Land Ho! Visiting a Young Island

The three year-old volcanic island (black) as seen from the SEA drone. Credit: Woods Hole
The three-year-old volcanic island (center) as seen from the SEA drone. Credit: Sea Education Association / SEA Semester

by Ellen Gray

Excitement was in the air when research scientist Dan Slayback of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, approached a small trio of islands in the South Pacific island nation of Tonga. It was October 8th, and Dan had joined the scientists and students with the Sea Education Association’s SEA Semester South Pacific cruise to visit a three-year-old island he’d only seen from space.

“There’s no map of the new land,” Dan said. It erupted from the rim of an underwater caldera in early 2015, nestled between two older islands. The older islands were on some nautical charts at coarse resolution, and the satellite observations appeared to show shallow beaches on the south side of the new island that would allow them to land. However, while satellites are powerful tools for looking at land on Earth, they are not omniscient about all the details on the ground – these beaches turned out to be too steep and the waves too rough for an easy landing.

The SSV Robert C. Seamans of Woods Hole's SEA Semester program at Hunga Tonga-Hunga Ha'apai. Credit: Dan Slayback
The SSV Robert C. Seamans of SEA Semester program at Hunga Tonga-Hunga Ha’apai in October, 2018. Credit: Dan Slayback

When the volcanic island burst into being in January 2015 it immediately captured the attention of NASA scientists keen to understand how new islands form and evolve on Earth – which may also give them clues about how volcanic landscapes interacted with water on ancient Mars. The new Tongan island is one of only three that has erupted in the last 150 years that have survived the ocean’s eroding waves longer than a few months. Dan and his colleagues Jim Garvin at Goddard and Vicki Ferrini at Columbia University have been watching it from satellites since its birth, trying to make a 3D model of its shape and volume as it changes over time to understand how much material has been eroded and what it is made of that makes it partially resistant to erosion. But while high-resolution satellite observations are revolutionary for studying remote regions – such as tiny islands in the vast Pacific Ocean – they can only tell you so much without actually visiting the place on the ground.

Dan and the SEA scientists and students, as well as a Tongan observer, sailed around to the calmer northern coast of the island, which still has no official name and is referred to by the combined names of its neighbors, Hunga Tonga-Hunga Ha’apai (or HTHH for short). On October 9th, they spent the day taking GPS measurements of the location and elevation of boulders and other erosional features visible in the satellite image.

NASA researcher Dan Slayback standing on the beach of Hunga Tonga-Hunga Ha'apai. Credit: NASA
NASA researcher Dan Slayback standing on the beach of Hunga Tonga-Hunga Ha’apai.

“We were all like giddy school children,” said Dan of their visit. “Most of it is this black gravel, I won’t call it sand – pea sized gravel – and we’re mostly wearing sandals so it’s pretty painful because it gets under your foot. Immediately I kind of noticed it wasn’t quite as flat as it seems from satellite. It’s pretty flat, but there’s still some gradients and the gravels have formed some cool patterns from the wave action. And then there’s clay washing out of the cone. In the satellite images, you see this light-colored material. It’s mud, this light-colored clay mud. It’s very sticky. So even though we’d seen it we didn’t really know what it was, and I’m still a little baffled of where it’s coming from. Because it’s not ash.”

Editor’s  Note: Dan later learned that clayey materials washing out from the cone, even a cone from an ash-dominated eruption, is not unexpected. Similar mud deposits have been observed on other small oceanic island volcanoes, as a weathering product from tropical rains that wash fine particles down from the higher elevations and turn them into small mud-flows that are deposited in the low, flat areas around the base of the volcano.

Mud was only one of the surprises. Dan and the students were able to get up-close photos of the vegetation beginning to take root on the isthmus connecting the island to its neighbor, and patches likely seeded by bird droppings on the volcanic cone’s flank. A barn owl made a surprise appearance (they occur worldwide; the sighting was not, it turns out, particularly remarkable), likely living on the heavily vegetated older islands, as well as hundreds of nesting sooty terns that had taken shelter in the deep gullies etched into the cliffs surrounding the crater lake.

Vegetation taking root on the flat isthmus of Hunga Tonga-Hunga Ha'apai. The volcanic cone is in the background. Credit: Dan Slayback
Vegetation taking root on the flat isthmus of Hunga Tonga-Hunga Ha’apai. The volcanic cone is in the background. Credit: Dan Slayback
Sooty terns are nesting in the gullies around the crater lake. Can you spot the chicks? Credit: Dan Slayback
Sooty terns are nesting in the gullies around the crater lake. Can you spot the chicks? Credit: Dan Slayback

But Dan was there for the rocks. In addition to collecting small samples (with Tongan permission) for mineral analysis back at Goddard’s Non Destructive Evaluation Lab, the other main goal of his visit was to figure out what the actual elevation was of the island.

“The point is to try to take the satellite imagery and tie it to a known reference point, particularly the vertical elevation. The software that generates Digital Elevation Models (a 3D map) from stereo imagery is using a geoid model, and it’s not great in remote places like this. So if you were standing there with your GPS and you’re looking at the ocean at sea level and it’s telling you you’re at four meters elevation, you’re like, But I’m not! I’m at sea level,” he said. So he wanted to find a reasonable adjustment to the geoid model for local mean sea level.

The cliffs of the crater lake are etched with erosion gullies. Credit: Dan Slayback
The cliffs of the crater lake are etched with erosion gullies. Credit: Dan Slayback

Using a high-precision GPS unit with both a stable and mobile unit, Dan and the students helping him took about 150 measurements that narrow down each point’s location and elevation to better than 10 centimeters. In addition, they used SEA’s drone to do an aerial survey of the island for another layer of observations to use to make a higher-resolution 3D map of the island.

“It really surprised me how valuable it was to be there in person for some of this. It just really makes it obvious to you what is going on with the landscape,” Dan said. One feature that was eye-opening in person was the deep erosional gullies that run down the side of the volcanic cone. “The island is eroding by rainfall much more quickly than I’d imagined. We were focused on the erosion on the south coast where the waves are crashing down, which is going on. It’s just that the whole island is going down, too. It’s another aspect that’s made very clear when you’re standing in front of these huge erosion gullies. Okay, this wasn’t here three years ago, and now it’s two meters deep.”

A SEA student takes a GPS point in one of the gullies. Credit: Dan Slayback
A SEA student takes a GPS point in one of the gullies. Credit: Dan Slayback

Dan and the SEA Semester group only had one additional morning on the island before bad weather moved in and they had to retreat to the ship. Now back at Goddard, he’s processing the new data and developing a more realistic 3D model of the island, which he and his colleagues will use to figure out its volume and how much ash and volcanic material erupted from the vent on along the rim of the submarine caldera below. Big questions remain, such as what does the shallow sea floor around the island look like and are hydrothermal processes occurring that may solidify the material and allow it to resist erosion for decades to come. Dan hopes to return next year to find more answers.

 

Meet Corey Walker, NASA Earth Science Intern and Aspiring Educator

Corey Walker presents his research findings to the Student Airborne Research Program group. Credits: NASA / Megan Schill
Corey Walker presents his research findings to the Student Airborne Research Program group. Credits: NASA / Megan Schill

By Corey Walker / NASA ARMSTRONG FLIGHT RESEARCH CENTER, PALMDALE, CALIFORNIA /

My name is Corey Walker. One of the most incredible things I’ve done on paper is become a NASA intern through the agency’s Student Airborne Research Program, otherwise known as SARP. Why? I grew up in Etowah County, Alabama which has a poverty rate well above the national average. At the end of the year, I will be one of just 8 percent of people from my hometown who will have achieved a bachelor’s degree. I’ve come to recognize that the opportunity I’ve had is somewhat of an anomaly for many who have watched my success.

