Another outbreak of pyrocumulonimbus clouds in Australia

January 4th, 2020 |

Himawari-8

Himawari-8 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images [click to play animation | MP4]

Following a multi-day outbreak in late December 2019, Australian bushfires flared up again across far eastern Victoria and far southeastern New South Wales (along and ahead of a cold frontal passage) on 04 January 2020. A JMA Himawari-8 Target Sector was positioned over that region, providing images at 2.5-minute intervals — “Red” Visible (0.64 µm) images displayed the large smoke plumes with embedded pyro-convection, while Shortwave Infrared (3.9 µm) images revealed the widespread fire thermal anomalies or “hot spots” (clusters of red pixels).

Himawari-8 Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.4 µm) images (below) showed the development of 2 pyrocumulonimbus (pyroCb) clouds — the first over southern New South Wales west of Cooma (station identifier YCOM), and the second to the southwest of YCOM (near the border between Victoria and New South Wales). The second pyroCb eventually exhibited cloud-top infrared brightness temperature (IRBT) values of -70ºC and colder (purple pixels). To be classified as a pyroCb, a deep convective cloud must be generated by a large/hot fire, and eventually exhibit cloud-top 10.4 µm IRBTs of -40ºC and colder (thus assuring the heterogeneous nucleation of all supercooled water droplets to ice crystals within the thunderstorm anvil).

Himawari-8 Shortwave Infrared (3.9 µm, top) and "Clean" Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm, top) and “Clean” Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

An aircraft flying very near or through one of these pyroCb clouds experienced severe turbulence:



Farther to the north, another pyroCb developed near Nowra, New South Wales (YSNW) — which briefly exhibited a -40ºC cloud-top IRBT at 0319 UTC, but then re-intensified around 08 UTC (below).

Himawari-8 Shortwave Infrared (3.9 µm, top) and "Clean" Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm, top) and “Clean” Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

In a sequence of VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 um) images from NOAA-20 and Suomi NPP as viewed using RealEarth (below), the Nowra pyroCb was less ambiguous during the 03-04 UTC time period — and the aforementioned pair of pyroCbs straddling the border between Victoria and New South Wales were also evident.

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

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

===== 06 January Update =====

GOES-16 Natural Color RGB images + Smoke Detection derived product [click to play animation | MP4]

GOES-16 Natural Color RGB images + Smoke Detection derived product [click to play animation | MP4]

On 06 January, GOES-16 (GOES-East) Natural Color RGB images (above) displayed the hazy signature of high-altitude smoke (originating from previous episodes of Australian fires) over parts of Chile and Argentina — and the corresponding GOES-16 Smoke Detection derived product flagged much of this feature as “High Confidence” smoke (red).

In addition, GOES-17 (GOES-West) True Color RGB images created using Geo2Grid (below) showed a dense pall of smoke over the South Pacific Ocean (northeast of New Zealand). This was smoke from the 04 January outbreak of fires.

GOES-17 True Color RGB images [click to play animation | MP4]

GOES-17 True Color RGB images [click to play animation | MP4]

===== 08 January Update =====

GOES-17 True Color RGB images, 05-08 January [click to play animation | MP4]

GOES-17 True Color RGB images, 05-08 January [click to play animation | MP4]

Full Disk GOES-17 True Color RGB images from the AOS site (above) showed the slow eastward transport of a dense pall of smoke (hazy shades of tan to light brown) across the South Pacific Ocean during the 05-08 January period.

Late in the day, GOES-17 True Color images also showed a small area of smoke drifting southward across the coast of Antarctica (below).

GOES-17 True Color images [click to play animation | MP4]

GOES-17 True Color images [click to play animation | MP4]

This was confirmed by the OMPS Aerosol Index product (below), which displayed a small lobe becoming detached from one of the larger smoke features crossing the South Pacific Ocean.

