GOES-12 is retired from service

August 16th, 2013

The GOES-12 Sounder has sent its last data, ending more than 12 years of service. The GOES-12 Sounder was turned off at 1100 UTC on 13 August. GOES-12 was launched on July 23, 2001, and GOES-12 transmitted data from 16 August 2001 – 7 January 2002, and then more or less continuously from January 16, 2003 onward, a lengthy record of data collection for a geostationary satellite. GOES-12 initially served as GOES-East, replacing GOES-8. After April, 2010, when GOES-13 began service as GOES-East, GOES-12 was moved to 60 West longitude and supplied data over South America. The end of its fuel supply after a dozen years in orbit requires a decommissioning that is scheduled for Friday 16 August.

GOES-12 Sounder Imagery over South America, 0931 UTC on 13 August 2013

GOES-12 Sounder Imagery over South America, 0931 UTC on 13 August 2013

The last GOES Sounder images were centered over Bolivia, as shown above. Sounder data can be used to estimate Total Precipitable Water, or Cloud Top Pressure. A toggle between these last two products from GOES-12 is shown below.

GOES-12 DPI Total Precipitable Water and Cloud-Top Pressure, nominal time of 1100 UTC 13 August 2013

GOES-12 DPI Total Precipitable Water and Cloud-Top Pressure, nominal time of 1100 UTC 13 August 2013

The GOES-12 Imager was turned off at approximately 2330 UTC on 15 August 2013; De-orbit maneuvers are scheduled at 0100 and 1300 UTC on 16 August 2013.

The loss of data flowing from GOES-12 will have an impact on the GOES-13 scanning strategy. During routine GOES-13 scanning, there are six South American images every three hours. However, during past GOES-13 Rapid Scan Operations (RSO), only one South American Image was scanned every three hours — the Southern Hemisphere Short Sector (SHSS) that was south of the Equator, west of South America. (An example is here). In the scanning strategy now, a South American Image over the southern Amazon Basin (the South American ‘A’ Sector; here is a second example) will be produced near the top of the hour, and a South American Image over the southern part of the Continent (the South American ‘B’ Sector; here is a second example) will be produced near the bottom of the hour. An RSO call late on 13 August yielded the following two images in an hour.

GOES-13 South America Sectors (A and B)

GOES-13 South America Sectors (A and B)

=================UPDATE 16 August 2013=======================

GOES-12 10.7 µm infrared channel images (click image to play animation)

GOES-12 10.7 µm infrared channel images (click image to play animation)

The Imager was shut off around 2340 UTC on August 15 2013. The loop above shows the final two days of the Full Disk imagery. The final set of Imager imagery — all five channels — is below.

GOES-12 Imager over South America, 2328 UTC on 15 August 2013

GOES-12 Imager over South America, 2328 UTC on 15 August 2013

GOES-12 produced many excellent loops. Perhaps the most famous, a visible imagery loop of Hurricane Katrina in the Gulf of Mexico, is available here (Or here as a Quicktime movie).

The Memphis Derecho of July 22 2003

July 31st, 2013
GOES-12 10.7 µm IR imagery (Click Image to play animation)

GOES-12 10.7 µm IR imagery (Click Image to play animation)

On the morning of July 22, 2003, a strong derecho moved through metropolitan Memphis, TN, with winds exceeding hurricane-force. The most significant impact of this storm was a loss of power caused in part by the many trees that were downed by the winds. The Storm Report for the day from the Storm Prediction Center shows a cluster of wind reports in and around Memphis and Shelby County. The National Weather Service office in Memphis produced a report on this event that includes radar imagery and a discussion of surface and upper-air observations. More information on this derecho is here. What do satellite data show for this event?

The animation of 10.7 µm imagery, above, shows the development of convection in southeast Kansas and northwest Arkansas that then moves eastward into the mid-South, hitting Memphis around 1200 UTC. Several overshooting tops are evident as the storms pass near Memphis, with the coldest brightness temperatures at 196K! Past derechosdiscussed on this blog (such as the one that hit the East Coast in 2012) were characterized by a channel of moisture and instability aligned with the storm motion, allowing the propagating thunderstorm complex access to a rich source of moisture and instability. This event in 2003 was no different. GOES-12 Sounder retrievals — during that year, 3×3 fields-of-view were used (versus single pixels now) — of Total Precipitable Water, Convective Available Potential Energy (CAPE) and Lifted Index (LI), show abundant moisture and instability aligned west-to-east across northern Arkansas. CAPE values exceeded 3000 J/kg, Total Precipitable Water was greater than 2 inches, and Lifted Indices were near -10.

GOES-10/GOES-12 Sounder-Derived Total Precipitable Water (3x3 Field of View) (Click Image to play animation)

GOES-10/GOES-12 Sounder-Derived Total Precipitable Water (3×3 Field of View) (Click Image to play animation)

GOES-10/GOES-12 Sounder-Derived Convective Available Potential Energy (CAPE) (3x3 Field of View) (Click Image to play animation)

GOES-10/GOES-12 Sounder-Derived Convective Available Potential Energy (CAPE) (3×3 Field of View) (Click Image to play animation)

GOES-10/GOES-12 Sounder-Derived Lifted Index (3x3 Field of View) (Click Image to play animation)

GOES-10/GOES-12 Sounder-Derived Lifted Index (3×3 Field of View) (Click Image to play animation)

GOES-12 Visible Imagery (Click Image to play animation)

GOES-12 Visible Imagery (Click Image to play animation)

Visible imagery, above, from GOES-12 shows the convection continuing to develop as it moves across the Mississippi River into Memphis. Several Overshooting tops are evident, as well as parallel cloud lines at the cirrus level that are usually associated with turbulence. GOES-10, as GOES-West, was also able to capture the convection as it moved through Memphis (below).

