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Exploring Antarctica by Sea, Air and Land

Peering Through Polar Ice - Mon, 12/08/2014 - 12:26
Antarctica map NASA

(Click on map for larger image)

Early winter in the Northern Hemisphere marks the start of austral summer in the Southern Hemisphere, and the beginning of the Antarctic field season. Each year, several thousand scientists head to the icy continent to take advantage of the relatively mild, though still very harsh, weather and the 24-hour daylight; the next time the sun will fall below the horizon at Antarctica’s McMurdo Station is February 20, 2015.

Lamont-Doherty Earth Observatory scientists are among the many researchers currently doing fieldwork in Antarctica. They’re leading and participating in expeditions near, above and on the continent, doing critical studies that will advance understanding of Antarctica’s land and sea processes.

Lamont biogeochemist Sonya Dyhrman is aboard an icebreaking ship, the R/V Nathaniel B. Palmer, for one month. In that time she’ll slowly travel south from Punta Arenas, Chile to research sites located off the Western Antarctic Peninsula. Dhyrman, graduate student Harriet Alexander and the other cruise scientists are investigating polar food web dynamics, with a focus on the feeding and swimming behavior of krill, a small shrimp-like crustacean. During the research cruise, Dyhrman and Alexander will collect samples of water and phytoplankton from a number of different sites. Their goal is to understand the physiological ecology of phytoplankton, which form the base of the marine food web in the Southern Ocean, and are a major source of food for krill.

 Lamont-Doherty scientists Robin Bell, Chris Bertinato, Nick Frearson, Winnie Chu and Tej Dhakal with IcePod.

Lamont-Doherty scientists Robin Bell, Chris Bertinato, Nick Frearson, Winnie Chu and Tej Dhakal with IcePod.

More than two thousand miles south, six scientists from Lamont’s Polar Geophysics Group are at McMurdo Station, a U.S. Antarctic research center located on Ross Island. They’re deploying an ice imaging system, known as IcePod, which consists of ice-penetrating radar, infrared and visible cameras, a laser altimeter and other data-collection instruments. IcePod attaches to a New York Air National Guard LC-130 aircraft and measures, in detail, the ice surface and the ice bed; important data that enables the scientists to track changes in ice sheets and glaciers.

The scientists are testing the instrumentation and training the New York Air National Guard in the deployment and operation of the instrument; this is the first time IcePod is being used in Antarctica. After the testing and training, IcePod will be operated in up to 15 other flights for routine data collection.

Also at McMurdo Station are Lamont geologists Sidney Hemming and Trevor Williams. The two scientists and their colleagues Kathy Licht and Peter Braddock will soon fly to a field site in the remote Thomas Hills, near the Weddell Sea in the Atlantic sector of Antarctica. There they’ll spend four weeks making observations and collecting rock samples from the exposed tills on the edge of the massive Foundation Ice Stream, as well as from the Stephenson Bastion and Whichaway Nunataks.

Lamont-Doherty's Trevor Williams and Sidney Hemming (left), with colleagues Kathy Licht and Peter Braddock.

Lamont-Doherty’s Trevor Williams and Sidney Hemming (left), with colleagues Kathy Licht and Peter Braddock.

The group is examining how ice sheets in the Weddell Sea embayment will respond to changing climate, specifically how Antarctic ice retreats and which parts of the ice sheet are most prone to retreat. Understanding the behavior of the Antarctic ice sheets and ice streams provides critical information about climate change and future sea level rise.

Thanks to the Internet and the scientists’ dedication to outreach, it’s possible to join their Antarctic expeditions without donning extreme cold weather gear. Follow the Dyhrman’s cruise activities on Twitter via @DyhrmanLab and #TeamDyhrman, and learn more about their research on the cruise website.

The IcePod team is blogging about their fieldwork on State of the Planet, and updates from the Lamont geologists in the Thomas Hills can be found on Twitter via @Trevor_On_Ice and #AntarcticaG297.

 

Rapid Warming Hits Antarctica's Shallow Seas - LiveScience

Featured News - Fri, 12/05/2014 - 09:58
Shallow ocean waters everywhere around Antarctica have warmed steadily for the past 40 years. Lamont's Stan Jacobs comments.

