This Week in Ice: Nov. 12–18

This week, NASA’s Operation Icebridge offered us more spectacular views of Antarctica. Operation Icebridge uses research aircraft to capture images of Earth’s polar ice “to better understand connections between polar regions and the global climate system. IceBridge studies annual changes in thickness of sea ice, glaciers and ice sheets.”

This is one of my favorites:

 

Sea Ice

Sea ice extent and concentration in both the Arctic and Antarctic remain well below average. You can read a full summary of October’s Arctic and Antarctic sea ice conditions here.

ARCTIC

Arctic sea ice grows rapidly at this time of year. October’s Arctic sea ice concentration was the fifth lowest on record for that month (satellite data from 1979 to present).

Current conditions: 

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Credit: NSIDC

arctic

Credit: NSIDC

Unlike Antarctic sea ice, which is usually only one to two years old due to seasonal melting, Arctic sea ice can last for multiple years. This animation shows how older Arctic sea ice is now thinning and melting.

 

ANTARCTIC

As days lengthen and temperatures increase in Antarctica, with the approach of the Austral summer, sea ice melts. October was tied with 2002 for the latest maximum sea ice extent and the second lowest Antarctic maximum extent (satellite data, 1979 to present).

Current conditions:

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Credit: NSIDC

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Credit: NSIDC

This one by Zach Labe shows more data:

Wind has a large role in sea ice formation, comparable to or even more important than temperature and rain says researcher Massimo Frezzotti. This research explores the processes that have affected sea ice variability, as well as the abundance of seals and penguins in the Ross Sea, over the last ten thousand years.

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Antarctic krill under ice                                                Copyright © Marlo Garnsworthy

Krill are small shrimp-like crustaceans and a vital link in marine food chains. Antarctic krill, depicted in my painting, feed sea birds, penguins, seals, and whales.

A study in the Weddell Sea has shown that sea ice is a critical habitat for krill larvae during winter, and they find refuge from predators under the ice. But while it may be safer, it is not a food-rich environment. Krill do graze under the ice during the day, then at night drift down and away to more favorable feeding zones.

Glaciers & Ice Shelves

This graphic shows how land ice has decreased in Antarctica and Greenland from 2002 until the present.

One of the numerous reasons we should care about ice loss is that melting ice sheets not only raise sea levels but will have an effect on tides the world over. New research shows that, as ice sheets melt, sea levels don’t rise evenly across the world, and it matters which glaciers melt. In some places tide ranges will be increased, and in others reduced, thereby impacting coastal communities. These changes could also have an effect on larger scale ocean currents. Ocean currents affect our global climate, among other things. (Sea ice also has an effect on ocean currents, a subject I’ll be exploring in weeks to come.)

NASA has provided a new tool to show how sea level rise may affect 293 coastal cities around the world.

The Pine Island Glacier, which flows into West Antarctica’s Amundsen Sea, makes the biggest contribution to sea level rise. This is the same glacier that carved a massive iceberg, four times the size of Manhattan back in September (and a mere month later, it broke into pieces too small to track). Here, warmer waters interact with floating ice, weakening the ice shelf from below.

Watch an Alaskan glacier retreat over time:

 

Icebergs

Thanks to Operation Icebridge, we have our first closeup views of massive iceberg A-68A, previously only seen via satellite imagery.

iceberg

Credit: NASA/Nathan Kurtz

Scientist Stef Lhermitte notes further cracks in the Larsen C ice shelf, from which A-68 (the initial even larger iceberg) calved back in July.

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Copyright © Marlo Garnsworthy

In the absence of any other significant iceberg news, I offer this picture of a wind-and-sea-tossed  iceberg I took during a gale in Antarctica’s Ross Sea. Note the blue ice to its left. Blue ice looks that way because, over thousands of years, it has become very compressed, pushing out the air bubbles that give ice and snow its white appearance. Blue icebergs consist of very old ice, which has calved from glaciers and ice shelves into the sea.

And to finish, I hope you’ll enjoy this excellent series of short videos, showing how satellites have been monitoring life on Earth for over 20 years.

 

As always, I am not a scientist, just a writer/illustrator and science communicator passionately in love with sea ice. I welcome input and corrections by polar scientists as I learn more about this remarkable and vital part of our planet and bring this knowledge to a wider audience. 

 

 

 

Salt Marshes Stink!

marsh

This week’s science adventure took me to a salt marsh in Barrington, Rhode island, with scientists Kenny, Tom, and Scott. With a wheelbarrow, numerous steel rods, two plastic step-stools, a plank of wood, several bags of quick-drying concrete, food and water for a hard day’s work, and sophisticated equipment that talks to satellites, we trudged through spongy, oozing, pungent coastal marsh.

And boots. Don’t forget tall, waterproof boots—-or waders if you’re lucky—-if you venture into the marsh. A salt marsh floods with the tides, and it’s a boggy, stinky, and treacherous place.

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Careful where you step, or the marsh may suddenly swallow a limb.

