Overnight, I got to take part in a truly historic Operation IceBridge (OIB) mission, and I couldn’t be happier and more excited to tell you all about it! This mission, called Mid-Weddell, was probably the most complex not only of 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 because:
- The weather in the Weddell Sea has to be clear (as in no low or high clouds), so ICESat-2 can see the sea ice that we are flying over;
- 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 nine seconds, whereas it takes us multiple hours 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. 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. Then I plugged these values into my code program and changed our flight path so we could fly over the same sea ice. We monitored the winds during our 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.
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 [on our flight] enjoyed it.
Right before 1:35am local time, John Sonntag began a 10-second countdown. When zero was reached, ICESat-2 crossed directly above our plane, thus “playing tag with the satellite” and making history. 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.”
This piece was adapted from NASA's Earth Expeditions blog.
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 Bahya, 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!
This piece was originally published on the NASA Earth Expeditions blog.
Alex Niebergall is a PhD student in Earth and Ocean Sciences at Duke University and worked aboard the R/V Sally Ride in the North Pacific in August and September.
Before I joined the science crew aboard the R/V Sally Ride and set sail for the middle of the Pacific Ocean for my first ever research cruise, I can honestly say I did not know what to expect. Would it be an adventure? I hoped so. Would it be long hours in the lab? Undoubtedly. Would it be like stepping into National Talk-Like-A-Pirate-Day for an entire month? Maybe not. What I did know is that the research cruise meant 34 days on the open ocean doing what I love, and that was the only enticement I needed to sign up!
For me, it has always been about the ocean. Don’t get me wrong, I love science. I know this because my time as a researcher has taken me to far more windowless labs in the basements of old science buildings than remote, dream-like field locations, and I have enjoyed every second of this work too! But even this windowless basement science ties back to Earth, the environment, and most importantly (in my eyes) the ocean. Throughout elementary and high school, I was drawn to science and math because they gave me new ways to look at the world around me. Suddenly, every baseball game was a math problem—the velocity of the pitch, the angle of impact, the parabolic motion of the ball as it headed into the outfield (why, no… I’ve never been very good at sports, how did you guess?).
As an avid outdoorswoman, I've found science unlocking even more secrets. Physics and geology courses taught me about wave motion and erosion. Biology, ecology, genetics, and evolution classes allowed me to go to tide pooling and appreciate the radial symmetry of an ochre sea star while understanding its predatory role in the intertidal ecosystem. A firm grasp of chemistry allowed me to look at the ocean on a much smaller scale—a system of salinity gradients, dissolved nutrients, and pH balance. (Not to mention that chemistry makes cooking more interesting!) These subjects were interesting because I saw them every day around me, connected and continuously in flux, influencing each other in every way and giving me a new appreciation for all the activities and places I already loved.
Oh, the places we’ll go…
In truth, science has taken me to some of the coolest places I could possibly imagine. As an undergrad, I went to field sites in the depths of the Northern California wilderness that look so wild and untouched they could be the set for the next Jurassic Park movie. I’ve been to redwood forests studying ecosystem dynamics. Science training took me to the underwater kelp jungles of Monterey Bay, California, and offshore Oregon where I learned, among other things, that measuring baby sea stars (sometimes the size of my thumb nail) becomes infinitely more challenging in a surge that forces you 8 feet in either direction. I also learned that sea creatures (specifically sea otters and trigger fish) have the ability and the instinct to irreparably damage science equipment, but THAT is a story for another time! Research took me to the underwater paradise that is the coral reefs of Indonesia, where night diving with bioluminescent dinoflagellates meant that the water around me perfectly mirrored the stars that sparkled out of the darkness overhead.
Now as a brand new graduate student in Earth and ocean science, I found myself living on a floating laboratory in the middle of the Pacific Ocean, with a view of the waves as far as the eye can see in a blue hue that is unlike anything I ever saw in my life. My group’s project aboard the ship was focused on quantifying how the plankton communities in the ocean influence carbon export by estimating the net community production at the ocean’s surface. We did this by measuring biological oxygen concentrations in the surface water and pairing these data with genetic analyses of the microbial community. These measurements allowed us to infer how much carbon was being taken up by biological processes and, thus, taken out of the atmosphere.
With this project, those same subjects I learned to love in the tenth grade—chemistry, ecology, genetics, math—tied together (with the help and expertise of many, many other dedicated scientists) to give us a comprehensive view of what is happening in the ocean and how it affects our planet’s climate.
