These images are day-time Earth (upper) and night-time Earth (lower) observed by the
GLI thermal channel (wavelength: 10.8 micro meter) during one day of February 9, 2003. You can measure temperature of ground surface and sea surface with less effect from the atmosphere by using this channel in the atmospheric window.
You can see that the tropical zone is warm while the polar zone is cold. Some areas in Siberia, Greenland and Antarctica are approximately -40ºC, so they appear very cold. You can also find cool areas in the tropical zone, but they are cold cloud tops of cyclones and thick clouds.
The Advanced Earth Observing Satellite-II (ADEOS-II or "Midori-II") flies on a kind of polar orbit (approximately 803 km altitude, approximately 99 degree inclination) and circles the Earth 57 times in four days (14 and a quarter times per day). In this orbit, ADEOS-II flies on a descending path (from north to south) above the day side of the Earth and on an ascending path (from south to north) above the night side of the Earth. The upper image was thus observed along the descending path, and the lower image, along the ascending path. White areas indicate areas with no data (not observed).
Mar. 14, 2003
