Using Polar-Orbiting Satellite Imagery from Direct Broadcast sites to understand Elsa

July 6th, 2021 |

Suomi NPP Adapative Day Night Band imagery, 0636 UTC on 6 July 2021 (Click to enlarge)

AOML (The Atlantic Oceanographic and Meteorological Laboratory) maintains a Direct Broadcast antenna site that holds satellite imagery (created using CSPP — the Community Satellite Processing Package) created when a tropical system — such as Elsa — is within the download footprint of the AOML antenna.  This imagery — particularly in the microwave — is useful to describe the system’s structure. The Day Night Band image above, from Suomi NPP at 0636 UTC, shows a non-symmetric storm with the bulk of clouds to the east and south of the surface center (at that time near 23.9 N, 82.3 W, i.e., in the Florida Straits to the south of Dry Tortuga).  Rainfall, as diagnosed using MIRS algorithms and microwave ATMS (Advanced Technology Microwave Sounder) data from NPP, below, shows the asymmetry of the storm as well:  almost all the diagnosed rain is east of the center. (It’s helpful that both infrared imagers and microwave sounders are on the same satellite!)

Suomi NPP ATMS-derived Rain Rate, 0637 UTC on 6 July 2021 (Click to enlarge)

The GCOM-W1 (supported by JAXA) satellite also scanned Elsa shortly before 0700 UTC on 6 July.  Microwave observations at ~36 GHz, below, and at 89 GHz, farther below, can help to characterize the structure of the storm. Indeed, observations at/around 85-89 GHz are used in the MIMIC TC product as described here.

GCOM AMSR-2 observations at 36.5 GHz, 0649 UTC on 6 July 2021 (Click to enlarge)

GCOM AMSR-2 observations at 89.0 GHz, 0649 UTC on 6 July 2021 (Click to enlarge)

In addition to the AOML site, the CIMSS Direct Broadcast site contains Polar Orbiting imagery in near-real time. The afternoon 88.2 GHz image from (NOAA-20) ATMS is shown below.  Cold cloud tops associated with strong scattering by ice of the 88.2 GHz signal are apparent.

NOAA-20 ATMS Channel 16 Brightness Temperature, 1845 UTC on 6 July 2021 (Click to enlarge)


There are a multitude of polar orbiters such that observations show up in clusters of time.  However, for a better time animation, it’s still best to rely on GOES-16!  The animation below, from CSPP Geosphere, shows a sheared storm south and west of Ft Myers FL.  Indeed, an 1800 UTC 6 July 2021 shear analysis from the CIMSS Tropical website (here, from this site), shows westerly shear of 25-30 knots.

GOES-16 True-Color imagery, 6 July 2021 from 1730 to 1920 UTC (Click to animate)

For the latest information on Elsa, consult the webpages of the National Hurricane Center, or the SSEC/CIMSS Tropical Weather Page.

Cyclone Damien makes landfall in Western Australia

February 8th, 2020 |

Himawari-8

Himawari-8 “Clean” Infrared Window (10.4 µm) images [click to play animation | MP4]

2.5-minute rapid scan JMA Himawari-8 “Clean” Infrared Window (10.4 µm) images (above) showed Cyclone Damien making landfall as a Category 2 storm in Western Australia on 08 February 2020. Well west of the storm center, winds gusted to 49 knots at Barrow Island (YBWX). The eye remained intact for several hours after Damien moved inland.

GCOM-W1 AMSR2 Microwave (85 GHz) imagery from the CIMSS Tropical Cyclones site (below) showed the eye at 1710 UTC.

GCOM-W2 AMSR2 Microwave (85 GHz) image [click to enlarge]

GCOM-W2 AMSR2 Microwave (85 GHz) image [click to enlarge]

Just prior to landfall. cloud-top gravity waves were evident in VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP, as viewed using RealEarth (below).

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

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


Tropical Storm Damien was also seen in the first-light image from Russia’s Elecro-L3 satellite, a few hours before Damien reached Category 1 hurricane intensity.

Typhoon Kammuri makes landfall in the Philippines

December 2nd, 2019 |

Himawari-8

Himawari-8 “Clean” Infrared (10.4 µm) images [click to play animation | MP4]

2.5-minute interval rapid scan JMA Himawari-8 AHI “Clean” Infrared (10.4 µm) images (above) showed Typhoon Kammuri as it made landfall in the Philippines around 1500 UTC on 02 December 2019. Kammuri rapidly intensified from a Category 2 to a Category 4 storm (ADT | SATCON) shortly before landfall — it had been moving over very warm water (Sea Surface Temperature | Ocean Heat Content) in the Philippine Sea.

VIIRS Infrared Window (11.45 µm) from Suomi NPP at 1707 UTC and NOAA-20 at 1757 UTC viewed using RealEarth (below) depicted Kammuri 2-3 hours after landfall.

VIIRS Infrared Window (11.45 µm) from Suomi NPP at 1707 UTC and NOAA-20 at 1757 UTC [click to enlarge]

VIIRS Infrared Window (11.45 µm) from Suomi NPP at 1707 UTC and NOAA-20 at 1757 UTC [click to enlarge]

GCOM-W1 AMSR2 Microwave (85 GHz) imagery at 1725 UTC (below) revealed a large eye and nearly circular eyewall.

GCOM-W1 AMSR2 Microwave (85 GHz) image at 1725 UTC [click to enlarge]

GCOM-W1 AMSR2 Microwave (85 GHz) image at 1725 UTC [click to enlarge]

VIIRS imagery and NUCAPS profiles near the North Pole

August 22nd, 2019 |

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

A sequence of 4 consecutive Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.4 µm) images (above) showed a small swirl of clouds associated with a weak area of low pressure near the North Pole — north of Greenland (surface analyses) — on 22 August 2019.

Suomi NPP VIIRS Visible (0.64 µm) images, with plots of NUCAPS availability [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) images, with plots of NUCAPS availability [click to enlarge]

There were Suomi NPP NUCAPS soundings available in the vicinity of the surface low (above) — profiles from the 4 squared green dot locations (green dots indicate successful sounding retrievals from both the CrIS and ATMS instruments) which were closest to both the surface low and the North Pole (below) revealed characteristically-low arctic tropopause heights of around 7-8 km, and surface temperatures dropping to below freezing at the 2 most northerly points of 88.28º and 88.57º N latitude. Note: the Suomi NPP (SNPP) CrIS anomaly that began on 24 March 2019 was resolved via a switch to the redundant Side-2 electronics on 24 June — so CrIS data once again became available for incorporation into SNPP NUCAPS soundings beginning on 01 August. Training material for NUCAPS in AWIPS is available here.

NUCAPS temperature (red) and dew point (green) profiles [click to enlarge]

NUCAPS temperature (red) and dew point (green) profiles [click to enlarge]

According to GCOM-W1 AMSR2 data (source), this weak surface low was over a portion of the Arctic Ocean where sea ice concentration was still high (below).

GCOM-W1 AMSR2 sea ice concentration [click to enlarge]

GCOM-W1 AMSR2 sea ice concentration [click to enlarge]