Oceanus Online Archive
Lakes and Climates Have Their Ups and Downs
Between 5,400 and 3,000 years ago, something happened to New England’s climate. The region became drier. Water levels in lakes dropped. Several droughts persisted for hundreds of years, changing the […]
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How Long Can the Ocean Slow Global Warming?
It is 4:30 a.m., far from land. A group of scientists clad in bright yellow foul-weather gear gathers in the open bay of a research ship. They wait in the […]
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Ocean Circulation and a Clam Far From Home
In my first year of graduate school, I was stumped by a big question on my final exam in biological oceanography. Maybe I had missed the relevant lecture or an […]
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The Once and Future Circulation of the Ocean
The short history of modern oceanographic observations—less than a century’s worth, really—doesn’t give us a long track record to evaluate how the ocean’s circulation has operated and changed in the […]
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What Other Tales Can Coral Skeletons Tell?
In 2003, we traveled by ship to the New England Seamounts—a chain of extinct, undersea volcanoes about 500 miles off the East Coast of North America—to help collect dead corals […]
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The Coral-Climate Connection
Are the climate changes we perceive today just part of the Earth system’s natural variability, or are they new phenomena brought about by human activities? One way to find out […]
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Analyzing Ancient Sediments at Warp Speed
Like a toy out of a science fiction story, the X-ray fluorescence core scanner reveals intimate details of the composition of ancient mud and sediment–which can contain a variety of clues about past climate and environmental conditions on Earth–without breaking the surface. In a matter of hours, the XRF simultaneously captures digital photographs and X-ray images of every millimeter of a core sample, while detecting the presence of any of 80 chemical elements.
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An Ocean Warmer Than a Hot Tub
Scientists have found evidence that tropical Atlantic Ocean temperatures may have once reached 107°F (42°C)—about 25°F (14°C) higher than today. The surprisingly high ocean temperatures occurred millions of years ago […]
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The Flywheel of the Arctic Climate Engine
A key component of the Arctic climate clockworks is the Beaufort Gyre?a bowl of cold, icy, relatively fresh waters north of Alaska that is swept by prevailing winds into a circular swirl larger than the Gulf of Mexico.
Read MoreIs Global Warming Changing the Arctic?
In the Arctic, the air, sea ice, and underlying ocean all interact in a delicately balanced system. Four ambitious Arctic projects are pulling back the icy veil that shrouds our understanding of the Arctic Ocean?s role in our climate system. (First of a five-part series.)
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Fresher Ocean, Cooler Climate
Large and climatically sensitive regions of the North Atlantic Ocean have become less salty since the late 1960s, a trend that could alter global ocean circulation and spur climate changes by the 21st century.
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Joyce, Evans Give Testimony on Oceans to Congress
WHOI scientists Rob Evans and Terry Joyce testified June 8 before the House Subcommittee on Fisheries and Oceans, chaired by Wayne Gilchrest (R-Md.) in a continuing effort to help educate the U.S. House of Representatives on the oceans.
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The Great Flood of New York
An ice dam forming a large Ice Age lake collapsed 13,350 years ago, sending a flood down the Hudson River Valley and causing dramatic climate changes.
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Rising Sea Levels and Moving Shorelines
Changes to the shoreline are inevitable and inescapable. Shoals and sandbars become islands and then sandbars again. Ice sheets grow and shrink, causing sea level to fall and rise as water moves from the oceans to the ice caps and back to the oceans. Barrier islands rise from the seafloor, are chopped by inlets, and retreat toward the mainland. Even the calmest of seas are constantly moving water, sand, and mud toward and away from the shore, and establishing new shorelines.
How the Isthmus of Panama Put Ice in the Arctic
The long lag time has always puzzled scientists: Why did Antarctica become covered by massive ice sheets 34 million years ago, while the Arctic Ocean acquired its ice cap only about 3 million year ago?
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Shifting Continents and Climates
Sixty-five millions years ago, dinosaurs had just become extinct, and mammals were starting to dominate the planet.
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Moving Earth and Heaven
The mountains rise, are lashed by wind and weather, and erode. The rivers carry mud and debris from the mountains into the ocean, where they settle onto the relatively tranquil seafloor and are preserved. The sediments bear evidence about where they came from, what happened to them, and when. By analyzing, measuring, and dating these seafloor sediments, scientists can piece together clues to reconstruct when and how fast their mountain sources rose to great heights millions of years ago, and how the climate and other environmental conditions may have changed in response.
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Geochemical Archives Encoded in Deep-Sea Sediments Offer Clues for Reconstructing the Ocean’s Role in Past Climatic Changes
Geochemical Archives Encoded in Deep-Sea Sediments Offer Clues for Reconstructing the Ocean’s Role in Past Climatic Changes
Paleoceanographers are trying to understand the causes and consequences of global climate changes that have occurred in the geological past. One impetus for gaining a better understanding of the factors that have affected global climate in the past is the need to improve our predictive capabilities for future climate changes, possibly induced by the rise of anthropogenic carbon dioxide (CO2) in the atmosphere.
Ground-Truthing the Paleoclimate Record
Sediment Trap Observations Aid Paleoceanographers
The geological record contains a wealth of information about Earth’s past environmental conditions. During its long geological history the planet has experienced changes in climate that are much larger than those recorded during human history; these environmental conditions range from periods when large ice sheets covered much of the northern hemisphere, as recently as 20,000 years ago, to past atmospheric concentrations of greenhouse gases that warmed Earth’s polar regions enough to melt all of the ice caps 50 million years ago. Since human civilization has developed during a fairly short period of unusually mild and stable climate, humans have yet to experience the full range of variability that the planet’s natural systems impose. Thus, the geological record has become an extremely important archive for understanding the range of natural variability in climate, the processes that cause climate change on decadal and longer time scales, and the background variability from which greenhouse warming must be detected
Computer Modelers Stimulate Real and Potential Climate, Work Toward Prediction
Although weather forecasting is accepted by the public as part of daily life, oceanic forecasting is not yet so advanced. There are, however, successful examples of oceanic forecasting—one is the newly developed skill to predict El Nino/Southern Oscillation (ENSO) events, largely due to improvements in ocean modeling.
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Oceans & Climate
The past decade has brought rapid scientific progress in understanding the role of the ocean in climate and climate change. The ocean is involved in the climate system primarily because it stores heat, water, and carbon dioxide, moves them around on the earth, and exchanges these and other elements with the atmosphere.
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Sedimentary Record Yields Several Centuries of Data
Natural climate changes like the Little Ice Age and the Medieval Warm Period are of interest for a few reasons. First, they occur on decade to century time scales, a gray zone in the spectrum of climate change. Accurate instrumental data do not extend back far enough to document the beginning of these events, and historical data are often of questionable accuracy and are not widespread geographically.
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Transient Tracers Track Ocean Cimate Signals
Transient tracers provide us with a unique opportunity to visualize the effects of the changing climate on the ocean. They trace the pathways climate anomalies follow as they enter and move through the ocean and give us valuable information about rates of movement and amounts of dilution. This knowledge is important for developing ocean-climate models to predict long term climate changes.
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