Suomi NPP OMPS Aerosol Index composites, 04-08 January (credit: Colin Seftor, SSAI)

Suomi NPP OMPS Aerosol Index composites, 04-08 January (credit: Colin Seftor, SSAI)

 

Multi-day outbreak of pyrocumulonimbus clouds across southeastern Australia

December 29th, 2019 |

Himawari-8 Shortwave Infrared (3.9 µm, top) and Longwave Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm, top) and Longwave Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

JMA Himawari-8 Shortwave Infrared (3.9 µm) and Longwave Infrared Window (10.4 µm) images (above) showed a large bushfire (dark black to red pixels in the 3.9 µm imagery) in far southeastern Victoria, Australia — which quickly burned its way to the coast and produced 3 distinct pulses of pyrocumulonimbus (pyroCb) clouds on 29 December 2019. To be classified as a pyroCb, the deep convective cloud must be generated by a large/hot fire (in this case, the Cann River fire complex), and eventually exhibit cloud-top 10.4 µm infrared brightness temperatures of -40ºC and colder (assuring the heterogeneous nucleation of all supercooled water droplets to ice crystals).

The coldest cloud-top 10.4 µm infrared brightness temperature was -62.6ºC (darker green pixels) at 1650 UTC. According to rawinsonde data from Melbourne (below), this corresponded to an altitude near 13 km.

Plots of rawinsonde data from Melbourne, Australia [click to enlarge]

Plots of rawinsonde data from Melbourne, Australia [click to enlarge]

The long/narrow thermal anomaly of the hot bushfire — which burned southwestward all the way to the coast — was outlined in dark black pixels on VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP, as viewed using RealEarth (below).

w (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]

===== 30 December Update =====

 Himawari-8 Shortwave Infrared (3.9 µm, top) and Longwave Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm, top) and Longwave Infrared Window (10.4 µm, bottom) images [click to play animation | MP4]

A Himawari-8 Target Sector was positioned over southeastern Australia beginning at 2312 UTC on 29 December, providing images at 2.5-minute intervals — a comparison of Shortwave Infrared and Longwave Infrared Window imagery (above) revealed the formation of several additional pyroCb clouds as southeastern Victoria bushfires continued to grow in number and size. During the daytime, pyroCb cloud tops will appear warmer (darker gray) than those of conventional thunderstorms in the 3.9 µm imagery, due to enhanced reflection of solar radiation off the smaller ice crystals found in the pyroCb anvil. Development of the multiple deep convective pyroCb clouds on this day may have been aided by forcing for ascent provided by an approaching cold front and mid-tropospheric trough, along with favorable upper-tropospheric jet streak dynamics.

The coldest Himawari-8 cloud-top 10.4 µm brightness temperature on 30 December was -73.15ºC at 13:24:41 UTC (violet pixel near the coast); this was 5ºC colder than the coldest temperature of -68.1ºC  — at an altitude of 15 km — on 12 UTC rawinsonde data from Melbourne (below). During the 12-hour period between the 2 soundings, the coded tropopause ascended from a height of 13.1 km (-63.7ºC) at 00 UTC to 14.2 km (-67.5ºC) at 12 UTC.

Plots of rawinsonde data from Melbourne, Australia at 00 UTC (yellow) and 12 UTC (cyan) [click to enlarge]

Plots of rawinsonde data from Melbourne, Australia at 00 UTC (yellow) and 12 UTC (cyan) [click to enlarge]

In a toggle between VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP is shown (below), a large pyroCb cloud was seen moving eastward away from the bushfires.

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]

===== 31 December Update =====

Suomi NPP VIIRS Day/Night Band, Shortwave Infrared, Near-Infrared & Active Fire Product images at 1455 UTC on 31 December (credit: William Straka, CIMSS) [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm), Shortwave Infrared (3.75 µm and 4.05 µm), Near-Infrared (1.61 µm and 2.25 µm) & Active Fire Product images at 1455 UTC on 31 December (credit: William Straka, CIMSS) [click to enlarge]

Suomi NPP VIIRS Day/Night Band, Shortwave Infrared, Near-Infrared & Active Fire Product images (above) showed nighttime signatures of the widespread bushfires across Victoria and New South Wales at 1455 UTC on 31 December (or 1:55 am local time on 01 January). In the town of Mallacoota, about 4000 people were forced to evacuate their homes and take shelter along the coast (media report). The surface air temperature at Mallacoota Airport briefly increased to 49ºC (120ºF) at 8:00 am local time as the fires approached (below).

A sequence of daily Aqua MODIS True Color RGB images with an overlay of VIIRS Fire Radiative Power showed the fires and smoke during the 29-31 December period (below).

