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Imagine a parcel of warm and salty water travelling northward through the North Atlantic Ocean. As it moves, it gradually loses water through evaporation into the atmosphere – this water creates rain in faraway places. As evaporation happens, the parcel of water becomes saltier and denser. By the time it gets to Greenland, it is [...]

Since 1992, satellites have been providing continuous global coverage of changes in ocean surface heights. The first satellite to provide such coverage, TOPEX Poseidon, was launched in 1992. Although only designed to serve for three years, it provided data until 2005. Jason I, TOPEX Poseidon’s replacement, began operating in 2001 and Jason II was launched [...]

In Brief: Volcanic dust stimulated a large phytoplankton bloom in August 2008. On August 7, 2008, the Aleutian Island volcano of Kasatochi erupted, spewing out volcanic ash rich in minerals such as aluminum, magnesium, iron and calcium. Winds carried this ash to the subarctic northeast Pacific Ocean. About 20 percent of Earth’s ocean surface, including [...]

In Brief: Some Caribbean coral reefs experienced over 16 weeks of heating stress during 2010, which will likely result in large-scale coral reef mortality. Shallow-water coral reef ecosystems are some of the most diverse and economically important ecosystems in the world. These ecosystems support fisheries that feed hundreds of millions of people. Coral reefs are [...]

In Brief: The number of storms in the Southern Ocean has shown an upward trend since the 1950s. Early mariners that explored the Southern Hemisphere’s waters noticed strengthening of the winds the further south they went. They gave nicknames to the latitudinal bands: “the roaring forties,” “the furious fifties” and the “screaming sixties.” The storms [...]

In Brief: Less chlorophyll in the North Pacific Gyre can influence Pacific tropical cyclone dynamics. Many factors influence how many tropical cyclones form in the tropical Atlantic and Pacific oceans each year, how severe these storms become and the tracks they follow. One of the most important factors is surface water temperatures. One key variable [...]

Preliminary results indicate that on September 10, 2010, the Arctic sea ice reached its annual minimum extent of 1.84 million square miles. This is the third lowest extent on record after the 2008 and record low 2007 seasons, and 22 percent below the 1979-2009 average minimum. This year’s melt season started late, leading to the [...]

Along America’s East Coast, blue mussels (Mytilus edulis) have traditionally been an important food source for larger species. They are also commercially farmed and even help improve water quality by filtering out pollutants as they feed. As recently as 50 years ago, blue mussels could be found as far south as the waters around Cape [...]

The oceans are currently absorbing about 22 million tons of carbon dioxide (CO2) each day and have absorbed an estimated 525 billion tons of CO2 over the last 200 years. Trivia Question: As the oceans absorb more carbon dioxide, they become… a. more basic (higher pH). b. more acidic (lower pH). c. richer in nutrients. [...]

Oceanic phytoplankton – microscopic organisms that use the sun’s energy to convert carbon and water into the sugars that make up their bodies – account for about half of the production of organic, or living, matter on Earth. These phytoplankton feed the zooplankton, which eventually feed the larger fishes that feed seabirds, marine mammals and [...]

Many of Earth’s great ice masses, which collectively form the cryosphere, are floating on ocean surfaces. There are three main collections of floating ice: the Arctic sea ice, the Antarctic ice shelves and the Antarctic sea ice. All three components have seasonal fluctuations, with the Antarctic sea ice showing the most dramatic differences between winter [...]

For about the past two million years, Earth’s climate system has been characterized by glacial cycles that last between 80,000 to 120,000 years. These cycles have long periods when the Earth cools and ice sheets build up to their maximums, followed by relatively short warming periods when the ice retreats and then “interglacial periods” like [...]

Warm ocean surface temperatures in the North Atlantic provide the warm and moist air that fuels hurricanes, which develop out of random disturbances in the tropics that provide the spark for these storms. Warmer waters in the North Atlantic generally mean more fuel for the storms. But did you know that surface temperature conditions in [...]

The coral reefs around the 3,700 square mile Florida Keys National Marine Sanctuary provide habitat for 5,500 species as well nursing, feeding and breeding grounds that support a 20 million pound per year fishery. Water temperatures in the sanctuary fluctuate annually between about 68 and 86 degrees Fahrenheit. These waters, which reach their annual peak [...]

By most estimates, Earth’s sea level rose by 3.5 mm per year between 1993 and 2006. About one-seventh of this sea level rise can be attributed to ice melt on one island – two to three days worth of the summertime melt water from the island could supply the New York Metropolitan area’s water needs [...]

There is more energy in the Earth’s climate today than there was in 1950. This increase in energy exists in warmer air temperatures, less ice, more extreme rainfall events, warmer land surfaces and warmer rivers and lakes. The vast majority of the cumulative energy gain, however, is in the oceans. The upper 2300 feet of [...]

One of Earth’s most dramatic seasonal cycles is the waxing and waning of the sea ice that surrounds Antarctica, the driest, darkest and coldest continent. At its maximum extent at the end of the Southern Hemisphere winter in September, a 6.9 million square mile expanse of ice extends from Antarctica’s shores out into the Southern [...]

Over the past century, the Arctic was cooler than normal from 1900-1915, warmer than normal during the 20′s, 30′s and 40′s, cooler than normal during the 50′s, 60′s and 70′s and has been warmer than normal from the early 1980′s to today. Trivia Question: During warm periods in the Arctic, is the Antarctic generally: a)   [...]

Melting ice and intensification of Earth’s water cycle appear to be impacting how salty ocean waters are. How salty the water is affects sea levels as well as Earth’s thermohaline circulation – the ocean currents driven by differences in temperature and salinity. Both changes in sea levels and the thermohaline circulation can have consequences for [...]

Teleconnections occur when an event in one part of the world impacts another part of the world. One frequent source of teleconnections is the El Niño-Southern Oscillation (ENSO).  ENSO is the periodic shift in wind patterns and sea-surface temperatures over the tropical Pacific Ocean. ENSO’s teleconnections include control over the number of winter storms impacting [...]