Increase in Gulf of Mexico water turbidity in the wake of Hurricane Irma

September 11th, 2017 |

Suomi NPP VIIRS true-color RGB images on 07 September and 11 September [click to enlarge]ep

A comparison of Suomi NPP VIIRS true-color Red-Green-Blue (RGB) images on 07 September (before Irma) and 11 September (after Irma) revealed a marked increase in turbidity of the shallow Continental Shelf waters off the coast of southern/southwestern Florida and the Florida Keys. Irma moved through that region on 10 September as a Category 3 hurricane — and even though the center of Irma moved northward off/along the west coast of Florida (with a wind gust to 75 mph at Key West) , the strongest winds were recorded along/near the east coast of Florida: wind gusts to 92 mph and 109 mph and 142 mph — stirring up particulates within the shallow Continental Shelf waters.

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

Large-scale (CONUS) VIIRS true-color before-Irma and after-Irma images are available here and here. Note that the cloud shield of Irma had expanded as far westward as Kansas, Texas and Oklahoma on 12 September ( GOES-16 true-color images) — in addition to large areas of dense smoke from wildfires in the Pacific Northwest (blog post) which was drifting eastward across the northern US.

Widespread Smoke in the Pacific Northwest

September 6th, 2017 |

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

Dry weather over the Pacific Northwest (and over Idaho and Montana) has created an ideal environment lately for wildfires, and much of the region is shrouded in smoke from those fires as shown in the Suomi NPP True Color Imagery, above, from this site.  Note the red points that are Suomi-NPP-detected fires; they persist from day to day, and some grow in size during the course of the animation. GOES-16 Animations of True Color (in this case, the CIMSS Natural True Color product that is created using Bands 1, 2 and 3 (0.47 µm, 0.64 µm and 0.86 µm, respectively)), below, (also available here; a similar product from CIRA is available here), show the pall of smoke as well. Air Quality Alerts from the National Weather Service were widespread on 6 September.

CIMSS Natural True Color, every 15 minutes, from 1400-2130 UTC on 6 September 2017 (Click to animate)

GOES-16 has multiple channels and products that can view both the Smoke and the Fires that produce the smoke. In addition to the visible imagery, Fire Products, below, can characterize the Temperature, Power (in megawatts) and area (in square meters) of the fire detected by GOES-16.  On this day, clouds over the fires in Oregon mean that satellite detection is challenged, even though the by-product, smoke, is apparent.  Fires over Idaho are readily apparent however.  These fires were also detected by the 3.9 µm Shortwave Infrared channel on GOES-16, the traditional fire-detection channel (used in concert with 10.3 µm, the clean window channel).  Imagery at 1.6 µm and 2.2 µm imagery can also be used to highlight hot fires;  that will be the subject of a future blog post.

GOES-16 Fire Products: Fire Temperature, Fire Power and Fire Area, 2037 UTC on 6 September 2017 (Click to enlarge)

 

The mp4 animation, below, shows CIMSS Natural True Color over the Full Disk on 5 September 2017.  The Full Disk View allows a better visualization of how the smoke is moving (and underscores how widespread it is) — and it shows Hurricane Irma as well.

CIMSS Natural True Color, every 15 minutes, on 5 September 2017 (Click to animate)

 

NOAA creates many Smoke-related products, some of which are easily accessible at this link.

Hurricane Irma in the eastern Atlantic Ocean

September 1st, 2017 |
Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images (Click to enlarge)

Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images (Click to enlarge)

A toggle between nighttime images of Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) data at 0347 UTC (courtesy of William Straka, SSEC/CIMSS) showed a high-resolution view of the eye of Category 3 Hurricane Irma.

 

Toggle of CIMSS True Color, GOES-16 Split Window Difference (10.3 µm – 12.3 µm) field, and GOES-16 Dust RGB Product, 1315 UTC on 1 September 2017 (Click to enlarge)

GOES-16 data (ABI and GLM) posted on this page are preliminary, non-operational and are undergoing testing

The animation above cycles through imagery from 1315 UTC on 1 September, showing CIMSS GOES-16 True Color Imagery, The GOES-16 Split Window Difference (10.3 µm – 12.3 µm), and the GOES-16 Dust RGB (Red-Green-Blue) Product. The Split Window Difference field highlights moist air (bright red in the enhancement) to the south of Irma, and also dryer air (blue in the color enhancement), to the north. The Saharan Air Analysis, below, from the CIMSS Tropical Weather Website, corroborates the placement of the dry air to the north of Irma, and Total Precipitable Water estimates (from here) also show dry air. This dry air could influence further strengthening of the storm in the short term.

Saharan Air Layer analysis on 01 September 2017 (Click to animate)

Irma is near the eastern edge of the GLM Domain for GOES-16 in the central Test position at 89.5 W Longitude; the animation below, with GLM Group information (every 10 minutes) over ABI Band 13 (10.3 µm, every 30 minutes from the Full Disk Domain), shows little lightning near the center of Irma on 30/31 August. Lightning was more active on 1 September.

GOES-16 ABI “Clean Window” 10.3 µm Infrared Imagery, every half hour, with GLM Group Data plotted in 10-minute increments from 0000 UTC on 30 September through 1200 UTC on 1 September 2017 (Click to animate)

Satellite trends with Irma show the development of an eye structure, as seen below in the screen capture from the GOES-13 Floater (source) at 1745 UTC, and DMSP-16 SSMIS Microwave (85 GHz) at 1829 UTC on 1 September.

