By Elena Solohin, Florida International University /NEW ORLEANS, LOUISIANA/
My colleague, Emily, and I, with Florida International University’s Wetland Ecosystems Research Lab, kicked off our 2021 field season with a trip to the Mississippi River Delta to conduct research for NASA’s Delta-X project. We met up with a team of scientists from Louisiana State University and spent two weeks conducting fieldwork across the vast salt meadow, cordgrass marshes and freshwater wetlands of Louisiana’s Atchafalaya and Terrebonne Basins.
More specifically, we set out into the marshes by boat to collect soil cores and biomass (organic matter) from below- and above-ground, and to measure marsh elevation. The data we collected will contribute to Delta-X’s main goal – to project future wetland vulnerability along coastal Louisiana under various scenarios of sea level rise and sediment supply using state-of-the-art remote sensing tools, field observations, and modeling approaches across the two basins.
Our field work was both exciting and challenging. Our boat rides out to the sampling sites were their own adventures especially with the windy, bumpy, and at times, foggy conditions we encountered. When it was time to get out of the boats, we met our next obstacle – navigating the wetlands, dominated by tall cattail, on foot. Walking through the swampy ground is challenging for even the most experienced wetland scientists!
While trying to keep six feet apart from other teams, we took photographs of the wetland vegetation and recorded water levels. The photographs offered a bird’s eye view of the marsh landscapes and vegetation diversity. While we were working, we also marveled at the blue, over-arching sky, the teeming wildlife around us – including a few sets of beady alligator eyes sticking out of the marsh — and above all, the unique beauty of Louisiana’s coastal wetlands.
After each day of hard work, we were glad to have some time to take a break, even if it was in the same marshy area we’d been working. Now, we’re looking forward to processing the samples we collected to generate the data needed to help understand and predict future wetland vulnerability along coastal Louisiana.
By John Mallard and Tamlin Pavelsky, University of North Carolina /NEW ORLEANS, LOUISIANA/
Cruising through a bayou during recent fieldwork in the Mississippi River Delta, our boat driver casually pointed out an alligator and zoomed on by without slowing. After seeing us scramble to get out our phones to take a picture, though, he realized that perhaps these scientists from the piedmont of North Carolina were a bit less used to seeing alligators than the locals of southern Louisiana, and obliged us by circling back around for some pictures.
This alligator is one of the many species of animals and plants that depend on the unique habitat provided by the bayous, marshes, lakes, and rivers of southern Louisiana. Equally dependent on them are people; we rely on them to protect inland towns from tropical storms, support recreational and commercial fishing, and provide transportation networks for global shipping. With this vital role of the region in mind, DeltaX is measuring how water and sediment move through the delta to learn how and why marshes are changing in the area.
Our team, Tamlin Pavelsky and John Mallard from the University of North Carolina, was in the delta in early March to install sensors that measure water level in the marshes, bayous, and lakes. DeltaX is measuring the water surface elevation and extent via aircraft (NASA’s AirSWOT and UAVSAR), which allow us to get measurements across a very large area. Our sensors provide a check on these airborne measurements at the points where we install them. This process of checking our airborne measurements against points on the “ground” is called “validation,” and is a crucial part of using airborne measurements.
Of course, fieldwork had to be modified due to COVID. Prior to fieldwork the team quarantined at home and then formed a pod for the trip. Instead of flying down and buying groceries on site, we rented a car and packed two coolers full of food for the week. We wore masks at all times when we were outside of our accommodations. We self-monitored for COVID symptoms every day. Although these precautions added some time to our work, we were extraordinarily grateful to UNC and to NASA for helping us figure out how to work safely and successfully!
The sensors we installed are pressure transducers. When underwater, they record the pressure of water pushing on a membrane inside the sensor, and then we use that weight to determine the depth of water above them. The sensors are only about the size of a cigar, but they can record tens of thousands of measurements without running out of battery. The sensors we installed in March will stay in the field through Fall, when we’ll return to retrieve them and download the data.
Our work was done from a small motorboat whose flat hull was specially designed to work in shallow water. On a typical day we would meet our hired boat driver at a local boat ramp to put the boat in the water just after breakfast and be back at the boat ramp by 3 p.m. after installing 5-9 sensors. On board, we had about a dozen 10’ lengths of PVC taking up a whole side of the boat, along with our sensors, tools, and food and snacks for the day.
