1. African Dust Event July 15 – July 27, 2008 Daily Satellite Images Prepared by Bryan Lambeth, P.E. Texas Commission on Environmental Quality Monitoring Operations Division September 2009

2. African Dust The following satellite images track dust originating from the Saharan Desert in northern Africa as it travels across the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico from July 15 through July 27, 2008. Normally the ocean surface appears very dark when skies are clear and the air is clean. Clouds are usually a bright white. Haze from dust can be detected in cloud-free areas over water by a brightening of the normally dark surface. The brightness corresponds to the intensity of the haze, with greater brightness indicating a higher concentration of dust. Haze boundaries are usually not sharp with a gradual decrease in intensity near the edge of the dust cloud, unlike clouds, which usually have sharp boundaries. Higher clouds also cast tell-tale shadows in late daytime images.

3. Dust cloud emerging from African Coast July 15, 2008 1745 UTC Clean air

4. July 16, 2008 1745 UTC Clean air Dust cloud moving over Cape Verde Islands

5. July 17, 2008 1745 UTC Dust cloud moving across Atlantic Ocean Clean air

6. July 18, 2008 1745 UTC Clean air Dust cloud moving across Atlantic Ocean

7. July 19, 2008 1745 UTC Dust cloud approaching Lesser Antilles Clean air

8. July 19, 2008 2045 UTC Dust cloud approaching Lesser Antilles Clean air

9. July 20, 2008 2045 UTC Dust cloud moving across Lesser Antilles Clean air

10. July 21, 2008 2045 UTC Dust cloud moving through eastern Caribbean Sea Clean air

11. July 22, 2008 2045 UTC Dust cloud moving through Caribbean Sea Clean air

12. July 22, 2008 2215 UTC Saharan dust Danny Clean air

13. July 23, 2008 2215 UTC Danny Clean air Saharan dust

14. July 24, 2008 2215 UTC Saharan dust Clean air

15. July 25, 2008 2215 UTC Saharan dust Clean air

16. July 26, 2008 2215 UTC Saharan dust Clean air

17. July 27, 2008 2215 UTC Saharan dust Clean air