Blowing dust in New Mexico and Texas

March 26th, 2010 |
GOES-12 visible images

GOES-12 visible images

McIDAS images of the GOES-12 0.65 µm visible channel data (above) showed the development of a large plume of blowing dust across parts of southern New Mexico and western Texas late in the day on 26 March 2010. Surface winds gusted to 84 mph at El Paso in Texas, with the blowing dust temporarily reducing the surface visibility to 0.1 mile.

A 250-meter resolution Aqua MODIS true color Red/Green/Blue (RGB) image from the SSEC MODIS Today site (below) revealed that at the time of the Aqua satellite overpass (20:24 UTC), plumes of blowing sand were already beginning to stream northeastward from the White Sands National Monument and Missile Range in southern New Mexico — the blowing sand had already reached the partially snow-covered Sacramento Mountains located to the east of Alamogordo. At that time, the surface visibility at Alamogordo was 5 miles…but within 3 hours the visibility there dropped to 0.5 mile.

Aqua MODIS true color image (viewed using Google Earth)

Aqua MODIS true color image (viewed using Google Earth)

With the approach of darkness, the GOES-12 (GOES East) visible channel imagery could no longer be utilized to track the location and movement of the thick airborne dust — however, the older GOES-11 (GOES West) satellite imager instrument still retains a 12.0 µm channel that is helpful for creating a simple 10.7 – 12.0 µm (channel 04 – channel 05) IR temperature difference product that is useful for tracking airborne dust (and also volcanic ash) at night. Such a sequence of GOES-11 10.7 – 12.0 µm images (below) showed that the dust plume (yellow to cyan color enhancement) continued to move eastward and northeastward across Texas and into southwestern Oklahoma during the hours after sunset.

GOES-11 10.7-12.0 µm IR temperature difference images

GOES-11 10.7-12.0 µm IR temperature difference images

A few hours later, a similar MODIS IR difference product created by subtracting the brightness temperatures of the 11.0 µm and 12.0 µm channels (below) showed that the leading edge of the dust (yellow color enhancement) had moved as far as northern Oklahoma and extreme southern Kansas. Note the “cleaner” appearance of the MODIS IR difference product, a result of the higher spatial resolution (1 km) and improved spectral response of the IR channels on the MODIS instrument compared to the GOES imager.

Aqua MODIS 11.0-12.0 µm IR temperature difference product

Aqua MODIS 11.0-12.0 µm IR temperature difference product

The ABI instrument aboard the GOES-R satellite will mark the return of the 12.0 µm channel on the GOES imager, which will allow such phenomena to be more easily identified and tracked.

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