GOES-13 10.7 µm Infrared Imagery, 1745 UTC, 1 September 2017 (Click to enlarge)

The evolution of the eye is also apparent in the GOES-16 Visible Imagery (0.64 µm), below, from 1315-1815 UTC on 1 September 2017.

GOES-16 Visible (0.64 µm) Imagery, 1315-1815 UTC, 1 September 2017 (Click to animate)

For more information on Irma, consult the webpages of the National Hurricane Center or the CIMSS Tropical Weather Website.

Total solar eclipse of 21 August 2017 – a satellite perspective

August 21st, 2017 |

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

GOES-16 CONUS Sector images (at 5-minute intervals)

GOES-16

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

During the total solar eclipse of 21 August 2017,  the lunar umbra was evident on imagery from the GOES-16  0.5 km resolution (at satellite sub-point) “Red” Visible band (0.64 µm) (above) and 1.0 km resolution Near-Infrared “Vegetation” band (0.86 µm) (below).

GOES-16 Near-Infrared

GOES-16 Near-Infrared “Vegetation” (0.86 µm) images [click to play animation]

The shadow was also prominent in other Visible and Near-Infrared bands, as shown in a 4-panel comparison of GOES-16 “Blue” Visible (0.47 µm, upper left), “Red” Visible (0.64 µm, upper right), “Vegetation” (0.86 µm, lower left) and “Snow/Ice” (1.61 µm, lower right) images (below).

GOES-16

GOES-16 “Blue” Visible (0.47 µm, upper left), “Red” Visible (0.64 µm, upper right), “Vegetation” (0.86 µm, lower left) and “Snow/Ice” (1.61 µm, lower right) images [click to play animation]

GOES-16 true-color Red-Green-Blue (RGB) images from the SSEC Geostationary Satellite site (below) showed another view of the shadow. A GOES-16 Full-Disk true-color animation (courtesy of  Kaba Bah, CIMSS) is available here; a composite of eclipse shadow images can be seen here.

GOES-16 true-color RGB images [click to play animation]

GOES-16 true-color RGB images [click to play animation]

The 3.9 µm Shortwave Infrared band is also sensitive to reflected solar radiation — particularly that which is reflected from land surfaces and cloud tops composed of small spherical supercooled water droplets (and to a lesser extent, small ice crystals) — which causes this band to sense warmer (darker gray to black) brightness temperatures compared to the other ABI infrared bands. Therefore, a loss of sunlight within the eclipse shadow will lead to cooling (lighter shades of gray) 3.9 µm brightness temperatures (below).

GOES-16 Shortwave Infrared (3.9 µm) images [click to play animation]

GOES-16 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

Taking a closer look at eastern Missouri and southern Illinois as the solar eclipse shadow was passing over that region shortly after 1800 UTC (1:00 pm local time), GOES-16 “Red” Visible (0.64 µm) images (below) revealed that the pronounced decrease of incoming solar radiation appeared to temporarily suppressed the development of widespread boundary layer cumulus clouds. Note that increase in hourly surface temperatures was also halted, with some locations even experiencing a slight cooling (1-3 ºF) due to reduction of heating within the lunar umbra.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with hourly surface reports plotted in yellow [click to play animation]

GOES-16 Shortwave Infrared (3.9 µm) images (below) also showed a slight cooling — seen as a lighter shade of red enhancement — across the region.

GOES-16 Shortwave Infrared (3.9 µm) images, with hourly surface reports plotted in yellow [click to play animation]

GOES-16 Shortwave Infrared (3.9 µm) images, with hourly surface reports plotted in yellow [click to play animation]

GOES-16 Mesoscale Sector images (at 1-minute intervals)

GOES-16 "Red" Visible (0.64 µm) images, with station identifiers plotted in yellow [click to play animation]

1-minute GOES-16 “Red” Visible (0.64 µm) images, with station identifiers plotted in yellow [click to play animation]

A “floating” Mesoscale Sector provided 1-minute imagery during the eclipse (above).

Polar-orbiting satellite images (Terra MODIS, and Suomi NPP VIIRS)

Terra MODIS Visible (0.65 µm). Land Surface Temperature product, Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Terra MODIS Visible (0.65 µm), Land Surface Temperature product, Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images [click to enlarge]

A toggle between Terra MODIS Visible (0.65 µm), Land Surface Temperature product, Shortwave Infrared (3.7 µm) and Infrared Window (11.0 µm) images (above) showed the eclipse shadow as it was centered over western Nebraska around 1748 UTC. Without a time series of MODIS Land Surface Temperature product images, it is difficult to gauge the exact amount of surface cooling brought about within the shadow of totality. A large-scale high resolution Terra MODIS Visible image is available here (courtesy of Liam Gumley, SSEC).

Suomi NPP VIIRS Visible (0.64 µm), Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

A comparison of Suomi NPP VIIRS Visible (0.64 µm), Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images (above) showed the shadow center over eastern Tennessee around 1833 UTC. A closer comparison of Day/Night Band and Infrared images (below) revealed the  presence of cloud features that made it difficult to see a signature of any city lights that may have come on in the Nashville TN (KBNA) metropolitan area.

Suomi NPP VIIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]