Doc Rivas' Blog

Sunday, April 15, 2012

El Paso's Dust Storm - Images // April 14 2012

It was a very bad day for El Paso, TX, residents. Here are the images I got (click to enlarge) and a couple of more images Tom found.

This from NASA-Terra MODIS data:

Dust aerosol detection algorithm result.

From NASA - Aqua MODIS data

Dust aerosol detection algorithm result.

This is an image with a higher resolution view to the dust storm:

And finally, a very nice animation of GOES IR data:

(original here on Tom's web)

Sunday, March 18, 2012

Dust Storm - Southwestern US - March 18 2012

Today I had the privilege of being asked by a "Dust-Storm" expert the following:
"There is massive amounts of dust today in New Mexico and El Paso. But on the satellite I can't easily tell which is dust and which is cloud. Can you run your algorithm today and see if it differentiates them?" - Dr. Thomas Gill

Unfortunately, the algorithm was "trained" or "taught" to discriminate clouds, that is, wherever there is a cloud, don't bother searching for dust. The original premise by some NASA experts and I was that, since my algorithm uses thermal spectral bands near the infra-red spectrum, any cloud would significantly deteriorate the thermal emission of the dust aerosols; in other words: it would mess up the whole algorithm. So anyway, what I am trying to say is that all clouds are "mapped" to black (non-dusty) aerosols.

Below are the results of my algorithm. On the left we have true color images and on the right we have the output of my algorithm; on the first row is shown MODIS-Terra and on the second MODIS-Aqua, 17:35 UTC and 2050 UTC, respectively.

This dust storm was classified as "severe" and it is probably the worst in the last five years. Here is the full overpass of MODIS-Terra and my algorithm's output...

This is the GOES East animation of the event; as you can see, there is a large number of clouds moving over the area of the incident, making almost impossible to analyze using traditional infra-red imagery.

Finally, here are some pictures of friends and videos uploaded by other people.

El Paso, TX...

Las Cruces, NM...

Albuquerque, NM...

Wow, right?

Monday, March 12, 2012

Is dust from Africa going north?

Yesterday I was looking at Terra's satellite imagery and noticed something that looked like a huge dust cloud from the north pole going south; however, after a careful review I came to the conclusion that it is the other way around: it appears that a high concentration of dust aerosols from Africa were somehow compressed into a dense dust cloud and pushed north. I may be wrong of course. Here are two images: 1) True color MODIS-Terra overpasses. 2) The output of my dust aerosol detection algorithm. (Click to zoom in)

Tuesday, January 31, 2012

Dust Storm in Texas Jan/22/2012 // Catching Up

This is data of the dust storm event of January 22nd, 2012.

Location: North-West Texas.
Time: Between 05:00 1/22 and 15:00 1/23 UTC

Blowing dust developed in New Mexico, Texas, and Oklahoma on 22 January 2012. Winds of 60-70 mph gusted Texas, and reduced visibility to 0.5 miles. A large number of individual blowing dust plumes converged into a single large blowing dust cloud. The primary large dust plume moved to the northeast Oklahoma, meanwhile, smaller dust plumes moved southeast Oklahoma and Texas panhandle regions behind a secondary cold front.

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