A heavy curtain of dust wafted over southern Afghanistan and northern Pakistan
Monday, and scientists studied it in these two satellite images.
The dust appears to be blowing out of the Sistan basin, which is on the Afghan-Iranian
border. The Sistan basin is a vast complex of lakes and marshes fed by small
streams and rivers flowing primarily from the mountainous highlands of Afghanistan.
The dust masks the arid deserts of Afghanistan and Pakistan and is sweeping
around the Chagai Hills, the dark land in the center of the storm. The crescent
of the Siahan Mountain Range in Pakistan is preventing the dust from blowing
further south.
Once airborne, the dust cools considerably, which makes it stand out in the
bottom image, which reveals temperatures. Here, the dust is as much as 40 degrees
Celsius cooler than the hottest regions on the ground.
The land temperature in this image reaches up to 135 degrees Fahrenheit (57
degrees Celsius) in pockets where the land is darker, and therefore, absorbs
more sunlight. Patches of clouds also show up as extremely cold blue regions
in the temperature image. Though the dust is easy to see in this image, surface
temperature images can make dust storms easier to spot when the dust is the
same color as the ground.
