Jet streams are high-level winds, five to ten miles above the Earth's surface, created when warm and cold air masses meet. Shifts in the location of jet streams change temperatures and precipitation zones at the surface. El Nino begins when the westward trade winds weaken and a large warm water mass, called a Kelvin wave, is allowed to move eastward along the equator in the Pacific Ocean. This wave is currently occupying most of the tropical Pacific Ocean. It will take another month or two before the wave disperses.
Scientists use the data to produce global maps of ocean circulation.
Sea surface height data are essential to understanding the role oceans play in regulating global climate, one of the least-understood areas of climate research. The image was taken on September 18, 1994. This Hubble Space Telescope image shows one of the most complex planetary nebulae ever seen, NGC 6543, nicknamed the Cat's Eye Nebula. A preliminary interpretation suggests that the star might be a double-star system. The dynamical effects of two stars orbiting one another most easily explains the intricate structures, which are much more complicated than features seen in most planetary nebulae.