ScienceDaily (May 16, 2008) — A large quantity of nitrogen compounds -- emitted into the atmosphere by humans through the burning of fossil fuels and the use of nitrogen fertilizers -- enters the oceans and may lead to the removal of some carbon dioxide from the atmosphere, concluded a team of international scientists led by Texas A&M University Distinguished Professor of Oceanography and Atmospheric Sciences Robert Duce.
The team of 30 experts from institutions around the world presented its conclusions in the current issue of the journal Science.
Human-caused atmospheric nitrogen compounds are carried by wind and deposited into the ocean, where they act as a fertilizer and lead to increased production of marine plant life. The increase in plant life causes more carbon dioxide to be drawn from the atmosphere into the ocean. This process results in the removal of about 10 percent of the human-caused carbon dioxide in the atmosphere, thus potentially reducing the climate warming potential, according to the team's paper.
However, some of the nitrogen deposited in the ocean is re-processed to form another nitrogen compound called nitrous oxide, which is then released back into the atmosphere from the ocean. Nitrous oxide is a powerful greenhouse gas itself -- about 300 times more powerful per molecule than carbon dioxide -- thus cancelling out about two-thirds of the apparent gain from the carbon dioxide removal, Duce explained. "But of course, the whole system is so complex that we're still rather unsure about what some of the other impacts might be within the ocean," he said.
In most areas of the ocean, nitrogen is the nutrient that limits the production of plant life, Duce said. So when all of the nitrogen in an area of the surface ocean is used up, no more plant life forms in that area. The team found that human-caused nitrogen deposits account for up to one-third of the external input of nitrogen into the ocean, and this increase in nitrogen available for the production of plant life causes more plants to form, Duce explained.
Oceanic plant life is produced from marine carbon (bicarbonate) in the ocean, and that amount of bicarbonate is in equilibrium with the carbon dioxide in the atmosphere. So when more bicarbonate is used up to produce marine plant life, it disrupts the equilibrium, and carbon dioxide is drawn down to the ocean from the atmosphere to restore the balance, Duce explained.
Thus, the human-caused nitrogen fertilization of the ocean removes some of the most important greenhouse gas -- carbon dioxide -- from the atmosphere, Duce said. This gain, however, is offset by the nitrogen compound, nitrous oxide, that also forms in the ocean due to the nitrogen fertilization and is re-emitted into the atmosphere as a powerful greenhouse gas, he added.
"If you don't consider the impact of human-caused nitrogen when trying to model climate change, you're missing a possibly significant part of the overall carbon cycle as well as the nitrogen cycle," Duce said. "So nitrogen deposition is potentially a very important factor in the climate change issue."
According to the team's calculations, about 54 million tons of nitrogen produced from human activities entered the ocean from the atmosphere in the year 2000. The team also found that the current nitrogen emissions are about 10 times what they were in 1860, Duce said. He added that the amount of nitrogen entering the atmosphere is expected to rise in the coming decades with the increase in demand for energy and fertilizers, and the team estimates that by the year 2030, human-caused nitrogen emissions will have risen to around 62 million tons per year.
"Clearly, there is much that we do not know about the extent and timescale of the impacts of this nitrogen deposition on the oceans and the subsequent feedbacks to the climate system," Duce said. "The implications are complex and interactive, and this is a very important issue that policy makers need to address and that scientists trying to model and understand the future of climate and climate change need to take into consideration."WEATHER NOTE
Storm Chasers to Avoid Chasing Storms in Crane County
by Michael Stafford
A recent arrest in Crane County is keeping some storm chasers out of that part of West Texas.
You may recall last week, we showed you that Deputy arresting a professional storm chaser who was helping the Weather Service, and had refused to leave the area.
Now, the head of one storm chasing group says many professionals and volunteers plan to avoid Crane County in the future.
Those volunteers and professionals associated with the National Association of Storm Chasers and Spotters or NASCAS is the group we've been speaking with.
