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.
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.
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.
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.
“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.
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.”
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.
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 .
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.
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.
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.
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.
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.
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.”
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.”
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.”
Michael is a PhD student at the University of Washington in Seattle.
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.
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.
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.
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.
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.
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.
NASA’s Operation IceBridge (OIB) fall campaign in the Antarctic has been a much different experience for me compared to past campaigns. This is in part because of my new role and responsibilities as deputy project scientist for OIB, but also because I am currently in the southern hemisphere for the first time and seeing Antarctic sea ice and land ice for the first time in person! If that wasn’t enough new stuff, I am now spending 12 hours a day flying over Antarctica, almost nearing the South Pole. (That is the topic of a future blog…so stay tuned!)
These flights are long (I mean really long) and the days are also long. We have to get to the airport two hours before the flight, and it takes about 25 minutes to get to the airport in Punta Arenas, Chile. Once there, John Sonntag, Eugenia DeMarco, and I go over the satellite imagery available to us as well as some weather forecast models of Antarctica so we can decide which missions are the most viable for maximum data collection during flight.
This is nerve-wracking in two ways: 1) We have limited satellite imagery so the model forecasts don’t always get the weather correct. This is because there are relatively few observations for the models to ingest in Antarctica and the Southern Ocean to include in their forecasts. Basically, the more observations available the better the chance that the models will get the weather forecasts correct. 2) If we make the wrong call and pick a mission where the weather turns out to be different from the forecasts and we are unable to collect good data, we are wasting the project’s valuable flight hour time and money. Let’s just say flying a big plane like the DC-8 is not cheap. So that’s a lot of pressure.
The reason why our flights are much longer in the Antarctic compared to the Arctic is that the time it takes to get to Antarctica from where we are based, Punta Arenas, is two to hours hours long, meaning that’s how long it takes before we can begin our mission and collect data. About half of our flight time is high-altitude transit. One would think there would be a lot of down time; however, for me this is not the case. I am very big on outreach and giving back by sharing with students of all ages what I do in my job, how I got interested in science, and the science that I do. One of the great things about OIB and NASA airborne science in general is that we have the ability to connect and chat with students in classrooms all over the world during our flights.
So this is how I choose to spend my down time on science flights. Teachers can connect their classrooms with us and ask all types of questions, from climate change to what OIB does, what we studied in school, and what we eat on the plane. I have been partaking in this for a few campaigns now, and the majority of the teachers come back campaign after campaign, connecting with us multiple times.
One of these teachers is Marci Ward, who teaches third grade in Fairbanks, Alaska, and is fascinated with airborne science and is dedicated and enthusiastic about exposing her students to all types of science. Last spring, when we were stationed in Fairbanks for our Beaufort sea ice flights, I had the opportunity to go to her classroom and talk to her students in person about OIB on one of our down days. Shortly thereafter, I was able to connect with her students again on the plane chat the following week. They were so excited to meet me in person and to chat with me on the plane, it really made me feel good about what I was doing and that I was making a difference (aka giving me the warm and fuzzies inside).
It is very humbling to know that you can have such an impact on students and hopefully inspire and motivate them to pursue a career in science, math, or whatever subject they are passionate about. And it is even better when we receive feedback from the students and teachers, such as Janell Miller, a middle school teacher located in a high-poverty area of central California. “Believe me, your outreach matters to students,” she said. “It brings in a whole world they would not have been able to access first hand. The IceBridge project—speaking with scientists and engineers—this has a lasting impact. I’ve had former students who participated in this chat years ago, when I taught elementary school, write that this was one of their best school memories in their senior papers.”
After 12 hours in the air today, we arrive back in Punta Arenas and make it back to our hotel anywhere from one to two hours after we land. The days can be exhausting, and we know that we will be doing this all again tomorrow. But I also know that along with collecting all of this extremely valuable data of Antarctic ice, I and other scientists and engineers aboard also make an impact on students all over the world. Personally, I find it even more important for me to be continually proactive in the student chats because I hope to encourage and inspire young female students to be interested and pursue careers in math and science, areas where we are currently underrepresented and crucially needed.
Andrew is a PhD student at the University of Wisconsin-Madison.
Climate models are essential tools to predict climate’s evolution in the next few decades and beyond. Given current computational capabilities, most global models cannot resolve every scale and process; therefore, we often parameterize (i.e. simplify) the mathematical representation of the processes to obtain results in a reasonable amount of time.
Cloud processes are among the most difficult to parameterize for a number of reasons: clouds form on many different spatial scales, have highly variable time scales, and require simultaneous knowledge of a large number of factors that affect their evolution. Precipitation processes are even harder to capture in climate models because they occur on more highly variable spatial and time scales.
Additionally, the presence of aerosols, such as smoke or dust, further complicates the problem because aerosols’ effects on cloud and precipitation processes often depends on the type and amount of aerosol present. Overall, our knowledge of how aerosols interact with clouds and precipitation is highly uncertain, especially over remote areas like the ocean. In order to better understand these processes and their impacts on the global radiation and energy budgets – essentially, how heat moves around our planet – we require highly accurate measurements of these aerosol and cloud interactions.
NASA’s Observations of Aerosols above Clouds and their Interactions, or ORACLES, field campaign has set out to do just that. We are collecting a highly thorough, robust dataset aimed at challenging our current theories about cloud/aerosol interactions and how aerosols affect cloud and precipitation processes in stratocumulus clouds. These clouds might not be as visually stunning as ones associated with severe weather, but to atmospheric scientists, they are very important because they cover a large fraction of Earth’s subtropical oceans and have a large impact on earth’s energy budget. The ORACLES campaign, taking place over the Southeast Atlantic Ocean, bridges an observational data gap where ground and airborne observations are presently limited.
