Oceanography

Predicting climate change depends on many factors not properly included in current forecasting models, such as how the major polar ice caps will move in the event of melting around their edges. This in turn requires greater understanding of the processes at work when ice is under stress, influencing how it flows and moves.

The immediate objective is to model the flow of ice sheets and glaciers more accurately, leading in turn to better future predictions of global ice cover for use in climate modeling and forecasting.

The 2007 Intergovernmental Panel on Climate Change report was wrong, say a group of researchers, but not about whether there was global warming. Rather, the report underestimated its effects concerning ocean temperature and associated sea level increases between 1961 and 2003 - by 50 percent.

The report in the June 19 edition of Nature compared climate models with observations that show sea levels rose by 1.5 millimeters per year in the period from 1961-2003. That equates to an approximately 2 inch increase in ocean levels in a 42-year span.

Not exactly WaterWorld but not insignificant either.

Activities such as aquaculture, shipping and recreational boating have led to an army of marine alien species hitchhiking around the globe.

And only you can stop them.

Queen's University Belfast is attempting to find out exactly where and how non-native species get a foothold in a new area. To do this it is asking for help from the public to record what they have seen.

Part of the Marine Aliens consortium, co-ordinated by the Scottish Association for Marine Science, the project will use the information gathered to look at how invasions can be slowed or preferably prevented. It is very difficult to eradicate an organism once it has become established in a new area.

The snowball Earth hypothesis posits that the Earth was covered from pole to pole in a thick sheet of ice for millions of years at a time. 635 million years ago, an abrupt release of methane from ice sheets that extended to Earth's low latitudes spiked global warming and ended the last "snowball" ice age, say researchers. The researchers believe that the methane was released gradually at first and then very quickly from clathrates - methane ice that forms and stabilizes beneath ice sheets.

Also called marsh gas, methane is a colorless, odorless gas. As a greenhouse gas, it is about 30 times more potent than carbon dioxide. When the ice sheets became unstable, they collapsed, releasing pressure on the clathrates. The clathrates then began to de-gas.

This transition "from 'snowball Earth' into a warmer period shows the compelling need for research on abrupt climate change in Earth's history," said H. Richard Lane, program director in NSF's Division of Earth Sciences.

An international team of scientists surveying the waters of the continental shelf off the West Coast of North America has discovered for the first time high levels of acidified ocean water within 20 miles of the shoreline, raising concern for marine ecosystems from Canada to Mexico.

Researchers aboard the Wecoma, an Oregon State University research vessel, also discovered that this corrosive, acidified water that is being “upwelled” seasonally from the deeper ocean is probably 50 years old, suggesting that future ocean acidification levels will increase since atmospheric levels of carbon dioxide have increased rapidly over the past half century.

“When the upwelled water was last at the surface, it was exposed to an atmosphere with much lower CO2 (carbon dioxide) levels than today’s,” pointed out Burke Hales, an associate professor in the College of Oceanic and Atmospheric Sciences at Oregon State University and an author on the Science study. “The water that will upwell off the coast in future years already is making its undersea trek toward us, with ever-increasing levels of carbon dioxide and acidity.

Since the 1980’s Dr. Joseph M. Prospero, professor of Marine and Atmospheric Chemistry at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, has pioneered studies in the worldwide measurement of aerosols, fine particles suspended in the atmosphere and carried by winds.

His team’s work focuses on the aerosol chemistry of the marine atmosphere. They are particularly interested in the long-range transport of pollutants from the continents to the oceans and their impact on climate and on biogeochemical processes in ocean waters.

Starting in 1980 Prospero established a network of island stations in the North and South Pacific Oceans. These stations made continuous measurements of the concentration of major aerosol species that play a role in climate: mineral dust, nitrate, sulfate, and sea salt. The network was eventually extended to the Indian Ocean and Antarctica. Throughout the 80’s and into the late 90’s the UM team maintained a total of 30 stations in constant operation in all ocean regions. The data obtained are unique and they have played a critical role in the development and testing of the global chemical transport models used in the recent climate assessment carried out by Intergovernmental Panel on Climate Change.

Census of Marine Life-affiliated scientists, plumbing the secrets of a vast underwater mountain range south of New Zealand, captured the first images of a novel “Brittlestar City” established against daunting odds on the peak of a seamount – an underwater summit taller than the world’s tallest building.

Its cramped starfish-like inhabitants, tens of millions living arm tip to arm tip, owe their success to the seamount’s shape and to the swirling circumpolar current flowing over and around it at roughly four kilometers per hour. It allows Brittlestar City’s underwater denizens to capture passing food simply by raising their arms, and it sweeps away fish and other hovering would-be predators.

Discovery of this marine metropolis, announced today along with important new insights into seamount geology and physics, highlighted a month-long April expedition to survey the Macquarie Ridge aboard the Research Vessel Tangaroa of New Zealand’s National Institute of Water & Atmospheric Research, host of the Census of Marine Life seamount programme, CenSeam. The voyage was largely funded by the New Zealand Foundation for Research, Science and Technology.

Marine scientists led by Dr. Lothar Stramma from the Leibniz Institute of Marine Sciences (IFM-GEOMAR) in Kiel, Germany say they have made an alarming new discovery - in some regions of the world oceans, oxygen essential for marine organisms is declining.

The new study documents that the oxygen values in tropical oceans at a depth of 300 to 700 meters have declined during the past 50 years. As large marine organisms can either no longer exist in these areas or they would avoid them, the expanding oxygen minimum zones may have substantial biological and economical consequences.

The oxygen distribution in the ocean is not homogenous. At the eastern boundaries of the tropical oceans at depths between 200 and 800 metres, there are areas with reduced oxygen, the so-called oxygen minimum zones (OMZ). Rising CO2 levels are causing a temperature increase of the ocean and a general decline of oxygen solubility in the water.

Scientists at the Georgia Institute of Technology have discovered a new climate pattern called the North Pacific Gyre Oscillation.

This new pattern explains changes in the water that are important in helping commercial fishermen understand fluctuations in the fish stock. They also believe that as the temperature of the Earth warms, large fluctuations in these factors could help climatologists predict how the oceans will respond in a warmer world.

“We’ve been able to explain, for the first time, the changes in salinity, nutrients and chlorophyll that we see in the Northeast Pacific,” said Emanuele Di Lorenzo, assistant professor in Georgia Tech’s School of Earth and Atmospheric Sciences.

While the recent Arctic summer was the warmest on record satellite images from the Antarctic summer have shown the largest sea-ice extent ever recorded, according to the Polarstern expedition. ANT-XXIV/3 was dedicated to examining the oceanic circulation and the oceanic cycles of materials that depend on it. Warming is a lot less global when you get south of Chile, it seems.

In the coming years autonomous measuring buoys will be used to find out whether the cold Antarctic summer induces a new trend or was only a 'slip.'

Under the direction of Dr. Eberhard Fahrbach, Oceanographer at the Alfred Wegener Institute, 58 scientists from ten countries were on board the research vessel Polarstern in the Southern Ocean from 6 February until 16 April, 2008. They studied ocean currents as well as the distribution of temperature, salt content and trace substances in Antarctic sea water.