It’s hard to describe the stench of the marsh’s thick black mud. Mix rotten eggs, worn and moldy socks, and a briny tang, and you might be getting close. It’s an odor I’ve come to love, living in coastal Rhode Island, reminding me of happy days in my kayak, floating by spindly spider and fighting fiddler crabs, mussels, oysters, tiny fish called mummichogs, and graceful great blue herons and egrets. You can feel the abundance of life around you.

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Fiddler crab

Wetlands are areas of high productivity, meaning uncountable plants are breathing, growing, and reproducing, using sunlight to turn carbon dioxide and water into food for themselves and other organisms.

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Both migrating and resident Canada geese visit the salt marsh.

Macro-algae, various marsh grasses, and islands of shrubs, juniper trees, and other plants grow here. As Tom tells me, “Wetlands are now thought to be as productive as rain forests.”

It’s thrilling to be surrounded by one of the planet’s greatest carbon sinks. (A carbon sink is an area where productivity is high. Here masses of carbon dioxide—a major greenhouse gas—are taken up by plants.) Salt marshes, like other areas of high productivity such as rain forests and the Southern Ocean, are vital for mitigating global warming and climate change.

Today, Kenny and Tom are installing SETs—“surface elevation tables.” It’s an appropriate acronym for points set in concrete. Scott then uses sophisticated equipment to determine the elevation of each.

“I’m tying the SET into the National Spatial Reference System,” says Scott. “Water levels are rising, and salt marshes need to rise at the same pace. Otherwise they will flood and turn into mudflats—where vegetation can no longer grow.”

They will return to this marsh—and others like it—again and again over the years, measuring how its elevation and health change over time. Will they grow and rise? Will growth keep up with rising sea levels? Or will they sink, die, and regress?

stake

Scott and Kenny work together to pound a long metal pole deep into the spongy ground.

Tom, who has been mixing concrete to hold the stake in place, stands and stretches. This is hard physical work, and we are tired, wet, and filthy. He gazes out over the waving marsh grasses. “I grew up by the salt marsh. We could play football on the marsh in those days.”

kt

Tom concretes the stake into place, while Kenny spreads powdered rock called feldspar.

“You couldn’t do that now,” Kenny says matter-of-factly. We look down at the soggy peat below us. It ripples beneath us with each strike of the post hammer. “Especially here—this marsh is so degraded.”

“They didn’t used to stink as bad,” says Tom. “A lot of the stinkiness is due to the fact that they are now drowning in place due to sea level rise, sadly.”

Now Kenny is shaking out white powdery feldspar over two sections of the plot. “The feldspar is for what’s called a marker horizon,” he says. “As organic and inorganic material gets deposited on it over time, we can later take a small core and measure how much has accumulated over the feldspar over time, divide by time, and you get a surface accretion rate.”

“Why should we care about marshes?” I ask as they all take a breather. Kenny and Tom reel off a list of reasons.

Salt Marsh Facts:

  • Salt marshes grow on coasts and in estuaries the world over. In the US, they can be found on every coast.
  • Salt marshes stink due to the gases given off by decomposing organic matter.
  • The soil is composed of spongy peat (decomposing plant matter) and thick mud.
  • The marsh is frequently flooded, then drained, by salty tidal water.
  • Salt marshes provide a habitat—including food, shelter, and a safe place for juveniles—for over 75% of the fish and selfish humans enjoy.
  • Humans love wetlands and estuaries too for fishing and shell-fishing, boating, paddling, birding, and more.
  • Salt marshes protect shorelines from erosion and buffer wave action, especially during storms.
  • They trap sediment, which also helps protect the estuary.
  • They absorb rainwater and reduce coastal flooding.
  • They filter water and absorb excess nutrients (e.g., from fertilizers), thereby keeping beaches and waterways cleaner.

Salt marshes might stink, but what’s not to love about them? They are essential for our economy, culture, and environment.

marsh

We love the salt marsh!

You can see an interview with Kenny in this piece by the Providence Journal.

Kenneth Raposa is a salt marsh ecologist with The Narragansett Bay National Estuarine Reserve, Tom Kutcher is a wetland scientist with Rhode Island Natural History Survey, and Scott Rasmussen is an environmental scientist with the Environmental Data Center at the University of Rhode Island. This project is funded through the RI Coastal Resources Management Council (CRMC) to establish two additional long-term salt marsh monitoring sites to complement the existing few sites. The goal is to build a strong network of long-term sites around all coastal RI to gain a better understanding of what is happening to salt marshes throughout the state.

This Week in Ice, Oct. 10-14

I’m posting a littler earlier this week—so much has happened in ice.

Adelies C

A highlight of our SNOWBIRDS Transect research cruise was watching the Adélie penguins, by far the most entertaining and—I have to say it—cute creatures I’ve ever seen. One couldn’t help but be enchanted and amused by these little fellows as they bob their heads and chatter, waddle-running on little legs and belly-scooting across the pack ice, tumbling over their own feet and each other.

So, it’s gut-wrenching to read that in a colony of around 36,000 Adélie penguins, only two chicks have survived. The others starved to death. Sea ice conditions in that area forced adult penguins to travel much farther to find food. Next week, environmental groups and officials will meet to discuss the creation of a Marine Protected Area off eastern Antarctica, prohibiting fishing of krill, thereby helping relieve stress on some penguin colonies and other marine life.