I wanted to participate in this Q&A blog to share my experience with the NASA SARP program and to express my gratitude towards those who have given someone like me a chance to succeed. I also want to encourage the next generation of student scientists to apply for opportunities like SARP to broaden their skill sets and to experience what field research and lab analysis is all about.

What do you think it takes to become a NASA intern

CW: The conditions that create a NASA intern are variable depending on who you ask. However, for me it begins with ordinary people who have extraordinarily impacted my life. Along the way family, friends, teachers, and mentors have taught me the value of perseverance,  working hard, and pushing yourself beyond known limits.

Corey interacts with fellow SARP interns on the flightline at NASA’s Armstrong Flight Researcher Center’s facility in Palmdale, California. Credits: NASA / Megan Schill
Corey interacts with fellow SARP interns on the flightline at NASA’s Armstrong Flight Researcher Center’s facility in Palmdale, California. Credits: NASA / Megan Schill

Why did you apply?

CW: The answer to this question lies in the evolution of my interests. For example, when I was a freshman, I was an English major. I applied the skills I learned with my time in the English department to the development of a YouTube channel, which I’ve since neglected. My sophomore year, I changed my major to nursing. While in this major, I applied myself to the rigorous study of science. Through this study, I produced a bit of character development and self-confidence. As science education molded me, I decided to study biology and education as a double major. I’m proud to report that I graduated this month. As a future science educator, I want to use my experience in the classroom to leverage curiosity and the understanding of complex systems. I also want to inspire the next generation to apply themselves towards their own challenging, individual goals like the one I achieved by working for NASA.

This isn’t the first time you’ve applied with the program. What inspired you to persevere and apply again?

CW: I have heard lots of teachers say something cliché like, “You can do anything you set your mind to.” I personally believe in this phrase, first because I am an optimist, and second because I think humans are powerful when they decide to act. However, I think that there is a responsibility that comes with believing this phrase. Personally, I think it would be unfair for me to tell my students to believe in themselves if I first did not believe in me. In a lot of ways, applying to SARP again is just myself modeling for students the act of taking responsibility for my beliefs. I also hope my second application to SARP teaches students an important lesson. Failure is feedback.

2018 Student Airborne Research Program Interns. Credits: NASA / Megan Schill
2018 Student Airborne Research Program Interns. Credits: NASA / Megan Schill

Why do you think internship opportunities like SARP are important for college students?

CW: I came to SARP from a small, liberal arts institution in East-Central Kentucky called Berea College. I am the first SARP alum from my school. The connections I made with this research experience will be extremely valuable to future generations. I intend to help someone else from Berea find the opportunity to work at NASA by connecting them to the network of scientists I have created. I also think opportunities like SARP are a great resume booster. This research experience under my belt will certainly prepare me better for graduate school.

What do you think undergraduate students can benefit from most by participating in opportunities like SARP?

CW: SARP is interesting because it puts you in an environment where you are forced to learn new things you’ve never thought about studying. As an educator, I am a big proponent of discovering new things. While at SARP, I was introduced to analytical tools and software like ENVI and MATLAB. I even had the opportunity to work with ArcGIS and ArcMap. This made me see a side of science that was utterly new and outside to anything I had ever contemplated.

Another thing that is beneficial about SARP is the way you get to be inspired by all kinds of interesting scientists and experiences. Some of my favorite moments were when I got to hold Sherwood Rowland’s Nobel Prize and see a real Mars lander being built at JPL for the 2020 mission.

Corey Walker sits in the cockpit jump seat aboard the NASA DC-8 during a science flight. Credits: NASA / Megan Schill
Corey Walker sits in the cockpit jump seat aboard the NASA DC-8 during a science flight. Credits: NASA / Megan Schill

Describe your research project and group.

CW: Something I noticed while flying in Southern California was all the tile or red-shingle roofs. This was certainly different from where I grew up and intrigued me. Because of my experiences being a volunteer firefighter with the city of Berea, I began to wonder how defensible red-shingle roofs were compared to wood shingle roofs if exposed to wildfire. This interest, along with help from mentors Alana Ayasse and Dr. Dar Roberts gave me the desire to develop a project where I mapped fire risk using remote sensing instruments. In my project, I successfully mapped materials like non-photosynthetic vegetation (NPV) or dead grass, green vegetation (GV) and soil and road in Goleta. I then compared maps I made to the location of the Holiday Fire, which started on July 11, 2018 and destroyed 28 structures.

How did you collect data for your research?

CW: I used data taken from NASA’s ER-2 16 days prior to the Holiday Fire. It was important for me to use data that was as close to the fire date as possible. I did this in order to accurately assess what kinds of materials were on the ground before the fire started.

The SARP Wildfires team collects field data in Central California. Credits: NASA / Megan Schill
The SARP Wildfires team collects field data in Central California. Credits: NASA / Megan Schill

What did you learn from the research?

CW: Not only did I show that the Holiday Fire occurred in a high fire risk area, but I also found interesting patterns. More specifically, my maps showed high fire risk in areas to the north and south of Goleta’s urban center where there is less road and more vegetation. My maps also show high fire risk in areas where property values are higher, which is a little alarming. For example, to the north, I found properties costing upwards of $700,000 surrounded with materials that could easily burn.

How do you plan to use this internship experience and your education going forward?

CW: Because of SARP, all the kids at the high school I teach at think I’m “cool.” This should be the objective right? It is interesting how working for a widely known name can inspire students and make them believe they could also do something “crazy” like working for NASA. Besides bringing my experiences into the classroom, I’ve decided I want to pursue a PhD in Earth Sciences and one day become a professor.

I’ve recently become interested in a hazards program at Oxford in the UK. I’ve certainly gained some self-confidence from getting to work for NASA, which has given me the desire to aim for a school like Oxford.

There is a professor named Dr. Tasmin Mather at Oxford who has used the European Space Agency’s Sentinel-1 to study volcanoes for the benefit of international communities. I find this work to be interesting as a scientist and volunteer firefighter. I like the way she uses science to inform the public of hazardous threats. I think it would be really cool to use my experience at SARP as a way to set me apart when I apply, so that I could one day work with someone like Dr. Mather.

Left to right: Chan Oh and Corey Walker. Chan was Corey’s roommate during college.
Left to right: Chan Oh and Corey Walker. Chan was Corey’s roommate during college.

Is there anyone else you’d like to recognize that has helped along your journey?

CW: I want to recognize and thank my family who have invested their time, resources and love into my success. I also had a number of teachers and mentors who went out of their way to push me out of my comfort zone. Lastly, I want to thank my wife Emily, who sacrificed time that could be spent together so that I could do science in California. Thank you all.

For more information on the Student Airborne Research Program and to apply visit: https://baeri.org/sarp-2019/

To read other blogs written by current and former SARP students visit: https://blogs.nasa.gov/earthexpeditions/?s=SARP

On the Iceberg Highway

The research ship Sanna of the Greenland Institute of Natural Resources. Credits: NASA/JPL-Caltech

by Carol Rasmussen / NORTHWEST GREENLAND /

If you remember the movie Titanic, this looks like a terrible place for a cruise. But to a captain with a lifetime of experience navigating around Greenland, it was a safe passage. And to scientist Ian Fenty of NASA’s Jet Propulsion Laboratory in Pasadena, California, it was a great place for research.

