Archive for Sea Ice

Cosmic Journeys : Earth in 1000 Years

Posted in 2014 with tags , , , , , , , , , , , on March 22, 2014 by MARIE EMMANUELLE QUILICHINI

This edition of COSMIC JOURNEYS explores the still unfolding story of Earth’s past and the light it sheds on the science of climate change today. While that story can tell us about the mechanisms that can shape our climate. it’s still the unique conditions of our time that will determine sea levels, ice coverage, and temperatures.

Ice, in its varied forms, covers as much as 16% of Earth’s surface, including 33% of land areas at the height of the northern winter. Glaciers, sea ice, permafrost, ice sheets and snow play an important role in Earth’s climate. They reflect energy back to space, shape ocean currents, and spawn weather patterns. 

But there are signs that Earth’s great stores of ice are beginning to melt. To find out where Earth might be headed, scientists are drilling down into the ice, and scouring ancient sea beds, for evidence of past climate change. What are they learning about the fate of our planet… a thousand years into the future and even beyond?

30,000 years ago, Earth began a relentless descent into winter. Glaciers pushed into what were temperate zones. Ice spread beyond polar seas. New layers of ice accumulated on the vast frozen plateau of Greenland. At three kilometers thick, Greenland’s ice sheet is a monumental formation built over successive ice ages and millions of years. It’s so heavy that it has pushed much of the island down below sea level. And yet, today, scientists have begun to wonder how resilient this ice sheet really is.

Average global temperatures have risen about one degree Celsius since the industrial revolution. They could go up another degree by the end of this century. If Greenland’s ice sheet were to melt, sea levels would rise by over seven meters. That would destroy or threaten the homes and livelihoods of up to a quarter of the world’s population.

With so much at stake, scientists are monitoring Earth’s frozen zones… with satellites, radar flights, and expeditions to drill deep into ice sheets. And they are reconstructing past climates, looking for clues to where Earth might now be headed… not just centuries, but thousands of years in the future.

Periods of melting and freezing, it turns out, are central events in our planet’s history.
That’s been born out by evidence ranging from geological traces of past sea levels… the distribution of fossils… chemical traces that correspond to ocean temperatures, and more. 

Going back over two billion years, earth has experienced five major glacial or ice ages. The first, called the Huronian, has been linked to the rise of photosynthesis in primitive organisms. They began to take in carbon dioxide, an important greenhouse gas. That decreased the amount of solar energy trapped by the atmosphere, sending Earth into a deep freeze. 

The second major ice age began 580 million years ago. It was so severe, it’s often referred to as “snowball earth.” The Andean-Saharan and the Karoo ice ages began 460 and 360 million years ago. Finally, there’s the Quaternary… from 2.6 million years ago to the present. Periods of cooling and warming have been spurred by a range of interlocking factors: the movement of continents, patterns of ocean circulation, volcanic events, the evolution of plants and animals.

The world as we know it was beginning to take shape in the period from 90 to 50 million years ago. The continents were moving toward their present positions. The Americas separated from Europe and Africa. India headed toward a merger with Asia. The world was getting warmer. Temperatures spiked roughly 55 million years ago, going up about 5 degrees Celsius in just a few thousand years. CO2 levels rose to about 1000 parts per million compared to 280 in pre-industrial times, and 390 today. 

But the stage was set for a major cool down. The configuration of landmasses had cut the Arctic off from the wider oceans. That allowed a layer of fresh water to settle over it, and a sea plant called Azolla to spread widely. In a year, it can soak up as much as 6 tons of CO2 per acre. Plowing into Asia, the Indian subcontinent caused the mighty Himalayan Mountains to rise up. In a process called weathering, rainfall interacting with exposed rock began to draw more CO2 from the atmosphere… washing it into the sea. Temperatures steadily dropped. 

By around 33 million years ago, South America had separated from Antarctica. Currents swirling around the continent isolated it from warm waters to the north. An ice sheet formed. In time, with temperatures and CO2 levels continuing to fall, the door was open for a more subtle climate driver. It was first described by the 19th century Serbian scientist, Milutin Milankovic. 

He saw that periodic variations in Earth’s rotational motion altered the amount of solar radiation striking the poles. In combination, every 100,000 years or so, these variations have sent earth into a period of cool temperatures and spreading ice.

