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Global Warming And The Arctic
THE ARCTIC HALOCLINE—When sea ice forms, it releases salt into surface waters. These waters become denser and sink to form the Arctic halocline—a layer of cold water that acts as barrier between sea ice and deeper warmer water that could melt the ice. (Illustration by Jayne Doucette, WHOI)
Are these temporary phenomena or the first hints of long-term climate change? The answers are critical because the Arctic will not just feel the impacts of climate change, it will also cause a cascade of other global changes. As the Arctic goes, most researchers say, so goes the planet. In the Arctic, the air, sea ice, and underlying ocean all interact in a delicately balanced system. To understand why, you have to follow the water. 'The ice factory'. It starts at the narrow Bering Strait between Alaska and Siberia, where cold and relatively less salty water from the Pacific Ocean enters the largely enclosed Arctic Ocean. In winter, frigid winds from the icy Alaskan interior blast over the shallow Chukchi Sea. The cold air freezes coastal seawater into sea ice and then pushes it farther out to sea, leaving new pockets of seawater available for freezing. This is "the ice factory," which, in the process of manufacturing ice, also transforms the seawater left behind......... Posted by: Tyler Permalink Source Oceans Warmer than a Hot Tub
"These temperatures are off the charts from what we've seen before," said Karen Bice, a paleoclimatologist at Woods Hole Oceanographic Institution (WHOI). Bice reported the findings Feb. 17 at the annual meeting of the American Association for the Advancement of Science (AAAS) in St. Louis and is also lead author of a study would be published in an upcoming issue of the journal Paleoceanography, published by the American Geophysical Union. Bice and a multi-institutional team of researchers studied three long columns of sediment cored from the seafloor in 2003 off Suriname, on the northeast coast of South America, by the drillship JOIDES Resolution, operated by the international Ocean Drilling Program......... Posted by: Tyler Permalink Source Oceans May Soon Be More Corrosive Compare To The Time Dinosaurs Died
Caldeira's computer models have predicted that the oceans will become far more acidic within the next century. Now, he has compared this data with ocean chemistry evidence from the fossil record, and has found some startling similarities. The new finding offers a glimpse of what the future might hold for ocean life if society does not drastically curb carbon dioxide emissions. "The geologic record tells us the chemical effects of ocean acidification would last tens of thousands of years," Caldeira said. "But biological recovery could take millions of years. Ocean acidification has the potential to cause extinction of a number of marine species." When carbon dioxide from the burning of coal, oil, and gas dissolves in the ocean, some of it becomes carbonic acid. Over time, accumulation of this carbonic acid makes ocean water more acidic. When carbonic acid input is modest, sediments from the ocean floor can buffer the increases in acidity. But at the current rate of input--nearly 50 times the natural background from volcanoes and other sources--this buffering mechanism is overwhelmed. Prior estimates suggest that in less than 100 years, the pH of the oceans could drop by as much as half a unit from its natural value of 8.2 to about 7.7. (On the pH scale, lower numbers are more acidic and higher numbers are more basic.)......... Posted by: Tyler Permalink February 19, 2006, 11:14 PM CT How the World Will End  Someday the world will end. It's inevitable. But how will it happen? Stephen Wagner offers four possibilities. A pole shift could occur. Imagine if Antartica was on the new equator. A meteor will strike our planet. There's a possibility that some day in the future a large meteor will strike Earth. It may or may not destroy the planet. Yellowstone National Park is directly on top of one of the largest super volcanoes on the planet. Apparently, it is 40,000 years over due for an eruption. If this volcano did erupt we would plunge into a volcanic winter. And finally, the last catastrophic event to look out for is an ice age caused by global warming. We are seeing some of the effects of global warming today in recent violent weather. You can build a bomb shelter and hide out in it until the Earth ends, or you can live your life without fearing the inevitable. Read the Four Scariest Predictions for Our Planet here. Read more.... No Safe Level For Ozone Traffic is a major source of ozone production The study, sponsored by the Environmental Protection Agency and the Centers for Disease Control, found that if a safe level for ozone exists, it is only at very low or natural levels and far below current U.S. and international regulations. A 10 part-per-billion increase in the average of the two prior days' ozone levels is associated with a 0.30 percent increase in mortality. The current study builds on research published in November 2004 in the Journal of the American Medical Association, which was the first national study of ozone and mortality. "This study investigates whether there is a threshold level below which ozone does not affect mortality. Our findings show that even if all 98 counties in our study met the current ozone standard every day, there would still be a significant link between ozone and premature mortality," said Michelle Bell, lead investigator on the study and assistant professor of environmental health at the Yale School of Forestry and Environmental Studies. "This indicates that further reductions in ozone pollution would benefit public health, even in areas that meet regulatory requirements."........ Posted by: Tyler Permalink Cargo, Fuel Safely Unloaded at Antarctic The tanker Lawrence H. Gianella sits alongside the ice pier at McMurdo Station in Antarctica. Fuel mandatory to heat the stations and power aircraft and other vehicles is currently being transferred from a tanker into storage tanks on land. The cargo vessel American Tern arrived at McMurdo Station's ice pier on Feb. 2. With its cargo safely offloaded, and with recyclable materials and other goods stowed aboard, the Tern was escorted out of McMurdo Sound by the Russian icebreaker Krasin earlier this week. The cargo ship has steamed safely beyond the ice-clogged region and is now headed north. NSF chartered the Krasin to cut and maintain a channel through the thick, multiyear ice covering the Ross Sea and the sound into McMurdo Station. Meanwhile, the tanker Lawrence H. Gianella is offloading fuel and is expected to complete its operations by Feb. 11, when it too will be escorted north through the sea ice. With the safe arrival and off-load of the ships, preparations for the long, dark Antarctic winter at McMurdo are nearing completion......... Posted by: Tyler Permalink Snow Research NRC institutes dedicate time, expertise and resources pursuing and perfecting solutions to diverse snow and ice-related problems. Over the years, this research has ranged from protecting Canadians from avalanches to studying the effects of snow and ice on structures and transportation. NRC even has special facilities to test our northern conditions. Knowledge sharing is a major part of NRC's contributions. The NRC Institute for Research in Construction (NRC-IRC) publishes useful resources like the National Building Code and the Canadian Building Digest which provide valuable construction guidance and standards. These publications cover topics like Snow Loads on Roofs, among others. Avalanches From 1956 to 1991, scientists studied life-threatening and infrastructure damaging snow - avalanches. At NRC offices in Vancouver and a NRC research facility in Rogers Pass, B.C., scientists helped with the construction of avalanche prone areas of the Trans-Canada highway. They also contributed to a better understanding of avalanche control mechanisms and hazard evaluation......... Posted by: Tyler Permalink Source Roadblocks Contributing To Natural Gas Price Hikes While a number of factors contribute to higher natural gas prices, scientists in Argonne's Environmental Science Division scoured federal and state environmental laws, regulations and policies that were developed to meet environmental protection goals, but that may also constrain natural gas exploration, production and transportation. These factors can limit access to natural gas supplies, create production delays or increase costs. "Our goal in writing Environmental Policy and Regulatory Constraints to Natural Gas Production," explained report author Deborah Elcock, "was to identify specific existing and potential environmental laws, regulations and policies which, while developed to meet legitimate environmental protection goals, can at the same time, constrain natural gas exploration, production and transportation." Understanding these constraints helps decision-makers develop policies that eliminate or reduce the impacts of such constraints, set priorities for regulatory reviews, and target research and development efforts to help the nation meet its natural gas demands......... Posted by: Tyler Permalink Read more.... Snows Of Kilimanjaro Disappearing And the impact of the loss of that ice atop Africa 's highest peak - disregarding the loss of tourism that will follow the vanishing ice - could add to the heavy drought burden already facing those living near that mountain. For Lonnie Thompson, professor of geological sciences, his third expedition to the summit of Kilimanjaro was all too much like visiting a sick friend in failing health. In 2002, Thompson and colleagues shocked the scientific community with their prediction that the ice fields capping the mountain would disappear between 2015 and 2020, the victims, at least in part, of global warming. Returning to his campus office last week, he admits that nothing has happened to alter that prediction. In fact, the mountain's ice fields may disappear sooner. "The change there is so dramatic," he said. "We can see it both in the field and from aerial photographs of the mountaintop. I would say it is on track to disappear, and the rate of ice loss may even be accelerating. "But we need to look at the numbers to confirm that." The "numbers" he refers to are the combined data gathered from both the most recent and earlier expeditions, and from aerial surveys of the ice fields. By comparing these with past data, they can calculate just how much of Kilimanjaro's ice has vanished. About 82 percent of the ice fields were lost between the time they were first mapped in 1912 and 2000......... Posted by: Tyler Permalink Source February 7, 2006, 10:06 PM CT Antarctic ice shelf retreats happened before A study of George VI Ice Shelf on the Antarctic Peninsula is the first to show that this currently 'healthy' ice shelf experienced an extensive retreat about 9500 years ago, more than anything seen in recent years. The retreat coincided with a shift in ocean currents that occurred after a long period of warmth. Whilst rising air temperatures are thought to bethe primary cause of recent dramatic disintegration of ice shelves like Larsen B, the new study suggests that the ocean may play a more significant role in destroying them than previously thought. The University of Durham's, Dr Mike Bentley, one of the leaders of the project said,. 'We know that rising air temperatures can break up ice shelves but there has been a suspicion for some time that the role of the ocean may have been underestimated. This is some of the first evidence that a shift in ocean currents can actually destroy ice shelves. In this case it's possible that a preceding warm period may have primed the ice shelf to disintegrate when the ocean currents shifted.' The researchers analysed sediments from the bottom of a freshwater lake close to the edge of the present George VI Ice Shelf. The results revealed that about 9500 years ago the ice shelf retreated, allowing the sea to flood into the lake. The ice shelf didn't reform until 1500 years later, and has been present ever since......... Posted by: Tyler Permalink |
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