Mysterious Mineral

Geopoetry - Fri, 12/05/2014 - 08:30
Bridgmanite was identified in a shock-melt vein within the Tenham meteorite. Photograph by Chi Ma, Caltech

Bridgmanite was identified in a shock-melt vein within the Tenham meteorite. The mineral was named in honor of Percy Bridgman, who pioneered the diamond anvil cell for high-pressure research. Photograph by Chi Ma, Caltech

 

So common, yet far out of sight,

Mineralogists longed for a bite.

Formed deep inside,

Or when rocks collide,

At long last, a name: bridgmanite!

 

__________________________________________________________

Further reading:

Discovery of bridgmanite, the most abundant mineral in Earth, in a shocked meteorite, Tschauner et al. (2014) Science

Earth’s Most Abundant Mineral Finally Gets a Name, National Geographic

Space Rock Sheds Light on Mysterious Mineral on Earth, LiveScience

This is one in a series of poems written by Katherine Allen, a researcher in geochemistry and paleoclimate at the Lamont-Doherty Earth Observatory and the Department of Marine and Coastal Sciences at Rutgers University.

 

A Texas-Sized Block of Ice…

Peering Through Polar Ice - Thu, 12/04/2014 - 22:20
Icepod flying over the Antarctic ice towards Mt. Erebus (photo W. Chu)

Icepod and the LC-130 flying over the Antarctic ice towards Mt. Erebus. Photo: W. Chu

The first dedicated Antarctic Icepod mission was flown out across the center of the Ross Ice Shelf. Ice shelves are thick floating extensions of the ice sheet that form as the ice flows off the continent and into the surrounding ocean. These are critical ice features in Antarctica, bounding a full 44 percent of her coastline, where they serve as a buttress to slow the ice movement off the continent into the ocean.

Icepod flying over the front of the Ross Ice Shelf. Along the shelf edge sections of thinner sea ice appear grey on the water surface. (Photo W. Chu)

Icepod flying over the front of the Ross Ice Shelf. Along the shelf edge sections of thinner sea ice appear grey on the water surface. Photo: W. Chu

The Ross Ice Shelf is the largest of the Antarctic ice shelves, measuring just under the size of the state of Texas. It is several hundred meters thick, although most of this is below the water surface. Along the ~ 600 kilometer front edge of the shelf, the ice towers up to 50 meters in height; a sheer vertical wall of white and the iridescent blue of compressed ice. 

The goal of the six-and-a-half-hour mission was to test how the Icepod could image the varying processes at the base of the ice shelf and how well the gravimeter would work flying 90m/sec.

Sea ice covers much of the polar oceans both in the Arctic and Antarctic during the winter months.  Unlike the ice sheet which forms over land, sea ice freezes directly on the surface of the ocean when the temperature is cold enough. It influences our Earth's climate, and holds a critical place in the food web in these regions.

Sea ice covers much of the polar oceans both in the Arctic and Antarctic during the winter months. Unlike the ice sheet, which forms over land, sea ice freezes directly on the surface of the ocean when the temperature is cold enough. Sea ice influences our Earth’s climate, and holds a critical place in the food web in these regions. Photo: W. Chu

The gravimeter is a new addition to the Icepod suite of instruments. Housed separately inside the plane, the gravimeter requires a very stable platform. The instrument will be critical for determining the water depth beneath the Ross Ice Shelf, the least explored piece of ocean floor on our planet. The plan was to cross the front of the ice shelf towards Roosevelt Island, then fly inland until the plane crossed the J9 site where the first hole through the ice shelf was drilled in the early 1970s as part of the Ross Ice Shelf Project (RISP). Icepod would then fly back toward McMurdo along a line where there are plans for another science project to drill next year.

Roosevelt Island in the Ross Ice Shelf, Antarctica (Image from NSIDC)

High resolution satellite image of Roosevelt Island in the Ross Ice Shelf, Antarctica. Floating ice appears flat and smooth like the ice in this image from NSIDC.