We would navigate to pre-determined locations to install sensors, which were usually on the edge of the water, and the driver would gently run the bow aground to keep us in place. Then we pushed a PVC pipe into the mud as far as we could by hand and finished the job with the post pounder.
We needed to get them deep enough into the mud so that a slit cut in the side of PVC was below the water line and would allow water into the pipe. We tied the sensor to the cap of the pipe using Kevlar cord that is highly resistant to wear, and hung it inside the pipe so that it was below the water surface. At each location we took measurements of the height of the pipe, the length of the cord, and depth of the water so that we could later translate the depth of water measured above the sensor to the actual depth of water at that point. After installing the sensor, we marked the location with a handheld GPS device and moved on to the next site.
On some days we only traveled a few miles and had to take the boat out of the water multiple times to drive to different boat ramps, but on our last day we put in at a single ramp and traveled more than 70 miles across the lakes and bayous of Terrebonne Bay. The weather was sunny, low 70s, and we had lunch on a narrow beach by an inlet separating the Gulf of Mexico from the bay. We watched birds and dolphins fishing for their own lunch of small fish and crustaceans in the inlet. It was a wonderful break at the end of a successful field trip. After a challenging year with so many disruptions of our work, among so many other things, it was such a relief to feel like we’re starting to be able to “get back to work”!
By Amanda Fontenot, Louisiana State University /NEW ORLEANS, LOUISIANA/
Although most of my work happens in the lab, office, or home, field days are some of the most important days of the year for my research. “Going to the field” is when we get to physically visit the wetlands that we spend so much of our time describing, researching, and caring about. Field days can require a lot of effort and time to execute, but they can also be a beautiful time to get out of the office and even have some fun with our colleagues.
I am a graduate student at Louisiana State University (LSU), and I am working towards my Masters of Science in Coastal and Ecological Engineering. I work with Dr. Robert Twilley in the Coastal Systems Ecology Lab at LSU, and my thesis research falls under NASA’s Delta-X Project. In October 2019, Dr. Andre Rovai and I laid a total of sixty-nine feldspar marker horizons at our seven Delta-X field sites in order to measure short-term sediment accretion. This March we traveled back to our markers in the Atchafalaya and Terrebonne basins of coastal Louisiana to measure this accretion.
We made these “markers” by pouring custer feldspar (a fine, white, mineral powder used in ceramics) on top of the soil surface. We use this material because it stays intact and provides a clear indication of when the experiment started. Over time, a soil layer forms on top of the white marker from both plant production and material that is deposited from rivers and the Gulf of Mexico. After placing the marker, our team comes back every 6 months and measures how thick that newly formed soil layer is on top of our marker. We then can divide that number by how many days it has been since we laid the marker, and we end up with a short-term sediment accretion rate. This rate is important in understanding how these wetlands will compete with increasing sea levels and local subsidence that threatens a majority of Louisiana’s coastal wetlands.
Most field days start pretty early in the morning, and this campaign was no exception. Our LSU team (Dr. Andre Rovai, Brandon Wolff, and I) left campus around 4:30 a.m. and headed to the boat launch to put our boat in the water. Since these sites are pretty mucky and we need to be careful to not step on our markers, we also travel with an airboat and our handy dandy airboat operator, Cade. After the boats are in the water, we drive to our sites and get to enjoy a nice sunrise on the water.
Depending on the morning, we usually get to our site around 9:00 or 10:00am and huddle up for a game plan. For this campaign, we needed to complete four tasks at each site: 1) measure accretion on top of our feldspar markers, 2) collect 50cm deep soil cores that help characterize the site, 3) deploy two water level recorders that collect data every 15mins, and 4) measure marsh elevation at varying points using our RTK instrument, which uses satellite-based positioning systems like GPS to estimate the elevation of a point. In the morning, we usually discuss in what order we might finish these tasks and who is in charge of each part of the process.
Most days, I am the one measuring and recording our accretion numbers for the feldspar markers. In order to minimize how much we disturb the soil around and within our feldspar marker, we use what’s called a “cryo-coring” technique – which we have affectionally named collecting “marsh popsicles.” In the field, we push a long, skinny copper pipe into the soil where we previously laid our marker and pump liquid nitrogen into the pipe. Since the liquid nitrogen gets so cold, some of the soil freezes around the pipe and ‘Voilà!’ we pull up our “marsh popsicle.”
