A look back at “Hurricane Huron” in 1996

September 14th, 2018 |

GOES-8 Visible (0.65 µm) images, with hourly surface wind barbs and gusts [click to play animation | MP4]

GOES-8 Visible (0.65 µm) images, with hourly surface wind barbs and gusts [click to play animation | MP4]

GOES-8 Visible (0.65 µm) images (above) showed the cloud features — including spiral banding and a cloud-free core resembling an eye — associated with a deepening area of low pressure over Lake Huron (surface analyses) on 14 September 1996. This storm acquired some characteristics of a tropical cyclone, being referred to in the literature as “Hurricane Huron“.

50th anniversary of the launch of ATS-1, the first geostationary satellite

December 6th, 2016 |

Today marks the 50th anniversary of the launch of ATS-1 on 06 December 1966. ATS-1 was the first meteorological satellite to be placed into a geostationary orbit — an example of one of the first ATS-1 visible images is seen below, and QuickTime movies are available which show animations of some early ATS-1 images. More information is available from SSEC and NOAA/NESDIS.

ATS-1 visible image (11 December 1966)

ATS-1 visible image (11 December 1966)

25-year anniversary of the 1991 Mount Pinatubo eruption

June 15th, 2016 |

GMS-4 Infrared Window (11.5 µm) images [click to play animation]

GMS-4 Infrared Window (11.5 µm) images [click to play animation]

During the first 2 weeks of June 1991 the Mount Pinatubo volcano on the island of Luzon in the Philippines began to produce a series of eruptions, culminating in the climactic eruption beginning at 0227 UTC on 15 June. An animation of 5-km resolution GMS-4 Infrared Window (11.5 µm) images (above) spans the period from 1831 UTC on 12 June to 1831 UTC on 16 June, and showed the very large volcanic cloud following the 15 June eruption (the animation pauses at the 0230 UTC image on 15 June — just after the time of the major eruption). Also evident in the imagery was the westward movement of what became Category 3 Typhoon Yunya (known locally in the Philippines as Diding) toward Luzon. A larger-scale version of the animation is available here.

A closer view of the GMS-4 Infrared Window (11.5 µm) images (below) revealed interesting characteristics of the volcanic plume which penetrated the tropopause (which was at an air temperature of around -83º C, according to nearby rawinsonde reports) during the 3-8 hours following the onset of the 0227 UTC eruption. Note the initial appearance of a small area of very warm IR cloud-top IR brightness temperatures (-21.6º C at 0631 UTC, and -25.7º C at 0730 UTC) which then blossomed outward and became a westward-moving stratospheric plume that was notably warmer than the majority of the cold volcanic cloud canopy (which exhibited IR brightness temperatures in the -80º to -90º C range, denoted by the violet to yellow color enhancement).

GMS-4 Infrared Window (11.5 µm) images [click to enlarge]

GMS-4 Infrared Window (11.5 µm) images [click to enlarge]

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NOAA-10 AVHRR Infrared Window (10.8 µm), Visible (0.91 µm) and Shortwave Infrared (3.7 µm) images [click to enlarge]

NOAA-10 AVHRR Infrared Window (10.8 µm), Visible (0.91 µm) and Shortwave Infrared (3.7 µm) images [click to enlarge]

A higher-resolution (1.1-km) view of the post-eruption cloud was provided by NOAA-10 AVHRR images at 1034 UTC on 15 June (above). Even though it was just past sunset over the Philippines, the narrow stratospheric plume could be seen towering above the canopy of the main volcanic cloud (the plume was at a high enough altitude — estimated at a maximum of 40 km (reference 1 | reference 2) — to still be illuminated by sunlight). The summit of Pinatubo is located 8.7 miles/14 km west-southwest of what was then Clark Air Force Base (station identifier RPLC). On the 10.8 µm Infrared Window image, cloud-top gravity waves could be seen propagating radially outward from the overshooting top located above the volcano (which exhibited a minimum IR brightness temperature of -86º C, violet color enhancement). Note the much warmer IR brightness temperatures (as warm as -31º C, green color enhancement) associated with the stratospheric plume just off the west coast of Luzon. A closer view is available here.

About 10 hours prior to the climactic eruption, a volcanic ash cloud from one of the earlier eruptions was captured by NOAA-10 AVHRR images at 2329 UTC on 14 June (below). Around this same time it can be seen that Yunya was making landfall as a minimal-intensity typhoon along the eastern coast of Luzon. A closer view is available here.

NOAA-10 AVHRR Infrared Window (10.8 µm), Visible (0.91 µm) and Shortwave Infrared (3.7 µm) images [click to enlarge]

NOAA-10 AVHRR Infrared Window (10.8 µm), Visible (0.91 µm) and Shortwave Infrared (3.7 µm) images [click to enlarge]

GOES-3 is being decommissioned

May 27th, 2016 |
GOES3_VIS_1545_18MAY1980

GOES-3 Visible Image from 18 May 1980 at 1545 UTC (Click to enlarge)

GOES-3 started service on 16 June 1978 and was the operational GOES-West satellite until the late 1980s. Having lost imaging capabilities, it started a second long life as a communications satellite; GOES-3 is currently the oldest operating satellite. Decommissioning will begin on 8 June and run for 15 days. If final decommissioning happens as planned on 23 June, GOES-3’s service life will be 38 years, 7 days.

GOES-3’s arguably most famous imagery occurred during the eruption of Mount St. Helens on 18 May 1980, shown above (click here for an animation of the eruption, courtesy of Barry Roth, SSEC; Tim Schmit, NOAA/ASPB also provided longer visible animations: MP4 | animated GIF).

A comparison of GOES-3 Visible (0.65 µm) and Infrared Window (11.5 µm) images, below, showed that a large portion of the volcanic cloud exhibited IR brightness temperatures of -60º C (dark red color enhancement) or colder as the feature moved rapidly eastward during the first 10 hours following the eruption. It is interesting to note that an “enhanced-V” or cold/warm (-65º/-47º C) thermal couplet signature was evident on the initial 1545 UTC Infrared image (zoom), as the volcanic ash cloud rapidly rose to an estimated altitude of 12 to 16 miles (20 to 27 km) above sea level.

GOES-3 0.65 µm Visible (top) and 10.7 µm Infrared Window (bottom) images [click to play animation]

GOES-3 0.65 µm Visible (top) and 11.5 µm Infrared Window (bottom) images [click to play animation]

Some early examples of full disk GOES-3 images (on 20 November 1978) are shown below, courtesy of Tim Schmit, NOAA/ASPB.

GOES-3 Visible (0.65 µm) and Infrared Window (11.6 µm) images [click to enlarge]

GOES-3 Visible (0.65 µm) and Infrared Window (11.6 µm) images [click to enlarge]