Aqua MODIS True Color RGB images with an overlay of VIIRS Fire Radiative Power [click to enlarge]

Aqua MODIS True Color RGB images with an overlay of VIIRS Fire Radiative Power [click to enlarge]

A multi-day Himawari-8 GeoColor animation covering the period 28 December – 01 January is available here.

Eruption of the Whakaari volcano on White Island, New Zealand

December 9th, 2019 |

“Red” Visible (0.64 µm) images from Himawari-8 (left) and GOES-17 (right) [click to play animation | MP4]

A brief eruption of the Whakaari volcano on White Island, New Zealand occurred around 0110 UTC on 09 December 2019 — “Red” Visible (0.64 µm) images from JMA Himawari-8 and GOES-17 (GOES-West) showed the small volcanic cloud as it fanned out east of the island (above).

A signature of the volcanic cloud was also seen in VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP, as viewed using RealEarth (below). The cloud exhibited a rather warm infrared brightness temperature, since the Wellington VAAC only estimated the maximum height to be

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

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

The volcanic plume contained elevated levels of SO2 which drifted south-southeastward, as seen in a McIDAS-V image of Sentinel-5 TROPOMI Vertical Column SO2 at 0206 UTC (below).

Sentinel-5 TROPOMI Vertical Column SO2 (credit: Bob Carp, SSEC) [click to enlarge]

Sentinel-5 TROPOMI Vertical Column SO2 (credit: Bob Carp, SSEC) [click to enlarge]

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).

Plots of the coldest overshooting top 10.4 µm brightness temperatures on Himawari-8 Target Sector (2.5-minute interval) and Full Disk (10-minute interval) images during the 0002-0502 UTC time period on 30 November (below) showed that the closest (in time**) Full Disk image BTs were often within a degree C of the Target Sector images — but the magnitude of rapid fluctuations of BT seen in the 2.5-minute data were well not captured by the 10-minute data. For the 4 Target Sector images exhibiting BTs of -103ºC and colder (0112, 0127, 0204 and 0259 UTC) only one of the closely-corresponding Full Disk images exhibited a similarly cold BT (0110 UTC, with -103.0ºC). The coldest Target Sector BT was -103.55ºC at 02:59:44 UTC, while the coldest Full Disk BT was -103.0ºC at 01:13:34 UTC.

**The actual time that closely-corresponding Target Sector and Full Disk scans were imaging Kammuri differed by about 1 minute and 15 seconds — for example, the 01:12:15 UTC Target Sector scanned Kammuri’s coldest overshooting tops at 01:12:19, while the 01:10:00 Full Disk scanned those same overshooting tops at 01:13:34 UTC.

Plots of coldest Himawari-8 10.4 µm brightness temperatures on 2.5-minute Target Sector (blue) and 10-minute Full Disk (green) images [click to enlarge]

Plots of coldest Himawari-8 infrared (10.4 µm) brightness temperatures on 2.5-minute Target Sector (blue) and 10-minute Full Disk (green) images [click to enlarge]

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). In addition, on the plot of Himawari-8 infrared BTs shown above it can be seen that the previous record for coldest documented BT (-102.2ºC with Tropical Cyclone Hilda in 1990) was eclipsed on 9 Target Sector and 4 Full Disk images.

 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]

The Himawari-8 Infrared image closest (time-wise) to the NOAA-20 image was at 04:22:15 UTC, and its 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]

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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]

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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 or GK2A (courtesy KMA) visible imagery were combined to create stereoscopic imagery of the storm on 30 November, as shown below from 2100 UTC on 29 November to 0820 UTC on 30 December.  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 2100 UTC on 29 November to 0820 UTC on 30 November 2019 (Click to animate)

10-minute Full Disk images of GK2A Cloud Top Temperature and Cloud Top Height products (source) are shown below. A large canopy of CTT values as cold as -80ºC and CTH values up to 15 km were seen associated with Typhoon Kammuri during the period 0000-0500 UTC.

KMA GK2A Cloud Top Temperature product [click to play animation | MP4]

KMA GK2A Cloud Top Temperature product [click to play animation | MP4]

KMA GK2A Cloud Top Height product [click to play animation | MP4]

KMA GK2A Cloud Top Height product [click to play animation | MP4]