To some, the idea of being a floating speck in the middle of the ocean may seem isolating (or at the very least, nausea-inducing). To me, it is the coolest place I’ve ever been. The view reminds me that I am a small part of something big, not just as a junior scientist in the immense scientific undertaking that is the EXPORTS project, but also as one small human in the middle of an enormous planet that we have the privilege to explore, admire, question, and hopefully understand. Today, I am a happy, and very lucky, scientist because I was on this wild adventure, working alongside some of the most inspirational and dedicated scientists I have ever met.
But tomorrow? Tomorrow I am eagerly waiting to see where science will take me next.
This piece was originally published on NASA's Earth Expeditions blog.
NASA has been tracking Florence since it began moving toward the East Coast of the United States and continued to monitor the storm as it inched across the Carolinas and farther inland. The space agency is sparing no available resource in working to keep disaster responders and agencies such as FEMA and the National Guard informed with the latest information to assist in decisions on everything from evacuations to supply routes and recovery estimates.
Here’s a snapshot of some of the ways NASA has been monitoring the storm and its repercussions:
LAND, ATMOSPHERE NEAR REAL-TIME CAPABILITY FOR EOS
NASA’s Land, Atmosphere Near real-time Capability for EOS (Earth Observing System) (LANCE) provides data and imagery from Terra, Aqua, Aura, Suomi NPP, and GCOM-W1 satellites in less than three hours from satellite observation to meet the needs of the near real-time applications community. LANCE leverages existing satellite data processing systems in order to provide such products from select EOS instruments. These data meet the timely needs of applications such as numerical weather and climate prediction, forecasting and monitoring natural hazards, agriculture, air quality, and disaster relief.
ARIA FLOOD EXTENT MAPS
The Advanced Rapid Imaging and Analysis (ARIA) team at NASA’s Jet Propulsion Laboratory in Pasadena, California, created a flood extent map from Sentinel-1 synthetic aperture radar data acquired 12 hours after Hurricane Florence made landfall. The map, which was pushed to FEMA’s SFTP server (and is available to download), depicts areas of the Carolinas in light blue pixels that are likely flooded.
Media reports provided anecdotal preliminary validation. This map was cross-validated with ARIA’s earlier flood proxy map. This flood proxy map should be used as guidance to identify areas that are likely flooded, and may be less reliable over urban and vegetated areas.
To overcome that limitation, NASA’s Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) instrument aboard NASA’s C-20A aircraft is slated to fly over flooded areas to validate and improve these maps as well as provide near real-time imagery to assist local, state and federal partners.
For example, barrier islands and the immediate coastlines have borne the brunt of the storm surge and wind damage, resulting in the destruction of property along the coastline. UAVSAR imagery will help to clarify areas that have been impacted. Rapid acquisition of UAVSAR imagery revealing damaged homes and infrastructure provides higher spatial resolution details to complement “damage proxy maps” and other change detection approaches applied from routinely collected imagery or special collections from international partners.
VISIBLE INFRARED IMAGING RADIOMETER SUITE
The Day/Night Band sensor of the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi-National Polar-orbiting Partnership and Joint Polar Satellite System satellite platforms (both NOAA partnerships) provide global daily measurements of nocturnal visible and near-infrared light. The VIIRS Black Marble product suite detects light in a range of wavelengths from green to near-infrared, including city lights and lights from other activity.
On September 14, 2018 North Carolina officials said the number of power outages due to Florence was more than half a million. The NASA Black Marble product suite has been used to assess disruptions in energy infrastructure and utility services following major disasters. The night-time imageries are useful for pre-event and post-event mapping and monitoring of power outages in cloud-free conditions.
Satellites make weather monitoring possible
NASA relies heavily on its fleet of Earth-orbiting satellites as well as satellites from partner institutions for data that feeds into critical weather and climate models. Below is a summary of a few of those assets:
ATMOSPHERIC INFRARED SOUNDER
Aboard the Aqua satellite, the agency’s Atmospheric Infrared Sounder (AIRS), in conjunction with the Advanced Microwave Sounding Unit (AMSU), was able to capture three-dimensional images of the storm’s approach by sensing emitted microwave and infrared radiation. Warm colors in the infrared image (red, orange, yellow) show areas with little cloud cover, while cold colors (blue, purple) show areas covered by clouds at high, cold altitudes. The darker the color, the colder and higher the clouds and the stronger the thunderstorms. In partnership with the National Oceanic and Atmospheric Administration, these atmospheric observations are assimilated into operational prediction centers around the world to improve hurricane path prediction and other forecasts.