The acting Director, Warren Faidley, says in 20 years he's never had any problems with law enforcement.
In fact, he says troopers and officers have welcomed their help during times of severe weather, because they're helping protect the public.
Faidley tells NewsWest Nine they're going to avoid Crane County in the future, because they believe another arrest is immenent if they go there.
"Well, I think the main reason we're upset is because there were numerous witnesses and also video. So there was very little question of what actually occurred. I think with that kind of information you can draw a pretty fair conclusion. So, a lot of people I've spoken to from storm spotters to storm chasers and just everybody in between from researchers to news people from out of the area are pretty much going to try to avoid the area," Faidley said.
The Sheriff's Office has maintained the Deputy was in the right, and that the storm chaser was obstructing the highway, which is a Class B Misdemeanor.
Crane County does have its own volunteers from that area, but as Faidley says it's always good to have a professional organization assisting with the process when lives are in danger.
Only time will tell what affect this may have on Crane County when severe weather hits there in the future.
1. 695…Tri-State Tornado…March 18, 1925
2. 317…Natchez, Mississippi…May 7, 1849
3. 255…St. Louis, MO…May 27, 1896
4. 203…Gainesville, GA…April 6, 1936
5. 216…Tupelo, Mississippi…April 5, 1936
6. 181…Woodward, Oklahoma…April 9, 1947
7. 143…Amite, Louisiana to Purvis, Mississippi…April 24, 1908
8. 117…New Richmond, Wisconsin…June 12, 1899
9. 115…Flint, Michigan…June 8, 1953
10. 114…Waco, Texas…May 11, 1953
Source: Christopher Burt’s book Extreme Weather…
Yachtsman's £40k boat sinks under the waves
A MAJOR salvage operation was underway last night to lift a £40,000 yacht which sank in the Menai Strait as its owner celebrated his 60th birthday.
Trevor Shirley was spending the weekend with his wife at Anglesey’s Gazelle hotel as a treat, when his precious boat slipped beneath the waves.
The couple had launched the yacht from Beaumaris on Friday, and sailed her in the Puffin Island area before mooring her opposite the hotel, where she could be seen in her full glory.
But when they came down from breakfast on Sunday the boat – called the Hindsight – had disappeared from view.
Mr Shirley, from Warrington, had spent the winter refitting the yacht to a gleaming condition.
Hotel owner Mary Brain was serving breakfast on Sunday morning when the couple realised something was wrong.
"They came down for breakfast and said let’s go and have look at the boat, but it wasn’t there," said Mary.
"It was launched on Friday and it must have gone down on Saturday night or Sunday morning," she said.
The couple were devastated when they realised that the mast sticking out of the water was the vessel that was their pride and joy.
A salvage team from Beaumaris Marine Services was called and divers checked the stricken vessel on Monday morning and sealed the fuel tanks.
Diver Scott Waterman from Quest Diving, Menai Bridge, inspected the hull on his first dive.
"The water was very clear on Monday and the sea was flat calm," said Scott, who has been involved in three other similar rescues.
"It was obvious the vessel hadn’t been involved in a collision as the hull was completely intact.
"She was still on the mooring but that hadn’t fouled so the reason for the sinking is still unknown," he said.
On Wednesday Scott and his team fixed lifting strops to the boat’s hull and attached 12 tonne flotation bags.
"We took gas down there and inflated the bags until she started to lift and that pulled her off the bottom," said Scott.
"Timing was quite important because it has to be done at slack water otherwise the boat’s volume causes too much drag," he said.
Yesterday onlookers praised the salvage team for their efforts as the boat partially resurfaced back into view.
"The boat came up in the upright position which is also very important for bringing it back to shore," said Scott.
As the high tide ebbed the salvage team were able to pump the water out of her hull and were hoping to refloat her on the next high tide today (Thursday).
Mr Shirley, who had spent months refurbishing his boat was to upset too talk about the incident but the salvage team believe the boat can be repaired.RS