A couple of weeks ago, I talked about the Maud Rise polynya, also known as the Weddell polynya, which opened up in the Weddell Sea about a month ago. A polynya is an area of open water within the ice pack.

The Maud Rise polynya, which I read has grown to about 80,000 square km (30,000 square miles), is currently about the size of South Carolina, Maine, Lake Superior, Tasmania, or Switzerland, depending on where you read this news–which finally hit the mainstream this week.

It’s the dark blue patch near the top of the image.

maud 1

It looks a bit like a whale or shark…

maud 2

I believe this image is from Sentinel 1.

News reports say scientists are “puzzled” or “mystified” about what’s causing it, since the polynya is far from the sea edge. However, the Antarctic Report notes that the seamount (underwater mountain) for which the polynya is named rises 3,500 m deep to 1,700 m deep, creating eddies, which bring warmer water closer to the surface.

Such openings in sea ice affect our global climate. And here’s a (fun?) related story.

There is no doubt that as the planet warms, the sea ice extent is changing and/or acting in unexpected and troubling ways. Glaciers, too, are affected.

Satellite imagery has shown an upside-down canyon forming beneath the Dotson Ice Shelf. This video from the Center for Polar Observation and Modeling explains this process well:

 

Meanwhile, massive iceberg B-44, which calved (= broke off) from the Pine Island Glacier in September, has developed new cracks.

pine

So, it’s been a big week in ice—and, hopefully, one that makes you think.

To finish off, here’s something as mesmerizing as it is fascinating:

 

As always, I am not a scientist, just a writer/illustrator and science communicator passionately in love with sea ice. I welcome input and corrections by polar scientists as I learn more about this remarkable and vital part of our planet, and then bring this knowledge to a wider audience. 

Eelgrass Adventure

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This week’s science adventure took me to the watery underworld of Long Island Sound with scientists Mike Bradley and Scott Rasmussen as part of a US Fish and Wildlife Service research project. Our goal: to check the extent and health of eelgrass beds along the Connecticut and Long Island shores.

We pound across the Sound on a glorious autumn morning. Terns and gulls wheel and dive, feasting on jumping fish. It’s a perfect day for fishing, and we pass numerous small boats doing just that. Coastal New England, USA, is famous for its bountiful and diverse seafood.

“Eelgrass provides habitat for juvenile fish and shellfish,” says Mike. “So, if you like fish and shellfish, you should care about eelgrass.” Eelgrass also helps stabilize the sandy areas close to shore and in estuaries.

Prior to our adventure, Mike mapped the possible extent of eelgrass by studying dark patches near the shore from areal imagery–photographs taken of calm waters at low tide from a plane early this summer. Seaweed–known by scientists as macroalgae (because seaweed is actually large algae)–can also appear as dark patches. So, using an underwater video camera, we traveled along multiple straight lines–or transects–across each area, and Mike plotted where eelgrass was actually present.

FullSizeRender (1)

Mike plots eelgrass, while Scott maneuvers the video camera and cheery Tom Halavik, retired from the US Fish & Wildlife Service, drives the boat.

From the boat, eelgrass is a shifting golden-green tapestry beneath, and seaweed looks dark and foreboding. But viewed from below, eelgrass and seaweed beds are a colorful, gently swaying, otherworldly forest. Clams and oysters litter the bottom, spider and green crabs scuttle and hide, and fish such as tautog hunt for prey.

Capture (1)

Tautog on the hunt

Mike will return numerous times to Long Island Sound to complete the survey of over 300 eelgrass beds, covering approximately 2,500 acres. The video and mapping data he collects will be used by biologists to monitor the health of eelgrass along this section of New England coastline.

Near the end of our journey, in a quiet aqua-watered cove of Plum Island, we were treated to a delightful encounter with up to twenty seals, who popped their heads up to study us before continuing to fish and play. It was a magical end to my eelgrass science adventure!

FullSizeRender (2)

Spot the seals!

Eelgrass Facts

  • There are 15 species of eelgrass–Zostera–and they are widespread along coastlines in the Northern Hemisphere, as well as parts of Australia and Africa.
  • Eelgrass needs significant sunlight to grow, so it’s found in shallow waters and does better in clear, not murky water.
  • Its success is also affected by water temperature and quality. As water temperatures increase while our planet warms, eel grass becomes less successful, which means habitat for juvenile fish and shellfish declines.
  • Increased nitrogen in the water–due to runoff from fertilizer, detergents, etc.–benefits macro-algae, which competes with eelgrass.

This project is a partnership between the Environmental Data Center of the University of Rhode Island and Suzanne Paton, Senior Biologist at Southern New England’s US Fish and Wildlife Service. The funding for this survey was provided by the EPA Long Island Sound Study, and the information will help evaluate water quality and habitat restoration projects that have been implemented over the years. This data will be compared to data collected in 2002, 2006, 2009, and 2012 by the US Fish & Wildlife Service in collaboration with the EPA to assess long-term trends and progress toward the restoration of this important habitat. 

Thanks, Mike Bradley, for taking me along!