The collected radar data showed remarkable variability over the ice. Crossing over Roosevelt Island, the change from floating shelf ice to marginal crevasses (deep cuts or openings in the ice) to ice sitting directly on the bedrock was imaged. The variation in the reflection from the bottom of the ice probably represented the different processes occurring at the ice sheet base. In some places there was evidence of ice being added to the bottom of the shelf.

When the RISP team, which included Lamont’s Stan Jacobs, drilled through J9 in the 1970s, they found refrozen ice with a structure that resembled waffles. That team also captured pictures of fish beneath the ice shelf, demonstrating that the area below was not the wasteland that it was originally believed to be. Icepod overflew the best fishing hole on the Ross Ice Shelf while the team looked at the pictures of the bright-eyed fish in the Science paper, and smiled. It is almost 50 years later, and while we have a much better understanding of Antarctica, there remains so much that is unexplored.

Icepod and the LC-130 returned to Willie Field and began immediately to plan for the next flight.

The LC-130 sitting on the ice runway (Credit N. Frearson)

The LC-130 sitting on the ice runway. Photo: N. Frearson

For more on the IcePod project: http://www.ldeo.columbia.edu/res/pi/icepod/

 

Heat Turbocharged California’s Epic Drought - Climate Central

Featured News - Thu, 12/04/2014 - 12:00
California's rain shortfall isn't unprecedented, but its parched soils are. Researchers blame the heat. Lamont's Park Williams comments.

CO2 Emissions Produce Maximum Warming in 10 Years: Study - NBC News

Featured News - Thu, 12/04/2014 - 12:00
Lamont's Peter deMenocal comments on a new study finding that CO2 packs most of its warming impact in 10 years.

Antarctic Ice Shelf Being Eaten Away by Sea - Science

Featured News - Thu, 12/04/2014 - 12:00
Cites oceanographic research by Lamont's Stan Jacobs.

Why are Past Surface Temperatures and CO2 Concentrations Important?

The Climate Epoch - Wed, 11/26/2014 - 14:36

This blog is an outgrowth of my own research examining the past temperature of Earth’s surface and the relationship of temperature to the Earth’s carbon system. I became interested in the scientific aspects of this work as a geology undergraduate, staring at regular layers of rocks in the countryside of central Italy, back and forth, dark and light. These layers were related to past oscillations of the climate, warmer and cooler, related to long-term changes in the incoming solar radiation entering our planet from the sun. Such changes are small, but positive and negative feedbacks in the Earth system interact to translate the small changes into the radically layered rocks we see in outcrops. This was the start of a journey of discovery that continues to this day and is the foundation of my research at the Lamont-Doherty Earth Observatory.

Oscillating limestone rock layers, Italian Alps

Oscillating limestone rock layers, Italian Alps. Photo: Kelsey Dyez

How does the carbon dioxide (CO2) content of the atmosphere influence climate? This question was first seriously considered in the mid- to late-1800s, amid an accelerating, newfound interest in the natural sciences on the European continent. Specifically, the Victorians were fascinated by looking backward in time, at periodic extreme cold spells, also known as ice ages, when glaciers as tall as skyscrapers covered vast areas of land that today are free from ice.

The discourse about past climates began with this approach, through a discussion about how the driving forces in the Earth system might have caused our globe to periodically enter and exit the ice ages. Many factors, including emissions from volcanoes, the rearrangement of continents, the evolution of plants and vegetation, solar sun-spot cycles, and even asteroid impacts can and do impact the average surface temperature of the planet.

Yet time and again scientists returned to the role that greenhouse gases, and specifically carbon dioxide (CO2), play in the climate system. CO2 molecules in the atmosphere absorb heat (infrared radiation) coming from the Earth’s surface and then re-radiate some of that heat back to the surface to generate a warming effect. How is this related to the glacial ice age cycles of the past?

 CO2 molecules in the atmosphere absorb heat coming from Earth's surface and re-radiate some of that heat back to the surface to generate a warming effect

Simplified greenhouse effect: CO2 molecules in the atmosphere absorb heat coming from Earth’s surface and re-radiate some of that heat back to the surface to generate a warming effect.