On our popsicles, we see our feldspar marker as a white ring around the muddy popsicle. I measure the distance from the top of our popsicle (marsh surface) to that white ring (feldspar marker) with calipers and record it in my field notebook to look at later. Usually by the time we collect all the popsicles we need at the site, we go collect our soil cores and then are ready to eat lunch. We bring our own lunch to enjoy but what’s almost guaranteed is a plethora of light blue Gatorade and Andre’s signature glass bottle of Coke.
After lunch, we continue working on the other tasks for a few hours and try to help out the other field team from Florida International University (FIU) if we finish up before them. When we all finish up our field tasks, we start the long journey home. We pack up our supplies, put samples on ice, change clothes if we got too messy or wet in the field – those boat rides can get really chilly otherwise — and drive the boats back to the launch. At the launch, we get the boats back on the trailer and drive back to LSU, arriving later in the evening.
Depending on the weather, we might go out to another site the next day, meaning a meeting time of 4:30 a.m. back at the school. After we finish at campus, I race home to shower, eat dinner if we haven’t stopped somewhere on the drive back to Baton Rouge, clean my field clothes, and jump in bed to do it all over again the next day. Each team member plays an important role in the field, whether that be holding open bags to store samples, operating our liquid nitrogen tanks, or making sure everyone stays hydrated while we work. Although field days can be quite tiring and stressful, the work that our team accomplishes not only works towards the goals of the Delta-X project but increases the general knowledge of Louisiana’s coastal wetlands and the ecosystem services they provide.
By Dan McGrath and Randall Bonnell, Colorado State University /CAMERON PASS, COLORADO/
The word lightspeed conjures different images for different people. Star Wars fans may connect lightspeed to the Millennium Falcon, while radar scientists may think of the velocity of electromagnetic energy. Radio waves, a form of electromagnetic energy, travel at “lightspeed” through a vacuum, but when they encounter snow, they slow down drastically. Sounds bad, right? It might be if you’re trying to get somewhere fast, but if you’re trying to measure the amount of snow on the ground, it’s just what you’re looking for.
Over the past four months, our team from Colorado State University, along with teams across the western United States, has been tramping around in the snow each week trying to figure out just how much those radio waves might be slowing down. Why? In 2021, the NASA SnowEx campaign is focused on testing the use of airborne L-band Interferometric Synthetic Aperture Radar (InSAR). In this method, an instrument aboard a plane sends out radio waves to measure changes in snow-water equivalent (SWE) – or the amount of water stored in the snowpack – down below. The basic premise of this approach is that as more and more snow accumulates on the ground, it takes a radar wave longer and longer to travel from the aircraft, through the snow to the ground, and back to the aircraft. Each week, the NASA Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) team flies a plane overhead to collect InSAR observations of the snowpack. Meanwhile, we collect ground observations to document changes in snow depth, SWE, and other characteristics of the snow to help evaluate InSAR as a way of measuring SWE.
There are a lot of different ways to measure snow on the ground. You can probe it to measure its thickness or temperature, you can dig through it to measure its mass and density, and you can employ all kinds of fancy equipment to measure things like the surface area of grains of snow, or spectral reflectance. But trying to determine any of these details on a global scale from instruments in space becomes much more difficult. Even a fundamental question, like how much SWE is in a basin, can be difficult to answer.
Radio waves might be one answer to this difficult question. As radio waves travel through the snowpack, their velocity depends on the density of the snow. For example, denser snow means the radio waves will move more slowly. If we can measure the travel time (or phase, more on that later) of those radio waves very precisely, we can calculate SWE accurately. For these reasons, the SnowEx21 campaign is an exciting campaign – but what makes it even more important is its applicability. In 2022, NASA and Indian Space Research Organization (ISRO) will launch NISAR, a space based InSAR mission. It will carry a L-band (1-2 GHz frequency) radar instrument, meaning that those slow radar waves we’re evaluating from UAVSAR will soon be making the trip from space!
During the SnowEx21 Campaign, our team has been making weekly trips to Cameron Pass, a site at about 10,000-foot elevation about two hours west of Fort Collins, Colorado. One of the key observations we made each week was repeat ground-penetrating radar (GPR) surveys along multi-kilometer transects. GPR works by transmitting a radar pulse into the snow and measuring the two-way travel time and strength of the returning signal to produce a radargram. These surveys are particularly valuable for evaluating UAVSAR, as there is significant overlap between the methods.
