Super Rapid Scan Operations are called on GOES-East or GOES-West when meteorologists want to investigate phenomena that occur over very short timescales. Typically, SRSO imagery is taken every minute. However, gaps exist because of responsibilities to other regions. For example, when the National Hurricane Center requested SRSO observations of Hurricane Bill, satellite imagery was still required to observe tornadic thunderstorms over the upper midwest, and to fulfill international treaty obligations to provide full disk imagery every three hours. GOES-R, scheduled for launch in 2015, will have enhanced observational capabilities, enabling SRSO and full-disk scanning simultaneously. Indeed, ABI on GOES-R will scan a full disk image every 15 minutes, a CONUS image every 5 minutes, and a 1000×1000 km area every 30 seconds, simultaneously.

In the case of Hurricane Bill, the SRSO helped define the small cloud vortices within the hurricane eye, as seen in the image above. These vortices have been observed in previous hurricanes as well — mostly notably in Hurricane Isable in 2003. The SRSO visible loop is here (Warning: 25 M animated gif) and the SRSO color enhanced infrared loop is here. IR Brightness temperatures within the eye are in the 290-300 K range, somewhat cooler than the sea surface temperature in this region. The small vortices within the eye are low clouds.

GOES-11 "split window" IR difference product (10.7 - 12.0 µm)

A series of volcanic eruptions from Sarychev Peak (located in the central Kiril Islands) began on 10-11 June 2009, and GOES-11 “split window” IR difference images (above) showed a good signature of one of the ash plumes (yellow to cyan color enhancement) as it began to move eastward across the North Pacific Ocean on 16 June 2009.

AWIPS images of the MTSAT + GOES-11 IR channel with overlays of the MTSAT high density winds (below) showed the high-altitude flow that was helping the volcanic ash plume features to move southeastward around 40-60 knots (according to the Volcanic Ash Advisories that were issued on 16 June).

GOES-11 is the last of the current GOES series to have the 12.0 µm IR channel on the imager instrument package, which allows the calculation of such a “split window” IR difference product for volcanic ash detection. Once GOES-11 is replaced by either GOES-13 or GOES-14 as the operational GOES-West satellite, the geostationary volcanic ash detection ability will be greatly diminished over the eastern North Pacific Ocean…until the launch of the Advanced Baseline Imagery (ABI) on the GOES-R satellite.

MTSAT + GOES-11 IR images, MTSAT high density winds