The most common scanning strategy for GOES-R satellites since GOES-16 became operational has been “Flex” Mode, Mode 3: During each 15 minutes, 1 full disk, 3 CONUS and 30 Mesoscale scans are achieved (Link showing Mode 3 Scanning. This YouTube Video shows Mode 3 Scanning with two adjacent mesoscale sectors). (Mode 4 — continuous 5-minute full disk imagery — has been implemented as well, as noted here).

In early 2014, before launch, researchers at NOAA’s Advanced Satellite Products Branch and CIMSS in Madison, Wisconsin suggested that some of the time where the ABI wasn’t scanning (The white space in this graphic) could be used to provide larger CONUS (or PACUS) scans. This didn’t happen, in part because it changed the dimensions of an ABI sector. However, in August 2014, an email exchange with the lead ABI instrument designer from Harris Corporation led to the concept of using the extra time instead to increase the cadence of full disk imaging from every 15 minutes to every 10 minutes in the “flex” mode. (Click to see a ‘Time-time’ chart of Mode 6 for GOES-16, and for GOES-17;  You might notice that GOES-16 and GOES-17 have slightly different Mode 6 scanning strategies.  Mode-6M for GOES-17 differs because of the timings of different calibration looks meant to mitigate errors associated with the faulty Loop Heat Pipe (link 1, link 2, link 3). Changes were need to in the ground system to support this new scan mode, and those changes are now operational.

The change to 10-minute full disk imagery matches the scanning of JMA’s AHI imager (and it will match the next generation EUMETSAT imager as well). It also gives the finer time resolution in the full disk domains for monitoring convection, fires, volcanic ash plumes, turbulence, etc., in regions outside CONUS and PACUS scans. In particular, Alaska region of the National Weather Service receives full-resolution Alaska sectors created from the full-disk imagery, and those sectors will now switch from a 15-minute cadence to a 10-minute cadence.  All of Central and South America will now also have imagery every 10 minutes!

This page at the goes-r.gov website has more information on scanning strategies. You can also find more information about scanning schedules and scan sectors here.

Many Baseline Products will also adopt the 10-minute cadence.  For example, compare the GOES-16 Baseline Cloud Top Temperature imagery above, from April 2, with Mode 6 scanning and 10-minute temporal resolution at the end of the animation, with the GOES-16 Baseline Cloud Top Temperature with Mode 3 and 15-minute temporal resolution below from April 1. (An animation with Mode 6 scanning at the end showing Band 13 “Clean Window” 10.3 µm imagery is here).

Additional Full Disk animations covering a 6-hour period — 3 hours before/after the 1600 UTC Mode 6 activation time — are available from GOES-17 (Visible | Water Vapor) and GOES-16 (Visible | Water Vapor).

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The Spring Hill Fire began to burn in central New Jersey around 1745 UTC (1:45 PM EDT) on 30 March 2019. GOES-16 (GOES-East) Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (above) showed the hot thermal signature of the fire as it burned into the subsequent nighttime hours and the following morning. Smoke from the fire drifted northeastward, reducing the surface visibility at Lakehurst Naval Air Station (KNEL), Toms River (KMJX) and Belmar (KBLM).

GOES-16 also initially viewed this area with 1-minute imagery from 1700-1859 UTC (since the Mesoscale Sector #1 normally covers New Jersey), and first displayed a fire hot spot around 1745 UTC. The animation below shows Visible imagery (0.64 µm), with Shortwave Infrared imagery in the background. One-minute data was valuable during these two hours because the rapidly moving clouds occasionally allowed brief views of the surface. It’s also easier to identify the smoke plume as a coherent structure with a 1-minute cadence (vs. the 5-minute cadence available with CONUS scans). At 1900 UTC, GOES-16 Mesoscale Sector #1 was repositioned to cover developing convection over the mid-Mississippi River Valley, so 1-minute views of New Jersey were terminated.

