Wednesday, May 30, 2007

Climate Change Signal Detected In The Indian Ocean

The signature of climate change over the past 40 years has been identified in temperatures of the Indian Ocean near Australia. “From ocean measurements and by analysing climate simulations we can see there are changes in features of the ocean that cannot be explained by natural variability,” said CSIRO oceanographer Dr Gael Alory.

“These oceanic changes are almost certainly linked to changes in the heat structure of the atmosphere and have led to a rise in water temperatures in the sub-tropical Indian Ocean of around two degrees Celsius.

“At the same time, we are seeing changes in ocean circulation in tropical regions as a result of a long-term weakening of the Pacific Ocean trade winds. This affects sea surface temperature in regions relevant to the source and distribution of rainfall across southern Australia,” Dr Alory said.

The research – by Dr Alory, his CSIRO Wealth from Oceans National Research Flagship colleague, Dr Gary Meyers, and CSIRO Marine and Atmospheric’s Dr Susan Wijffels – has recently appeared in the journal, Geophysical Research Letters. The paper examines trends in Indian Ocean temperatures over 40 years that can help scientists and resource managers understand fluctuations in rainfall patterns over southern Australia.

The research, contributing to the Australian Climate Change Science Program and partly funded by the South East Australia Climate Initiative, combined access to ocean observations using the volunteer ‘ships of opportunity’ program and a set of models used by scientists in developing the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment. Thanks to the operators and crew of commercial ships, Australian scientists have access to a regular series of ocean measurements to a depth of 800 metres across the Indian Ocean.

The team’s key findings were:

  • a general warming of the ocean surface indicating the influence of rising atmospheric temperatures;
  • a strong warming (about 2°C over 40 years) between 40°S and 50°S down to a depth of 800 metres;
  • and, sub-surface cooling in the tropics due to deep waters rising closer to the surface.

Dr Alory says the research confirmed a long-held view that temperature changes in the Pacific and Indian oceans can be partly explained by the effect of the ‘Indonesian throughflow’ – a system of currents which transports water between the oceans through the maze of straits and passages in the Indonesian Archipelago.

“The cooling is occurring between Australia and Indonesia where the Indonesian throughflow emerges into the Indian Ocean and is linked to the observed weakening of Pacific Ocean trade-winds,” he says. The models also helped to explain trends in the subtropical Indian Ocean temperatures and changes in relevant ocean features. In this area, the deep-reaching warming is due to a strengthening of westerly winds drawing a southward shift in ocean current patterns. These findings are consistent with research in the South Atlantic and South Pacific ocean basins.

He said that the change in atmospheric conditions altering ocean temperatures – weakening of Pacific Ocean trade winds and strengthening of westerly winds – have been mostly attributed to human activity: the production of aerosols (tiny atmospheric particles), ozone depletion, and greenhouse gases. Strengthening westerlies are related to changes in the Southern Annular Mode – an atmospheric feature similar to the El Nino Southern Oscillation and considered the dominant influence on Southern Hemisphere atmospheric variability.

Dr Alory said climate models used in the IPCC Fourth Assessment show that changes in westerly wind patterns are expected to intensify in a global warming scenario and to accentuate the southward shift in sub-tropical ocean circulation patterns.

Sunday, April 29, 2007

my first post

Hello world

Across the waves

Row Hard No Excuses, a documentary about two Americans who cross the Atlantic in the final months of 2001, begins with a juxtaposition of images and sounds. First, calm blue water, the sound of oars pushing it, and a pink sunset over the ocean. Then the two men, bloodied, bearded and weary from days of endless rowing. Water surrounds them, and the only way to get home is to keep rowing. Their faces show shock and determination; they are reaching for something deeper, something impossible, because they have no other choice.

When the rest of the country was reeling from the Sept. 11 terrorist attacks, Concord native Tom Mailhot and his rowing partner, John Zeigler, were embarking on a 3,000-mile race from the Canary Islands off the coast of Africa to Barbados in the Caribbean.

A film chronicling their voyage is playing at independent film festivals across the country. It was screened this weekend in Boston. The film draws on the video dairies of the 36 teams who made the voyage, as well as onshore footage.

The race took 58 days, and the men arrived gaunt and dehydrated, with sores covering much of their bodies. Mailhot, now 47, had to physically straighten out his fingers for six months after the trip because they were curled from holding the oars. He had to take a year off from paddling to heal a torn rotator cuff.

Still, Mailhot says he's been asked to do the race again. He's considering it.