We dig snow pits and measure the density of the snowpack to determine a velocity for converting the GPR-measured travel time to depth and SWE. By taking repeat measurements in the same areas week after week, we can measure a change in travel time, snow depth, and SWE between each interval, thereby providing a direct comparison to what UAVSAR is measuring. UAVSAR and other InSAR-based approaches measure changes in phase (a portion of an electromagnetic wave) between two subsequent radar acquisitions. This change in phase, on par with the change in travel time for our GPR instrument, is the key to detecting changes in SWE. However, phase changes are inherently complex and there is still much to discover regarding their interpretation. That is where other ground observations come into play.
Each week, we dug snow pits at two different sites to measure density, stratigraphy, and temperature of the snowpack. Density measurements are used to estimate a radar velocity for calculating snow depth and SWE from GPR travel times. Stratigraphy observations identify layers in the snowpack, which may influence InSAR or GPR observations. Temperature (and its corresponding gradient within the snowpack) is used to understand how snow crystals are changing and for identifying the presence of liquid water, as water strongly influences radar velocity. Additionally, understanding soil conditions – like whether the ground is frozen or thawed – and ground cover such as vegetation is key to interpreting InSAR observations. Outside of the pit, we also measured snow depths using a GPS-equipped probe, providing an additional approach to measure the change in SWE between each UAVSAR flight.
While intergalactic space travel is still science fiction, the use of radar to measure our global snow resources from space is becoming a reality. The SnowEx21 campaign is providing a critical link between theory and practice and, after a good deal of data analysis, it will undoubtedly leave a refined view of the capabilities and limitations of L-band InSAR for measuring changes in SWE. Such progress is necessary, as snow is a critical and highly valued resource relied on by billions of individuals around the world. Climate change is directly impacting this resource in a multitude of ways, including a reduction in the length of the snow-covered season and the total amount of snow that accumulates, and the impacts are predicted to become much more severe by mid-century. As such, the need for accurate, global estimates of SWE has never been more urgent. While SnowEx21 is only one small part of the puzzle, we’re hopeful that the progress made during this campaign will contribute to realizing this goal.
We’re so saddened by the loss of our teammate Dr. Gemma Teresa Narisma. She was a passionate climate researcher and the Philippine lead for the Cloud, Aerosol, and Monsoon Processes Philippines Experiment (CAMP2Ex).
As the director of the Manila Observatory and a professor at Ateneo de Manila University, she not only helped plan the research, but she aggressively brought students into the CAMP2Ex project, helping lead the next generation of meteorologists and climate researchers in forecasting weather for flights and data collection.
“We witnessed brightness, peace, curiosity, joy, courage and determination,” Simone Tanelli of NASA’s Jet Propulsion Laboratory said, in Gemma’s remembrance. “And Gemma was right at the center of that, emanating them, and the whole Manila Observatory team shone with them.”
Gemma’s expertise was internationally recognized: She served as an author on the Intergovernmental Panel on Climate Change’s (IPCC) Sixth Assessment Report and received numerous awards honoring her work as a researcher. Gemma was one of the leading subject matter experts in the Philippines on climate resilience, severe weather and natural hazards. She was consulted at every level of the Philippine government.
Gemma was a dedicated and enthusiastic teammate and mentor; a role model for younger scientists and a friend to all who met her. Her smile lit up a hangar, and it was a joy to watch her celebrate as her students took their first science flights with CAMP2Ex.
“The world has lost a valuable scientist, and the Philippines has lost an environmental spokeswoman, but we have lost a beloved friend” said Jeffrey Reid, U. S. Naval Research Laboratory.
By Gabrielle Antonioli, Montana State University /BOISE, IDAHO/
Being a snow scientist is an interesting career. Growing up in a small town in Montana, I was immersed in snow. But I saw it as one set thing—a blanket, unmoving, a cold, white mass. Only far later in life did I learn what a changing and integral role snow plays in our day-to-day life. Snow drives the winter economies of most Western states, acts as water reservoirs for those same regions and far beyond and is a fundamental part of life—whether we see it fall on our city streets or not.
I wasn’t always interested in studying snow, though. I received my bachelor’s degree in organismal biology, aimed at a career in medicine. A fundamental switch flipped in my brain as I worked in mountain environments, found snow science and ski mountaineering mentors, and realized that snow could be as changing and complex as any living organism. Mitigating risk and hazard while skiing – alongside trying to understand the evolution of a snowpack in a given mountain range – evolved into an encompassing and engaging mental and physical process for me. It is from this divergence in thought and passion that I found my path to the Earth sciences while skiing, teaching avalanche education, and backcountry ski-guiding. I am now completing a master’s in Earth sciences, focusing on snow science, at Montana State University. Amidst finishing this degree remotely due to the COVID-19 pandemic, I chose to move to Idaho and test my skills in a different environment. I am now working as a research technician for the NASA SnowEx project based in Boise, Idaho.