GOES-10 Visible Imagery (Click Image to play animation)

GOES-10 Visible Imagery (Click Image to play animation)

Dorian

July 25th, 2013
GOES-13 (left) and GOES-12 (right) visible imagery

GOES-13 (left) and GOES-12 (right) visible imagery images

Tropical Storm Dorian has formed in the far eastern Tropical Atlantic, just west of the Cape Verde Islands. The visible imagery above, from GOES-13 (left) and GOES-12 (right) shows the evolution of the storm in the morning on July 25th. The position change in six hours between 0845 UTC and 1445 UTC suggests a steady west-northwest movement. GOES-12 (scheduled to be decommissioned on 16 August) sits above 60 W vs. 75 W for GOES-13. Accordingly, GOES-12 has a more top-down view of the storm (near 35 W on July 25th) and GOES-13’s view is more oblique. This explains the more circular presentation in the GOES-12 imagery compared to GOES-13. A similar difference in geometry is apparent in the 10.7 µm imagery shown below. A slow increase in the storm organization is also obvious in the animation below.

GOES-13 (left) and GOES-12 (right) 10.7 µm imagery

GOES-13 (left) and GOES-12 (right) 10.7 µm imagery imagery

MIMIC Total Precipitable Water, 1300 UTC 25 July 2013

MIMIC Total Precipitable Water, 1300 UTC 25 July 2013

Future development of the storm depends strongly on the environment through which the storm will move. Morphed microwave data (above) suggests that the atmosphere ahead of the storm is dryer, as total precipitable water values are less than 40 mm in the central tropical Atlantic. However, there is robust feed of moisture from the Equator near the South American coast into the storm and ocean surface temperatures are progressively warmer along the projected path of the storm. Sounder data from this site, shown below, suggests that Dorian is moving into a dryer and more stable environment. (In the imagery below, Dorian is the small storm at the far eastern edge of the sounder footprint, near 15 N and 35 W)

GOES-12 Sounder DPI values of Lifted Index and Total Precipitable Water, 1300 UTC on 25 July 2013

GOES-12 Sounder DPI values of Lifted Index and Total Precipitable Water, 1300 UTC on 25 July 2013

ASCAT Scatterometer winds, and Total Precipitable Water, around 1100 UTC on 25 July 2013

ASCAT Scatterometer winds, and Total Precipitable Water, around 1100 UTC on 25 July 2013

Scatterometer winds from ASCAT, above, show tropical storm-force winds north of the storm center. The storm itself is embedded within a rich moisture feed from the ITCZ. Further information and graphics on the storm are available at the CIMSS Tropical Weather Website and the CIMSS GOES-R Tropical Overshooting Tops Website. Refer to the National Hurricane Center website for official forecasts and storm discussions. People along the southeast coast of the United States and in the Caribbean Sea should monitor the progress of this early-season storm.

Eruption of the Tungurahua volcano in Ecuador

July 14th, 2013
GOES-13 false-color Red/Green/Blue (RGB) image

GOES-13 false-color Red/Green/Blue (RGB) image

Tungurahua is an active stratovolcano in Ecuador (Wikipedia); a Landsat-8 false-color image showed the partially snow-covered dome of the volcano on 13 July 2013. On the following day, the Washington Volcanic Ash Advisory Center issued a volcanic ash advisory due to an explosive eruption that occurred at 11:51 UTC on 14 July 2013. A GOES-13 false-color Red/Green/Blue (RGB) image created using the NOAA/CIMSS GOES-R Volcanic Ash Detection Algorithm (above) highlighted a warm thermal anomaly and a volcanic cumulonimbus (based upon very rapid cloud top cooling rates and cold IR brightnesss temperature values) minutes after the eruption began — during the “11:45 UTC” GOES-13 image, the satellite was actually scanning the region of the volcanic eruption at 11:58 UTC.

GOES-15 (left), GOES-12 (center), and GOES-13 (right) visible images

GOES-15 (left), GOES-12 (center), and GOES-13 (right) visible images

A comparison of the early stages of the volcanic cloud as viewed from GOES-15 (GOES-West), GOES-12 (GOES-South America), and GOES-13 (GOES-East) is shown with visible channel images (above) and IR channel images (below). The actual times that each of the satellites were scaning the region of the volcanic eruption are noted in the labels, and the images are shown in the native projection for each individual satellite.

The GOES-13 satellite was the first to detect to volcanic cloud, since it was scanning the area at 11:58 UTC (about 7 minutes after the beginning of the eruption). The oblique viewing angle from the GOES-15 satellite helped to highlight the darker gray appearance of the ash-laden volcanic cloud, and reveal the long shadow being cast to the west of the tall feature (estimated to be as high as 45,000 feet above ground level). The volcanic cloud appeared largest on the GOES-12 images due to the more direct viewing angle, as well as the later scan time.

GOES-15 (left), GOES-12 (center), and GOES-13 (right) IR images

GOES-15 (left), GOES-12 (center), and GOES-13 (right) IR images

Animations depicting the volcanic cloud evolution are shown using GOES-12 0.65 µm visible channel, 6.5 µm water vapor channel, and 10.7 µm “IR window” channel images (below). Since a large amount of water vapor is usually exhaled during such explosive eruptions, the extent of the volcanic cloud can be more easily followed on the water vapor channel images.

GOES-12 0.65 µm visible channel images (click image to play animation)

GOES-12 0.65 µm visible channel images (click image to play animation)

GOES-12 6.5 µm water vapor channel images (click image to play animation)

GOES-12 6.5 µm water vapor channel images (click image to play animation)

GOES-12 10.7 µm IR channel images (click image to play animation)

GOES-12 10.7 µm IR channel images (click image to play animation)