** The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. **

A comparison of GOES-16 and GOES-13 Shortwave Infrared (3.9 µm) images (above) showed numerous fire “hot spot” signatures (black to yellow to red pixels, with red being the hottest) from prescribed burning across the Flint Hills region of eastern Kansas and northeastern Oklahoma on 11 April 2017. Such fires are an annual tradition in this area, required to preserve the tallgrass prairies — for example, over 2.7 million acres were burned during Spring 2016. The 2-km spatial resolution (at satellite sub-point) and 5-minute scan interval of GOES-16 allowed for more accurate detection and monitoring of the fires (compared to the 4-km spatial resolution and 15-30 minute scan interval of GOES-13).

The corresponding Visible GOES-16 (0.64 µm) vs GOES-13 (0.63 µm) images (below) tracked the development and transport of smoke from the fires. Hourly reports of surface visibility (in statute miles) are plotted in red; at Fort Riley, Kansas, smoke reduced the visibility from 10.0 miles at 21 UTC to 1.0 mile at 23 UTC, adversely affecting air quality there.

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** The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. **

GOES-16 Visible (0.64 µm) images (above) revealed the presence of an eddy in the high-turbidity nearshore waters of southern Lake Michigan on 08 April 2017. The animation was created using 5-minute “CONUS” Sector images; an animation using 1-minute Mesoscale Sector images is available here.

A sequence of Terra and Aqua MODIS true-color Red/Green/Blue (RGB) images viewed using RealEarth (below) showed that the eddy began to develop on 07 April.

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GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing.

GOES-16 includes both a clean infrared window (10.33 µm) and a so-called ‘dirty’ infrared window channel (12.30 µm). The clean infrared window is in a part of the electromagnetic spectrum where there is very little absorption of energy by water vapor; in the dirty infrared window, modest amounts of water vapor absorption occur. The brightness temperature difference, nicknamed the Split Window Difference (SWD for short), can highlight differences in moisture in clear skies.

The toggle above shows the SWD (10.33 µm – 12.30 µm) at 1430 UTC on 7 April 2017. A pronounced gradient stretches southeast to northwest from Louisiana to northeast Kansas and extreme southeastern Nebraska.  Values over Missouri, for example, are around 0.9-1.0 K vs. 1.7-2.2 K over Oklahoma.  The gradient in the brightness temperature difference aligns very neatly with the 850-mb dewpoint temperature from the Rapid Refresh. You can use this product to monitor moisture return from the Gulf of Mexico.

AWIPS Note: The Default enhancement in AWIPS for the Split Window Difference, shown above, does not include large enough negative values. The Split Window Difference value can exceed -5 K in regions of dust. See this link for a different enhancement for this case with a wider range of temperature differences. A similar image uses the mean 1000-700 mb dewpoint temperature rather than values from the single 850-mb level.

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An animation of this imagery (not shown) shows general increases in the SWD values with time.  A consistent signal of moisture will be present only if the temperature decreases with height in the moist layer (that is — if there is no inversion).  An increase in the SWD does not necessarily show an increase in moisture — it can, rather, signify an increase in near-surface temperature (for more information, consult this article by Lindsey et al.). The gradient in the field can remain, however, as in this example.

The Split Window Difference field does an exemplary job of detecting contrails over the southern Plains. The toggle below shows that the SWD signal of cirrus is more distinct than in the 1.378 µm Cirrus Channel! (Thanks to Matt Bunkers of WFO Rapid City for noting this!)

(Note that the SWD was something that was available from GOES-8 through GOES-11. Link)

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EUMETSAT Meteosat-10 Shortwave Infrared (3.9 µm) images (above) showed the thermal signature or “hot spot” (darker black pixels) of fires resulting from US missile strikes at Syria’s Shayrat Air Base on 07 April 2017. The warmest infrared brightness temperature was 300.22 K on the 0030 UTC image (the SEVIRI instrument was scanning the Shayrat region at 00:40 UTC), which was about 25 K warmer than the surrounding background temperatures; though the fires were much smaller than the nominal 3 km spatial resolution of the 3.9 µm detector, the sub-pixel effect enables a signal of the fire radiative power to be registered.

A toggle between the 0015 and 0030 UTC images displayed using McIDAS-V (below; courtesy of William Straka, SSEC) highlights the appearance of the thermal signature at Shayrat Air Base. Two persistent hot spots located northeast of Palmyra could have been due to refinery or mining activities.

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