Mount Rinjani volcanic ash plume

November 4th, 2015

Suomi NPP VIIRS true-color RGB images [click to enlarge]

Suomi NPP VIIRS true-color RGB images [click to enlarge]

The Mount Rinjani volcano in Indonesia began a period of eruptions on 25 October 2015; the ash plume became very apparent on Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images from RealEarth on 03 and 04 October (above). The volcanic ash disrupted flights at Denpasar Airport in Bali (the red dot at the southern tip of the island) for several days.

A GOES-R volcanic ash height product (derived using Himawari-8 AHI data) from the SSEC Volcanic Cloud Monitoring site indicated that the plume reached heights of 10 km (dark blue color enhancement) at times during the 03-04 October period (below).

Himawari-8 Volcanic Ash Height product [click to play animation]

Himawari-8 Volcanic Ash Height product [click to play animation]

McIDAS-V images of Suomi NPP VIIRS Day/Night Band (0.7 µm), near-IR (1.6 µm), shortwave IR (3.74 µm), and IR (11.45 µm) images (below, courtesy of William Straka, SSEC) showed the hot spot and nighttime glow of the summit of the Rinjani volcano at 1733 UTC on 04 November.

Suomi NPP VIIRS Day/Night Band (0.7 µm), near-IR (1.6 µm), shortwave IR (3.74 µm), and IR (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm), near-IR (1.6 µm), shortwave IR (3.74 µm), and IR (11.45 µm) images [click to enlarge]

Typhoon Dolphin approaches Guam

May 14th, 2015
Himawari-8 11.22 µm infrared channel images (click to play animation)

Himawari-8 11.22 µm infrared channel images (click to play animation)

The animation above (available here as an mp4, and here on YouTube) shows 11.22 µm infrared imagery at 2.5-minute time steps (bottom) and 10-minute time steps (top) from Himawari-8 on 14 May 2015. Category 2 intensity Typhoon Dolphin is approaching Guam, seen at the left edge of both panels in the frame. The 2.5-minute imagery gives a much better indication of the quick rise and decay of overshooting tops (IR brightness temperatures of the storm tops approach -95º C!). A 10-minute time step cannot fully resolve the evolution of these features. The 2.5-minute time step also better captures the divergent flow (and outward-propagating gravity waves) at the top of the central dense overcast. No eye was yet apparent in the infrared imagery, or on DMSP SSMI 85 GHz microwave imagery.

A similar animation from the previous day, 13 May, is shown here: gif, mp4, YouTube. The better organization of the storm on 14 May is readily apparent.

How high are the clouds in the Central Dense Overcast (CDO)? Cloud Heights are available from CLAVR-x (Clouds from AVHRR Extended). Data from Geostationary Satellites are processed and are available to download here. Values from COMS-1 and from MTSAT-2 (displayed with McIDAS-V) suggest maximum cloud heights near 55,500 feet.

The MIMIC Total Precipitable Water (TPW) product, below, showed that Typhoon Dolphin was able to tap rich moisture from the Intertropical Convergence Zone (ITCZ) during the 13-14 May period; TPW values within the tropical cyclone circulation were often in the 60-65 mm or 2.5-2.6 inch range (darker red color enhancement).

MIMIC Total Preciptable Water product (click to play animation)

MIMIC Total Preciptable Water product (click to play animation)

Visible Imagery from Himawari-8, just after sunrise on 15 May, show continuous development of short-lived overshooting tops to the east of Guam. More information on the storm is available at the CIMSS Tropical Cyclones site, the JMA Tropical Cyclone site and the Joint Typhoon Warning Center.