SnowEx is a multi-year NASA campaign to study snow using remote sensing. This involves things like radar, remote-controlled aircraft (UAVs), light detection and ranging (LiDAR), and more. This research is designed to inform plans for a future NASA satellite that would study snow from space. The primary instrument we’re using this year is Inteferometric Synthetic Aperture Radar (InSAR). InSAR flies over the Boise site each week, as well as other sites located near more distant mountain ranges, and uses radar to estimate the depth of the snow. We compare the measurements over time as InSAR continues its weekly flights over this site. The change in snow depth is directly related to the change in how much water is stored in the snowpack, which scientists call snow water equivalent (SWE). This is particularly important in mountain ranges that supply water to urban areas.
Even the most precise remote sensing instruments need to be validated with actual snow data collected in the field. For this reason, the field teams of technicians set out to various study plots across the Western U.S. each week to dig snow pits, identify the structure of the snowpack, measure density and liquid water content, and track each new snowfall. We travel on snowshoe, ski, or snowmobile. The teams I am on visit sites using backcountry skis with removable sticky skins and a special binding that rotates to either free the heel of a ski boot or lock it in place, designed for both uphill and downhill travel.
For our first field campaign mid-January, our team drove a winding highway to reach a mountain trailhead far outside of Boise known as Banner Summit, the upper reaches of which source water for rivers and groundwater that Boise locals utilize. We loaded our packs with science gear and used skis to reach the Banner Summit research site. In addition to the density scales and SWE measuring devices we bring, each site has stationary equipment in place to measure a bevy of meteorological variables—like new snowfall, SWE, total depth of snow, and wind speed. The depth and SWE measured by these set stations is also compared to the InSAR estimates, in addition to our on-the-ground measurements.
So, why is so much time and effort being devoted to finding a better way to monitor snow cover if we have things like snow telemetry stations (we call them SNOTELs) and stream gauges already in place to monitor snowfall and subsequent runoff? The answer is that there are disparities in weather patterns, rising rain lines (or the elevation at which rain is cold enough to turn to snow) in the mountains, and the ever-changing climate that is at our doorstep. For my master’s thesis, I measured variability in snowfall amounts on different types of terrain and during various storms Hyalite Canyon, Montana. I ski in this canyon often and know that the upper elevation SNOTEL under-reports snowfall amounts by about half—not due to instrumentation error, but due to the location of the station as well as the terrain surrounding it. Not only is this a common problem, but disparities like this make a huge difference for avalanche and hydrologic forecasters alike. I am hopeful that in the future, fusing different technologies like those in use for SnowEx, along with validation from on-the-ground data like my snow pits, will alleviate these issues and help locations that rely on snow melt for water more accurately monitor and plan for the future.
Cloud formation in the atmosphere depends on the presence of tiny particles called aerosols. ACTIVATE scientists are working to understand how variations in these particles from human and natural sources affect low lying clouds over the ocean and how those clouds in turn affect the removal of these particles from the atmosphere.
Despite racing against impending harsh weather conditions, a red and white World War II aircraft flew slowly and steadily over the icy waters surrounding Greenland in August and September. Three weeks delayed by pandemic restrictions, scientists from NASA’s Jet Propulsion Laboratory inside this retrofitted DC-3 plane started dropping hundreds of probes as part of an annual expedition known as the Oceans Melting Greenland (OMG) Project.
Since 2016, the OMG project has conducted numerous flights over the waters near Greenland’s lengthy and jagged coastline. They drop roughly 250 probes each year (though they managed a record 346 during this extraordinary 2020 expedition) which then relay temperature and salinity data. The team uses this information to help determine how much the surrounding ocean is contributing to Greenland’s ice melt.
“The glaciers are reacting very strongly to the ocean and we ignore that at our peril,” said JPL scientist and principal investigator Josh Willis. “The oceans have the potential to melt the ice very quickly and drive the sea level rise even higher than we expected.”
If it all melted, Greenland’s ice could contribute as much as 25 feet of sea level rise—though Willis assures us that this is not expected within the next year, or even the next 100 years. The big question that his team is trying to help answer is rather the speed at which the ice is melting.
