Appendix A

Human Observation of Oceanographic
Phenomena from Space

The sun's reflection from the surface of the sea, referred to as sun glitter, has proven to be the most valuable tool in the visual observation of the ocean from space. Not only can the fine details of near-shore turbulence be examined. but it is the only method by which dynamics in the open ocean and around islands can be seen.
    In the golden center of the sun's reflection, a smooth sea surface reflects brighter than a sea roughened by waves. The sun is reflecting directly to the observer as it would from a mirror. This is known as "forward reflection" and permits observing and photographing the ocean's surface (Cox and Munk, 1954).
    Sea slicks or water moving with the wind reflect brightly, whereas water flowing against the wind, producing choppy waves on the surface, has a diffuse, dull reflection. Not only are these reflective differences easily seen but they photograph well. They have been recorded also by weather satellites and synthetic aperture radars.
    On the edge of the sun's reflection, the golden colors change to blues. In this part of the glitter pattern, smooth water has a dark color and roughened water has a light blue color. The glare into the lens, of both eye and camera, is far less on the edge of the reflection than in the very center. As a result, fine details of sea-surface turbulence can be lost in the central glare of the sun's reflection. The edge of the reflection field offers the best opportunity to observe complex ocean surface phenomena (Sculley-Power, 1986).

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