The GOES Fire Detection and Characterization Algorithm (the Baseline fire-detection product) is shown below. This product is not computed in Mesoscale Domains, so only CONUS imagery with a 5-minute cadence is shown. The widespread cloud cover affected the signal, but the fire was still detected. Note that the Fire Power product identified the fire pixels more frequently (consider the 1832 UTC image, for example).

The rapid growth of the fire thermal signature was apparent in a sequence of 3 daytime and 3 nighttime VIIRS Shortwave Infrared (3.74 µm) images from NOAA-20 and Suomi NPP (below). Note: some of the NOAA-20 images — 1750 UTC on 30 March, along with 0609 and 0749 UTC on 31 March — are incorrectly labeled as Suomi NPP.

Signatures of the fire were also seen in a comparison of Suomi NPP VIIRS Near-Infrared (1.61 µm and 2.24 µm), Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images (below, courtesy of William Straka, CIMSS).

A little science on the night shift (thread)! We’ve gotten many questions about the smoke across central and northern NJ tonight. This smoke is originating from the Spring Hill Forest Fire in Penn State Forest in Burlington County. #njwx pic.twitter.com/OW8GmTS1Ii

— NWS Mount Holly (@NWS_MountHolly) March 31, 2019

===== 01 April Update =====

In a comparison of Terra MODIS True Color and False Color RGB images on 01 April from the MODIS Today site (above) the fire burn scar was evident in the False Color image.

The appearance of the burn scar was also seen in a before/after toggle between Terra MODIS False Color RGB images on 27 March and 01 April (below).

A closer view of the 01 April Terra MODIS False Color RGB image using RealEarth (below) showed that the northeastern edge of the burn scar was near Route 72 (which had to be closed as the fire was being contained), and may have threatened structures at Coyle Field.

===== 08 April Update =====

A 30-meter resolution Landsat-8 False Color RGB image from 08 April (above) provided a very detailed view of the Spring Hill Fire burn scar. It suggested that the fire did cross Route 72 at Coyle Field.

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A sequence of three GOES-16 Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images with 1-minute plots of GLM Events (above) showed the brief signature of a meteor over the Florida Panhandle during the 0353-0354 UTC time period on 31 March, or 11:53-11:54 PM Eastern Daylight Time on 30 March 2019. The bright meteor signature was captured over northern Taylor County, northwest of the Perry-Foley Airport (station identifier K40J) — the GLM Events are plotted at their approximate location on the Earth’s surface (using the default GLM parallax correction).

The GOES-16 ABI instrument was scanning that portion of the Florida Panhandle at 03:52:54 UTC, slightly earlier than the time that the fireball flash was sensed by the GLM instrument, so no corresponding thermal signature was evident in the infrared imagery.

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A toggle between 30-meter resolution Landsat-8 False Color Red-Green-Blue (RGB) images viewed using RealEarth (above) revealed a large ice lead that had opened up to the east of Utqiagvik (Barrow), Alaska on 28 March 2019. Snow and ice appear as darker shades of cyan in the RGB image, with open water exhibiting a dark blue to black appearance.

A sequence of True Color RGB images from NOAA-20 / Suomi NPP VIIRS and Terra MODIS (below) showed the ice lead becoming wider with time during a 5-hour period (note: the time stamps on the images do not reflect the actual time each satellite passed over the Utqiagvik area). The MODIS image appeared the sharpest, since that instrument has a 250-meter resolution in the visible spectral bands (compared to 375 meters for VIIRS).

In a 14-day series of Terra MODIS composites (below) it can be seen that the same general ice fracture line had opened and closed a few times during the 15-28 March period, depending on the influences of surface wind stress and sea currents. Days with strong and persistent southwesterly winds led to an opening of the ice lead (such as 20 March); however, the largest 1-day change — and the largest opening of the ice lead — occurred from 27-28 March (MODIS | VIIRS), when the strong southwest winds were bringing unseasonably warm air (over 30ºF above normal) across the area. The daily high temperature at Utqiagvik on 28 March was 30ºF, which set a new record high for the date (the normal high temperature for 28 March is -3ºF). Incidentally, this period of above-normal temperatures contributed to Utqiagvik having its warmest March on record.

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