Ian is a co-investigator for NASA’s Oceans Melting Greenland (OMG) campaign, a five-year project to measure the effects of ocean water on Greenland’s rapidly melting glaciers. In August, he was the sole OMG representative on a research cruise to glacier fronts in northwest Greenland. And where there are glaciers, there are icebergs.

Ian Fenty. Credits: NASA/JPL-Caltech

Through a professional connection with marine biologist Kristin Laidre of the University of Washington, Seattle, Ian had an opportunity to join the Greenland Institute of Natural Resources’ (GINR) week-long research cruise in northwestern Greenland. Malene Juul Simon of GINR’s Climate Division and Laidre planned the trip to deploy underwater acoustic instruments at glacier fronts — an important habitat for narwhals. These long-toothed Arctic whales navigate and hunt by making clicking sounds and listening to the echoes bouncing off nearby rocks or prey. The acoustic instruments pick up the narwhals’ sounds, documenting their activity at the glacier fronts.

The GINR instruments are attached to moorings—lines more than half a mile long, with a half-ton anchor at one end and the instruments and floats attached at intervals to the other end. Ian realized that adding OMG sensors of water temperature and salinity to the lines would produce a unique local dataset for OMG and benefit the narwhal research as well. The scientists agreed to collaborate, and Ian joined the team in Upernavik, Greenland, for an eight-day cruise.

Getting close to glacier fronts means encountering icebergs. Although Greenland’s bergs don’t match Antarctica’s for sheer size, the island’s fjords and shallow waters are littered with everything from modest lumps to tablelands that dwarf the 106-foot-long (32.3-meter-long) Sanna.

The view from Sanna’s bridge. Credits: NASA/JPL-Caltech

“The captain was an expert pilot, with decades of experience in this kind of ship,” Ian said. “It was mesmerizing to watch them navigate through a field of icebergs to get to the instrument sites. His concentration was really impressive.” The crew usually work on fishing trawlers that are at sea for weeks, often in much worse weather than the researchers encountered.

Once at a proposed site, the researchers had to decide whether a mooring could survive there for two years. “There were some places that looked good on paper, but when you got there, you could see that they were on the iceberg highway,” Ian said –meaning  a current carrying icebergs from a glacier’s calving front.

An iceberg can not only rip the line off the anchor, it can drag the entire mooring out to sea, anchor and all. One mooring from Southeast Greenland washed up in Scotland, almost 1,500 miles (2,400 kilometers) away.

If the planned site looked dicey, the researchers would look for a nearby spot protected by an island or other feature that was still close to the calving front and deep enough to be attractive to narwhals. When they had agreed on a new site, the researchers programmed their instruments, and the crew tied them on the line.

Then they dropped the whole assembly, surface end first, along a course about a kilometer long. When the anchor dropped, it pulled the line into the proper vertical orientation.

The ocean environment may have been wild, but the ship was civilized. The six researchers and six crew were supplied with wifi, meals to suit both Greenlandic and European tastes, wet and dry labs, and comfortable bunkrooms.

“I have to give a lot of credit to Kristen and Malene for organizing the team,” Ian said. “It was a fantastic experience to work with so many different researchers in related but different areas. Pick any random pair, and they would be explaining something new to each other. The camaraderie was great. We definitely were collectively more than the sum of our parts.”

Juul Simon (center) and fellow researchers. Credits: NASA/JPL-Caltech

Ian will return next summer to change batteries on his instruments. The moorings are equipped to help the researchers find them among next summer’s icebergs. “There’s a simple mechanism that sits just above the anchor and listens for a specific tone sequence,” Ian said. “When we come up in the ship, we play that song and boom! It lets go of the line, and the line comes up to the surface. The mooring has a satellite phone, and it sends its current coordinates to us by email.

“I’ll be getting email from my instrument. That’ll be a special day.”

A Few of My Favorite (Frozen) Things

Sastrugi, crevasses, sea ice, and bergy bits—a few of my ever-changing favorite things. Credits: NASA/Kate Ramsayer

by Kate Ramsayer / ANTARCTICA /

I knew they were my favorite as soon as I saw them. Sastrugi, the ice dunes of the polar desert, covered the landscape when I first flew low over Antarctica with Operation IceBridge. They were amazing—winds had shaped them into repeating patterns, appearing as diamonds or fish scales or branching tree roots. They were the only texture in the vast ice sheet that stretched as far as the eye could see.

The next day, however, crevasses took the top spot. Gigantic cracks that bent around mountains as the mass of ice crept toward the ocean—those were definitely my new favorite ice formations. As our IceBridge team took measurements down a path that ICESat-2 would trace from its orbit in space, I wondered how the height profile from these instruments could reflect these seemingly bottomless and terrifying cracks in the ice.

Then sea ice made an appearance. Icebergs were trapped at awkward angles in the frozen floes, and new ice spreading across open waters in translucent blues and whites—those had to be the most artistic formations, right? Maybe so—in my mind—until the next flight, which measured a newly created gigantic iceberg, and I glimpsed the jumble of bergy bits and sea ice in the rift between it and the glacier.

A glacier on the Antarctic Peninsula flows into the Bellingshausen Sea. Credits: NASA/Kate Ramsayer

At least I would be safe from a new favorite ice formation on my last flight, I thought. A survey farther inland of a region we had flown before, it should be old hat. But no. As we flew toward the site, the skies cleared over the Antarctic Peninsula, revealing glacier after glacier after glacier, all textbook examples of how spectacular glaciers can be.

Every day flying over Antarctica with the Operation IceBridge campaign brought a new incredible stretch of ice that left me, a new visitor to the continent, awestruck. Many members of the team have been surveying the continent for years, using a suite of instruments to map the ice and bedrock and monitor change. I couldn’t pick a favorite view, and can’t imagine they could either, so instead I just asked some of the IceBridge crew for an example of one of the neatest things they’ve seen flying over Antarctica.

Actually seeing Pine Island and Thwaites glaciers, which she has studied for more than a decade, is a highlight for Brooke Medley, IceBridge’s deputy project scientist. Her research showed that enough ice flows out of each glacier to contribute 1 millimeter to global sea level rise per decade. They’re massive glaciers, and flying over them puts into perspective just how massive they are. Credits: NASA/Kate Ramsayer 
The vastness of the Antarctic ice sheet can leave Eugenia DeMarco, IceBridge’s project manager, speechless. It’s just raw nature, she said, and provides a glimpse of what early explorers might have felt when they first ventured to this distant part of the world. Credits: NASA/Kate Ramsayer
In massive ice streams that appear solid and unmoving, it’s the crevasses that remind you the ice is in motion, said Thorsten Markus, ICESat-2 project scientist. These giant breaks form as the faster ice downstream pulls away from the slower ice upstream. Credits: NASA/Brooke Medley 
From above, crevasses can appear as wrinkles on fabric. Credits: NASA/Kate Ramsayer
The ice may seem desolate, but there’s life in Antarctica, and Lyn Lohberger, an aircraft mechanic and safety technician, points to seals visible on the ice floes. They provide a contrast as well, he said—the black seals on the white ice, with blue seas and sky. Credits: NASA/Jeremy Harbeck
Icebergs that have broken off of glaciers and ice shelves create different three-dimensional shapes in the flat sea ice, noted Victor Berger, with the CReSIS snow radar team. And Tim Moes, DC-8 project manager, pointed out the blue color of the older ice visible in the bergs. Credits: NASA/Kate Ramsayer
Operation IceBridge has surveyed Arctic and Antarctic ice for a decade, collecting scientific data on the changing ice. It’s the best office window view, said Jim Yungel, Airborne Topographic Mapper team lead—and it never gets old. Credits: NASA/Kate Ramsayer

Iceberg Ahead!