"It was one of the greatest experiences of my life out there," he said. "I certainly don't want to die, but when you come close, it really makes you appreciate life."

Zeigler, now 57, said his fiancée would "drop him like a stone" if he ever made the trip again. The 2001 race was the last straw in his marriage, and Zeigler said he wouldn't want to risk his new relationship.

Still, when the sores healed, the memory of crossing an ocean on nothing but sheer guts makes Zeigler nostalgic.

"It's flattering to have some people think you did something phenomenal," he said. "I guess it was a considerable effort."

Mailhot's friend's son, Luke Wolbach, pieced together footage to create Row Hard No Excuses. It took a few years to produce because Wolbach had two children in the interim, Mailhot said.

Zeigler, who builds boats and works in a food-distributing business, still races. He and Mailhot, who works as a contractor and a kayaking guide, plan to compete in some races together this year.

Tori Murden, the first woman to row solo across the Atlantic, helped Mailhot and Zeigler prepare for the cross-Atlantic race. In the film, she considers what motivates anyone to take on the difficult feat.

"There are people who get it, who understand why somebody would want to row across an ocean," Murden says in the film. "There are other folks who would never.

"Is it King Arthur in search of the grail? Or is it Ahab in search of a white whale? They're not very far apart. And it's easy to think you're off on some virtuous tangent when really, you're just off on a tangent."

Hungry for a challenge

Mailhot attended Concord High School and Kimball Union Academy, later moving to Ipswich, Mass., where he took up kayaking. His parents still live in Concord. He'd played hockey most of his life and spent some time in the minor leagues until an eye injury ended his career.

Mailhot found the motion of paddling similar to swinging a hockey stick. In his first year of kayaking, he was already winning races. Before long, he'd left his job at the Boston Architectural Center to race and kayak around the world. In 1993, he paddled across the Bay of Fundy, a 14-hour trip between Nova Scotia and New Brunswick. The stretch of sea has the largest difference in high and low tides in the world. Mailhot had to time his trip perfectly to avoid getting caught in the tides, but the weather nearly spoiled his plans.

"The winds were changing and the seas were getting big," he said. "We worried about getting swept out into the Gulf of Maine."

Mailhot also paddled across the Bering Straight and Cape Horn. He raced in swan boats - war canoes with 20 paddles - in Asia for the U.S team with Zeigler.

"If he had been born 100 years ago, Tom would've been one of those adventurers exploring new lands," Mailhot's former girlfriend, Sarah Evertson, says in the film. "But there aren't a whole lot of options for men these days to go on quests like that."

Zeigler, who works in Moonachie, N.J., had dreamed of rowing across the Atlantic since he was a teenager. Sir Chay Blyth, an English paratrooper, rowed with another man across the Atlantic in 1966. It took them 92 days. In 1997, Blyth created a race across the Atlantic, the Ward Evans Atlantic Challenge. Zeigler asked Mailhot if he wanted to try it.

It took at least 600 hours to build their boat, the American Star, and the materials and equipment for the race cost $150,000. The race entry fee alone was $19,000. There was no cash prize; the only reward for the first-place finisher would be a trophy.

Mailhot and Zeigler didn't have official sponsors like some of the other teams. They relied on their own savings and donations from friends and family.

Open water, open sores

When the men left the Canary Islands on Oct. 7, 2001, Mailhot remembers the depressing feeling of leaving his family onshore and heading into the vast ocean. To quit would be devastating, but death was also a distinct possibility. Two support yachts followed the fleet, but they could be days away from a distressed crew. If a team quit and called for rescue, they had to burn their boat to keep the shipping lanes clear.

Within two days, the men were chafing from the friction between their clothes and skin and the rowing seats. Mailhot started rowing naked to avoid blistering sores, but Zeigler's sores progressed quickly and after five days, he had a hole the size of a silver dollar on his rear end.

"I don't know if I could have endured what he did," Mailhot said.

Zeigler said, "Sore muscles, I can deal with. . . . Trying to deal with absolutely outrageous pain, it was a little bit too much for me."

The men learned within the first few days that they had fallen to the back of the pack. They'd been caught in an eddy that knocked them from 6th place to 21st. They'd hoped to finish in the top five.

"That was devastating," Mailhot said.

The men rowed together 12 to 14 hours during the day, then took turns throughout the night, sleeping two to three hours at a time. But sleeping was difficult and Zeigler's pain made it hard for him to row alone, so the men often rowed together.

Nothing came easily on the water. The heat and salt water wore on their bodies and they couldn't eat some of the 900 pounds of food they brought on board. They tossed some overboard.

