GOES-17 becomes the operational GOES-West satellite

February 12th, 2019 |

GOES-17 Full Disk

GOES-17 Full Disk “Red” Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 Mid-level Water Vapor (6.9 µm) images [click to play animation | MP4]

GOES-17 Mid-level Water Vapor (6.9 µm) images [click to play animation | MP4]

GOES-S (named GOES-17 once it reached geostationary orbit) was launched on 01 March 2018. Beginning at 1800 UTC on 12 February 2019, it became the operational GOES-West satellite (replacing GOES-15, which was launched in March 2010). The period of transition to operational status is shown on Full Disk images of “Red” Visible (0.64 µm) and Mid-level Water Vapor (6.9 µm) images (above).

In an animation of GOES-17 images from the 16 ABI spectral bands, centered on the Big Island of Hawai’i (below), an increase in cumulus clouds was evident in the Visible and Near-Infrared bands (1-6) along with a warming signature of the island summits (Mauna Kea and Mauna Loa) in the Infrared bands (7-16) as daytime heating increased during the morning hours. Weighting functions for all of the Infrared bands which are not strongly affected by water vapor absorption (7, and 11-16) have peaks at/near the surface — and the presence of dry air within the middle troposphere shifted the three Water Vapor band (8-10) weighting functions downward to allow some of the island summit thermal signature to be sensed. This dry air aloft (and a lack of cirrus clouds over the island) also enabled the summits to be sensed by the 1.37 µm Near-Infrared “Cirrus” band (4).

GOES-17 images from the 16 ABI spectral bands, centered on the Big Island of Hawai'i [click to play animation | MP4]

GOES-17 images from the 16 ABI spectral bands, centered on the Big Island of Hawai’i [click to play animation | MP4]

A comparison of all 16 ABI bands from GOES-17 covering most of Alaska and the adjacent Bering Sea is shown below.

Image loop that cycles through all 16 ABI Bands from GOES-17, covering most of Alaska [click to play MP4 animation]

Image loop that cycles through all 16 ABI Bands from GOES-17, covering most of Alaska [click to play MP4 animation]

In the animation below (source), GOES-17 and GOES-16 (GOES-East) Longwave Infrared (11.2 µm) images have been combined and displayed in a Mollweide projection. This shows the broad area of coverage provided by the current GOES constellation, which reaches from far eastern Australia to far western Europe and Africa.

GOES-17 + GOES-16 Infrared (11.2 µm) images [click to play animation | MP4]

GOES-17 + GOES-16 Longwave Infrared (11.2 µm) images [click to play animation | MP4]

Although the GOES-17 ABI instrument experiences a nocturnal Loop Heat Pipe (LHP) cooling problem (also discussed here) — which increases around the time of the Spring and Autumn equinox —  the issue only affects the emitted Longwave Infrared spectral bands (bands 08-16), and only for periods lasting as long as a few hours (peaking daily around 1300-1330 UTC). Trends of the Focal Plane Module (FPM) temperature of the ABI instrument can be monitored at this site — and examples of Band 09 (6.9 µm Water Vapor) imagery from 11 February are shown below. Note how the images return to normal after the peak FPM temperatures cool from around 97 K to around 80 K. More information on the daily variation of FPM temperatures throughout the year is available here, here and here.

Sequence of GOES-17 Band 09 (6.9 µm Water Vapor) images during a spike in the Focal Plane Module temperature on 11 February 2019 [click to enlarge]

Sequence of GOES-17 Full Disk Band 09 (6.9 µm Water Vapor) images during a spike in the Focal Plane Module temperature on 11 February 2019 [click to enlarge]

Sequence of GOES-17 CONUS sector Band 09 (6.9 µm Water Vapor) images during a spike in the Focal Plane Module temperature on 11 February 2019 [click to enlarge]

Sequence of GOES-17 CONUS sector Band 9 (6.9 µm Water µm) images during a spike in the Focal Plane Module temperature on 11 February 2019 [click to enlarge]

The LHP cooling issue affects various ABI spectral bands to differing degrees, with the Band 14 (11.2 µm Longwave Infrared) imagery being the least impacted — this can be seen in a Full Disk animation covering the same time period (below).

Sequence of GOES-17 Full Disk Band 14 (11.2 µm Longwave Infrared) images during a spike in the Focal Plane Module temperature on 11 February 2019 [click to enlarge]

GOES-17 and GOES-15 will operate in tandem from their respective locations of 137.2º West and 128º West longitude through early July 2019 — so GOES-15 imagery can be used during times when GOES-17 is adversely affected by the LHP cooling issue.