The NASA DC-8 aircraft’s shadow is dwarfed in scale by the B-46 iceberg. Credits: NASA/Brooke Medley

by Kate Ramsayer / THE SKIES ABOVE ANTARCTICA /

The crack that would become B-46 was first noticed in September 2018 – and the berg broke the next month.

NASA’s Operation IceBridge flew over a new iceberg that is three times the size of Manhattan on Wednesday – the first known time anyone has laid eyes on the giant berg, dubbed B-46, that broke off from Pine Island Glacier in late October.

The flight over one of the fastest-retreating glaciers in Antarctica was part of IceBridge’s campaign to collect measurements of Earth’s changing polar regions. Surveys of Pine Island are one of the highest priority missions for IceBridge, in part because of the glacier’s significant impact on sea level rise.

On Wednesday, IceBridge’s approach to the iceberg began far above the glacier’s outlet, in the upper reaches of ice that will eventually flow into the glacier’s trunk. There, as far as the eye can see, it was flat and it was white.

As the aircraft headed toward the glacier’s outlet in the Amundsen Sea, snow-covered crevasses became visible when sunlight struck at just the right angle. Every once in a while, a dark hole appeared in the crevasses where the snow had fallen through, providing a glimpse into the depths of the ice sheet. Then the holes got bigger.

The crevasses and dunes became a jumbled mess of ice, as Pine Island Glacier picks up speed as it flows to the sea. The crevasses got deeper and wider, swirling around each other. Striated snow layers in white and pale blue were visible down the crevasse walls, like an icy version of the slot canyons in the American West.

Crevasses in Pine Island Glacier indicate how fast the ice is moving. Credits: NASA/Kate Ramsayer
Crevasses in Pine Island Glacier get larger as the ice moves faster toward the Amundsen Sea. Credits: NASA/Kate Ramsayer

Then finally – the berg. Satellite imagery had revealed a massive calving event from Pine Island in late October, and the IceBridge crew was the first to lay eyes on the newly created iceberg.

The glacier ends in a sheer 60-meter cliff, dropping off into an ocean channel filled with a mix of bergy bits, snow, and newly forming sea ice. On the other side, a matching jagged cliff marked the beginning of B-46, as it stretched across the horizon.

The rift between Pine Island Glacier and a new giant iceberg, dubbed B-46, in Antarctica. Credits: NASA/Kate Ramsayer

“From this perspective at 1,500 feet, it’s actually really difficult to grasp the entire scale of what we just looked at,” said Brooke Medley, Operation IceBridge’s deputy project scientist who has studied Pine Island Glacier for 12 years. “It was absolutely stunning. It was spectacular and inspiring and humbling at the same time.”

Even though it had calved just over a week ago, the berg was already showing signs of wear and tear. Cracks wove through B-46, and upturned bergy bits floated in wide rifts. The iceberg will probably break down into smaller icebergs within a month or two, Medley said.

Iceberg calving is normal for glaciers – snow falls within the glacier’s catchment and slowly flows down into the main trunk, where the ice starts to flow faster. Eventually it encounters the ocean, is lifted afloat, and over time travels to the edge of the shelf. There, ice breaks off in the form of an iceberg. When the amount of snowfall and ice loss (from iceberg calving and melt) are the same, a glacier’s in balance. So it’s hard to link a particular iceberg like B-46 to the increasing ice loss from Pine Island Glacier.

A sheer wall of the new iceberg B-46 looms over a mix of sea ice, bergy bits, and snow at the base of Pine Island Glacier, as seen from a NASA Operation IceBridge flight on Nov. 7, 2018. Credits: NASA/Kate Ramsayer

But the frequency, speed, and size of the calving is something to keep an eye on, Medley said. In 2016, IceBridge saw a crack beginning across the base of Pine Island; it took a year for an actual rift to form and the iceberg to float away.

The crack that would become B-46 was first noticed in September 2018 – and the berg broke the next month.

They’re not the biggest glaciers on the planet, but Pine Island and its neighbor, Thwaites, have an oversized impact on sea level rise. Enough ice flows from each of these West Antarctic glaciers to raise sea levels by more than 1 millimeter per decade, according to a study led by Medley. And by the end of this century, that number is projected to at least triple.

“It’s deeply concerning,” Medley said. The geography of these glaciers make them highly susceptible to ice loss: relatively warm waters cut under the ice shelf, weakening it from below. This shock to the system has the capability to initiate an unstoppable retreat of these glaciers. There’s a reason Pine Island and Thwaites are dubbed the “weak underbelly” of Antarctica.

NASA has been monitoring Pine Island Glacier from aircraft since 2002, and IceBridge started taking extensive measurements of the fast-moving ice in 2009.

“Both Pine Island and Thwaites are ready to go and to take their neighboring glaciers with them,” Medley said. “Ice is getting sucked out into the ocean – and it’s hard to stop it.”

Send Me a Postcard From Station P, Will You?

Satellite image of ocean color showing variations in phytoplankton biomass in the Northeast Pacific Ocean (cyan colored swirls). Station P is at the bottom of the image, hidden under the clouds. Credits: NASA

Adrian  Marchetti is an associate professor in the department of Marine Sciences at the University of North Carolina at Chapel Hill and was aboard the R/V Roger Revelle for the EXPORTS field campaign this August and September.

So perhaps you read about the EXPORTS cruise and have heard about this place called Station P. You are now probably wondering why NASA would fund a mission that includes two research vessels spending over three weeks at this place?  Well, to some, Station P (also known as Ocean Station Papa or P26) is simply a point on a map in the middle of the North Pacific Ocean – latitude 50 degrees north, longitude 145 degrees west.  But to others it is much more than that.

Historically, in the 1950’s the Canadian weather service established a program to position ships off the west coast of Canada to forecast the incoming weather and sea state conditions. Station P was occupied for six weeks at a time by one of two alternating weather ships. Spending that much time at sea at one location can get, well, boring.  To help pass the time, the crew collected samples and obtained measurements of the ocean. In the early days, these included bathythermograph casts that measured ocean temperatures at various depths.  As more sophisticated approaches were developed to measure additional ocean properties, they started collecting samples for analysis of seawater chemistry (salinity, nutrient concentrations, etc.), chlorophyll concentrations (used as a proxy for phytoplankton biomass) and performed the occasional plankton haul to discover what critters called Station P their home.

A few decades later, with the development of new satellite technologies that enabled the monitoring of weather conditions from space (thanks NASA!), the weather ships became obsolete, and so the program was discontinued in the early 1980s. But as a result of the decades-long time series, what became apparent was the critical need for long-term monitoring of the ocean.  So the Department of Fisheries and Oceans Canada established the Line P program made up of a transect where Station P is the endpoint.  Today the Line P program is one of the longest ongoing oceanographic time series.

Map of the Line P transect, ending at Station P (also known as Ocean Station Papa or P26) in the Northeast Pacific Ocean. Credits: Karina Giesbrect.

