Stereoscopic views of Hurricane Bill

August 20th, 2009 |

BillStereoLoop

GOES-14, which was launched on 27 June and is now undergoing post-launch check-out, is over the Equator at 90 degrees W longitude, whereas GOES-12, the operational GOES-East, is over the Equator at 75 W Longitude. The two satellites give slightly different views of Hurricane Bill, and stereoscopy can be used to view the visible imagery, allowing three dimensions to be perceived. This is done by crossing your eyes to produce three images; when the middle image comes into focus, three dimensions can be perceived.

In this case, stereoscopy shows vertical structure to the clouds, and also the presence of cirrus over the Hurricane eye.

Hurricane Bill and SRSO Scanning

August 20th, 2009 |

BillVIS1942_mag

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.