Group items tagged

Warming and Melting Mass loss from the ice sheets of Greenland and Antarctica account for a large fraction of global sea-level rise. Part of this loss is because of the effects of warmer air temperatures, and another because of the rising ocean temperatures to which they are being exposed. Joughin et al. (p. 1172) review how ocean-ice interactions are impacting ice sheets and discuss the possible ways that exposure of floating ice shelves and grounded ice margins are subject to the influences of warming ocean currents. Estimates of the mass balance of the ice sheets of Greenland and Antarctica have differed greatly-in some cases, not even agreeing about whether there is a net loss or a net gain-making it more difficult to project accurately future sea-level change. Shepherd et al. (p. 1183) combined data sets produced by satellite altimetry, interferometry, and gravimetry to construct a more robust ice-sheet mass balance for the period between 1992 and 2011. All major regions of the two ice sheets appear to be losing mass, except for East Antarctica. All told, mass loss from the polar ice sheets is contributing about 0.6 millimeters per year (roughly 20% of the total) to the current rate of global sea-level rise.

December 18, 2012 The Ten Best Ocean Stories of 2012 | | | Share on redditReddit | Share on diggDigg | Share on stumbleuponStumble | Share on emailEmail | More Sharing ServicesMore Two market squids mating 2012 was a big year for squid science. Photo Credit: © Brian Skerry, www.brianskerry.com Despite covering 70 percent of the earth's surface, the ocean doesn't often make it into the news. But when it does, it makes quite a splash (so to speak). Here are the top ten ocean stories we couldn't stop talking about this year, in no particular order. Add your own in the comments! 2012: The Year of the Squid From the giant squid's giant eyes (the better to see predatory sperm whales, my dear), to the vampire squid's eerie diet of remains and feces, the strange adaptations and behavior of these cephalopods amazed us all year. Scientists found a deep-sea squid that dismembers its own glowing arm to distract predators and make a daring escape. But fascinating findings weren't relegated to the deep: at the surface, some squids will rocket themselves above the waves to fly long distances at top speeds. James Cameron Explores the Deep Sea Filmmaker James Cameron has never shied away from marine movie plots (See: Titanic, The Abyss), but this year he showed he was truly fearless, becoming the first person to hit the deepest point on the seafloor (35,804 feet) in a solo submarine. While he only managed to bring up a single mud sample from the deepest region, he found thriving biodiversity in the other deep-sea areas his expedition explored, including giant versions of organisms found in shallow water. Schooling sardines form a "bait ball." Small fish, such as these schooling sardines, received well-deserved attention for being an important part of the food chain in 2012. Photo Credit: © Erwin Poliakoff, Flickr Small Fish Make a Big Impact Forage fish-small, schooling fish that are gulped down by predators-should be left in the ocean for larger fish, marin

RISE ABOVE PLASTIC (RAP) SUCCESS! Green Ambassadors, in partnership with The Surfrider Foundation and The Algalita Marine Research Foundation, created the Rise Above Plastics Program, a student speaker series that encourages Los Angelenos to curb their single-use habits. Through the program, students learn about the impact of plastics on our lives and the environment, including plastic marine debris, chemicals and toxins. Students spread the word to their peers and the community by delivering engaging presentations that encourage practical solutions. In addition to learning about the inherent problems of living in a throwaway society, students learn the value of teamwork and polish their public speaking and presentation skills. In 2009, nearly 20 students participated in the program, delivering 30 presentations to more than 850 students and community members!

"On the Rise A new report from the United Nations says the Earth is getting warmer faster than people once thought, and that sea levels are expected to rise. "

Ice Sheets and Sea Level Rise By: Claire L. Parkinson, Oceans and Ice Branch, Code 971, NASA Goddard Space Flight Center, Greenbelt MD 20771, e-mail: clairep@neptune.gsfc.nasa.gov Exercise: Determine the amount that sea level would rise, averaged around the globe, in response to the complete melting of (a) the Greenland ice sheet, (b) the Antarctic ice sheet, and (c) both the Greenland and Antarctic ice sheets.

NARRATOR: Even though the ocean covers seventy percent of the Earth's surface, people tend to know more information about land than the sea. As a result, our understanding of the ocean is often incomplete or full of misconceptions. How well do you know the ocean? You may think Earth has five separate oceans. They're clearly labeled on our maps. But, in actuality, these are all connected, and part of one global ocean system. Ever wonder why the ocean is blue? You may have heard its because the water reflects the color of the sky. Not quite. Sunlight contains all the colors of the rainbow. When it hits the ocean, it gets scattered by the water molecules. Blue light is scattered the most, which is why the ocean appears blue. Even more interesting is that floating plants and sediments in the water can cause light to bounce in such a way for the ocean to appear green, yellow, and even red! Another idea some people have is that the sea floor is flat. Actually, just like land, the sea floor has canyons, plains, and mountain ranges. And many of these features are even bigger than those found on land. You may also think that our ocean's saltwater is just a mix of water and table salt. Not so. Seawater's "salt" is actually made of dissolved minerals from surface runoff. That is, excess water from rain and melting snow flowing over land and into the sea. This is why the ocean doesn't have the same level of salinity everywhere. Salinity varies by location and season. Finally, you may have heard that melting sea ice will cause sea levels to rise. In reality, sea ice is just frozen seawater, and because it routinely freezes and melts, its volume is already accounted for in the ocean. Sea levels can rise, however, from ice that melts off land and into the ocean. Understanding basic facts about the ocean is important since it affects everything from our atmosphere to our ecosystems. By knowing your ocean, you are better prepared to help protect it.

"Science 25 November 2011: Vol. 334 no. 6059 p. 1040 DOI: 10.1126/science.334.6059.1040 * News & Analysis Climate Change Humans Are Driving Extreme Weather; Time to Prepare 1. Richard A. Kerr Figure View larger version: * In this page * In a new window Thai floods 2011 Hurricane Katrina 2005 Texas drought 2011 "CREDITS (LEFT TO RIGHT): PAULA BRONSTEIN/GETTY IMAGES; JEFF SCHMALTZ, MODIS RAPID RESPONSE TEAM, NASA/GSFC; NOAA" An international scientific assessment finds for the first time that human activity has indeed driven not just global warming but also increases in some extreme weather and climate events around the world in recent decades. And those and likely other weather extremes will worsen in coming decades as greenhouse gases mount, the report finds. But uncertainties are rife in the still-emerging field of extreme events. Scientists cannot attribute a particular drought or flood to global warming, and they can say little about past or future trends in the risk of high-profile hazards such as tropical cyclones. Damage from weather disasters has been climbing, but the report can attribute that trend only to the increasing exposure of life and property to weather risks. Climate change may be involved, but a case cannot yet be made. Despite the uncertainties, the special report from the Intergovernmental Panel on Climate Change (IPCC) released 18 November stresses that there is still reason for taking action now. The panel recommends "low-regrets measures," such as improvements in everything from drainage systems to early warning systems. Such measures would benefit society in dealing with the current climate as well as with almost any range of possible future climates. The report takes a cautious, consensus-based approach that draws on the published literature. Headlines and even some scientists may point to the current Texas drought or the 2003 European heat wave as the result of the strengthening greenhouse. But the report fin

Warming to Cause Catastrophic Rise in Sea Level? Stefan Lovgren for National Geographic News Updated April 26, 2004

"and a controversial bill prescribing how North Carolina can forecast future sea level rise for planning became law. "

Resources: Glaciers and Global Sea Level Rise - November 2005

"Rising Waters Scientists worry as huge glaciers melt into the sea."