 

Fukushima Radioactive Fallout in Alaska. Wildlife Health Implications

Posted in 2014 with tags , , , , , , , , , , on February 3, 2014 by MARIE EMMANUELLE QUILICHINI

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Scientists present links between unusual Alaska seal deaths and Fukushima fallout – Skin lesions, hair loss, lethargy – ‘Pulsed release’ when built-up radionuclides were set free as ice melted – “Wildlife health implications” due to radiation exposure discussed

radiation exposure (pdf),

Jan. 20-24, 2014 (emphasis added): 2011 Fukushima Fall Out: Aerial Deposition On To Sea Ice Scenario And Wildlife Health Implications To Ice-Associated Seals (Dr. Doug Dasher, John Kelley, Gay Sheffield, Raphaela Stimmelmayr) –

On March 11, 2011 off Japan’s west coast, an earthquake-generated tsunami struck the Fukushima Daiichi nuclear power plant resulting in a major nuclear accident that included a large release of airborne radionuclides into the environment. Within five days of the accident atmospheric air masses carrying Fukushima radiation were transiting into the northern Bering and Chukchi seas.

 During summer 2011 it became evident to coastal communities and wildlife management agencies that there was a novel disease outbreak occurring in several species of Arctic ice-associated seals.Gross symptoms associated with the disease included lethargy, no new hair growth, and skin lesions, with the majority of the outbreak reports occurring between the Nome and Barrow region. NOAA and USFWS declared an Alaska Northern Pinnipeds Usual Mortality Event (UME) in late winter of 2011.

The ongoing Alaska 2011 Northern Pinnipeds UME investigation continues to explore a mix of potential etiologies (infectious, endocrine, toxins, nutritious etc.), including radioactivity. Currently, the underlying etiology remains undetermined. We present results on gamma analysis (cesium 134 and 137) of muscle tissue from control and diseased seals, and discuss wildlife health implications from different possible routes of exposure to Fukushima fallout to ice seals.

 Since the Fukushima fallout period occurred during the annual sea ice cover period from Nome to Barrow, a sea ice based fallout scenario in addition to amarine food web based one is of particular relevance for the Fukushima accident. Under a proposed sea ice fallout deposition scenario, radionuclides would have been settled onto sea ice. Sea ice and snow would have acted as a temporary refuge for deposited radionuclides; thus radionuclides would have only become available for migration during the melting season and would not have entered the regional food web in any appreciable manner until breakup (pulsed release).

The cumulative on-ice exposure for ice seals would have occurred through external, inhalation, and non-equilibrium dietary pathways during the ice-based seasonal spring haulout period for molting/pupping/breeding activities. Additionally, ice seals would have been under dietary/metabolic constraints and experiencing hormonal changes associated with reproduction and molting.

http://www.globalresearch.ca/fukushima-radioactive-fallout-in-alaska-wildlife-health-implications/5366358

Wonders in the Antarctic Sea and Sky

Posted in 2013 with tags , , , , , , on December 11, 2013 by MARIE EMMANUELLE QUILICHINI

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http://earthobservatory.nasa.gov/IOTD/view.php?id=82499&src=eoa-iotd

Lenticular clouds are a type of wave cloud. They usually form when a layer of air near the surface encounters a topographic barrier, gets pushed upward, and flows over it as a series of atmospheric gravity waves. Lenticular clouds form at the crest of the waves, where the air is coolest and water vapor is most likely to condense intocloud droplets. The bulging sea ice in the foreground is a pressure ridge, which formed when separate ice floes collided and piled up on each other.

See more photography from the 2013 Antarctic IceBridge campaign here and here. Read a blog about the campaign on our Notes from the Field page

Cosmic Journeys : Earth in 1000 Years

Posted in 2013 with tags , , , , , , , , , , , , , , on November 22, 2013 by MARIE EMMANUELLE QUILICHINI

This edition of COSMIC JOURNEYS explores the still unfolding story of Earth’s past and the light it sheds on the science of climate change today. While that story can tell us about the mechanisms that can shape our climate. it’s still the unique conditions of our time that will determine sea levels, ice coverage, and temperatures.

Ice, in its varied forms, covers as much as 16% of Earth’s surface, including 33% of land areas at the height of the northern winter. Glaciers, sea ice, permafrost, ice sheets and snow play an important role in Earth’s climate. They reflect energy back to space, shape ocean currents, and spawn weather patterns.

But there are signs that Earth’s great stores of ice are beginning to melt. To find out where Earth might be headed, scientists are drilling down into the ice, and scouring ancient sea beds, for evidence of past climate change. What are they learning about the fate of our planet… a thousand years into the future and even beyond?

Polar Bear Cams Live-Stream Historic Migration Of Threatened Population

Posted in 2013 with tags , , , , , , , , , , , , , , , on November 6, 2013 by MARIE EMMANUELLE QUILICHINI

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http://www.huffingtonpost.com/2013/11/05/polar-bear-cam-hudson-bay-churchill-canada_n_4220319.html?utm_hp_ref=climate-change

What’s better than a panda cam? In terms of cuteness, not much. But if you’re looking to swap “cute” for “carnivore,” these polar bear cams, currently live-streaming from near Churchill, Canada, will knock your socks off.

