GOES-13 brought out of storage

June 21st, 2019 |

GOES-13 Visible (0.63 µm) images [click to play animation | MP4]

GOES-13 Visible (0.63 µm) images [click to play animation | MP4]

GOES-13 was taken out of storage on 19 June 2019 to begin a period of Image Navigation and Registration (INR) testing — the Satellite Data Services positioned a spare rooftop antenna to begin ingesting the GVAR data from the satellite (positioned over the Equator at 60.2º W longitude) . Visible images from 21 June are displayed above. According to NOAA: “With the established performance of NOAA’s new geostationary satellites, GOES-16 (as GOES-East) and GOES-17 (as GOES-West), and a healthy GOES-14 in reserve, NOAA can provide GOES-13 to the Air Force for their weather forecasting needs. After a check of the GOES-13 instruments, NOAA will operate the satellite on behalf of the Air Force during its remaining life span.”

A 5.5-hour animation of all five spectral bands of the GOES-13 Imager is shown below.

Images from all 5 spectral bands of the GOES-13 Imager [click to enlarge]

All 5 spectral bands of the GOES-13 Imager [click to enlarge | MP4]

Water Vapor images from GOES-17 (GOES-West), GOES-15, GOES-16 (GOES-East) and GOES-13 (below) — all centered at Glasgow, Montana — showed the development of an anomalously-deep (for 21 June) mid-tropospheric cutoff low over eastern Montana. The images are displayed in the native projection of each satellite.

Water Vapor images from GOES-17, GOES-15, GOES-16 and GOES-13, all centered at Glasgow, Montana [click to play animation | MP4]

Water Vapor images, from left to right: GOES-17, GOES-15, GOES-16 and GOES-13, all centered at Glasgow, Montana [click to play animation | MP4]

===== 25 June Update =====

All 5 spectral bands of the GOES-13 Imager [click to enlarge]

All 5 spectral bands of the GOES-13 Imager [click to enlarge]

A 23.5-hour animation of all five spectral bands of the GOES-13 Imager is shown above, centered over Wisconsin.

GOES-13 Visible (0.63 µm) images [click to play animation | MP4]

GOES-13 Visible (0.63 µm) images [click to play animation | MP4]

GOES-13 Visible images centered near Cape Verde in western Africa (above) showed that the INR quality of GOES-13 was still very good.

===== 26 June Update =====

GOES-13 Infrared Window (10.7 µm) and Visible (0.63 µm) images [click to play animation | MP4]

GOES-13 Infrared Window (10.7 µm) and Visible (0.63 µm) images [click to play animation | MP4]

A test of GOES-13 Rapid Scan Operations (RSO)was conducted on 26 June — a sequence of Infrared Window and Visible images (above) revealed the presence of a Mesoscale Convective Vortex (MCV) off the US East Coast, following the dissipation of its parent nocturnal thunderstorm.

Philadelphia Refinery Explosion in CONUS and Mesoscale Sectors

June 21st, 2019 |

GOES-16 Shortwave Infrared imagery (3.9 µm) from the CONUS sector (orange label) and Mesoscale sector (white label) scans over Philadelphia at the nominal time of 0821 UTC on 21 June 2019 (Click to enlarge)

An earth-shaking refinery explosion (News story 1, 2) occurred in Philadelphia, PA under variably cloudy skies on Friday morning 21 June 2019. The toggle above shows GOES-16 3.9 µm Shortwave Infrared imagery from the mesoscale sector (with 1-minute imagery) and from the CONUS sector (with 5-minute imagery) at similar nominal times, 0821 UTC. There is a noticeable difference between the character of the signal in the mesoscale sector and the CONUS sector. This chart shows that a CONUS sector scan (shown in Blue at that link for Mode 6A that applies to GOES-16) occurs over a span of time from either 76 seconds to 233 seconds, or from 376 seconds to 533 seconds every 10 minutes (600 seconds). The nominal time of the image will be when the scan starts. Thus, the CONUS time at 08:21 UTC — that shows a very hot spot — is scanning over Philadelphia at some time in the following 2+ minutes after the scan start time (08:21:54). The Meso scale time of 08:21 UTC is scanning Philadelphia at very close to 08:21:05 UTC.

The mesoscale sector from 0820 to 0826 UTC shows no scene quite so hot as the CONUS sector. The warmest brightness temperature from the mesoscale sector, 51.5 C, occurs in the 0823 UTC image. This contrasts with the warmest brightness temperature of 118.2 C in the CONUS sector! This suggests an ephemeral explosion or rapidly-changing cloud cover that frequently masked the view (or both!).  The GOES-16 CONUS sector scanned just at the right time; the Mesoscale sector, even with higher temporal resolution, did not see the worst of the explosion.

GOES-16 Shortwave Infrared imagery (3.9 µm) from the a Mesoscale sector (white label) over Philadelphia from 0821 to 0826 UTC on 21 June 2019 (Click to enlarge)

Toggles between the CONUS image at 0821 and the mesoscale sectors at 0822 UTC and at 0823 UTC suggest that GOES-16 CONUS sector scanned Philadelphia shortly after 0822 UTC. The shift between the CONUS and mesoscale sectors is in opposite directions at the two times. (Note that Philadelphia County is outlined in both of those linked-to toggles.)

As has been observed with other similar events (for example, here, here and here), a closer look at the area showed that a nighttime thermal signature of the fire was also evident in GOES-16 Near-Infrared 1.61 µm and 2.24 µm imagery (below).

