Volcanic Eruption on Kamchatka

March 26th, 2015
Himawari-8 Visible (0.64µm) Imagery (Click to animate)

Himawari-8 Visible (0.64µm) Imagery (click to animate)

Infrared imagery from Himawari-8 has a nominal resolution of two km (at the sub-satellite point), but a visible channel has a nominal resolution of 0.5 km which can provide imagery with great detail. In the example above, the visible imagery captures the eruption, beginning around 2210 UTC on 25 March 2015, of the Shiveluch volcano on Russia’s Kamchatka Peninsula. The volcanic plume then moves downstream in northwesterly flow. Himawari-8 remains in post-launch testing, the period when the satellite calibration and navigation is thoroughly checked.

Suomi NPP overflew this region multiple times on 26 March 2015. VIIRS data from a 0126 UTC overpass, below, taken from this website, show satellite-based diagnostics of this event. The animation cycles through a Brightness Temperature Difference (11µm – 12µm), Ash Loading, Ash Height and a False Color RGB presentation of the volcanic plume.

Suomi NPP VIIRS Brightness Temperature Difference (11µm -12µm), Ash Loading, Ash Height, and False Color Imagery, 0126 UTC 26 March 2015 (Click to enlarge)

Suomi NPP VIIRS Brightness Temperature Difference (11µm -12µm), Ash Loading, Ash Height, and False Color Imagery, 0126 UTC 26 March 2015 (click to enlarge)

Update: On 26 March, a Suomi NPP VIIRS true-color RGB image from the SSEC RealEarth site provided a nice view of the Shiveluch volcanic plume (below); also evident on the true-color image (as well as on images from the previous two days) to the north of Shiveluch were a pair of volcanic ash “fall streaks”, where the tan-colored ash landed on top of the existing snow cover.

Suomi NPP VIIRS true-color images from 24, 25, and 26 March

Suomi NPP VIIRS true-color images from 24, 25, and 26 March

GOES-15 also viewed the eruption, at the extreme edge of its limb, as seen on the sequence of 0.63 µm visible channel images below (Shiveluch is at the center of the images).

GOES-15 0.63 µm visible channel images (click to play animation)

GOES-15 0.63 µm visible channel images (click to play animation)

Sea fog along the northeast Florida coast

March 21st, 2015
GOES-13 0.63 µm visible channel images (click to play animation)

GOES-13 0.63 µm visible channel images (click to play animation)

GOES-13 (GOES-East) 0.63 µm visible channel images (above; click to play animation) showed a patch of sea fog just off the coast of northeastern Florida on 21 March 2015. As daytime inland heating increased, a sea breeze circulation began to draw some of the offshore sea fog toward the coast.

A closer view is provided by a Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image at 18:08 UTC (below), visualized using the SSEC RealEarth web map server site. The surface visibility at New Smyrna Beach was reduced to 1 mile at the time.

Suomi NPP VIIRS true-color image

Suomi NPP VIIRS true-color image

A web camera image at 18:17 UTC or 2:17 PM local time (below) showed the dramatic reduction in visibility as the dense sea fog moved inland at Dunlawton Beach (near Daytona Beach).

Dunlawton Beach webcam image

Dunlawton Beach webcam image

A comparison of Suomi NPP VIIRS 0.64 µm visible channel, 3.74 µm shortwave IR channel, and 11.45 µm longwave IR images (below) showed that the patch of sea fog exhibited a strong signal on the shortwave IR image (due to the efficient reflection of incoming solar radiation by the spherical water droplets), but no signal at all on the longwave IR image (since the temperature of the sea fog feature was nearly identical to that of the surrounding ocean waters).

Suomi NPP VIIRS 0.64 µm visible channel, 3.74 µm shortwave IR channel, and 11.45 µm longwaveIR channel images

Suomi NPP VIIRS 0.64 µm visible channel, 3.74 µm shortwave IR channel, and 11.45 µm longwaveIR channel images

The easterly to northeasterly onshore flow along the coast (enhanced by the sea breeze circulation) was well-depicted by the 18 UTC Real-Time Mesoscale Analysis (RTMA) surface winds (below).