"Macadamia nuts - you chew them and they turn into sawdust," Mailhot said. "You can't swallow them."

Sharks tapped the boat and sometimes followed them. Every five days, Mailhot dropped into the water for an hour to scrape barnacles off the bottom of the boat. A few times, he got back in just before a shark approached. Some crews were so afraid of the sharks they stopped scraping their boats.

"The bottom of their boats looked like beards," Mailhot said. Barnacles slow the boats, so Mailhot braved the sharks to make up more time.

When the waves grew large, it was easy for other boats to miss the American Star, a 23-by-6-foot plywood rowboat. On the 27th day of the trip, they were nearly hit by a bulk freight carrier. Mailhot yelled over a radio to the ship, and its crew finally responded when it was only half a mile away. Ships that large usually take three miles to stop, Mailhot said.

The first mate of the ship called to the American Star on the radio.

"There are many men on board who want to know why you do this," he said.

A daily prayer

Row Hard No Excuses focuses on the physical and mental difficulties of the race, but it also captures beautiful and humorous moments. After so many days under the hot sun, people can get a little loony. A crew member on another team starts talking into a teapot like it's a telephone. Mailhot and Zeigler speculate on whether they can return to the civilized world after passing gas so openly out on the water. (Soy milk, they say, was the culprit.)

Entering the water to scrape the boat relieved Mailhot's exhausted body. He'd find sunfish and sea turtles hiding in the shade of the boat. It was thrilling to see nature at its wildest, he said.

About halfway through the race, the boats hit the doldrums. Hurricane Olga, which was moving over the Caribbean, had disrupted the trade winds coming off of Africa. There were no waves to help the boats along and no wind to cool the heat. Zeigler and Mailhot suffered heat exhaustion, and the wounds covering Zeigler's underside were becoming infected. He worried he might never recover, and he considered quitting.

"It's like getting battery acid on your crotch," he said. "If we needed help, we were days away from it.

"Every day I said my little prayer," he said. "I started talking along the lines of, 'Help me bear this pain.' . . . From that point on I seemed to get stronger."

Hurricane Olga came back out over the ocean, and the men had to steer south to stay on the outskirts of the storm. Lightning shot out from every direction of some clouds, and the electricity in the air created St. Elmo's Fire, which lit up the boat, Mailhot said.

They skirted Olga, and headed to Barbados. About a mile offshore, they stopped and shook hands. Then they rowed in, their families and other bystanders cheering. They finished in 11th place after 58 days.

"It was one of the greatest feelings," Mailhot said. "I've only experienced that feeling a few other times in my life, that sense of accomplishment."

Tuesday, April 17, 2007

Arctic Ocean water study to begin

U.S. scientists are preparing a North Pole study, readying instruments that will make year-round observations of the water beneath the Arctic ice cap.

The Woods Hole Oceanographic Institution researchers will investigate changes in the waters of the upper layers of the Arctic Ocean that insulate surface ice from warmer, deeper waters.

The expedition is part of a multiyear, multi-institutional program to establish a real-time, autonomous Arctic Observing Network.

Two autonomous ice-based observatories will be anchored to the ice and will drift with the natural movement of the ice while observing water properties in the top 2,625 feet of the Arctic Ocean. The buoys are designed to last three years -- about the same lifespan as the ice floes that support them.

John Toole, principal investigator for the project and a senior scientist in the institution's Physical Oceanography Department, said: "Many climate models suggest the Arctic ice cover will melt within 50 years. We want to measure the changes in the water -- particularly the layered structure of the ocean -- in order to understand what mechanisms might lead the ice cap to melt from below."

Friday, March 30, 2007

Ocean Nourishment scheme

Researchers from Sydney University have discovered a way to remove carbon dioxide from the atmosphere and deposit it into the ocean.

The 'Ocean Nourishment Scheme' process mimics nature by introducing reactive nitrogen into the open ocean. Utilising natural sunlight, ocean nourishment economically changes CO2 into organic vegetable matter known as phytoplankton.

Fish and other marine life feed on this matter ensuring plentiful and healthy fish populations.

Over the past decade researchers at the University of Sydney have been investigating the environmental risks of Ocean Nourishment and its benefits in restoring the health of the ocean. The process provides the open ocean with the nutrients that are missing.

Each Ocean Nourishment scheme would create 10 million carbon credits per year, as much as a million hectares of new forest can produce.

The research is in the running for the $25 million Earth Challenge prize offered by Richard Branson.