Vog from the Kilauea Volcano in Hawaii
The Kileuea Volcano in Hawaii has been active lately. Sulfur dioxide produced by the active volcano was at such a high level that it actually forced Hawaii Volcanoes National Park to close for two days - 2000 people were evacuated as well. The park reopened on April 10, 2008 when the winds, back to a trade wind pattern (out of the northeast), finally blew the sulfur dioxide and "vog" (volcanic smog) away.
This image was captured by the MODIS on the Aqua satellite on April 9,2008. On the left half of the image you can see the large cloud of vog over the ocean. The Hawaiian islands are on the right half of the image, beneath the hazy layer of vog that caused so many problems.