Cold temperatures in Montana and North Dakota

February 8th, 2019 |

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Very cold surface air temperatures occurred in northeastern Montana and northwestern North Dakota on the morning of 08 February 2019 — with official lows of -50ºF near Antelope and Four Buttes in Montana and -47ºF at Bottineau in North Dakota (and according to MesoWest, -49ºF was registered at a Department of Transportation site west of Crosby in far northwestern North Dakota). GOES-16 (GOES-East) “Clean” Infrared Window (10.3 µm) images (above) revealed surface brightness temperatures across those areas were as cold as -47ºC (-53ºF).

A sequence of VIIRS Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 (below) showed similar surface brightness temperatures, with some pixels as cold as -48ºC (-54ºF). The color enhancement applied to the VIIRS images is the same as that used on the GOES-16 images above, with the red colors beginning at the -40ºC breakpoint (violets begin at -50ºC). While there is not a direct correspondence between satellite-sensed surface infrared brightness temperatures and air temperatures measured in an above-ground instrument shelter, with improving satellite spatial resolution the difference is often within 1-3ºC (or 2-5ºF).

VIIRS Infrared Window (11.45 µm) images from Suomi NPP (at 0753 and 0937 UTC) and NOAA-20 (at 0844 UTC) [click to enlarge]

VIIRS Infrared Window (11.45 µm) images from Suomi NPP (at 0753 and 0937 UTC) and NOAA-20 (at 0844 UTC) [click to enlarge]



Cyclogenesis along the US East Coast

February 4th, 2019 |


The approach of an upper-tropospheric Potential Vorticity (PV) anomaly induced rapid cyclogenesis just off the US East Coast on 04 February 2019, with the surface low rapidly occluding (surface analyses). The eastward-propagating PV Anomaly was apparent on GOES-16 (GOES-East) Air Mass RGB images from the AOS site (below) as darker shades of orange — transitioning to shades of red as the tropopause descended to lower altitudes bringing more ozone-rich air from the stratosphere into the atmospheric column.

GOES-16 Air Mass RGB images [click to play MP4 animation]

GOES-16 Air Mass RGB images [click to play MP4 animation]

A sequence of Infrared Window images from Terra MODIS (11.0 µm) and NOAA-20/Suomi NPP VIIRS (11.45 µm) (below) showed the cyclone at various stages of development. The surface low passed over  the Cape Lookout, North Carolina buoy as it was intensifying, with winds gusting to 44 knots around 12 UTC (winds/pressure | peak wind gusts).

Infrared Window images from Terra MODIS (11.0 µm) and NOAA-20/Suomi NPP VIIRS (11.45 µm), with plot of fixed buoy reports [click to enlarge]

Infrared Window images from Terra MODIS (11.0 µm) and NOAA-20/Suomi NPP VIIRS (11.45 µm), with plots of fixed buoy reports [click to enlarge]

A similar sequence of Visible images from Terra MODIS (0.65 µm) and NOAA-20/Suomi NPP VIIRS (0.64 µm) (below) showed the cyclone during daylight hours.

Visible images from Terra MODIS (0.65 µm) and NOAA-20/Suomi NPP VIIRS (0.64 µm), with plots of fixed buoy reports [click to enlarge]

Visible images from Terra MODIS (0.65 µm) and NOAA-20/Suomi NPP VIIRS (0.64 µm), with plots of fixed buoy reports [click to enlarge]

===== 05 February Update =====

GOES-16

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

After the primary center of circulation began to weaken, a pair of residual lower-tropospheric vortices (surface analyses) was seen to persist on GOES-16 “Clean” Infrared Window (10.3 µm) images (above), rotating around each other in a binary interaction known as the Fujiwhara effect. The two vortices were also evident in NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0620 UTC (below) — in spite of the lack of illumination from a New Moon, airglow alone was sufficient to provide an impressive “visible image at night” with the Day/Night Band. (note: the NOAA-20 VIIRS images are incorrectly labeled as Suomi NPP)

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0620 UTC [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0620 UTC [click to enlarge]

During the early morning hours, an undular bore was evident on GOES-16 “Red” Visible (0.64 µm) images (below), moving toward the westernmost vortex. As the bore began to move over warmer waters of the Gulf Stream, it slowly dissipated.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

Although not particularly intense, this slow-moving midlatitude cyclone was able to draw an appreciable amount of moisture northward from the tropics/subtropics as shown by the MIMIC Total Precipitable Water product (below).

