GOES-13: Full Disk Images at 30-Minute Intervals

December 10th, 2006 |

GOES-13 full disk water vapor image
As a part of the GOES-13 post-launch NOAA Science Test, the satellite provided continuous “full disk” images every 30 minutes for 2 consecutive days (09-10 December 2006); the current operational GOES full disk imaging interval is only once every 3 hours, but the Advanced Baseline Imager on GOES-R will provide full disk scans every 15 minutes. GOES-13 6.5µm “water vapor channel” imagery (above) showed cloudiness as well as non-cloudy water vapor circulations within the middle troposphere (Java animation), while the visible channel (below) provided a view of cloud features during the daylight hours (Java animation).
GOES-13 full disk visible image

GOES-13: Fire Activity in Arkansas

December 8th, 2006 |

GOES-13, GOES-12 3.9µm IR images

On 08 December 2006 (Day 2 of the GOES-13 post-launch NOAA Science Test), 3.9µm shortwave IR images from GOES-13 and GOES-12 (above) revealed several “hot spots” (black enhancement) due to fire activity (NOAA HMS) across parts of Arkansas (Java animation). The performance of the GOES-13 3.9µm IR channel was comparable to that of GOES-12 for this particular group of relatively small and short-lived fires — a plot of the GOES-13 vs GOES-12 shortwave IR brightness temperatures (below) for the fire that was located between Russellville (KRUE) and Hot Springs (KHOT) Arkansas showed similar values as that particular fire was reaching maximum size and intensity.
GOES-13 vs GOES-12 3.9µm temperature

GOES-13: Detecting Surface Features in Water Vapor Channel Imagery

December 8th, 2006 |

GOES-13, GOES-12 water vapor images
During Day 2 (08 December 2006) of the GOES-13 post-launch NOAA science test, a cold and dry air mass was moving eastward over the southern Great Lakes region; “water vapor channel” images from the GOES-13 and GOES-12 imagers (above) displayed what appeared to be a typical pattern of 6.5µm brightness temperature values. However, a Java animation of the GOES-13 and GOES-12 water vapor channel images  (with the map overlay removed) shows the outline of the southern portion of Lake Michigan as the pocket of driest air moved across that area.

Detecting surface-based features (or geographical boundaries) on the 6.5µm GOES imager water vapor channel is somewhat unusual, since the radiation sensed by that channel normally originates from the middle troposphere (generally from within the 500-300 hPa layer, or 5-9 km above the surface in a US Standard Atmosphere). However, on this particular day, the air mass located over the Upper Midwest region was rather cold and dry — the GOES-12 water vapor weighting function calculated using the rawinsonde data from Davenport, Iowa at 12 UTC on 08 December (below) indicates that a significant contribution to the water vapor channel radiance at that location was coming from altitudes as low as the 600-700 hPa layer. The warm waters of Lake Michigan were surrounded by relatively cold land surfaces (GOES-13 10.7µm IR image with surface temperature reports), and a signal from this strong thermal contrast was bleeding up through what little water vapor was present within the atmospheric column, allowing the outline of Lake Michigan to be detected on the GOES-12 and GOES-13 water vapor channel imagery.
Davenport, IA water vapor weighting function

GOES-13: First Day of Post-Launch NOAA Science Test

December 7th, 2006 |

GOES-13 visible channel image

07 December 2006 was the first day of the GOES-13 post-launch NOAA science test. The satellite was placed into Rapid Scan Operations mode, to monitor the development of lake-effect snow (LES) bands across the Great Lakes region. GOES-13 visible channel imagery (above) depicted well-defined, persistent LES bands that had developed over Lake Huron (Exeter, Ontario radar) and Georgian Bay (King City, Ontario radar) — a Java animation of GOES-13 visible images shows these LES bands moving inland over southeastern Ontario, where they produced 18-35 inches of snow (including 12 inches in a 3 hour period) in what was one of the worst snowstorms in nearly 3 decades for London, Ontario.

GOES-13 visible images centered farther to the south (below) revealed a particularly long LES band that was moving off Lake Michigan and drifting southeastward across southwestern lower Michigan, northeastern Indiana, and southwestern Ohio (Java animation). This LES band deposited as much as 11 inches of new snow in southwestern Michigan, with 5-6 inches falling farther downstream in parts of northeastern Indiana. A GOES-13 visible image from the following morning shows several narrow streaks of snow cover (oriented northwest to southeast across Indiana and Ohio), many of which were left by the LES bands seen on 07 December.
GOES-13 visible channel image