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Volcanic Ash Advisory Centers

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Finding data

When was the eruption?

Was it visible?

Getting the data

Finding Volcanic Cloud Data Retrospectively

We do this as part of our research, to thoroughly study the examples of volcanic clouds around the world, after the eruption--sometimes long after! Finding the data takes time to do.

Most satellites operate all the time, and eruptions are rare. Eruptions that can be seen by the satellites (those that are big enough, and go higher than the local clouds, and last long enough to be detectable when the satellite finally images) are much rarer. So the first thing we need to know is:

When was there an eruption?

This can usually be determined via the web, after some delay.

For recent activity try the Smithsonian Global Volcanism Network: If you are looking for an eruption within the last couple months, you will have to go to preliminary reports: Alternatively there is a whole host of other sites to find out about activity, including volcano observatories and press reports.

One issue here is that you must be sure of the local time and universal time. If you haven't mastered this, you won't succeed.

Was the eruption "visible" from space?

Next, was the eruption "visible" by the satellite? This is really difficult to answer, unless you are lucky. To be lucky is to find out someone has already found out that it is visible. Some examples of where you might find this out: a. from VAACs (Volcanic ash Advisory Centers): One center that frequently tells when it detects volcanic clouds is the Washington VAAC. Messages with attached graphics are especially helpful!

If you want TOMS data, you should see if the eruption happened at or slightly before "solar noon" at the volcano locality. This may not be the same as the local 1200 hour-- you should check this. TOMS data is only available around solar noon, so eruptions that happen just after noon are often missed because the clouds they produce dissipate before they are imaged.  Since TOMS has a large resolution, it is a good test to see if cloud/plume could be seen by other satellites.  If TOMS does see, then the other sensors will be able to detect it as long as it was in the right place at the right time.

Getting the data:

Once you find a good candidate, where there should be data, then you must actually get the data:

A. For TOMS data: see the TOMS site and follow the TOMS tutorial.

B. For browsing and ordering AVHRR, use the NOAA site:

You will need to register and get an account. Plan ahead where you will put these data!

C. For MODIS and other Terra data: the EOS Data Gateway is a good place to start.  For direct links to MODIS data, click here.

Having trouble? Refer to the user guide developed by Matt Watson

D. Useful links for GOES data: (GOES data are much more of a problem, because there is so much!)

For a general look at data sources try NOAA (Gary Ellrod) or Goddard list of GOES servers

GOES data for the last few days: (includes raw data)

Highlights from the GOES Volcano watch examples:

General source of GOES data (NOAA-NCDC):

Some very useful browsing sites which highlight GOES volcano data in real-time (these are useful if you are looking for current or very recent activity):

Hawaii site:

Wisconsin SSEC:

Washington VAAC:

E. ASTER data can be found at the EOS Data Gateway or on the ASTER homepage.  A word of caution: they have begun charging $55.00 for some of the datasets.

F. HIRS/2 data can be obtained from the EUMETSAT Data, Products, and Services page

| Michigan Tech Home | Department of Geological Engineering & Sciences | Remote Sensing Institute | MTU Volcanoes Page | Volcanic Clouds Web Site | Total Ozone Mapping Spectrometer (TOMS) | Volcanic Ash Advisory Centers (VAAC) | Smithsonian Institution | Alaska Volcano Observatory |