MIMIC Total Precipitable Water product [click to play animation | MP4]

MIMIC Total Precipitable Water product [click to play animation | MP4]

Meteorite impact in Cuba

February 1st, 2019 |

GOES-16 Split Cloud Top Phase (11.2 - 8.4 µm), Split Window (10.3 - 12.3 µm), Near-Infrared

GOES-16 Split Cloud Top Phase (11.2 – 8.4 µm), Split Window (10.3 – 12.3 µm), Near-Infrared “Cirrus” (1.37 µm) and “Red” Visible (0.64 µm) images [click to enlarge]

A meteorite landed near Viñales, Pinar del Río in western Cuba (about 58 miles or 93 km northeast of San Julian MUSJ) on 01 February 2019. GOES-16 (GOES-East) Split Cloud Top Phase (11.2 – 8.4 µm), Split Window (10.3 – 12.3 µm), Near-Infrared “Cirrus” (1.37 µm) and “Red” Visible (0.64 µm) images (above) revealed signatures of the airborne debris cloud as it drifted northeastward then eastward for about an hour after the impact (which occurred around 1817 UTC) — during that hour (from 1817 to 1917 UTC) the debris cloud traveled about 40 miles. A brief signature of another (lower-altitude) debris cloud moving southwestward was also seen immediately following impact, which was most apparent in the Split Window and Cirrus images.

The signatures in the Split Cloud Top Phase and Split Window imagery were due to the presence of mineral dust particles within the debris cloud — the emissivity properties of dust affects the sensed brightness temperatures differently for various infrared spectral bands. The Cirrus spectral band is useful for detecting the scattering of light by airborne particles such as ice crystals, volcanic ash, smoke or dust. The debris cloud was also casting a subtle shadow onto the surface, as seen in the Visible imagery.

Rawinsonde data from Key West, Florida (below) indicated that the northeastward to eastward drift of the debris cloud at a velocity of about 40 mph (35 knots) would have been occurring at altitudes of 4.9-5.5 km (pressures of 565-522 hPa).

Plots of rawinsonde data from Key West, Florida [click to enlarge]

Plots of rawinsonde data from Key West, Florida [click to enlarge]

The GOES-16 Geostationary Lightning Mapper also exhibited a signature around the time of the meteorite impact, as discussed here. Looking at GOES-16 Upper-level (6.2 µm), Mid-level (6.9 µm), Low-level (7.3 µm) and “Clean” Infrared Window (10.3 µm) images with plots of GLM Groups (below), a faint debris cloud signature could best be followed in the 7.3 µm imagery (AWIPS animation) after the 1817 UTC impact — but for a shorter time period than what was seen with the other GOES-16 examples shown above. While the Water Vapor band weighting functions for Key West had peaks at fairly low altitudes for 7.3 µm and 6.9 µm, the signature for any low/mid-tropospheric features would have been masked by absorption and re-radiation from moist layers within the upper troposphere.

GOES-16 Upper-level (6.2 µm, top left), Mid-level (6.9 µm, top right), Low-level (7.3 µm, bottom left) and

GOES-16 Upper-level (6.2 µm, top left), Mid-level (6.9 µm, top right), Low-level (7.3 µm, bottom left) and “Clean” Infrared Window (10.3 µm, bottom right) images, with GLM Groups accumulated during the 5-minute period ending at the image time plotted in red [click to play animation | MP4]

* GOES-17 imagery shown here is preliminary and non-operational *

The bright signature of the bolide exploding as it entered the Earth’s atmosphere was also detected by the GLM instrument on GOES-17, although the viewing angle was much larger (with a zenith angle of 67 degrees, vs 30 degrees from GOES-16). The GLM Groups detected by both GOES-17 and GOES-16 were plotted with and without the native parallax correction (below).

"Red" Visible (0.64 µm) and Low-level Water Vapor (7.3 µm) images from GOES-17 (left) and GOES-16 (right), with GLM Groups accumulated during the 15-minute period ending at 1830 UTC plotted in red [click to enlarge]

“Red” Visible (0.64 µm) and Low-level Water Vapor (7.3 µm) images from GOES-17 (left) and GOES-16 (right), with GLM Groups accumulated during the 15-minute period ending at 1830 UTC plotted in red [click to enlarge]