Earth is the water planet. Although forty percent of Earth’s population lives within or near coastal regions, the ocean impacts people everywhere. Most of Earth’s water is stored in the ocean – a driving force for weather and climate. The Earth’s surface is warmed unevenly by the sun. Heat, a form of energy, helps drive ocean and atmospheric circulation. The ocean absorbs and stores more heat than the atmosphere. Both the atmosphere and ocean are moving; the atmosphere does this quickly, the ocean slowly. Multiple forces keep the global ocean conveyor belt or Thermohaline Circulation in perpetual motion. Below the surface, deeper currents are driven by differences in density. Mixing and upwelling in the ocean, transport nutrient rich waters to the ocean’s surface. Nutrients sustain biological productivity in the ocean. Extreme variations in sea surface height and sea surface temperature effect ocean and atmospheric circulation. El Niño and La Niña occur when changing wind patterns displace warm and cool water in the equatorial Pacific. Both have global impacts. During either of these events the replacement of cold water by warm water leads to air temperature swings and changes in humidity. This alters weather patterns by steering storms and rainfall to new locations. Shifts in rainfall affect plant growth and areas impacted by drought. When heat is exchanged between the Ocean’s surface to the atmosphere it influences climate. For example, heat and moisture carried by the Gulf Stream northward bring warmer temperatures and a moderate climate to Europe. An eddy is a circular moving body of water that spins off a main current. Eddies play a major role transporting heat and nutrients. Thunderstorms are a frequent occurrence in the tropics. Some of these may become organized into large rotating systems with strong winds, growing into tropical storms or hurricanes. Tropical ocean basins like the Caribbean and the Gulf of Mexico retain substantial heat making these regions favorable for rapid storm intensification. By extracting large amounts of heat from the ocean, storms can become massive and destructive hurricanes. A driving force for weather and climate, the ocean is essential to life on Earth. It is the primary storehouse of Earth’s water. Without the ocean our planet would be uninhabitable. NASA satellites and their unique view from space are helping to unveil the vast and largely unexplored ocean.