The Greenhouse gases Observing SATellite (GOSAT) "IBUKI" observed the plume of the erupting Grimsvotn volcano in Iceland on May 23, 2011(UTC) and May 24, 2011(UTC), after it observed the plume for the first time on May 22, 2011(UTC). The plume that spread near Iceland on May 22, started to drift southwards, being pulled in by the swirl of low-presseure system by May 23. On May 24, the plume spread over the northern UK and reached Norway. These are color-composite images made from data acquired by the Cloud and Aerosol Imager (CAI) onboard GOSAT, "IBUKI" when it flew over Iceland multiple times. Green, red, and blue are assigned to 870 nm, 678 nm, and 380 nm spectral channels* of CAI. Black regions are the areas where "IBUKI" could not observe. The volcanic plume is shown in light-brown and black. The red circle indicates the location of Grimsvotn volcano.
Figure 1. The volcanic plume observed on May 22, 2011 (UTC). The image was made from data acquired by "IBUKI" when it flew over Europe twice, at 13:30 and 15:09 on May 22, 2011 (UTC) (22:30 on May 22 and 00:09 on May 23, 2011 (JST)). (Click on image to enlarge.)
* 870 nm, 678 nm, and 380 nm spectral bands are located in the near infrared, visible, and ultra violet spectral regions, respectively. "IBUKI" observed the sunlight reflected at land surfaces and clouds in these regions.
** "IBUKI" orbits the Earth in 98 minutes passing north and south poles each time at the altitude of 666 km. Thus the time difference between images taken in subsequent passes is about 98 minutes.
(National Institute for Environmental Studies)
The plume of erupting Grimsvotn volcano in Iceland was observed by the Greenhouse gases Observing SATellite (GOSAT) "IBUKI". The Grimsvotn volcano started its eruption on May 21, 2011, and the plume (in yellow and black) can be seen drifting northwards when the image was captured.The image was captured on May 22, 2011, at 15:09 (UTC) (on May 23, 2011 at 0:09 (JST)) when "IBUKI" flew over Iceland. (Click on the image to see in a new window.)