pattern may emerge from the animation.