So what’s so special about Station P?  Well, this mostly depends on who you ask. For one, the North Pacific is one of the largest ocean basins.  It undergoes periodic oscillations on approximately decadal timescales that can influence global climate. The North Pacific also represents the finish line of a long conveyer belt that transports deep waters from far-off regions of the planet to the surface.

From a biologist’s perspective (yes, I am a biological oceanographer), Station P also happens to reside in a so-called High Nutrient, Low Chlorophyll (HNLC) region where the growth of phytoplankton is limited by the availability of the micronutrient iron. This is a relatively new discovery, and although evidence for iron limitation in this region dates back to the early 1980s, the most compelling data was obtained in 2002 when Canadian scientists performed a large-scale iron fertilization experiment at Station P. The experiment was named the Subarctic Ecosystem Response to Iron Enrichment Study, or SERIES.

I participated in SERIES as a graduate student while completing my Ph.D at the University of British Columbia.  My Ph.D. research focused on pennate diatoms (a type of phytoplankton) of the genus Pseudo-nitzschiathat that dominate iron-induced blooms in many HNLC regions across the globe .

Microscope image of the pennate diatom Pseudo-nitzschia granii. Diatoms like this one are common responders to iron enrichment in many iron-limited regions of the ocean, including Station P. Credits: Adrian Marchetti.

These particular diatoms can achieve rapid growth rates at iron concentrations that would leave their coastal counterparts fully anemic and left for dead. These oceanic diatoms have many adaptations to survive in low-iron waters and sometimes flourish when new inputs of iron, which are primarily from atmospheric dust, periodically enter the ocean. Prior to SERIES I joined a number of Line P cruises adding iron to diatoms in bottles to make them bloom. We now know that not all phytoplankton are created equal and, given their extensive diversity and important role in contributing to the planet’s carbon cycle, we need to keep studying them.

During the SERIES experiment we also created a massive bloom of diatoms (you guessed it, dominated by Pseudo-nitzschia) as a consequence of adding several tons of iron to an initial patch of seawater approximately 80 square kilometers in size. At the peak of the bloom, the patch had grown to a size of about 700 square kilometers, representing one of the largest experimental manipulations on the planet to date. Fortuitously, the patch was captured by a satellite image of ocean sea surface color at the peak of the bloom, the only such image obtained throughout the entire SERIES experiment. Indeed, the North Pacific Ocean is known for having dense cloud cover almost every day of the year.

Satellite image from July of 2002 showing surface chlorophyll concentrations in the North Pacific. Warmer colors indicate more chlorophyll. The arrow is pointing to the enhanced chlorophyll concentrations due to a diatom bloom that developed as a result of the SERIES iron enrichment at Station P. Data courtesy of NASA’s SeaWiFS Project. Credits: Institute of Ocean Sciences/Jim Gower

So this brings us back to EXPORTS, which marked my seventh trip to Station P, so I am beginning to feel quite at home there.  With so many measurements obtained from Station P over the span of almost seven decades, what possibly is there left for us to learn?  Well, to put it bluntly—lots! In my career I have been fortunate enough to participate on a number of field missions, and by far the EXPORTS program constitutes one of the most extensive scientific undertakings I have been part of. Although, this time we were not adding iron into the ocean but instead making observations of its natural state by following the same parcel of water that passed through Station P.

Scientists retrieve an instrument that collects ocean optical measurements while aboard the R/V Revelle during the EXPORTS cruise. These optical measurements are similar to those obtained from satellites in space. Credits: Adrian Marchetti

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A primary objective of EXPORTS is to quantify the components of the ocean’s biological carbon pump, the process by which organic matter from the surface waters makes it’s way to ocean depths.  Scientists aboard both ships measured the processes that constitute the initial formation of organic matter by phytoplankton all the way to its export from the upper ocean or it’s remineralization back into inorganic carbon.

UNC graduate student Weida Gong hard at work collecting phytoplankton on filters aboard the R/V Revelle during the EXPORTS cruise. Credits: Adrian Marchetti.

Bacteria or little animals known as zooplankton that feed on phytoplankton, bacteria, or other small animals perform both these processes. Other scientists were focused on measuring the fate of the carbon that does sink out of the upper ocean by looking at the overall amount and what forms these sinking particles take.  It was quite an undertaking that had a lot of moving parts, all happening on two moving ships.

There was also a large effort to obtain as much information about this region using a multitude of underway systems that includes mass spectrometers, particle imaging “cytobots” and flow cytometers, autonomous instruments that includes gliders, floats and wire walkers, and instruments that collect optical measurements. Although we may consider ourselves lucky if we are able to obtain more than a handful of satellite images of ocean properties from space, we are making similar measurements from ships. We are also making new measurements that do not currently exist on satellites but perhaps will one day so that we can continue to develop new ways of monitoring our precious planet from above.

Through the years we have learned a lot about how this part of the ocean operates, yet there is still so much more for us to learn.  This is especially important at this period in Earth’s history as we continue to place considerable pressures on our valuable ocean resources.

And as for that postcard, well lets just say that it’s in the mail.

Compasses Get Quite Unhappy When Every Direction Is North

by Kate Ramsayer / 20,000 FEET ABOVE THE SOUTH POLE /

This was my first flight over Antarctica, and the vast expanse of ice – just white on the ground and blue in the sky as far as the eye can see – took my breath away.

As Operation IceBridge flew directly over the South Pole, my eyes went to the updating flight map. We were already off the edge of the map, as our survey line along 88 degrees south latitude had dropped below the extent of the Mercator projection. And now, as the latitude indicator counted up to 90 degrees and the crew counted down the seconds, I watched as our flight path showed the plane completely reversing course midair and looping up north. Of course, (and fortunately for my stomach) our actual DC-8 aircraft kept in a straight line.

OIB Deputy Project Scientist Brooke Medley shows the weird flight map path that results from flying around, then over, the South Pole. Credits: NASA/Kate Ramsayer
The Continuous Airborne Mapping By Optical Translator (CAMBOT) system images the Amundsen-Scott South Pole station as NASA’s DC-8 flying laboratory ascends after completing a survey line. Credits: NASA/Matt Linkswiler

Navigating can be tricky at the end of the world. While the mapping software went out of whack crossing over the pole, the actual flight software didn’t miss a beat – IceBridge Mission Scientist John Sonntag programmed it that way, knowing the ice-monitoring flights would need to handle the situation.

And although Halloween was last week, Saturday’s flight called for another trick – fooling the plane into flying a smooth arc around the 88 south line of latitude.

“Basically, we hack the autopilot,” Sonntag said. “We make the aircraft think that it’s lining up on a runway in bad weather, and the pilots can’t see. But what we’re really doing is lining it up on a data collection line, and doing it very precisely.”

West Antarctic mountains, on the way to the South Pole. (NASA/Kate Ramsayer)

He developed this system to deal with a quirk of flying at such a high latitude. If a plane is flying at the equator and wanted to go east, it would just go straight. But to go due east along the 88 south latitude line, the plane has to actually turn to the right a bit. If we wanted to circle the pole at 89 degrees latitude, we’d have to turn right even more.

Typical navigation procedures involve flying the shortest path between two points (known as a “great circle” path), where the aircraft’s heading varies continually to keep it on the flight path. But this far south, that would create a scalloped flight path: not efficient for the plane nor optimal for the instruments onboard, and – again – not friendly to my stomach. So Sonntag designed an autopilot system that can fly a perfect, smooth arc around the pole, along a mathematical concept called a loxodrome.

“I’m half engineer and half scientist, and this flight brings out the engineer nerd in me – I love this stuff,” Sonntag said. “Then seeing this in use, flying a 350,000-pound airplane around the South Pole – I mean, it’s nerd heaven.”