Suomi NPP VIIRS 0.64 µm visible channel image, with RTMA surface winds

Suomi NPP VIIRS 0.64 µm visible channel image, with RTMA surface winds

Eruption of the Villarrica volcano in central Chile

March 3rd, 2015
Suomi NPP VIIRS 0.7 µm Day/Night Band, 1.6 µm near-IR, 3.9 µm shortwave IR, and 11.45 µm longwave IR images

Suomi NPP VIIRS 0.7 µm Day/Night Band, 1.6 µm near-IR, 3.9 µm shortwave IR, and 11.45 µm longwave IR images

There was an explosive eruption of the Villarrica volcano in central Chile on the morning of 03 March 2015; the Buenos Aires VAAC issued their first volcanic ash advisory based upon initial detection on 06:38 UTC GOES-13 imagery, although media report and blog sources indicated that the eruption started closer to 06:00 UTC (3 am local time). A comparison of 06:07 UTC Suomi NPP VIIRS 0.7 µm Day/Night Band (DNB), 1.6 µm near-IR, 3.9 µm shortwave IR, and 11.45 µm longwave IR images (above; courtesy of William Straka, SSEC) revealed a bright glow on the DNB and near IR images, with a pronounced “hot spot” evident on the shortwave IR (yellow to orange pixels; the hottest shortwave IR brightness temperature was over 600 K!) and even the longwave IR (darker black pixels) images. The DNB image was particularly striking, with nearby clouds and surface features being illuminated by the eruption.

MODIS and GOES-13 multispectral false-color Red/Green/Blue (RGB) images from the NOAA/CIMSS Volcanic Cloud Monitoring site (below; click image to play animation) showed that there was detection of a thermal anomaly or “hot spot” (indicated by a red box) as early as 04:20 UTC (MODIS) and 05:45 UTC (GOES-13); the volcanic cloud filament — which was estimated to be at an altitude of 30,000 feet — could be seen drifting to the southeast following the eruption.

MODIS and GOES-13 false-color RGB images (click to play animation)

MODIS and GOES-13 false-color RGB images (click to play animation)

On GOES-13 10.7 µm IR channel images (below; click image to play animation), the volcanic cloud initially exhibited an IR brightness temperature as cold as -42ºC  (green color enhancement), but the cloud filament quickly became very diffuse and difficult to identify on the IR images by 09:38 UTC.

GOES-13 10.7 µm IR images (click to play animation)

GOES-13 10.7 µm IR images (click to play animation)

The 12 UTC rawinsonde profiles from Puerto Montt, Chile (station identifier SCTE) on 02 March and 03 March are shown below. On the 02 March profile, the -42º C temperature was at an altitude around 9400 meters or 30,800 feet; on the 03 March profile, -42º C was around 9100 meters or 29,900 feet.

Puerto Montt, Chile 12 UTC rawinsonde profiles on 02 March and 03 March

Puerto Montt, Chile 12 UTC rawinsonde profiles on 02 March and 03 March

On GOES-13 3.9 µm shortwave IR images (below; click image to play animation) a “hot spot” (black to yellow to red color enhancement) was seen for several hours after the initial eruption. The highest shortwave IR brightness temperature observed by GOES-13 was 340.8 K — much lower than than the >600 K observed with the higher spatial resolution Suomi NPP VIIRS instrument.

GOES-13 3.9 µm shortwave IR channel images (click to play animation)

GOES-13 3.9 µm shortwave IR channel images (click to play animation)

Lake effect snow band over Lake Michigan

February 26th, 2015
GOES-13 0.63 µm visible channel images (click to play animation)

GOES-13 0.63 µm visible channel images (click to play animation)

GOES-13 (GOES-East) 0.63 µm visible channel images (above; click image to play animation) showed the development and motion of a long single-band lake effect cloud feature over Lake Michigan on 26 February 2015. Snowfall from this band helped to boost total event accumulations (including other lake effect snow bands on the previous day) as high as 8 inches in the Chicago area, bringing this to the 3rd snowiest February on record there.

A comparison of the 18:39 UTC Suomi NPP VIIRS 0.64 µm visible channel image with the corresponding false-color Red/Green/Blue (RGB) is shown below. On the RGB image, snow, ice, and ice crystal clouds appear as varying shades of pink to red — and it can be seen that portions of the lake effect cloud band looked to be glaciated. Supercooled water droplet clouds appear as varying shades of white on this type of snow/ice-vs-cloud discrimination RGB image.

Suomi NPP VIIRS 0.64 µm visible channel and False-color RGB image (click to enlarge)

Suomi NPP VIIRS 0.64 µm visible channel and False-color RGB image (click to enlarge)

The 18:39 UTC Suomi NPP VIIRS 11.45 µm IR channel image (below) showed that cloud-top IR brightness temperatures were in the -20 to -30º C range (cyan to dark blue color enhancement) along the entire length of the lake effect cloud band, which also suggested that glaciation was likely.

Suomi NPP VIIRS 11.45 µm IR channel image (click to enlarge)

Suomi NPP VIIRS 11.45 µm IR channel image (click to enlarge)