Unlike icebergs—which float in water—glaciers sit atop a land mass, seemingly exposed and vulnerable to the warming atmosphere. While the atmosphere is a significant factor, it is not solely responsible for glacial melt. As the glaciers in Greenland start to ooze off the island in massive rivers of ice, they carve fjords into the landscape until they finally connect with the sea. While surface waters are generally frigid, the warmer ocean waters from below can cause the glacier to melt more quickly and speed up the amount of ice that drains off the land into the ocean.
Though the coronavirus pandemic had sweeping impacts across the globe, it didn’t halt environmental processes like Greenland’s glacial ice melt. It also didn’t impede the resolve of the OMG scientists to continue their work.
Starting in March up until the day they landed in Greenland on August 24, Willis says he wasn’t sure they would be able to collect their data this year. But cooperation between the various stakeholders, including NASA, the State Department, and the governments of Canada and Greenland, was key. Willis also gives credit to a huge amount of hard work by OMG’s Project Manager, Ian McCubbin of JPL, for making it possible. “If it wasn’t for McCubbin,” said Willis, “we’d still be sitting on our couches.”
Coordinating the scientists and equipment necessary for any expedition requires a great deal of planning, and the additional pandemic-related precautions made everything just a little bit more complicated.
“It was like a whole new layer, after you go across the border and go through customs and boarder control, now you also go through coronavirus screening,” Willis said.
In addition to getting tested a whopping seven times, two of which took place before even stepping foot in Greenland, Willis and the other members of the OMG team were very cautious. There was an initial isolation period after landing on the island during which they could fortunately work on the plane and equipment preparation, wearing masks when traveling to and from the site and no contact with locals. Greenland has had very few cases of COVID, and doesn’t have enough hospitals to handle any outbreaks, so the team was especially conscious of limiting their interactions with people there.
One exception was communicating with the nurses conducting their COVID-19 tests. “It was quite an experience getting tested this many times,” said Willis, “but the most fun was actually with nurses in Greenland, who were very nice and asked about our mission, so we got to tell them about what OMG was doing—and I suspect they followed along the rest of our journey on social media.”
Though some legs of the scientists’ expedition were delayed or more challenging as a result, Willis says it was well worth the extra effort to ensure everyone’s safety.
The outcome turned out to be a banner year for the project, despite the late start. Instead of heading north at the beginning of the month, it was already well into August when Project Manager Ian McCubbin and the three scientists from JPL—Ian Fenty, Mike Wood, and Willis himself—were able to meet with their flight crew from Kenn Borek Air.
Once they were on the ground in Greenland, their main concern was for the conditions they might encounter once back in the air.
“Weather starts to get pretty rough in September, and very rough in October.” said Willis. Fortunately, they were able wrap up their surveys by mid-September, mostly dodging the snow, sleet and wind that might impede their ability to drop all of the probes. “It was a sprint to the finish line, but we were able to accomplish everything we wanted to do and more.”
In fact, the team encountered unusually good conditions in the north east parts of the island, where ice and fog usually prevent access. As a result, they measured some glaciers that had never been sampled before.
When the project first began in 2016, the scientists also flew a jet with a radar strapped on the bottom to measure big swaths of glaciers from above, but NASA’s ICESat-2, an Earth-observing satellite that measures the mass of ice sheets and glaciers down to the inch that launched in 2018, takes care of that part of the mission now.
More than 45 scientific papers have now been published based on OMG data, with several more in progress. Willis says that every new discovery reminds them that the oceans are more important than they ever thought possible.
This year they noted new observations of Greenland’s largest glacier Jakobshavn, which has been closely monitored since the start of the project in 2016. In the first couple of years, the water near Jakobshavn cooled by 2.7 degrees Fahrenheit (1.5 degrees C)—a whole lot for a block of ice according to Willis. That cooling slowed the melting of the glacier, which then started growing instead. But early this year warm water returned to Jakobshavn and the recent observations suggest it is now thinning once again.
These continued discoveries from the project are very exciting for the scientists and organizations involved. Because of this, the OMG project has gotten approval to continue its research beyond the original end date, meaning that Willis and his crew will again be making their way back to Greenland next August, and this time hopefully without much delay.
Those flights are taking scientists over the western Atlantic Ocean to study how atmospheric aerosols and meteorological processes affect cloud properties. In addition, modelers will use data from these flights to better characterize how the clouds themselves, in turn, affect aerosol particle properties and the amount of time they spend in the atmosphere, as well as the meteorological environment. Coordinated flights between a King Air and an HU-25 Falcon allow researchers to fly above, below and through the clouds with a suite of instruments that can take measurements remotely, or from the air around the aircraft.