Himawari-8 0.6363 µm visible channel images (click to play animation)

Himawari-8 0.6363 µm visible channel images (click to play animation)

The nighttime glow of Hawaii’s Kilauwea volcano

April 28th, 2015
Himawari-8 3.9 µm shortwave IR images (click to play animation)

Himawari-8 3.9 µm shortwave IR images (click to play animation)

The Kilauwea Volcano on the Big Island of Hawai’i began erupting in March 2008 (blog post | USGS reference), and has been in a nearly continuous phase of activity since then. During the pre-dawn hours of 28 April 2015, thermal signatures of the Kilauwea summit lava lake and nearby lava flows could be seen on McIDAS-V images of 10-minute interval Himawari-8 3.9 µm shortwave IR images (above; click image to play animation). The dark black pixels represent the hottest IR brightness temperatures.

On the corresponding Himawari-8 2.3 µm near-IR channel images (below; click image to play animation), the clusters of bright white pixels represent the glow of the hot lava features.

Himawari-8 2.3 µm near-IR channel images (click to play animation)

Himawari-8 2.3 µm near-IR channel images (click to play animation)

A different view is provided by the polar-orbiting Suomi NPP satellite — a comparison of AWIPS II images of VIIRS 0.7 µm Day/Night Band and 3.74 µm shortwave IR data (below) revealed the locations of the hottest lava features (black to yellow to red color enhancement) at 11:40 UTC (1:40 am local time).

Suomi NPP VIIRS 0.7 µm Day/Night Band and 3.74 µm shortwave IR images

Suomi NPP VIIRS 0.7 µm Day/Night Band and 3.74 µm shortwave IR images

A longer animation using GOES-15 (GOES-West) 3.9 µm shortwave IR images (below; click image to play animation) showed considerable temporal fluctuation in the location and intensity of the hot lava pixels (black to yellow to red color enhancement). For the latest information on the Kilauea eruption, visit the Hawaiian Volcano Observatory.

GOES-15 3.9 µm shortwave IR images (click to play animation)

GOES-15 3.9 µm shortwave IR images (click to play animation)

Major sandstorm in the Arabian Peninsula

April 2nd, 2015
Visible satellite images and surface observations (click to play animation)

Visible satellite images and surface observations (click to play animation)

Visible satellite images from the SSEC RealEarth web map server (above; click image to play animation) revealed the hazy light gray signature of a major sandstorm that was advancing south-southeastward across the Arabian Peninsula on 02 April 2015. An Aqua MODIS true-color Red/Green/Blue (RGB) image (actual satellite overpass time was 10:20 UTC or 2:20 PM local time) is shown below — the dense cloud of airborne sand appeared as a lighter shade of tan.

Aqua MODIS true-color image

Aqua MODIS true-color image

A Suomi NPP VIIRS true-color image from the previous day (below) depicted the beginning phase of the sandstorm in the northern portion of Saudi Arabia, which consisted of a number of smaller plumes of blowing sand prior to consolidating into the large feature seen on 02 April.

Suomi NPP VIIRS true-color image (01 April)

Suomi NPP VIIRS true-color image (01 April)

The blowing sand reduced surface visibility to near zero at some locations, disrupting ground transportation, air traffic, and also closing schools. Visibility was reduced to 0.1 mile for several hours at Dubai International Airport (below), which is one of the world’s busiest in terms of volume of flights.

Time series of weather conditions at Dubai International Airport

Time series of weather conditions at Dubai International Airport

During the previous nighttime hours, McIDAS-V images of Suomi NPP VIIRS 0.7 µm Day/Night Band data (below; images courtesy of William Straka, SSEC) showed the arc-shaped leading edge of the sandstorm as it stretched from the United Arab Emirates across Saudi Arabia at 22:01 UTC or 1:01 AM local time. Since the Moon was in the Waxing Gibbous phase (at 98% of Full), it provided ample illumination for these “visible images at night”.

Suomi NPP VIIRS 0.7 µm Day/Night Band image

Suomi NPP VIIRS 0.7 µm Day/Night Band image

Suomi NPP VIIRS 0.7 µm Day/Night Band image

Suomi NPP VIIRS 0.7 µm Day/Night Band image