Typhoon Kammuri in the West Pacific Ocean, with record cold cloud-top temperatures

November 30th, 2019 |

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

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

2.5-minute interval JMA Himawari-8 AHI “Clean” Infrared Window (10.4 µm) images (above) showed a large canopy of cold cloud-top infrared brightness temperatures (BTs) associated with Category 1 Typhoon Kammuri in the West Pacific Ocean on 30 November 2019. Between 00 UTC and 05 UTC, many of the pulsing overshooting tops exhibited BTs -100ºC or colder (shades of red embedded in black on the coldest end of the scale). — the coldest BT was -103.55ºC at 02:59:44 UTC.

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images at 0421 UTC as viewed using RealEarth (below) revealed an area of very cold cloud-top infrared BTs (highlighted by the yellow region near the center of the storm). The coldest BT within that yellow area was -109.35ºC — which would qualify as the coldest cloud-top temperature on record as sensed by a meteorological satellite (Weather Underground).

 NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images at 0420 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images at 0421 UTC [click to enlarge]

The NOAA-20 VIIRS Infrared image at 0421 UTC is shown below with 2 different color enhancements — the darker blue colors of the 160-to-200 K enhancement help to highlight the colder BT regions (including the coldest 163.8 K or -109.35ºC pixel).

NOAA-20 VIIRS Infrared Window (11.45 µm), with different color enhancements (credit: William Straka) [click to enlarge]

NOAA-20 VIIRS Infrared Window (11.45 µm) image at 0421 UTC, with 2 different color enhancements (credit: William Straka, CIMSS) [click to enlarge]

On the closest (time-wise) Himawari-8 Infrared image at 04:22:15 UTC, the coldest cloud-top BT was -102.5ºC. In a toggle between magnified Himawari-8 Visible and Infrared images at that time (below), the -102.5ºC BT was located within the northernmost cluster of red pixels (where shadowing and texture in the Visible image highlighted the overshooting top).

Himawari-8 Visible (0.64 µm) and Infrared (10.4 µm) images at 0422 UTC [click to enlarge]

Himawari-8 Visible (0.64 µm) and Infrared (10.4 µm) images at 0422 UTC [click to enlarge]

The nearest upper air site was Babelthuop Airport/Koror on Palau Island, located south of the storm — the coldest temperature in their 00 UTC rawinsonde data (below) was -81.9ºC at an altitude of 16.7 km. Assuming that the overshooting top cooled at a lapse rate of around 7.5ºC per km of ascent beyond the -81.9ºC tropopause (reference), the altitude of the coldest -109.35ºC cloud top was likely near 19.5 km.

Plots of 00 UTC and 12 UTC rawinsonde data from Koror, Palau Island [click to enlarge]

Plots of 00 UTC and 12 UTC rawinsonde data from Koror, Palau Island [click to enlarge]

During the daylight hours on 30 November, Himawari-8 “Red” Visible (0.64 µm) images (below) revealed widespread cloud-top gravity waves which were moving outward away from intense convection with overshooting tops near the storm center. Many of these gravity waves were propagating along the tops of tendrils of transverse banding — especially within the southern semicircle of Kammuri.

Himawari-8

Himawari-8 “Red” Visible (0.64 µm) images [click to play animation | MP4]

—————————

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1604 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1604 UTC (credit: William Straka, CIMSS) [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from Suomi NPP at 1604 UTC (above) and NOAA-20 at 1654 UTC (below) showed mesospheric airglow waves propagating southward in the DNB images.

NOAA-20 Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1654 UTC (credit: William Straka, CIMSS) [click to enlarge]

NOAA-20 Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1654 UTC (credit: William Straka, CIMSS) [click to enlarge]

—————————

6.9 µm) images, with contours of Deep-Layer Wind Shear [click to enlarge]

Himawari-8 Water Vapor (6.2 µm) images, with contours of Deep-Layer Wind Shear [click to enlarge]

Himawari-8 Water Vapor (6.2 µm) images with contours of Deep-Layer Wind Shear (above) indicated that Kammuri was moving through an environment of low to moderate shear. Himawari-8 Water Vapor images with plots of satellite-derived Atmospheric Motion Vectors (below) showed a well-defined outflow channel north of the tropical cyclone.

Himawari-8 Water Vapor (6.9 µm) images, with Derived Motion Winds [click to enlarge]

Himawari-8 Water Vapor (6.2 µm) images, with plots of Derived Motion Winds [click to enlarge]


Himawari-8 (courtesy JMA) and GEO-KOMPSAT-2A (courtesy KMA) visible imagery were combined to create stereoscopic imagery of the storm on 30 November, as shown below from 0000 to 0800 UTC (with missing data between 0100 and 0400 UTC).  View the 3-dimensional image by crossing your eyes and focusing on the third image that becomes apparent in between the two images shown.

Visible (0.64 µm) Imagery from Himawari-8 (left) and GK2A (right) from 0000 to 0800 UTC on 30 November 2019 (Click to animate)

Using GEOKOMPSAT-2 and Himawari-8 Imagery to create Stereoscopic Imagery

November 14th, 2019 |

Visible (0.64 µm) Imagery from Himawari-8 (left) and GEOKOMPSAT-2A (right) at 0400 and 0500 UTC on 14 Nov 2019 (Click to enlarge)

Geostationary data from KMA‘s GEOKOMPSAT-2 satellite (over the Equator at 128º E Longitude, shown above at right) and from JMA‘s Himawari-8 Satellite (over the Equator at 140º E Longitude, shown above at left) can be used to create stereoscopic imagery. The imagery above, from 0400 and 0500 UTC on 14 November 2019, centered at 15º N, 150º E, shows Typhoon Fengshen. Visible imagery from both satellites show a well-developed central cluster of thunderstorms with little apparent indication of wind shear. Stereoscopic views of the storm allow the vertical structure of the system to be perceived.

Data processing for these images was accomplished using Geo2Grid, a software package that incorporates Satpy. (Previous Blog posts discussing Geo2Grid are here and here).

Very grateful acknowledgement of these data from KMA and from JMA is extended. Thank you!

Added:  Click here for an animation from 0300 to 0550 UTC on 14 November.  (Warning:  Large animated gif at 159 M).

First GEOKOMPSAT-2A imagery (in stereo view with Himawari-8)

February 4th, 2019 |

Himawari-8 (left) and GEO-KOMPSAT-2A (right) Full Disk Imagery, 0310 UTC on 26 January 2019 (Click to enlarge)

The Korean Meteorological Administration (KMA) has released its first true-color image created with data from the AMI sensor on the GEOKOMPSAT-2A (GK2A) satellite that was launched in late 2018.   This first image from GK2A is experimental and preliminary, just like the initial images from Himawari-8,  -9, GOES-16 and GOES-17 were preliminary:  all newly-launched satellites go through a check-out period during which radiometric and geometric calibration work is ongoing.  That is what is happening with the  GK2A satellite now.  Despite the preliminary nature of the GK2A imagery, however, it can be paired with Himawari-8 imagery to create stereoscopic views of the Earth — in true color!   To view the image pair in three dimensions, cross your eyes until three circles appear, and focus on the circle in the middle;  it should appear then as a sphere.

(Image pair courtesy Bodo Zeschke, Australian Bureau of Meteorology ;  Himawari image courtesy JMA ; GK2A image courtesy KMA and Dr. Hyesook Park. GEOKOMPSAT-2A is also known as Chollian-2a)