“The data have been really good so far,” Armin Sorooshian, ACTIVATE principal investigator and an atmospheric scientist at the University of Arizona, said of the summer flights. “We’ve seen some interesting features, like smoke from the wildfires on the West Coast.”
That smoke can seed clouds over the Atlantic Ocean.
Sorooshian is leading the campaign remotely from his home in Tucson, Arizona, where he and his wife are juggling work and the care of two children — a two-year-old boy and a baby girl who was born in July.
He admits it’s “a little tough.” But in a world where these flights could have been scrubbed from the calendar completely, Sorooshian isn’t interested in dwelling on the negatives.
“They’re good problems,” he said.
The ACTIVATE team began the first of two planned 2020 flight campaigns in February. They completed most of those flights, but had to pull the plug a little early in mid-March when concerns about the spread of COVID-19 began to sweep across the U.S. At that point, the fate of the second set of flights, originally scheduled for May and June, was — pardon the pun — very much up in the air.
As the COVID situation evolved, though, and as Langley leadership began to admit a limited number of research projects back on center with stringent safety protocols in place, it became clear there might be a glimmer of hope for ACTIVATE.
ACTIVATE is uniquely positioned among other current NASA airborne science missions because it’s based out of a NASA center, and the flight crew and many members of the science team are also based out of that center. John Hair, ACTIVATE project scientist with Langley’s Science Directorate, knew that from a purely logistical perspective, the mission could return to flight without the need for anyone to travel in from out of town.
“We had an opportunity because ACTIVATE has a relatively small crew that can operate the instruments in the aircraft, and do that, we felt, safely — albeit with some changes to the initial plans we set out,” he said.
Besides obvious stuff such as wearing masks and being mindful of social distancing, those changes include conducting the various daily flight planning meetings and pre-flight briefings completely via video conference. Researchers are also doing real-time monitoring of flight data from their homes. For researchers who are flying or need to be on center, the project has found ways to streamline some processes.
“For example, people are learning how to do their calibrations at the end of the flight after the instruments are already warmed up,” said Hair. “And then it only takes an hour to do.”
Compare that to the three or four hours it can take a researcher to warm up and calibrate an instrument before a flight.
The entire operation has taken a lot of careful planning and coordination between Langley’s Science Directorate, Research Services Directorate and Center Operations Directorate. Sheer determination has certainly played a role as well.
“We all signed up for supporting research as it comes in. ACTIVATE was in the middle of a major campaign and we wanted to get them back to flying as soon as we could,” said Taylor Thorson, ACTIVATE project pilot with Langley’s Research Services Directorate.
Sorooshian believes this experience could be instructive for the next round of flights, which are currently scheduled to kick off in February 2021 when COVID-19 could still be a significant concern.
It’s not just instructive from a safety perspective. Marine clouds are more scattered and difficult to forecast in the summer.
“Flying this summer also allows the team to hone the flight planning strategies, which can build upon heading into the next two years of flight campaigns,” he said.
For now, he and Hair are just happy to see a study they both care deeply about back in action.
“This is exciting that we’re out doing some flights,” said Hair. “People are excited to get the critical science data that we’re collecting on these flights.”
The ACTIVATE science team includes researchers from NASA, the National Institute of Aerospace, universities, Brookhaven National Laboratory, Pacific Northwest National Laboratory, the National Center for Atmospheric Research and the German Aerospace Center. The current flight campaign is the second of two in 2020, with two more to follow in 2021, and another two in 2022.
In the early 1900s, Ernest Shackleton attempted to travel across Antarctica, but as they neared the continent his ship became stuck in an pack of sea ice and was slowly crushed before it reached the landmass. Over 100 years later and on the opposite side of the globe in the Arctic, researchers in the massive, double-hulled icebreaker, Polarstern, are also stuck in a pack of sea ice – but this time on purpose. And this ship isn’t sinking any time soon.
Intentionally trapping itself in the sea ice, Polarstern drifts with the floe, which is a large pack of floating sea ice. Researchers set up “little cities” on the ice where they take measurements using delicate instruments. While it appears that the sea ice they walk on to reach these camps is stationary, everything is actually slowly drifting as wind and ocean currents push the gigantic slabs of ice.
MOSAiC is a multidisciplinary expedition, as researchers from a variety of fields – including marine biology, meteorology, and oceanography – collaboratively study Arctic changes.
