Satellite signatures of the Notre Dame Cathedral fire in Paris, France

April 15th, 2019 |

EUMETSAT Meteosat-11 Shortwave Infrared (3.92 µm) images, with airport identifiers plotted in red [click to play animation | MP4]

EUMETSAT Meteosat-11 Shortwave Infrared (3.92 µm) images, with airport identifiers plotted in red [click to play animation | MP4]

The subtle thermal anomaly (or “hot spot”) from the Notre Dame Cathedral Fire was evident in 4.8-km resolution (at satellite nadir) EUMETSAT Meteosat-11 Shortwave Infrared (3.92 µm) imagery (above) as a cluster of brighter yellow pixels just north of Paris Orly International Airport (LFPO) near the center of the images on 15 April 2019.

The fire reportedly began around 1650 UTC; the maximum 3.92 µm brightness temperature sensed by Meteosat-11 was 284.5 K (11.35ºC) on the 1745 UTC image, not long after the fire had spread to the large spire of the cathedral (Meteosat-11 was actually scanning the Paris area at 1756 UTC, since the Meteosat Second Generation satellites scan each Full Disk from south to north). Clouds approaching from the west began to mask the fire signature at 1930 UTC.

Even though high clouds had begun to move overhead, a thermal signature (darker black pixel) could still be seen in 1-km resolution Metop-A and Metop-C Shortwave Infrared (3.75 µm) images at 2009 and 2048 UTC (below, courtesy of William Straka, CIMSS). The maximum 3.75 µm brightness temperature detected by Metop was 291.1 K (18.0ºC).

Metop-A and Metop-C Shortwave Infrared (3.74 µm) images at 2009 and 2048 UTC [click to enlarge]

Metop-A and Metop-C Shortwave Infrared (3.75 µm) images at 2009 and 2048 UTC [click to enlarge]

Cyclone Idai makes landfall in Mozambique

March 14th, 2019 |

Meteosat-8 Infrared (10.8 µm) and DMSP-17 SSMIS Microwave (85 GHz) images of Cyclone Idai at 1630 UTC [click to enlarge]

Meteosat-8 Infrared Window (10.8 µm) and DMSP-17 SSMIS Microwave (85 GHz) images of Cyclone Idai at 1630 UTC [click to enlarge]

Cyclone Idai — which had been slowly intensifying over warm water within the Mozambique Channel since 09 March — made landfall as a Category 2 storm along the coast of Mozambique on 14 March 2019 (storm track). A toggle between Meteosat-8 Infrared Window (10.8 µm) and DMSP-17 SSMIS Microwave (85 GHz) images from the CIMSS Tropical Cyclones site (above) revealed a large and well-defined eye and eyewall structure at 1630 UTC. Idai had been rated at Category 3 intensity during 3 periods of time during its life cycle, most recently at 12 UTC on the day of landfall.

At 1911 UTC, Metop-A ASCAT winds in excess of 60  knots were sampled just west of the eyewall region (below).

Meteosat-8 Infrared Window (10.8 µm) image, with plots of Metop-A ASCAT winds at 1911 UTC [click to enlarge]

Meteosat-8 Infrared Window (10.8 µm) image, with plots of Metop-A ASCAT winds at 1911 UTC [click to enlarge]

A comparison of VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP, visualized using RealEarth, is shown below.

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

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

Idai had been moving through an environment of very low deep-layer wind shear — a favorable factor for maintaining its intensity — as shown in an animation of Meteosat-8 Infrared Window (10.8 µm) images (below).

Meteosat-8 Infrared Window (10.8 µm) images with contours of satellite-derived Deep-Layer Wind Shear valid at 18 UTC [click to enlarge]

Meteosat-8 Infrared Window (10.8 µm) images with contours of satellite-derived Deep-Layer Wind Shear valid at 18 UTC [click to enlarge]

The MIMIC TC product (below) suggested that Idai might have been in the early stage of an eyewall replacement cycle (ERC) just prior to making landfall. This, after completing a separate ERC during the preceding 48 hours.

MIMIC TC morphed microwave imagery [click to enlarge]

MIMIC TC morphed microwave image product [click to enlarge]

The eye of Idal was becoming cloud-filled as it approached the Mozambique coast, as seen on EUMETSAT Meteosat-8 High Resolution Visible (0.8 µm) images (below).

Meteosat-8 High Resolution Visible (0.8 µm) images [click to play animation]

Meteosat-8 High Resolution Visible (0.8 µm) images [click to play animation]

A time series of surface data from the port city of Beira FQBR (below) showed deteriorating conditions before observations ceased at 15 UTC.

