Northeast Africa continues to reel from the effects of the worst drought to strike the region in decades. The arid conditions are contributing to famines that the U.S. Department of State says are affecting more than 11.5 million people, particularly in Somalia, Ethiopia, Kenya and Djibouti.

The drought is tied to strong La Nina conditions that prevailed in late 2010 and early 2011. La Nina shifts ocean temperatures and air pressure over the Pacific Ocean, causing effects that ripple through weather patterns around the world. In East Africa, La Nina typically brings drought.

The current dry conditions are illustrated in a new map, created using nine years of data on surface relative humidity from the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft.

AIRS is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif.