Archive for the ‘Ocean Observations’ Category

What is a Rossby wave?

This item was filled under Basics, Facts, Ocean Observations, Tides and Currents


Oceanic and atmospheric Rossby waves — also known as planetary waves — naturally occur largely due to the Earth's rotation. These waves affect the planet's weather and climate. Waves in the ocean come in many different shapes and sizes. Slow-moving oceanic Rossby waves are are fundamentally different from ocean surface waves. Unlike waves that break along the shore, Rossby waves are huge, undulating movements of the ocean that stretch horizontally across the planet for hundreds of kilometers in a westward direction. They are so large and massive that they can change Earth's climate conditions. Along with rising sea levels, King Tides, and the effects of El Ni?o, oceanic Rossby waves contribute to high tides and coastal flooding in some regions of the world.

About this image: Rossby waves naturally occur in rotating fluids. Within the Earth's ocean and atmosphere, these planetary waves play a significant role in shaping weather. This animation from NASA's Goddard Space Flight Center shows both long and short atmospheric waves as indicated by the jet stream. The colors represent the speed of the wind ranging from slowest (light blue colors) to fastest (dark red).

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What is a tide gauge?

This item was filled under Basics, Facts, Ocean Observations, Tides and Currents


A tide gauge, which is one component of a modern water level monitoring station, is fitted with sensors that continuously record the height of the surrounding water level. This data is critical for many coastal activities, including safe navigation, sound engineering, and habitat restoration and preservation.

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What is a catcher beach?



Not to be confused with a dumping ground or heavily trashed public beach, a catcher beach typically receives its accumulations of debris due to its shape and location in combination with high-energy waves, storms, or winds. Awareness and common knowledge of these types of areas vary significantly by state, although many states have a good understanding of where catcher beaches are located. In many cases, catcher beaches are found in remote areas that are difficult to access and can be challenging in terms of debris cleanup and removal.

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What is a King Tide?

This item was filled under Basics, Facts, Ocean Observations, Tides and Currents


A King Tide is a non-scientific term people often use to describe exceptionally high tides. Tides are long-period waves that roll around the planet as the ocean is "pulled" back and forth by the gravitational pull of the moon and the sun as these bodies interact with the Earth in their monthly and yearly orbits. Higher than normal tides typically occur during a new or full moon and when the Earth is at its perigee, or during specific seasons around the country

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What is the difference between local sea level and global sea level?

This item was filled under Basics, Facts, Ocean Observations, Tides and Currents


Global sea level trends and relative sea level trends are different measurements. Just as the surface of the Earth is not flat, the surface of the ocean is also not flat — in other words, the sea surface is not changing at the same rate at all points around the globe. Sea level rise at specific locations may be more or less than the global average due to many local factors: subsidence, ocean currents, variations in land height, and whether the land is still rebounding from the compressive weight of Ice Age glaciers.

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Where do I get real-time and forecast coastal conditions?



NOAA's nowCOAST is a GIS-based webmap service that provides frequently updated ocean observations along with coastal and marine weather forecasts 24 hours a day. The free online map offers point-and-click access to 60 NOAA data products and services all in one place. With nowCOAST, you can get a one-stop-shop look at coastal conditions — real-time and forecast — before you do or plan anything on the water.

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How does sea ice affect global climate?

This item was filled under Facts, Ocean Observations, Ocean Science, Places


Sea ice is frozen water that forms, expands, and melts in the ocean. It is different from icebergs, glaciers, ice sheets, and ice shelves, which originate on land. For the most part, sea ice expands during winter months and melts during summer months, but in certain regions, some sea ice remains year-round. About 15 percent of the world's oceans are covered by sea ice during part of the year.

While sea ice exists primarily in the polar regions, it influences the global climate. The bright surface of sea ice reflects a lot of sunlight out into the atmosphere and, importantly, back into space. Because this solar energy "bounces back" and is not absorbed into the ocean, temperatures nearer the poles remain cool relative to the equator.

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What is the Pineapple Express?

This item was filled under Facts, Ocean Observations, Ocean Science


Atmospheric rivers are narrow regions in the atmosphere that transport much of the moisture from the tropics to northern latitudes. Atmospheric rivers are part of the Earth's ocean water cycle, and are tied closely to both water supply and flood risks.

A well-known example of a strong atmospheric river is called the "Pineapple Express" because moisture builds up in the tropical Pacific around Hawaii and can wallop the U.S. West Coast with heavy rainfall.

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How are satellites used to observe the ocean?

This item was filled under Basics, Economy, Ecosystems, Facts, Health, Ocean Observations


Satellites are amazing tools for observing the Earth and the big blue ocean that covers more than 70 percent of our planet. By remotely sensing from their orbits high above the Earth, satellites provide us much more information than would be possible to obtain solely from the surface.

Using satellites, NOAA researchers closely study the ocean. Information gathered by satellites can tell us about ocean bathymetry, sea surface temperature, ocean color, coral reefs, and sea and lake ice. Scientists also use data collection systems on satellites to relay signals from transmitters on the ground to researchers in the field—used in applications such as measuring tidal heights and the migration of whales. Transmitters on satellites also relay position information from emergency beacons to help save lives when people are in distress on boats, airplanes, or in remote areas.

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What is an oil seep?



Did you know that naturally occurring oil seeps from the seafloor are the largest source of oil entering the world ocean? In fact, they account for nearly half of the oil released into the ocean environment every year. Seeps occur when crude oil leaks from fractures in the seafloor or rises up through seafloor sediments, in much the same way that a freshwater spring brings water to the surface. The waters off of Southern California are home to hundreds of naturally occurring oil and natural gas seeps.

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