Eruption of the Cleveland Volcano, and a von Karman vortex street

May 5th, 2013 |
Suomi NPP VIIRS 0.64 µm visible  and 3.74 µm shortwave IR images

Suomi NPP VIIRS 0.64 µm visible and 3.74 µm shortwave IR images

A comparison of AWIPS images of Suomi NPP VIIRS 0.64 µm visible channel and 3.74 µm shortwave IR channel data (above) showed 2 signatures of an ongoing low-level eruption of the Cleveland Volcano located on the Aleutian Island chain of Alaska: a “hot spot” of 45.5º C (red color enhancement) on the shortwave IR image, and a thin plume of gas, steam, and minor amounts of ash streaming eastward at 22:33 UTC on 04 May 2013. The Cleveland volcano began the eruption around 13:00 UTC earlier that day. The volcano is located on the western portion of Chuginadak Island (denoted by the cyan range ring centered on the island) — however, note that the mapping navigation is slightly off on the images (making the volcano hot spot and plume source appear as if they were located in the waters just west of the island).

Several hours later, a Suomi NPP VIIRS 0.7 µm Day/Night Band image at 12:18 UC on 05 May (below) showed the bright night-time glow of the erupting Cleveland volcano.

Suomi NPP VIIRS 0.7 µm Day/Night Band image

Suomi NPP VIIRS 0.7 µm Day/Night Band image

Another feature of interest was the von Karman vortex street further to the east, as seen on 2 consecutive Suomi NPP VIIRS 0.64 µm visible channel images (below). Northwesterly flow within the marine boundary layer was being perturbed by the high terrain of the Aleutian Range on the tip of the Alaska Peninsula, with the resulting vortex street streaming southeastward downwind of the peninsula.

Suomi NPP VIIRS 0.64 µm visible channel images

Suomi NPP VIIRS 0.64 µm visible channel images