Weather radars were first developed during World War II, and radar technology has since expanded considerably. In the United States, WSR-88D radars are capable of observing (nearly) the entire country and are capable of notifying meteorologists of impending rain, snow, or destructive storms. But these radars are designed primarily to detect rainfall or ice particles larger than a small drizzle droplet. However, stratocumulus clouds are made up of even tinier cloud droplets, so the weather radar is not the best observing tool for them. Instead we need a radar system specifically designed for cloud detection.
Enter the NASA Jet Propulsion Laboratory’s 3rd generation Airborne Precipitation Radar (APR-3). With development beginning back in 2002, this radar system operates at three frequency bands used to measure thin clouds and light precipitation (W-band), light to moderate precipitation (Ka-band) and moderate to heavy precipitation (Ku-band). This is the first airborne radar system capable of measuring the atmosphere at three frequencies for the same location, which means it can simultaneously detect clouds and precipitation.
During the ORACLES campaigns from 2016 through 2018, the stratocumulus cloud decks we see most often frequently go undetected by the lower frequency Ku and Ka channels. But by including the high frequency W-band radar we can now see the stratocumulus cloud and characterize its structure at a very high resolution.
Occasionally, the APR-3 system in ORACLES measures both the cloud and precipitation. Detecting precipitation in multiple radar frequencies is useful as the high frequency W-band measurements commonly attenuates when precipitation gets too heavy – meaning the signal is somewhat lost because precipitating raindrops are too large. On the other hand, the other radar bands (usually Ka-band for ORACLES) can see this precipitation with little to no fading of the signal. The end result is that the multiple channels gives us the ability to better characterize the precipitation that’s happening. In turn, that gives us an opportunity to possibly provide a more accurate estimate of precipitation magnitude in these stratocumulus regions.
The ORACLES APR-3 contributes one component of a highly robust dataset designed to study the effects of aerosols on cloud and precipitation processes. Other direct and remote sensing instruments from the ORACLES field campaign collect highly detailed information about aerosol type and amount in the atmosphere – both of which are needed to properly assess cloud/aerosol interactions and their net effect on precipitation. Ultimately, ORACLES will greatly improve how we describe aerosol/cloud/precipitation interactions in future climate models.
by Joanne Speakman / NORTHWEST TERRITORIES, CANADA /
My name is Joanne Speakman and I’m from the Northwest Territories (NT) in Canada. I’m indigenous to the Sahtu Region and grew up in Délįne, a beautiful town of about 500 on Great Bear Lake. Now I live in Yellowknife, NT, and study environmental sciences at the University of Alberta. I was a summer student this year with the Sahtu Secretariat Incorporated (SSI), an awesome organization in the NT that acts as a bridge between land corporations in the Sahtu. My supervisor, Cindy Gilday, helped organize a once-in-a-lifetime opportunity for me and a fellow student from Délįne, Mandy Bayha, to fly with NASA. It was a dream come true.
One of NASA’s projects is called the Arctic-Boreal Vulnerability Experiment (ABoVE), which is studying climate change in the northern parts of the world. People from the circumpolar regions have seen firsthand how drastically the environment has changed in such a short period of time, especially those of us who still spend time out on the land. Weather has become more unpredictable and ice has been melting sooner, making it more difficult to fish in the spring. Climate change has also contributed to the decline in caribou, crucial to Dene people in the north, both spiritually and for sustenance.
Studies like ABoVE can help explain why and how these changes are happening. Along with traditional knowledge gained from northern communities, information collected by ABoVE can go a long way in helping to protect the environment for our people and future generations.
Wednesday, August 22, 2018:
It was exciting to meet the ABoVE project manager, Peter Griffith, and the flight crew because it’s amazing what they do, and to fly with them was an incredible opportunity to learn from one another. Although we were from different parts of the world, at the end of the day we are all people who care about taking care of the environment. We flew on a Gulfstream III jet to survey the land using remote sensing technology. We flew from Yellowknife to Kakisa, Fort Providence, Fort Simpson and then back to Yellowknife.
During the flight, crew ran the remote sensing system and they explained to us how it works. It got complicated pretty quickly, but from what I understood, a remote sensor is attached to the bottom of the plane and sends radio waves to the ground and bounce back, providing information about the land below and how it is changing from year to year.
August 24, 2018
NASA’s also working on building a satellite called the NASA-ISRO Synthetic Aperture Radar, or NISAR, which will help study the effects of thawing permafrost. Two of the lead scientists working on NISAR are Paul Siqueira and Bruce Chapman. While they were in Yellowknife, Mandy and I got invited to join them for a day to help collect field data.
We met with Paul and Bruce early in the morning and then drove out on the Ingraham Trail until we reached a small, marshy lake. We got out and walked along the lake’s edge, making measurements of the amount of marshy vegetation from the shore
to the open water, an area that I learned is called inundation. We used our own estimations and also a cool device that uses a laser to tell you exactly how far away an object is. Paul and Bruce will use the information we collected that day to figure out the best way to map wetlands, which will help the ABoVE project study permafrost thaw and help with development of the NISAR satellite by comparing our results to satellite images of the area.
In the afternoon, we surveyed a second lake, this time using a canoe. The sun came out and we saw ducks, a juvenile eagle, and many minnows swimming around. Nothing’s perfect, but this day was close to it and we learned a lot along the way.
Meeting and spending time with the NASA team, especially Bruce, Paul, and Peter, was the highlight of the two days. They’re incredibly kind and thoughtful and took the time to share their knowledge with us. ABoVE is a 10-year program and I hope there will be many more opportunities for northern youth to participate in such an exciting, inspiring project. There is so much potential out there. Thanks again for an amazingly fun learning experience!