Klyuchevskoi: Radiannet Example

The 1994 eruption of Klyuchevskoi Volcano in Kamchatka, Russia produced a volcanic cloud that was potentially hazardous to aircraft. The cloud from this eruption moved easterly for thousands of kilometers and crossed the polar air routes. To view a complete set of AVHRR images of the Klyuchevskoi volcanic cloud, click here. Additonal information on the eruption can be found on the Michigan Tech Volcanoes Page. The image on the right is a Space Shuttle photograph from mission STS-68, taken on October 1, 1994 at 01:00 GMT.

October 1, 1994 at 0640 Z

The band 4 image shows the volcanic cloud moving towards the south over the Pacific Ocean. Note that the presence of a wind shear near the volcano. In the band 4-5 image, the cloud is easily discriminated from the meteorlogical clouds, and an addtion region of the cloud is clearly defined where it is underlain by low clouds (in the southwest quadrant).

AVHRR Band 4 image (left) and Band 4-5 image (right).

Radiannet Plots

These plots are generated by Radiannet, using the input parameters specified by the user, and are used to evaluate if the appropriate parameters were choosen. The plot on the left is the Radius-Optical depth plot for the image shown above. The red dots are the actual AVHRR pixel values for the cloud, the solid lines are theoretical effective radius values and the dashed lines are theoretical optical depth values. Note that the cloud has a wide range of optical depths, and that the AVHRR values fit well inside the Radius-Optical Depth envelope constructed using the input conditions. (See below for input values).

Input parameters and output values

Execution Date  . . . . . .               Thu May  4 11:50:45 EDT 1995
ASCII Input Data File Name                                  ascii.0640
Plot Title  . . . . . . . .                Klyuchevskoi Volcanic Cloud
Plot Subtitle . . . . . . .               NOAA-12  10/1/1994  0640 UTC
Theoretical Particle Size Distribution  . . . .              Lognormal
The Scale of the Mass Retrieval . . . . . . . .  Frame Scale Retrieval
Aerosol Type  . . . . . . . . . . . . . . . . .               Andesite
 
Minimum Effective Radius (um)  . . . . . . . . . . . . . .        2.50
Maximum Effective Radius (um)  . . . . . . . . . . . . . .       15.00
Cloud-Top Temperature (K)  . . . . . . . . . . . . . . . .      216.00
Cloud-Base Temperature (K) . . . . . . . . . . . . . . . .      280.00
X Image Dimension  . . . . . . . . . . . . . . . . . . . .    14721.00
Y Image Dimension  . . . . . . . . . . . . . . . . . . . .        1.00
Pixel Area (km^2)  . . . . . . . . . . . . . . . . . . . .        4.00
Delta X  . . . . . . . . . . . . . . . . . . . . . . . . .        0.05
Band 4 Minus Band 5 Maximum Cutoff Value . . . . . . . . .        0.00
Number of Horizontal Lines . . . . . . . . . . . . . . . .       30.00
Number of Radii Lines  . . . . . . . . . . . . . . . . . .       20.00
 
Total Number of Volcanic Pixels  . . . . . . . . . . . . .    14721.00
Mean Effective Radius (um) . . . . . . . . . . . . . . . .        7.07
Mean Optical Depth of the Volcanic Pixels  . . . . . . . .        0.47
Mean Volcanic Pixel Mass (Mt)  . . . . . . . . . . . . . .       16.74
Total Volcanic Cloud Mass (Mt) . . . . . . . . . . . . . .   246500.00

Map of Silicate Mass Retrieval

The following image is a map of the mass retrieval using the parameters shown above. Note that in this case, the regions of high mass correspond closely with the regions of large band 4-5 temperature difference.

This page maintained by Dave Schneider (djschnei@mt u.edu)