This image shows three scenes taken from an animation created by TOPEX/Poseidon data of the ocean. The scenes show large-scale ocean waves with wavelengths of hundreds of kilometers, called Rossby waves. These waves carry a "memory" of weather changes that have happened at distant locations over the ocean. Scientists at Oregon State University are using the satellite data to track these waves as they move through the open ocean and have determined that at mid-latitudes the Rossby waves are moving two to three times faster than the existing theory predicts. Because Rossby waves can alter currents and their corresponding sea surface temperatures, the waves influence the way the oceans release heat to the atmosphere and, thus, are able to affect weather patterns. Precise information about how fast the waves travel may help forecasters improve their ability to predict the effects of El Nino events on weather patterns years in advance. The colors show variations in sea level in the Pacific Ocean. White and red indicate higher than average levels, while purple and magenta show lower than average levels. These scenes were taken by TOPEX/Poseidon in April, July and December 1993. The two small black circles in the April image show an area of warm water, called a Kelvin wave, moving along the equator toward the coast of the Americas. When this area of high sea level meets the coast, it creates two coastal waves, one traveling northward and the other traveling southward along the American coast. As these waves move poleward, Rossby waves "peel off" the coast and travel west. The solid lines show the crests of the waves (high sea level), while the dashed lines show wave troughs. TOPEX/Poseidon, a joint program of NASA and the Centre Nationale d'Etudes Spatiales, the French space agency, uses a radar altimeter to precisely measure sea-surface height. The Jet Propulsion Laboratory manages the U.S. portion of the TOPEX/Poseidon mission for NASA's Office of Mission to Planet Earth. #####