Sastrugi are fragile shapes on top of snow that are formed by winds. Sastrugi near the South Pole suggest there are two dominant wind directions. Credits: NASA/Brooke Medley

It was nerd heaven for me as well,  but for different reasons. This was my first flight over Antarctica, and the vast expanse of ice – just white on the ground and blue in the sky as far as the eye can see – took my breath away.

This particular survey route isn’t a favorite with the regular crew. There’s none of the dramatic mountains of the coastal glaciers, or icebergs calving into sea ice. But I loved seeing the repeating kaleidoscope patterns of the ice dunes called sastrugi (a favorite word AND a favorite ice formation, all in one!). From 1,500 feet up, it’s almost impossible to gauge how high they are, but it’s an incredible texture in this bleak, bright expanse of ice.

And this was a key flight for another reason: I’ve been writing for the ICESat-2 mission for more than five years, and in September I watched as it launched into orbit. ICESat-2 uses a laser instrument to measure the height and focuses on the polar regions. All of its orbits cross the globe at – you guessed it – 88 south latitude. So by flying this route a third of the way around the 88 south latitude circle, IceBridge is taking measurements that will help check a third of ICESat-2’s orbits.

The ATLAS lidar on ICESat-2 uses three pairs of laser beams to measure Earth’s elevation and elevation change. As a global mission, ICESat-2 collects data over the entire globe. However the ATLAS instrument is optimized to measure land ice and sea ice elevation in the polar regions, as is shown by this graphic representation of its orbital path around the South Pole. Credits: NASA

That means the satellite instrument I saw years ago when it was just an empty box in a cleanroom flew over that stretch of ice we measured 16 times, taking 60,000 height measurements each second. From 300 miles up, it measured the height of my new favorite sastrugi.

We Are The Land and the Land Is Us: Indigenous Women Accompany NASA Campaign Studying Climate Change in the Arctic

University environmental science students Joanne Spearman (left) and Mandy Bayha, from the Northwest Territories in Canada, inside NASA’s Gulfstream III jet during an ABoVE flight. Credits: NASA

My name is Mandy Bayha and I am from a small community called Délįnę [pronounced De-lee-nay] in Canada’s Northwest Territories. With a population of about 500, the community is nestled on the shores of the southwest Keith arm of the beautiful Great Bear Lake. The Sahtúotįnę (which means “people of Great Bear Lake”) have been its only inhabitants since time immemorial. The community is rich in culture and language and has a deep sense of love and connection to the land, especially the lake. I am a student in environmental science and conservation biology and also the indigenous healing coordinator (an initiative called “Sahtúotįnę Nats’eju”) for the Délįnę Got’įnę government. Under the guidance and mentorship of the elders, knowledge holders, and leadership of my community, I have been tasked to facilitate and implement a pilot project that aims to bridge the gap between traditional knowledge and western knowledge to create a seamless and holistic approach to health and wellness.

Traditional knowledge is relevant to everything we do, from healing, governance, and environmental management to early childhood development and education. Traditional knowledge encompasses virtually every human relationship and dynamic and outlines our relationships with each another, our Mother Earth, and our creator. As our elders say, “We are the land and the land is us. The land provides everything to us and is like a mother to us all and we all come from her.” It is our belief that everything is interconnected and in a constant relationship, forever and always.

On August 20 I traveled to Yellowknife to participate in the Arctic-Boreal Vulnerability Experiment, or ABoVE. Currently in its second year, this 10-year project is focused on the vulnerability and resilience of the Arctic and on understanding the effects of climate change on such a delicate ecosystem. ABoVE is important because it can provide a holistic view of climate change in the north by bringing together two knowledge systems: the traditional knowledge of my ancestors and western science. In fact, the project’s first guiding principle is to “recognize the value of traditional knowledge as a systematic way of thinking which will enhance and illuminate our understanding of the Arctic environment and promote a more complete knowledge base.”

I was able to participate in this incredible opportunity with a fellow Délįnę woman named Joanne Speakman, who is also an environmental science student. Our first day started on August 22, bright and early at 8 o’clock in the morning. We met the flight team at the Adlair Aviation hanger to undergo a safety briefing and egress training. It was like walking into a scene from the movie Armageddon. The two ex-U.S. Air Force test pilots were speaking a technical language riddled in codes, and the remote sensing engineers were spouting their checks and balances. I was thrilled to be surrounded by NASA employees all adorned in patches, jumpsuits, and ball caps. Afterward, Dr. Peter Griffith, the project lead, explained everything to Joanne and me in plain language. We then took a tour of the plane and learned how to exit in the unlikely event of an emergency. We were treated so nicely, and I felt more than welcome to participate.

We were invited to sit in a jump seat situated right behind the pilots during take-off and landing. Joanne got take-off and I got landing. What an experience that was! During our four-hour flight, which took us from Yellowknife to Scotty Creek (a permafrost research site near Fort Simpson), Kakisa, Fort Providence, and back to Yellowknife, Dr. Griffith sat with us and explained the ABoVE project. He gave us background on how the “lines”—the strips of areas that were scanned by the radar—were chosen and filled us in on research done in those areas previously, such as major burn sites, permafrost melt, carbon cycling, and methane levels. He referred to pictures while explaining how certain equipment as well as ground data calibration and validation techniques were used.

At work in the Gulfstream jet were flight engineer and navigator Sam Choi from NASA’s Armstrong Flight Research Center and radar operator Tim Miller from NASA’s Jet Propulsion Laboratory. Credits: Joanne Speakman

We also chatted with engineers from NASA’s Jet Propulsion Laboratory in Pasadena, California, who manned the remote sensing station on the flight. They explained that the remote sensing equipment, which was welded to the bottom of the Gulfstream III jet, is made of many tiny sensors that send signals to the ground that bounce back to a receiving antenna on the aircraft. The resulting data tell a story of what is happening on Earth’s surface, revealing features such as inundation (marshy areas where vegetation is saturated with water) and the rocky topography from the great Canadian shield, for example. The sensor they’re using is called an L-band synthetic aperture radar (SAR), which has a long wavelength ideal for penetrating the active layer in the soil. This is important for many reasons but mainly for indicating soil moisture.

Mandy Bayha gets a pilot’s view from the jupm seat as the NASA Gulfstream III comes in for landing, the town of Yellowknife on the shores of Great Slave Lake in view. Credits: Mandy Bayha

When flying above target areas, the pilots had to position the plane precisely on the designated lines to trigger the L-band SAR on the bottom of the plane, which would put the aircraft on autopilot mode and allow the sensor to “fly” the plane for the entire length of scanning the line. Once the scan was complete, the pilots would then take control of the plane again. The precision and accuracy for all those things to work in tandem was extraordinary to witness.

After the last scan, I hopped into the jump seat directly behind the pilots and watched them land the plane. Once on the ground, we were greeted by reporters with Cabin Radio (a local NWT radio station) who interviewed us and took our pictures with the Gulfstream III jet in the background. It was an absolute honor and a once-in-a-lifetime experience that I will never forget.

