Garrett’s Blog: Sahara Dust In Arkansas
Notice more haze than usual lately? Here’s a picture from Jesse Hays who snapped this picture of the dust suspended across the Arkansas River Valley on June 30th, 2014.
The dust originates from the Saharan Air Layer which resides over the northern part of Africa. Frequent dust storms will suspend the air particles and the particles will frequently find their way across the Atlantic. It’s somewhat less common to see them in Arkansas and it’s much more common in Florida and the Caribbean. Actually, it happens every year.
Because of thermal expansion due to heating near the equator, the atmosphere is often thicker and higher and the sand and dust particles are suspended thousands of feet into the air. These particular dust plumes often originate from a “Calima” (or a widespread dust storm of southeast or easterly winds) which affects the Canary Islands and often drops visibility significantly.
The dust particles over the Atlantic act as condensation nuclei and often have a negative influence for hurricane development by releasing more latent heat than normal due to more places in the atmosphere for water to condense; similar to cloud seeding.
The image above is from the NASA GEOS-5 (AOT) product (kzm Google Earth display) that shows dust and aerosols in the atmosphere on June 30th, 2014. You can see a concentration of dust around SW Texas and the gusty south winds which were blowing the dust northward into Arkansas. It’s probably enough to leave a coating on cars down south in Texas.
Locally, if you have dust allergies you’ll notice it more in the coming weeks. The extra material in the air should make for sunsets which have more orange and red colors to them. And of course, in the afternoon, you’ll notice that haze off in the distance. Weather is amazing, isn’t it?