“It’s more of a process study,” explained Steven Fons, a Ph.D. candidate at the University of Maryland and NASA’s Goddard Space Flight Center, who studied sea ice from March to May of this year. “The idea, then, is once everybody collects this data, we can compile everything and learn about the sea ice in the ocean, and the atmosphere and the ecology.”
Sea ice is an integral part of the Arctic climate system because it sits directly between the ocean and the atmosphere, moderating the exchange of heat and moisture. An important climate indicator, sea ice research identifies changes in other Arctic climate systems, including the ocean, atmosphere, ecology, and biogeochemical cycles. Basically, studying sea ice can give greater insight into how the entire Arctic is reacting to climate change.
For a small group of MOSAiC researchers, every Monday was a 14-hour workday spent at “Dark Sites,” named so because they are isolated from the bright lights of Polarstern. After traveling over a mile on snow machine, the team used hollow drills to remove cylindric cores from the sea ice floe. In the labs aboard Polarstern, these samples revealed the fascinating characteristics of sea ice.
“As ice forms, it will eject the salt away as it’s freezing,” said Fons. “The longer it stays around, the more salt essentially drains out of it.” Basically, high salt levels tell researchers that this particular ice formed in the most recent winter. This can reveal how the Arctic adjusts to higher temperatures, as the region is warming at a rate more than twice the global average.
In the Arctic, wind chill can reach frigid temperatures as low as minus 70 degrees Fahrenheit. Working in the cold without hand protection was impossible, so Fons wore thin gloves underneath his bulky mittens, which he removed when handling small objects. Even so, frequent warming breaks were necessary, which meant simple, one-minute tasks could take 10 times longer in Arctic conditions.
“Some of the really cold days, you can only last 30 seconds at a time taking off your big mittens,” he recounted. “You just have to put five zip ties on this cable, perfect. It should take one minute to do, but it would take 20 minutes because you have to keep warming your hands and [the zip ties] keep breaking in the cold.”
Native to Wisconsin, Fons is no stranger to subzero winters. Nonetheless, during this expedition he witnessed temperatures unlike anything he had ever experienced before. Icy winds bit into any exposed skin. His only relief: a thick, bushy beard and about ten layers of clothing.
In an ever-changing environment, researchers’ locations can be difficult to determine on the ice cover, which can literally shift beneath their feet. For MOSAiC, every measurement is paired with a GPS coordinate. However, the ice drifts, and so the latitude and longitude change every day. Instead, the immense icebreaker Polarstern is used as a point of reference, a sort of ground zero for field navigation.
“You’re given a position away from the ship, so a certain distance of x and y, and that will theoretically never change,” Fons explained. But even this system has its obstacles. “If the ice broke up and the ship moves a little bit, then you can lose your x-y positions, so it didn’t always work.”
Helicopters and planes accompany Polarstern, getting a birds-eye view of the stark white landscape. Flying high above the floe, planes take airborne measurements in a similar way to Operation IceBridge. Fons does research using data from NASA’s ICESat-2 – the satellite that surveys glaciers and sea ice around the globe – and he was lucky enough to validate some of the satellite’s measurements while researching with MOSAiC.
“On the ship, since we’re constantly drifting with the ice, we don’t exactly know where we’re going to be on any given day,” he said. “We got lucky that we happened to be drifting one day over a spot that ICESat-2 was going to fly over. We were able to jump on that opportunity and schedule a helicopter flight.”
Seasonal changes near the poles are unlike anywhere else on Earth. Summer and winter are really the only seasons these regions experience, characterized by a dramatic transition between complete darkness during winter days to total sunlight during the summer. Ten days after reaching Polarstern, Fons witnessed his first Arctic sunrise. As summer came, the Sun sailed over the horizon for longer and longer each day until it refused to set, resulting in the phenomenon of the “midnight sun.”
Ice dynamics, or the movement of ice slabs in the floe that changes the terrain, were a trademark of Fons’ three months on Polarstern. Sometimes, the researchers would wake up to massive leads, or ice fractures, blocking their usual routes. Other days, research tents would be buried in ice piles from leads that closed to form towering ridges. Sea ice dynamics had a wide appeal for study among MOSAiC teams. Below the floe, marine biologists and ecologists studied microorganisms. Within the ice itself, sea ice researchers examined crystallization patterns.
“With MOSAiC, what people are able to do is look at the ice at so many different scales and through many different lenses,” Fons summarized.