Ocean Facts

harmful algal bloom from space demonstrating upwelling

What is upwelling?

Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away. This process is known as “upwelling.” Upwelling occurs in the open ocean and along coastlines. The reverse process, called “downwelling,” also occurs when wind causes surface water to build up along a coastline and the surface water eventually sinks toward the bottom. Read more

National Ocean Service Mission: In the U.S., where over half of us live along the coast and more than 78 percent of our overseas trade by volume comes and goes along our marine highways, the health of our coasts is intricately connected to the health of our nation's economy. The National Ocean Service (NOS) translates science, tools, and services into action, to address threats to coastal areas such as climate change, population growth, port congestion, and contaminants in the environment, all working towards healthy coasts and healthy economies. About NOS