One way to think about this problem is to imagine the Earth system as a huge, naturally occurring experiment (though the sample size by most experimental standards is low). Sometimes the Earth has been warmer than today, even ice-free at the poles. When the ice melts, sea level rises, continents spring back after being depressed by the weight of the ice, and plants that need warmer weather expand their habitat pole-ward. The Earth has also been cooler than today, most recently at the last glacial maximum (~20 thousand years ago) when more ice was locked up in the polar ice sheets rather than in the ocean, making for lower sea level, which exposed more of what is today the ocean floor.

Today the framework of thought has turned around, so that instead of looking back through time to understand the climate of the past, we also try to learn lessons from the past to further our understanding of the climate of the future. By burning fossil fuels for heating, electricity, transportation and other purposes, humans add CO2 to the atmosphere. Yet, by comparing ways in which the Earth’s temperature, CO2 concentration, sea level and ice sheets have changed in the past, we are able to learn valuable lessons about the climate system of today and tomorrow. You can share in this adventure here.

NYC emitted 54 million tons of CO2 in 2010

New York City emitted over 54 million tons of CO2 in the year 2010. To imagine this number, every sphere here represents 1 ton of CO2 at the average surface temperature and pressure. Image: Carbon Visuals/Flickr

One last word of caution: At the turn of the last century, people also began to wonder if land-use and manufacturing—human-induced variability—could play a role in climate. Because this issue has become highly politicized, I won’t get into all the back-and-forth arguments here. That forum has other locations online. However, for a modern history of this fascinating topic, check out the American Institute of Physics (which can be found at http://www.aip.org/history/climate/co2.htm); and for more on the science, check out what the EPA has to say (http://www.epa.gov/climatechange/ghgemissions/gases/co2.html). Both purport an objective analysis of both the history and basic science involved.

The Worst Drought in 1,000 Years - Science News for Students

Featured News - Wed, 11/26/2014 - 13:27
Cites Dust Bowl research by Lamont's Richard Seager and Benjamin Cook.

This Bird Flies South for the Winter

Peering Through Polar Ice - Mon, 11/24/2014 - 22:39
Skier 95 with IcePod visible beneath the rear window lands on the Antarctic ice. (photo R. Bell)

Skier 95 with IcePod visible beneath the rear emergency door lands on the Antarctic ice. Photo: R. Bell

Migrating south in the winter is a behavior that Antarctic scientists share with many species of birds, although the scientists fly just a bit further south. For the IcePod team, it was time to join the migration so they could test their equipment in the most challenging environment the Earth has to offer. After three “equipment shake down” trips to Greenland over the last two years, 20 hours of flight time have been set aside for flights in Antarctica, part of the final hurdle in the commissioning of the pod.

The team arrived early this month at McMurdo Base on a large C-17 to –14°F weather and beautiful clear blue sky as the plane touched down on the Pegasus Blue Ice Runway. The first few days were spent in training for everything from driving trucks in the cold to being environmentally sensitive to the Antarctic microbes to a crash course on interpreting the complex way trash is handled in Antarctica — an impressive 60 percent of everything is recycled. 

Loading the gravity meter on loan from the Kiwi for the Antarctic test flights. (Photo R. Bell)

Loading the gravity meter on loan from the Kiwi for the Antarctic test flights. Photo: R. Bell

The gear arrived soon after the team… first the gravity meter, borrowed from New Zealand, wrapped in a warm, manly pinkish quilt. With many boxes being stacked in the aircraft, the color was selected for its high visibility to assist with quick location and unloading. The IcePod and the equipment rack had paused on their trip down in Pago Pago, arriving a few days after the rest of the gear, but it was all quickly set up and humming in a bright yellow and blue rack tent next to the Willy Airfield on the Ross Ice Shelf. While waiting to fly, a GPS was installed on top of the tent, and equipment was set up to test performance. Both the GPS and the gravity meter measured the movement of the ice shelf as it shifted up and down on the tide ~ 1 meter a day. In addition to the rhythmic up/down movement, the tent, the airfield and the ice shelf are all moving northwards at 30 cm or 1 foot a day.

