NASA Infrared Image of Tropical Cyclone Evan (image) NASA/Goddard Space Flight Center Share Print E-Mail Caption The AIRS instrument aboard NASA's Aqua satellite captured this infrared image of Tropical Cyclone Evan over the Samoa Islands on Dec. 13 at 0059 UTC. Evan's maximum sustained winds had increased to 90 knots (103 mph/166.7 kph) at the time of this image. The purple rounded area is Evan's center of circulation and is populated by strong thunderstorms that reach high into the troposphere where temperatures are as cold as -63 Fahrenheit (-52 Celsius). Those areas shaded in purple also indicate heavy rainfall. Credit NASA/JPL, Ed Olsen Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.