Tag Archives: greenland

Newly Discovered Icelandic Current Could Change North Atlantic Climate Picture

An international team of researchers, including physical oceanographers from the Woods Hole Oceanographic Institution (WHOI), has confirmed the presence of a deep-reaching ocean circulation system off Iceland that could significantly influence the ocean’s response to climate change in previously unforeseen ways.

The current, called the North Icelandic Jet (NIJ), contributes to a key component of the Atlantic Meridional Overturning Circulation (AMOC), also known as the “great ocean conveyor belt,” which is critically important for regulating Earth’s climate. As part of the planet’s reciprocal relationship between ocean circulation and climate, this conveyor belt transports warm surface water to high latitudes where the water warms the air, then cools, sinks, and returns towards the equator as a deep flow. (more…)

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Rising Oceans – Too Late to Turn the Tide?

*Melting ice sheets contributed much more to rising sea levels than thermal expansion of warming ocean waters during the Last Interglacial Period, a UA-led team of researchers has found. The results further suggest that ocean levels continue to rise long after warming of the atmosphere levels off.*

Thermal expansion of seawater contributed only slightly to rising sea levels compared to melting ice sheets during the Last Interglacial Period, a University of Arizona-led team of researchers has found.

The study combined paleoclimate records with computer simulations of atmosphere-ocean interactions and the team’s co-authored paper is accepted for publication in Geophysical Research Letters(more…)

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Warming Ocean Layers Will Undermine Polar Ice Sheets

*The UA-led research, based on climate models, shows that melting of the ice sheets will occur in this century and next.

Warming of the ocean’s subsurface layers will melt underwater portions of the Greenland and Antarctic ice sheets faster than previously thought, according to new University of Arizona-led research. Such melting would increase the sea level more than already projected.

The research, based on 19 state-of-the-art climate models, proposes a new mechanism by which global warming will accelerate the melting of the great ice sheets during this century and the next. (more…)

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With Global Warming, Arctic Access Will Diminish By Land But Improve By Sea

Global warming over the next 40 years will cut through Arctic transportation networks like a double-edged sword, limiting access in certain areas and vastly increasing it in others, a new UCLA study predicts.

“As sea ice continues to melt, accessibility by sea will increase, but the viability of an important network of roads that depend on freezing temperatures is threatened by a warming climate,” said Scott Stephenson, a UCLA graduate student in geography and the study’s lead author. (more…)

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Melting Ice on Arctic Islands a Major Player in Sea Level Rise

ANN ARBOR, Mich.— Melting glaciers and ice caps on Canadian Arctic islands play a much greater role in sea level rise than scientists previously thought, according to a new study led by a University of Michigan researcher.

The 550,000-square-mile Canadian Arctic Archipelago contains some 30,000 islands. Between 2004 and 2009, the region lost the equivalent of three-quarters of the water in Lake Erie, the study found. Warmer-than-usual temperatures in those years caused a rapid increase in the melting of glacier ice and snow, said Alex Gardner, a research fellow in the Department of Atmospheric, Oceanic and Space Sciences who led the project. The study is published online in Nature on April 20. (more…)

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Ancient Fossils Hold Clues for Predicting Future Climate Change, Scientists Report

By studying fossilized mollusks from some 3.5 million years ago, UCLA geoscientists and colleagues have been able to construct an ancient climate record that holds clues about the long-term effects of Earth’s current levels of atmospheric carbon dioxide, a key contributor to global climate change. 

Two novel geochemical techniques used to determine the temperature at which the mollusk shells were formed suggest that summertime Arctic temperatures during the early Pliocene epoch (3.5 million to 4 million years ago) may have been a staggering 18 to 28 degrees Fahrenheit warmer than today. And these ancient fossils, harvested from deep within the Arctic Circle, may have once lived in an environment in which the polar ice cap melted completely during the summer months.  (more…)

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Study Sheds Light on How Heat is Transported to Greenland Glaciers

Warmer air is only part of the story when it comes to Greenland’s rapidly melting ice sheet. New research by scientists at Woods Hole Oceanographic Institution (WHOI) highlights the role ocean circulation plays in transporting heat to glaciers.

Greenland’s ice sheet has lost mass at an accelerated rate over the last decade, dumping more ice and fresh water into the ocean. Between 2001 and 2005, Helheim Glacier, a large glacier on Greenland’s southeast coast, retreated 5 miles (8 kilometers) and its flow speed nearly doubled. (more…)

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War, Plague No Match for Deforestation in Driving CO2 Buildup

Stanford, CA —  Genghis Khan and his Mongol hordes had an impact on the global carbon cycle as big as today’s annual demand for gasoline. The Black Death, on the other hand, came and went too quickly for it to cause much of a blip in the global carbon budget. Dwarfing both of these events, however, has been the historical trend towards increasing deforestation, which over centuries has released vast amounts of carbon dioxide into the atmosphere, as crop and pasture lands expanded to feed growing human populations. Even Genghis Kahn couldn’t stop it for long. (more…)

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