Eruption of Manam in Papua New Guinea

October 19th, 2021 |

Himawari-8 True Color RGB images [click to play animated GIF | MP4]

The Manam volcano in Papua New Guinea erupted around 2200 UTC on 19 October 2021. JMA Himawari-8 True Color RGB images created using Geo2Grid (above) showed lower- to middle-altitude ash clouds (shades of tan to brown) moving westward and northward, while the main eruptive cloud — composed of a mixture of ash, SO2 and ice particles — spread out at high altitudes to the east and north. (Side note: brief flashes of sun glint off some of the island rivers were also seen.)  

Retrieved values of Ash Height from the NOAA/CIMSS Volcanic Cloud Monitoring site (below) indicated that the Manam eruption cloud reached maximum altitudes within the 16-18 km range. 

Himawari-8 Ash Height [click to play animated GIF | MP4]

Alisal Fire in Southern California

October 12th, 2021 |

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

GOES-17 (GOES-West) True Color RGB images created using Geo2Grid (above) showed the transport of smoke from the Alisal Fire in Southern California on 12 October 2021. The dashed line in the images is Highway 101 — a portion of which was closed, as the wind-driven fire raced toward the coast. Late in the day some low-altitude smoke began to move eastward along the coast, eventually reducing the surface visibility to 6 miles at Santa Barbara.

During the preceding overnight hours (at 0916 UTC or 2:16 am PDT), a comparison of Suomi-NPP VIIRS Shortwave Infrared and Day/Night Band images (below) revealed the thermal signature and nighttime glow of the fire. The VIIRS imagery was downloaded and processed via the SSEC/CIMSS Direct Broadcast ground station.

Suomi-NPP VIIRS Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

The Suomi-NPP overpass time of the fire region was actually 0926 UTC — and a time-matched comparison of Shortwave Infrared images from GOES-17 and Suomi-NPP (below) demonstrated that the superior spatial resolution of VIIRS instrument (~375 meters, vs ~2 km for the ABI on GOES-17) provided a more accurate depiction of the areal coverage of the fire.

Shortwave Infrared images from Suomi-NPP (3.74 µm) and GOES-17 (3.9 µm) [click to enlarge]

===== 13 October Update =====

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

On 13 October, GOES-17 True Color RGB images (above) showed that as offshore wind speeds relaxed, a shift to onshore flow recirculated some of the smoke inland — with smoke briefly reducing the surface visibility to 1.5 miles at Santa Barbara airport (below). Farther to the south, residual smoke from the previous day of burning was also evident, with some of it traveling as far as Isla Guadalupe (Guadalupe Island) nearly 400 miles away.

Time series of surface observation data from Santa Barbara Municipal Airport [click to enlarge]

Ongoing eruption of Cumbre Vieja (La Palma) in the Canary Islands

October 9th, 2021 |

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 (GOES-East) True Color RGB images created using Geo2Grid (above) showed the south-southeastward drift of an ash-laden volcanic cloud from Cumbre Vieja on La Palma in the Canary Islands on 09 October 2021. Since this most recent ongoing eruptive period began on 19 September, intermittent periods of volcanic clouds with an elevated ash content have been observed — and on this day, the darker tan to light brown appearance was an indication that higher ash concentrations were likely.     

In the corresponding GOES-16 Ash RGB  images (below), increasing shades of pink — which suggest a higher ash content — became apparent within a semi-circular volcanic cloud element after 1100 UTC.  

GOES-16 Ash RGB images [click to play animation | MP4]

A NOAA-20 VIIRS True Color image as viewed using RealEarth (below) also showed the darker tan to light brown shades of the ash-laden volcanic cloud.

NOAA-20 VIIRS True Color RGB image [click to enlarge]

GOES-16 retrieved products from the NOAA/CIMSS Volcanic Cloud Monitoring site (below) indicated that the more distinct pulse of ash-laden volcanic cloud had a maximum height in the 5-6 km range, and was composed of ash particles having an effective radius 10 µm and smaller. 

GOES-16 Ash Probability [click to play animation | MP4]

GOES-16 Ash Loading [click to play animation | MP4]

GOES-16 Ash Height [click to play animation | MP4]

GOES-16 Ash Effective Radius [click to play animation | MP4]

Pyrocumulonimbus clouds spawned by the KNP Complex wildfire in California

October 4th, 2021 |

GOES-17 Visible (0.64 µm, center), Shortwave Infrared (3.9 µm, center) and Infrared Window (10.35 µm, bottom) images [click to play animation | MP4]

The KNP Complex wildfire continued to burn in central California on 04 October 2021, producing a pair of pyrocumulonimbus or pyroCb clouds — one during the atypical late morning hours (beginning around 1530 UTC, or 11:30 am PDT) and the other during the more typical late afternoon hours (beginning around 2130 UTC, or 5:30 PM PDT). 1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed the pyroCB clouds, fire thermal anomalies or “hot spots” (clusters of red pixels) and cold cloud-top infrared brightness temperatures, respectively. The minimum 10.35 µm temperatures were near -60ºC. Note the relatively warm (darker gray) appearance of the pyroCb clouds in the 3.9 µm images — this is a characteristic signature of pyroCb cloud tops, driven by the smoke-induced shift toward smaller ice particles (which act as more efficient reflectors of incoming solar radiation, contributing to the warmer 3.9 µm brightness temperatures). Note: beginning at 1700 UTC, overlapping GOES-17 Mesoscale Sectors provided imagery at 30-second intervals.

1-minute GOES-17 True Color RGB images created using Geo2Grid (below) showed the first pyroCb cloud as it continued to move northeastward across the California/Nevada border, and then the second pyroCb cloud as it moved northwestward. The change in direction of motion was influenced by the approach of an offshore closed low from the west (250 hPa analysis: 12 UTC | 00 UTC). 

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