Surface observation data from Beira, Mozambique [click to enlarge]

Surface observation data from Beira, Mozambique [click to enlarge]


Incidentally, an overpass of the Landsat-8 satellite on 11 March provided a 30-meter resolution view of the eye (below), soon after Idai’s first period of rapid intensification to Category 3 strength (SATCON). Surface mesovortices were apparent within the eye.

Landsat-8 False Color image of the eye of Idai on 11 March [click to play a zooming animation]

Landsat-8 False Color image of the eye of Idai on 11 March [click to play a zooming animation]

Flooding from Idai led to hundreds of fatalities in Mozambique and Zimbabwe.

Eruption of Mount Etna in Italy

December 24th, 2018 |

VIIRS True Color RGB images from NOAA-20 (at 1110 and 1220 UTC) and Suomi NPP (at 1200 UTC) [click to enlarge]

VIIRS True Color RGB images from NOAA-20 (at 1110 and 1220 UTC) and Suomi NPP (at 1154 UTC) [click to enlarge]

A sequence of VIIRS True Color Red-Green-Blue (RGB) images from NOAA-20 and Suomi NPP viewed using RealEarth (above) showed the volcanic ash plume from an eruption of Mount Etna in Italy on 24 December 2018.

A toggle between NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images (below) revealed a colder cloud plume at higher altitude along the southern edge of the tan/brown volcanic ash plume. A thermal anomaly or “hot spot” (dark black pixels) could be seen at the snow-covered volcano summit.

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images at 1250 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images at 1250 UTC [click to enlarge]

The volcanic plume could be quantitatively analyzed using Suomi NPP VIIRS Ash Probability, Ash Height, Ash Loading and Ash Effective Radius products from the NOAA/CIMSS Volcanic Cloud Monitoring site at 1154 UTC (below).

Suomi NPP VIIRS Ash Probability, Ash Height, Ash Loading and Ash Effective Radius at 1154 UTC [click to play enlarge]

Suomi NPP VIIRS Ash Probability, Ash Height, Ash Loading and Ash Effective Radius at 1154 UTC [click to play enlarge]

Since the bulk of the volcanic plume was high in ash content with minimal water or ice cloud, a good signature was seen using Meteosat-11 Split Window (11-12 µm) Brightness Temperature Difference images (below).

Meteosat-11 Split Window (11.12 µm) Brightness Temperature Difference images [click to play animation]

Meteosat-11 Split Window (11.12 µm) Brightness Temperature Difference images [click to play animation]

Blowing dust in the Arabian Sea

November 3rd, 2018 |

Sequence of daily True Color RGB images from Terra MODIS, Aqua MODIS and Suomi NPP VIIRS, covering the period 01-03 November [click to play animation]

Sequence of daily True Color RGB images from Terra MODIS, Aqua MODIS and Suomi NPP VIIRS, covering the period 01-03 November [click to play animation]

Strong winds across southern Iran and Pakistan were lofting plumes of blowing sand/dust offshore over the Gulf of Oman and the Arabian Sea during 01 November, 02 November and 03 November 2018 — a sequence of daily composites of True Color Red-Green-Blue (RGB) images from Terra MODIS, Aqua MODIS and Suomi NPP VIIRS from RealEarth (above) showed the increase in dust transport during that 3-day period.

A comparison of True Color RGB images from Terra MODIS, NOAA-20 VIIRS, Suomi NPP VIIRS and Aqua MODIS on 03 November is shown below.

Comparison of True Color RGB images from Terra MODIS, NOAA-20 VIIRS, Suomi NPP VIIRS and Aqua MODIS on 03 November [click to play animation]

Comparison of True Color RGB images from Terra MODIS, NOAA-20 VIIRS, Suomi NPP VIIRS and Aqua MODIS on 03 November [click to play animation]

Metop-A and Metop-B ASCAT data (source) showed surface wind speeds in the 20-25 knot range emerging from the coast where plumes of blowing dust were located (below).

Meop ASCAT surface scatteromete winds [click to enlarge]

Meop ASCAT surface scatteromete winds [click to enlarge]

EUMETSAT Meteosat-11 High Resolution Visible (0.8 µm) images from 02 November and 03 November (below) showed the daily evolution of the dust plumes.

Meteosat-11 Visible (0.8 µm) images [click to play animation | MP4]

Meteosat-11 Visible (0.8 µm) images on 02 November [click to play animation | MP4]

Meteosat-11 Visible (0.8 µm) images on 03 November [click to play animation | MP4]

Meteosat-11 Visible (0.8 µm) images on 03 November [click to play animation | MP4]