Scott Brown, Tej Dhakal and Winnie Chu prepare the equipment for take off. (photo R. Bell)

Scott Brown, Tej Dhakal and Winnie Chu prepare the equipment for take off. Photo: R. Bell

Finally, IcePod was cleared to fly and complete her first Antarctic survey mission installed on a Pole Tanker mission flying on Skier 95. The flight was delayed as the C-17 practiced airdrops over the South Pole runway, but as soon as the C-17 was out of the way, icePod took off and headed south.

Icepod flies over the Antarctic ice with Mt. Erebus visible in the background. (Photo R. Bell)

Icepod flies over the Antarctic ice with Mt. Erebus visible in the background. Photo: R. Bell

Low elevation data was collected on the way out to make sure the C-17 was clear. All the instruments worked in the flight across the very flat Ross Ice Shelf, then over the Transantarctic Mountains and across the spectacular East Antarctic Ice Sheet.

IcePod team at South Pole (left to right) Scott Brown, Chris Bertinato, Tej Dhakal, unidentified, Winnie Chu (photo by R. Bell)

IcePod team at South Pole (left to right) Scott Brown, Chris Bertinato, Tej Dhakal, a new Antarctic colleague, Winnie Chu. Photo: R. Bell

The low angle of the sun made the mountains, crevasses and wind scour areas stand out beautifully in the imagery. The deep radar imaged the structure of the Ross Ice Shelf even from 21,000 feet. The infra-red camera showed the variable temperature of the different types of ice in the Beardmore Glacier and the high plateau. The gravity meter that had rolled in on the speed pallet was extremely stable. At the South Pole, Skier 95 offloaded fuel while the IcePod team made a quick trip to the actual pole.

The flight was a success – data collected on an opportune flight and fuel delivered.

For more on the IcePod project: http://www.ldeo.columbia.edu/res/pi/icepod/

 

Underwater Robot Allows Scientists to Map Uncharted Antarctic Sea Ice - CBS News

Featured News - Mon, 11/24/2014 - 13:53
Lamont's Chris Zappa explains how drones have aided data-collection efforts in Antarctica.

How I Learned to Love the Polar Vortex Hype - Salon

Featured News - Sat, 11/22/2014 - 12:00
Lamont's Adam Sobel writes about the upside to a growing public interest in the jargon of atmospheric science.

Lamont-Doherty Director Receives National Medal - News 12 Westchester

Featured News - Fri, 11/21/2014 - 12:51
Lamont director Sean Solomon receives the National Medal of Science from President Obama on Nov. 20.

New maps show Bering Sea Holds the World's Most Acidic Waters - Alaska Dispatch News

Featured News - Fri, 11/21/2014 - 12:00
Coverage of an ocean acidification study led by Lamont's Taro Takahashi.

Sea Ice Algae: An Arctic Food Chain Staple - LiveScience

Featured News - Fri, 11/21/2014 - 11:09
Photo slideshow featuring Arctic research by Lamont's Craig Aumack and Andrew Juhl.

Acid Maps Reveal Worst of Climate Change - Scientific American

Featured News - Thu, 11/20/2014 - 13:02
Coverage of new ocean acidity maps developed by Lamont's Taro Takahashi and colleagues.

Obama Honors Lamont-Doherty Director - (Rockland, N.Y) Journal News

Featured News - Thu, 11/20/2014 - 12:00
Lamont director Sean Solomon receives the National Medal of Science in a White House ceremony on Nov. 20.

A Planetary Fix? - Beacon Reader

Featured News - Thu, 11/20/2014 - 10:22
Profile of test project in Iceland co-led by Lamont-Doherty reesearchers to bury carbon emissions underground.

Antarctica's Mysterious Mountains Preserved By Ice - LiveScience

Featured News - Wed, 11/19/2014 - 17:37
Cites research led by Lamont's Tim Creyts.

40 Years of Scratching Reveals Ocean Acidification Data - Climate Central

Featured News - Tue, 11/18/2014 - 15:54
New maps developed by Lamont's Taro Takahashi and colleagues provide a measure of ocean acidification to measure future changes against.
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