Posted on March 21, 2015 by Bob Berwyn
New data will help shape conservation efforts in the waters around Antarctica
Australian and New Zealand researchers have tracked blue whales across thousands of miles in the Southern Ocean to help inform conservation efforts. Photo courtesy NOAA.
FRISCO — As a keystone species in marine ecosystems, blue whales have a significant impact in the ocean around Antarctica, but the population dynamics of the species in the region are still a mystery as the marine mammals recover from the decimation of the whaling era.
That may change following the recent six-week Australia-New Zealand Antarctic Ecosystem Voyage voyage, as researchers tracked the world’s largest creatures across thousands of miles of ocean, detecting their songs from as far as 750 kilometers away. Continue reading
Filed under: Antarctica, biodiversity, Environment, Marine biology, ocean conservation | Tagged: Antarctica, biodiversity, blue whales, marine mammals, Ross Sea, Southern Ocean | Leave a comment »
Posted on March 17, 2015 by Bob Berwyn
New ice core analysis shows less of an ‘offset’ than most models currently project
Increasing snowfall in Antarctica will moderate the rate of global sea level rise — but not as much as previously thought. bberwyn photo.
FRISCO — Detailed ice core records from Antarctica show that snowfall over the frozen continent increased about 5 percent for each degree (Celsius) of warming as Earth emerged from the last ice age.
The findings confirm that the increased snowfall will slightly offset sea level rise, as suggested by other research — but not as much as previously thought. That means that some computer models may be underestimating the amount and rate of future sea level rise if they’re based on inaccurate assumptions. Continue reading
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: Antarctica, climate change, global warming, sea level rise, snowfall | Leave a comment »
Posted on March 11, 2015 by Bob Berwyn
Southern Ocean winds and currents are key regulators of global temperature and carbon cycles.
Strengthening eddies drive heat deep into the sea
FRISCO — Shifting wind patterns across the Southern Ocean around Antarctica are having a big effect on the carbon cycle and on the heat transfer between the ocean and the atmosphere.
The changes are so profound that they are actually delaying the effects of global warming, according to a new study published in the Journal of Physical Research.
“Considering the Southern Ocean absorbs something like 60 percent of heat and anthropogenic CO2 that enters the ocean, this wind has a noticeable effect on global warming,” said lead author Dr Andy Hogg from the Australian National University Hub of the ARC Centre of Excellence for Climate System Science. Continue reading
Filed under: Antarctica, climate and weather, climate change, Environment, global warming | Tagged: circumpolar antarctic current, climate, global warming, southern annular mode, Southern Ocean | 1 Comment »
Posted on March 11, 2015 by Bob Berwyn
Will the West Antarctic Ice Sheet slip-slide away as the Southern Ocean warms up? bberwyn photo
A delicate balance
FRISCO — West Antarctica ice sheets are delicately anchored in place along a narrow sliver called the grounding zone, and new research shows that even slight increases in regional ocean and air temperatures are likely to destabilize the ice. The grounding zone is a sloping rock bed that lies below sea level.
In the new study, published this month in the Journal of Glaciology, Caltech scientists said future estimates of sea level rise need to take into account that the ice sheets are more sensitive to temperature perturbations driven by climate change than previously thought.
“Our results show that the stability of the whole ice sheet and our ability to predict its future melting is extremely sensitive to what happens in a very small region right at the grounding line. It is crucial to accurately represent the physics here in numerical models,” said study coauthor Andrew Thompson, an assistant professor of environmental science and engineering at Caltech. Continue reading
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: climate change, glaciology, global warming, sea level rise, West Antarctic Ice Sheet | Leave a comment »
Posted on March 3, 2015 by Bob Berwyn
Emperor penguin colony near Halley Bay. IMAGE COURTESY DIGITALGLOBE.
Genetic study tracks history of Antarctica’s emperor penguin populations
FRISCO — A genetic study shows that emperor penguins may have just barely survived the last ice age, with a few scattered populations enduring centuries of bitter cold and ice.
The study covers about 30,000 years and suggests that only three populations survived, including a climate refuge of sorts in the Ross Sea, where emperors may have been able to breed around a relatively small area of open water. The emperor penguins in that region evolved to become genetically distinct from other populations, which may support arguments for creating a Ross Sea marine protected area. Continue reading
Filed under: Antarctica, biodiversity, climate and weather, global warming | Tagged: Antarctica, climate change, emperor penguins, ice age, Ross Sea | Leave a comment »
Posted on February 11, 2015 by Bob Berwyn
Antarctic sea ice has expanded in the past few years, but overall, the planet is still losing an area of ice the size of Vermont and New Hampshire combined each year. bberwyn photo.
Growth in Antarctic ice extent doesn’t cancel out Arctic decline
FRISCO — NASA researchers who took a close look at both Arctic and Antarctic sea ice say that, overall, Earth has been losing ice at an average rate of about 13,500 square miles per year since 1979, equivalent to an area about the size of Maryland. Continue reading
Filed under: Antarctica, Arctic, climate and weather, Environment, global warming | Tagged: antarctic sea ice, climate change, global sea ice extent, global warming, NASA | Leave a comment »
Posted on February 5, 2015 by Bob Berwyn
New research shows that even the frigid fringes of East Antarctica are melting away under warming seas.
Warming ocean melts ice from below
FRISCO — It’s not just the West Antarctic ice sheets that are melting away as the surrounding ocean warms, Australian scientists reported after a six week voyage to the eastern side of the frozen continent.
A series of detailed measurements show that warm ocean water is melting the Totten Glacier — the largest in the region, with enough ice to raise sea level by several meters, according to the findings by the Australian Antarctic Division and partnering research organizations. Continue reading
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: Antarctica, climate change, East Antarctica, sea level, Totten Glacier | 1 Comment »