From Nov. 5-20, the cameras will document the migration of around 1,000 polar bears. They’re headed to the southwest corner of the Hudson Bay to await the formation of sea ice, which the bears will travel across in search of seals.

As the southernmost group of polar bears on the planet, the Hudson Bay population is particularly susceptible to inconsistent sea ice formation, which has become even more erratic as the Arctic warms. Per The Guardian, growing numbers of ice-free days have kept polar bears off the sea ice and away from their primary diet of seals, contributing to a long-term decline in population health.

A media release from Explore.org, one of the organizations behind the camera effort, estimates the Hudson Bay polar bear population is in its final decades of existence.

“Studies suggest [the bears are] losing nearly 2 lbs. a day while on land,” Steven Amstrup, the chief scientist for Polar Bears International, another organization involved in the effort, told LiveScience. “And they aren’t dieting intentionally.”

Amstrup added that bears have been forced to stay on land one extra day each year because of declining sea ice.

That trend is also seen on a more global scale, with polar bears struggling to survive as ice retreats further and further each summer. Notes National Geographic, some isolated areas in the Canadian Arctic and Greenland may serve as holdouts for polar bears through the next century, but with increased warming, says Amstrup, “even those last refuges will fail to sustain the icon of the Arctic.”

WATCH the live feed, above. Live cam footage courtesy of explore.org, Polar Bears International and Frontiers North Adventures.

http://www.huffingtonpost.com/2013/11/05/polar-bear-cam-hudson-bay-churchill-canada_n_4220319.html?utm_hp_ref=climate-change

Polar bear males frequently play-fight. During...

Polar bear males frequently play-fight. During the mating season, actual fighting is intense and often leaves scars or broken teeth. (Photo credit: Wikipedia)

Arctic Temperatures Reach Highest Levels In 44,000 Years, Study Finds

Posted in 2013 with tags , , , , , , , , , , , , on October 24, 2013 by MARIE EMMANUELLE QUILICHINI

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Plenty of studies have shown that the Arctic is warming and that the ice caps are melting, but how does it compare to the past, and how serious is it?

New research shows that average summer temperatures in the Canadian Arctic over the last century are the highest in the last 44,000 years, and perhaps the highest in 120,000 years.

“The key piece here is just how unprecedented the warming of Arctic Canada is,” Gifford Miller, a researcher at the University of Colorado, Boulder, said in a joint statement from the school and the publisher of the journal Geophysical Researcher Letters, in which the study by Miller and his colleagues was published online this week. “This study really says the warming we are seeing is outside any kind of known natural variability, and it has to be due to increased greenhouse gases in the atmosphere.”

The study is the first to show that current Arctic warmth exceeds peak heat there in the early Holocene, the name for the current geological period, which began about 11,700 years ago. During this “peak” Arctic warmth, solar radiation was about 9 percent greater than today, according to the study.

http://www.huffingtonpost.com/2013/10/24/arctic-temperatures-highest-44000-years_n_4157863.html?utm_hp_ref=climate-change

No, Arctic Sea Ice Has Not Recovered, Scientists Say

Posted in 2013 with tags , , , , , , , , , , , , , on September 20, 2013 by MARIE EMMANUELLE QUILICHINI

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Arctic sea ice loss during the 2013 melt season was equivalent to losing the entire area of states from Tennessee to Maine. Credit: Climate Central.

From Climate Central’s Andrew Freedman:

Arctic sea ice extent has likely reached its seasonal minimum, dropping to the sixth-lowest level in the 35-year satellite record. This year’s melt represents a significant gain in sea ice extent from last year — when the ice cover plummeted to a record low — but scientists cautioned that long-term trends are what is most important, with most projections still showing a seasonally ice free Arctic Ocean by the middle of the century, if not sooner. In addition, measurements of sea ice volume are at near-record low levels, indicating that the ice cover is unusually thin and vulnerable.

TO BE CONTINUED ON THE WEBSITE

http://www.huffingtonpost.com/2013/09/20/arctic-sea-ice_n_3957165.html?utm_hp_ref=climate-change

This time series, based on satellite data, sho...

This time series, based on satellite data, shows the annual Arctic sea ice minimum since 1979. The September 2010 extent was the third lowest in the satellite record. (Photo credit: Wikipedia)

The Lost Emperor: A Colony of Penguins Disappears by Wynne Parry,

Posted in animals with tags , , , , , , , , , , , , on March 7, 2011 by MARIE EMMANUELLE QUILICHINI

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