Nature Geoscience News

Scientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have overcome a seeming weakness of global climate models. They had previously not been able to simulate the extreme warm period of the Eocene. One aspect of this era that particularly draws interests to climatologists: It was the only phase in recent history when greenhouse gas concentration was as high as researchers predict it to be for the future. The AWI scientists have now found that the apparent model weakness is due to a misinterpretation of the temperature indicator TEX86. These molecules, which are produced by archaea do not record the surface temperature of the ancient ocean as expected, but rather the temperature of water depths up to 500 metres.

Icebergs the size of Singapore could be playing a bigger role in how much carbon the Southern Ocean absorbs than previously thought, a new study says. Icebergs that break off Antarctica could account for twice as much carbon dioxide stored in the Southern Ocean than previously believed, the study  suggested. The findings were published this week in Nature Geoscience. Pioneering research from the University of Sheffield’s Department of Geography discovered melting water from giant icebergs, which contains iron and other nutrients, supports hitherto unexpectedly high levels of phytoplankton growth. These plankton blooms - which can stretch for hundreds of miles - then absorb a substantial amount of carbon dioxide from the atmosphere and lock it into the ocean depths.

Global surface warming has slowed since the start of the twenty-first century, while Pacific heat uptake was enhanced. Analyses of ocean heat content suggest that the warm water was transferred to the Indian Ocean, through the Indonesian straits, reports "Natue". Scientists reported that the Indian Ocean heat content has risen sharply, accounting for more than 70% of the global ocean heat gain in the upper 700 metres of the Indian Ocean over the past decade. The scientists conclude the Indian Ocean has become increasingly important in altering global climate variability. A team led by University of Miami and National Oceanic and Atmospheric Administration (NOAA) researcher Sang-Ki Lee experimented with a global climate model.

Antarctica's ice paradox has yet another puzzling layer. Not only is the amount of sea ice increasing each year, but an underwater robot now shows the ice is also much thicker than was previously thought, a new study reports. The discovery adds to the ongoing mystery of Antarctica's expanding sea ice. According to climate models, the region's sea ice should be shrinking each year because of global warming. Instead, satellite observations show the ice is expanding, and the continent's sea ice has set new records for the past three winters. At the same time, Antarctica's ice sheet (the glacial ice on land) is melting and retreating. Measuring sea ice thickness is a crucial step in understanding what's driving the growth of sea ice…

The Atlantic Ocean has masked global warming this century by soaking up vast amounts of heat from the atmosphere in a shift likely to reverse from around 2030 and spur fast temperature rises, scientists said. The theory is the latest explanation for a slowdown in the pace of warming at the Earth's surface since about 1998 that has puzzled experts because it conflicts with rising greenhouse gas emissions, especially from emerging economies led by China. "We're pointing to the Atlantic as the driver of the hiatus," Ka-Kit Tung, of the University of Washington in Seattle and a co-author of Thursday's study in the journal Science, told Reuters.

A University of Houston (UH) professor led a team of scientists to uncover the largest single volcano yet documented on Earth. Covering an area roughly equivalent to the British Isles or the state of New Mexico, this volcano, dubbed the Tamu Massif, is nearly as big as the giant volcanoes of Mars, placing it among the largest in the Solar System. William Sager, a professor in the Department of Earth and Atmospheric Sciences at UH, first began studying the volcano about 20 years ago at Texas A&M’s College of Geosciences. Sager and his team’s findings appear in the Sept.

Woods Hole Oceanographic Institution (WHOI) scientists have found that carbon is stored in the soils and sediments of the Ganges-Brahmaputra basin for a surprisingly long time, making it likely that global warming could destabilize the pool of carbon there and in similar places on Earth, potentially increasing the rate of CO2 release into the atmosphere. The study, published in the current online edition of Nature Geoscience, examined the radiocarbon content of river sediments collected from the Ganges-Brahmaputra system draining the Himalayas. Using radiocarbon dating, WHOI researchers Valier Galy and Timothy Eglinton found that organic carbon resides in the basin for anywhere from 500 to 17,000 years.