Figure 10. Visible image of 1996 Super Typhoon Herb (top) from the Defense Meteorological Satellite Program shows the characteristic spiral band structure of hurricanes (called typhoons in the Pacific). The eye is the cloud-free area at the center, surrounded by dense overcast and tropical cirrus cloud extending far outward. A photograph of the eye wall of Hurricane Olivia taken from a reconnaissance aircraft on September 25, 1994 (bottom) shows the diagonal path of ascending air currents marked by striations in the cloud.