Fortunately, our incredible journey with NASA wasn’t yet complete. Joanne and I tagged along with two scientists, Paul Siqueira and Bruce Chapman, who are helping to build an Earth-orbiting satellite called the NASA-ISRO Synthetic Aperture Radar, or NISAR. We met up with Paul and Bruce early on the morning of August 24 and identified two lakes located just off the Ingraham Trail, a few kilometers outside of Yellowknife, to collect data that will help in the creation of algorithms to capture and interpret wetland and inundated sites via satellite and remote sensing.  We reached the shores of the first lake and split into two groups, one scientist and one student per group. We walked in separate directions in areas of inundation between the open water and the treeline surrounding the lake and took measurements using an infrared laser for accurate distances between the treeline and open water and made estimations and diagrams to fully detail the ground view.

A lake located just off the Ingraham Trail, a few kilometers outside of Yellowknife in Canada’s Northwest Territories, where data was collected that will help in the creation of algorithms to capture and interpret wetland and inundated sites via satellite and remote sensing. Credits: Mandy Bayha
University of Massachusetts Amherst scientist Paul Siqueira enjoyed the last canoe ride of the day with Joanne Speakman and Mandy Bahya. Credits: NASA/Bruce Chapman

 

We tackled the second lake with a canoe and could not have asked for better weather. We enjoyed our afternoon bathed in the sun. The waterfowl and minnows shared their home with us for a time. During our canoe ride, we learned a lot more about our scientist friends. They were part of a launch that carried some of the first remote sensing technology into space. This technology was then used to study the surface of Venus and Mars. How fortunate were Joanne and I to be able to listen and learn from such a brilliant crew of scientists who have had amazing careers.

It was an enriching and humbling experience to participate in the ABoVE project. If an organization such as NASA realizes that indigenous traditional knowledge is both valid and important, then I am hopeful for our next generation of indigenous people. I believe that this is the first step in reconciliation: acknowledgment and appreciation. I would be honoured to participate again; however, I am more than grateful to know that there is this collaboration happening and that it includes the indigenous Dene of the north.

Mahsi Cho (thank you)!

Chasing Sea Ice While Playing Tag With a Satellite

New sea ice growing in a lead at different stages of formation with the pink skies creating nice lighting on the ice. Credits: NASA/Linette Boisvert

 

by Linette Boisvert / PUNTA ARENAS, CHILE /

This mission, called Mid-Weddell, is probably the most complex of not only the fall 2018 Antarctic campaign but all of IceBridge.

Overnight I got to take part in a truly historic Operation IceBridge (OIB) mission and I couldn’t be more happy or excited to tell you all about it! This mission, called Mid-Weddell, was probably the most complex of not only the fall 2018 Antarctic campaign but all of IceBridge. To add to this, some unforeseen issues made this particular mission difficult. Upon landing after our previous mission, we were informed that there was a local fuel trucker strike. This meant NO FUEL for all of Punta Arenas, Chile. So we had no fuel for our plane, which meant we couldn’t fly the next day and had no clue when this strike would be resolved.

The strike was resolved after a few days, but the Mid-Weddell mission was again delayed when we found out that there were cracks in the NASA DC-8 pilot’s window. A new one had to be sent from Palmdale, California, and installed before we could fly again.

Local Chilean fuel truckers burning tires along the side of the road in protest. Credits: NASA/Jeremy Harbeck

 

NASA’s DC-8 Crew replacing the pilot’s window. Credits: Kyle Krabill

After all of these added stressors, we began to worry that we wouldn’t even be able to pull off this mission because it was an overnight flight and had to be timed perfectly with an ICESat-2 satellite overpass. These two mandatory factors are not so easy to achieve based on: 1) The weather in the Weddell Sea has to be clear, as in no low or high clouds, so that ICESat-2 can see the sea ice that we are flying over; 2) there has to be a crossover of ICESat-2 in the middle of the night and in the middle of the Weddell Sea.

Map of the Mid-Weddell sea ice mission. Credits: NASA/John Sonntag

In order to make things easier on ourselves (please note my sarcasm here), we were also “chasing the sea ice” during this flight. Why do we need to chase the sea ice, one might ask? Because sea ice, frozen floating sea water, is constantly in motion, being forced around by winds and ocean currents. This makes it rather difficult to fly over the same sea ice as ICESat-2  because the satellite can fly over our entire science flight line in about 9 seconds, where as it takes us multiple hours to do so by plane.  Thus, in order to fly over the same sea ice, the sea ice must be chased during flight.

A view of NASA’s DC-8 engines and wing as we were chasing the sea ice below. Credits: NASA/Linette Boisvert

Chasing the sea ice is essentially my OIB baby project, and before this campaign I diligently worked on writing code that would take in our latitudes and longitudes along our flight path, and, depending on the wind speed, wind direction, and our altitude from the plane, determine where the sea ice that ICESat-2 flew over would have drifted by the time our plane got there. This way we could essentially fly over the same sea ice that the satellite flew over. To do this we asked the pilots to take the plane down to 500 feet (yes, 500 FEET!!) above the surface and stay there for roughly a minute in order to take wind measurements. I then plugged these values into my code program and changed our flight path so that we could fly over the same sea ice. We monitored the winds during flight, and if they changed significantly we would do this maneuver again. Now how cool is that? I was in charge of changing our flight path as we flew! Can’t say I’d ever “flown” a plane before.

Lynette Boisvert, Operation IceBridge’s deputy project scientist, is “chasing the sea ice” during the science mission. Credits: NASA/Hara Talasila

 

During our flight and because of our flight path we were able to see multiple sunsets and sunrises as the sun bobbed up and down across the horizon.

Since our flight was a low-light flight it had to be conducted at night, so we took off from Punta Arenas at 7pm for an 11-hour flight, heading south to the Weddell Sea. During our flight and because of our flight path we were able to see multiple sunsets and sunrises as the sun bobbed up and down across the horizon. Because of the low lighting, the sky changed from oranges to pinks to blues, making for quite the show from the DC-8’s windows. Even the land ice lovers enjoyed it.

Sunrise over the Weddell Sea and sea ice below from the window of the DC-8 Credits: NASA/Linette Boisvert

Right before 1:35am local time, John Sonntag began a 10-second countdown, and when zero was reached, ICESat-2 crossed directly above our plane, thus “playing tag with the satellite” and making history, as it was the first time this was done since the satellite’s launch a little over a month ago. We all began chatting on our headsets about how awesome it was to be part of this mission and to be able to witness this moment. This is what OIB had been working toward since its beginning in 2009. The data gap was now successfully bridged between ICESat and ICESat-2.

An ICESat-2 flyover as seen from Punta Arenas, Chile, in the middle of the night. Credits: NASA/Jeremy Harbeck

Later, during the flight, I began to think about how everyone on the team really stepped up and how easily we were all able to work together to make this mission happen. I mean, we literally chased sea ice and played tag with a satellite during this flight! It took the pilots’ maneuvering, the aircraft crew’s hard work, the instrument teams’ and scientists’ steady collecting of data—everyone working together all night long—for this mission to run smoothly. I am truly grateful for everyone’s hard work and dedication and was so happy to be there that night. As we on OIB say, “Team work makes the dream work.”

IceBridge Deputy Project Scientist Linette Boisvert is interviewed, explaining how the crew chases sea ice in flight. Credits: NASA/Hara Talasila)

Chasing Clouds and Smoke Over the Southeast Atlantic

By Michael Diamond / SÃO TOMÉ AND PRÍNCIPE /

Michael is a PhD student at the University of Washington in Seattle.