GOES-16 Near-Infrared (1.61 µm and 2.24 µm) and Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

GOES-16 Near-Infrared (1.61 µm and 2.24 µm) and Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

Wildfire in the Seward Peninsula of Alaska

June 16th, 2019 |

GOES-17

GOES-17 “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed a smoke plume and pyrocumulus clouds in addition to the thermal anomaly (or “hot spot”) associated with the lightning-initiated North River wildfire burning in the far eastern Seward Peninsula of Alaska on 16 June 2019. It is interesting to note that shortly after the wildfire exhibited a peak Shortwave Infrared brightness temperature of 94.5ºC at 2124 UTC, a distinct pyrocumulus cloud “jump” was seen in the Visible imagery (which appeared to peak in vertical extent around 2131 UTC, as seen in this short animation).

A sequence of 3 Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Visible (0.64 µm) images (below) also showed the fire thermal anomaly (black to red pixels) and the smoke plume.

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Visible (0.64 µm) images, with surface observations plotted in yellow [click to enlarge]

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Visible (0.64 µm) images, with surface observations plotted in yellow [click to enlarge]

In fact, the south-southwestward transport of smoke restricted the surface visibility to 5 miles at Unalakeet and 4 miles at St. Michael (below), located about 100 to 150 miles from the fire respectively.

Time series plot of surface observation data from Unalakeet [click to enlarge]

Time series plot of surface observation data from Unalakeet [click to enlarge]

Time series plot of surface observation data from St. Michael [click to enlarge]

Time series plot of surface observation data from St. Michael [click to enlarge]

A NOAA-20 VIIRS True Color Red-Green-Blue (RGB) image viewed using RealEarth (below) showed significant residual smoke aloft (from the previous day of that wildfire’s growth) arcing westward then southward over the Bering Sea; however, since smoke is effectively transparent at the 11.45 µm Infrared Window wavelength, there was no smoke signature seen in that particular image.

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images [click to enlarge]

Reflection of sunlight from the Topaz Solar Farm in southern California

June 12th, 2019 |

GOES-17

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

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) images (above) revealed a bright reflection of sunlight off the large arrays of solar panels at Topaz Solar Farm in southern California (Google maps) — located between Black Mountain and California Valley — on 12 June 2019. Of particular interest are the vertical “stripes” emanating from the bright reflection signature in the 0.64 µm images, extending both northward and southward from the solar farm. These image artifacts are likely related to saturated ABI detector column amplifiers, due to an excess charge induced by intense sunlight reflection off the large solar panels.

Visible images displayed using McIDAS (below) are in the native GOES-17 satellite projection — removing the re-mapping inherent in the AWIPS images shown above — so the vertical striping artifacts are correctly oriented with respect to how the ABI swaths are scanned.

GOES-17 "Red" Visible (0.64 µm) images [click to play animation | MP4]

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

In multi-panel GOES-17 images that showed all 16 ABI bands (below) this reflection signature was apparent in the other visible and in most of the other infrared channels. The reflected energy was so intense that the Shortwave Infrared (3.9 µm) images displayed infrared brightness temperatures of 138.7ºC (411.85 K), the saturation temperature of the 3.9 µm detectors. Another interesting artifact: the so-called “Dark Pixels Around Bright Objects” that appear in the Visible (0.47 µm and 0.64 µm) and Near-Infrared (0.86 µm, 1.61 µm and 2.24 µm) spectral bands.

Multi-panel images of all 16 ABI bands of GOES-17 [click to play animation | MP4]

Multi-panel images of all 16 ABI bands of GOES-17 on 12 June [click to play animation | MP4]

However, note the absence of a solar farm signature in the Cirrus (1.37 µm), Water Vapor (7.3 µm, 6.9 µm and 6.2 µm) and CO2 (13.3 µm) images — the presence of a layer of moisture within the mid-troposphere (centered near the 500 hPa pressure level) absorbed upwelling radiation from the surface, then re-emitted radiation at the colder temperature of that moisture aloft (thereby masking the bright/hot solar farm signature). Plots of Infrared and Water Vapor weighting functions (below) showed significant peaks at higher altitudes (due to the aforementioned layer of mid-tropospheric moisture) for Bands 8, 9, 10 and 16 — while the other Infrared spectral bands had their strongest weighting function peaks at the surface, with minimal contributions from higher altitudes.

Infrared and Water Vapor weighting functions calculated using rawinsonde data from Vandenberg CA at 00 T on 13 June [click to enlarge]

Infrared and Water Vapor weighting functions calculated using rawinsonde data from Vandenberg Air Force Base CA at 00 UTC on 13 June [click to enlarge]

It is interesting to examine GOES-17 imagery from 5 days earlier (below) — due to a drier air mass over the area on 07 June (with a Total Precpitable Water value of 0.57 inch, vs 0.70 inch on 12 June), a faint signature of the solar farm reflection could even be seen in the Band 4 Cirrus (1.37 µm) imagery.

Multi-panel images of all 16 ABI bands of GOES-17 [click to play animation | MP4]

Multi-panel images of all 16 ABI bands of GOES-17 on 07 June [click to play animation | MP4]

Plots of the Infrared and Water Vapor weighting functions for that earlier day (below) showed higher-altitude peaks for bands 8, 9, 10 and 16 (similar to what was seen in the 12 June case).

Infrared and Water Vapor weighting functions calculated using rawinsonde data from Vandenberg Air Force Base CA at 00 UTC on 08 June [click to enlarge]