Description of Images
In this site, the sea ice distribution maps are shown. These maps are provided by JAXA/EORC.
- Description of AMSR-E Images
The above images show the sea ice concentration estimated from the data acquired by AMSR-E. Sea ice concentration is a ratio of ice cover per unit area. The open water area is 0% and the sea ice covered are is 100%. In this image, the sea ice concentration below 10% is cut down to 0%. The white indicates unobserved area.
The Advanced Microwave Scanning Radiometer for EOS (AMSR-E) is a modified version of AMSR which was on MIDORI-II (ADEOS-II). JAXA provided the instrument which was installed on NASA's Earth Observing System (EOS) Aqua platform. The ability to measure during both night and day is the advantage of microwave observation.
Thus, through non-precipitating clouds, the sea ice extent can be well distinguished using the night-time image. AMSR-E observes over the Sea of Okhotsk and the Japan archipelago between 0:30AM and 3:00AM (JST) every day.
A point to note is that there could be errors in estimating along the coast line. Additionally, the error will appear when a heavy low pressure system passes.
- Description of MODIS Images
MODIS (Moderate Resolution Imaging Spectroradiometer) is an optical sensor aboard the Terra and Aqua satellites. The images introduced here are received and elementally processed by JAXA Earth Observation Center (EOC). Subsequently, JAXA Earth Observation Research and application Center (EORC) does the near-real-time processing and makes the data public.
The 3 channels composite images (left two images) are false color composite images which allocate Ch.4 (wavelength 545 - 565 nm in the green band) of the MODIS sensor for red, Ch.2 (wavelength 841 - 876 nm in the near infrared band) for blue and Ch.5 (wavelength 1230 - 1250 nm in the shortwave length infrared band) for green. The sea ice and cloud can be distinguished, because the sea ice is emphasized in the light flesh color and cloud is emphasized in white.
The cloud flag image (right two images) is the result from using a high processing system for Global Imager (GLI) of MIDORI-II.
The images of last season can be seen in the "backnumbers"
page. In last season, the MODIS data used in this site were received and elementally processed by Tokai University Research and Information Center (TRIC).
The color legend of the cloud flag image
|White||Snow over land||Dimgray||Clouds|
|Cyan||Snow over Ice||Gray||Cloud Shadow|
|Navy||Water (open ocean)||Black||Not executed|
- Related Links
Earth Observation Research and application Center (EORC of JAXA)
Copyright EORC/ALL RIGHTS RESERVED.