Image 1: Michael Diamond in front of the P-3 at São Tomé International Airport before the October 10th, 2018, ORACLES flight. Photo credit: Rob Wood
Michael Diamond in front of the P-3 at São Tomé International Airport before the October 10th, 2018, ORACLES flight. Photo credit: Rob Wood

Our October 2018 deployment may be our last of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign, but it certainly won’t be our least. (We love each of our three deployments equally, of course.) During ORACLES, scientists from multiple NASA centers, universities, and other partners came together to study the complex interactions between smoke from fires on the African continent and low-lying clouds, called stratocumulus, over the Atlantic Ocean between September 2016 and October 2018.

Image 2: View of smoke produced by fires in southern Africa over low-lying clouds in the southeast Atlantic Ocean from onboard the P-3 during the October 10th, 2018, ORACLES flight. Photo credit: Michael Diamond
View of smoke produced by fires in southern Africa over low-lying clouds in the southeast Atlantic Ocean from onboard the P-3 during the October 10th, 2018, ORACLES flight. Photo credit: Michael Diamond

As my colleague Andrew wrote previously, climate models struggle to accurately capture the physical processes that occur when smoke particles, also known as aerosols, overlie and mix into clouds, in part because these processes occur at such small scales. The effects of aerosol-cloud interactions can include warming from sunlight being absorbed by the smoke and/or cooling from changes in the clouds’ brightness, coverage, and precipitation — it is still uncertain whether the heating or cooling effects cancel each other out or if one effect wins out in the end. We need the best observations we can get to better understand the fundamental physics and chemistry of this smoke-cloud system and use that knowledge to improve the models. Because the clouds and smoke we’re interested in are many miles away from land, the best way to study them is from the air.

Enter the NASA P-3 Orion: a four-engine turboprop plane that can directly sample the smoke plume and the clouds, from 20,000 feet in the air all the way down to just above the ocean surface.

Image 3: Michael Diamond (front) operating a Counterflow Virtual Impactor Inlet System (CVI), which lets instruments make aerosol measurements within the clouds, and Steve Broccardo (back) operating the 4STAR (Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument, a sunphotometer that can measure smoke properties at multiple wavelengths of light, aboard the P-3 on the October 10th, 2018, ORACLES flight. Photo credit: Andrew Dzambo
Michael Diamond (front) operating a Counterflow Virtual Impactor Inlet System (CVI), which lets instruments make aerosol measurements within the clouds, and Steve Broccardo (back) operating the 4STAR (Spectrometers for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument, a sunphotometer that can measure smoke properties at multiple wavelengths of light, aboard the P-3 on the October 10th, 2018, ORACLES flight. Photo credit: Andrew Dzambo

Initial results from our September 2016 deployment showed that, because it takes a fairly long time for the smoke from above to mix down into the cloudy layer, it may be best to study the smoke-cloud interactions by following individual cloud systems. This means we can account for how a cloud changes and evolves over time and how long the clouds and smoke have been in contact. For two of our ORACLES-2018 flights, we attempted to do just this, using a forecast model from the National Oceanographic and Atmospheric Administration (NOAA) to predict where clouds sampled on one flight would end up the next day, and then sampling the clouds there. For a fairly typical wind speed of around 10 knots, the clouds can travel approximately 300 miles in one day.

A great opportunity for this type of flight arose on October 2nd. The day before, a “pocket of open cells,” or POC, developed around the area we normally fly. In a POC, the stratocumulus clouds arrange themselves in a quasi-hexagonal pattern, with cloudy areas on the edges and clear skies in between. In “closed cell” clouds, which we sampled more regularly, the opposite pattern holds, with clear slots at the sides and overcast skies in between. During most ORACLES flights, we aimed to sample “polluted” clouds, with lots of aerosols in the air below the cloud. POCs are an interesting case because they tend to be very “clean,” removing aerosols from the air through drizzle. This precipitation is very likely the driving factor determining whether the clouds arrange themselves in open or closed cellular formations. We still have open questions remaining about whether aerosols can suppress precipitation and induce the open cells to transition into closed cells.

Image 4: True color image of the POC on October 1st from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The dotted black line shows the trajectory of a point (white circle) originally inside the POC for three days as it travels around the southeast Atlantic. The POC can be seen as the anvil-shaped collection of open cell hexagonal clouds between 8 and 12 degrees south and 0 and 8 degrees east. Image credit: Michael Diamond/NASA Worldview/NOAA Air Resources Laboratory (ARL)
True color satellite image of the POC on October 1st from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The dotted black line shows the trajectory of a point (white circle) originally inside the POC for three days as it travels around the southeast Atlantic. The POC can be seen as the anvil-shaped collection of open cell hexagonal clouds between 8 and 12 degrees south and 0 and 8 degrees east. Image credit: Michael Diamond/NASA Worldview/NOAA Air Resources Laboratory (ARL)

We first sampled the POC on October 2nd, flying above, below, and within the clouds. We were also able to sample another interesting feature: the white diagonal line of cloud that can be seen cutting through the POC near where we flew is called a ship track. Ship tracks are formed where the exhaust from ships emits particles and gases that form new aerosols, which can then interact with the clouds. (There are some other ship tracks visible in the satellite imagery from October 1st and October 2nd as well.) As expected, most clouds we sampled were drizzling and the below-cloud air was very clean. The more overcast linear feature in the ship track will help us better understand how clouds transition between open and closed cells.

Image 5: True color image of the POC on October 2nd from MODIS. The dotted black line shows the trajectory from before. The white circle is now at the location the original air was forecasted to have traveled to one day later. The POC can be seen as the anvil-shaped collection of open hexagonal clouds between 6 and 10 degrees south and 2 and 10 degrees east. Image credit: Michael Diamond/NASA Worldview/NOAA ARL
True color satellite image of the POC on October 2nd from MODIS. The dotted black line shows the trajectory from before. The white circle is now at the location the original air was forecasted to have traveled to one day later. The POC can be seen as the anvil-shaped collection of open hexagonal clouds between 6 and 10 degrees south and 2 and 10 degrees east. Image credit: Michael Diamond/NASA Worldview/NOAA ARL

On October 3rd, we set out on a mission to resample the POC and see how the clouds had changed and whether any smoke had been mixed into the below-cloud layer. We were heartened to see from our satellite imagery that the POC had traveled to roughly the same area we had forecasted. The POC by this time was dissipating: some well-developed open cells are still visible, but the POC boundaries had eroded and more “actinoform,” or lace-like, clouds had formed.

Image 6: True color image of the dissipating POC on October 3rd from MODIS. The dotted black line shows the trajectory from before. The white circle is now at the location the original air was forecasted to have traveled to two days later. The POC can be seen as the collection of open cells and actinoform clouds between 6 and 9 degrees south and 3 and 9 degrees east.)
True color satellite image of the dissipating POC on October 3rd from MODIS. The dotted black line shows the trajectory from before. The white circle is now at the location the original air was forecasted to have traveled to two days later. The POC can be seen as the collection of open cells and actinoform clouds between 6 and 9 degrees south and 3 and 9 degrees east.

More analysis will need to be done after we’ve had a chance to calibrate and quality control the data, but our initial readings suggested the below-cloud layer was still relatively clean, with some mixing of smoke from above evident.

At the end of this October 2018 deployment, data collection for the ORACLES campaign will be complete, but there will be plenty of science left to do. Not only do we have our own data to analyze, but there have been other American, British, French, German, and Namibian and South African teams studying similar questions in the same region that we will collaborate with. Together, the multiple field campaigns and model intercomparison projects just completed and currently in the works will greatly improve our understanding of smoke-cloud interactions over the southeast Atlantic and their implications for the regional and even global climate system.