MODERATE RESOLUTION IMAGING SPECTRORADIOMETER & CLOUDSAT
Another powerful instrument aboard the Aqua satellite (the same instrument is also aboard Aqua’s “twin” satellite, Terra) is the Moderate Resolution Imaging Spectroradiometer (MODIS). Aqua and Terra work in tandem to image the entire globe once every one to two days, which allows MODIS to capture a sweeping picture of any number of Earth dynamics, including storms, through its 36 spectral bands, or groups of wavelengths.
Here, a MODIS image of Florence is shown with a cross-section of the storm taken on the same day by NASA’s Cloudsat satellite. The CloudSat pass offers a unique view of Florence’s asymmetrical structure, the intense convection and rainfall churning inside the storm, and a complex vertical cloud structure that is not visible from above. The storm’s clouds reached an altitude of about 15 kilometers (9 miles) at their highest point—fairly high for a tropical cyclone. The darkest blues represent areas where clouds and raindrops reflected the strongest signal back to the satellite radar. These areas had the heaviest precipitation and the largest water droplets. The blue horizontal line across the data is the melting level; ice particles were present above it, raindrops below it.
MULTI-ANGLE IMAGING SPECTRORADIOMETER
Global multi-angle imagery of the sunlit Earth is the specialty of the Multi-angle Imaging Spectroradiometer (MISR) aboard NASA’s Terra satellite. The instrument takes seven minutes to capture images from all nine of its cameras to observe the same location. MISR can reveal areas of high cloud cover associated with strong thunderstorms as well as spot powerful outer rain bands, which can sometimes spawn tornadoes.
SOIL MOISTURE ACTIVE PASSIVE
Managed by the Jet Propulsion Laboraty in Pasadena, California, and in coordination with NASA’s Goddard Space Flight Center in Greenbelt, Maryland, the polar-orbiting Soil Moisture Active Passive (SMAP) satellite plays a key role in forecasting flooding conditions. SMAP measures the amount of water in the top 5 centimeters (2 inches) of soil everywhere on Earth’s surface every 2 to 3 days. This permits changes of soil moisture around the world to be observed over time scales ranging from the life cycles of major storms to repeated measurements of changes over entire seasons. SMAP is also capable of estimating wind speeds over the ocean, as shown in the image above.
INTERNATIONAL SPACE STATION ASSIST
Astronauts aboard the International Space Station (ISS) have been snapping images of Florence with handheld digital cameras throughout the storm’s progression. Once the storm has passed and cloud cover lessens, requests to document flooding and changes to the land surface will be sent to the crew as part of ongoing NASA ISS response to the International Disaster Charter activation for Hurricane Florence. Imagery of this type is then georeferenced by the Earth Science and Remote Sensing Unit at NASA’s Johnson Space Center in Houston.
Also aboard the ISS is the Lightning Imaging Sensor (LIS), which detects the distribution and variability of total lightning day and night in order to improve severe weather forecasting and further scientific study on the relationship between lightning, clouds, and precipitation. Over a 12-hour period, LIS observed an average of more than 5 lightning flashes every 90 seconds in the vicinity of Hurricane Florence on September 14, 2018.
This piece was originally published on NASA's Disaster Response blog.
Kulusuk Island is breathtakingly beautiful — a spectacular mountain backdrop, quaint village, turquoise icebergs, even adorable sled-dog puppies. But Oceans Melting Greenland Project Manager Steve Dinardo didn’t choose it as a base because of the scenery. “We came here to work,” he says.
Kulusuk is ideally located for surveying East Greenland, which the locals call the wild side of the island — even more remote and unpopulated than the west coast. But the weather changes quickly, and the little airport doesn’t have a hangar to protect the research plane. If you have any trouble here, you could be stuck for quite a while. Every day in the field is expensive, and winter is just around the corner.
So the five OMG team members push themselves to get as much done as possible each day.
To begin with, they fly as many hours as they legally can to collect data. After the plane lands, there are still hours of work ahead. The plane is fueled and checked over for the next flight, Steve looks at multiple weather forecasting models to create a forecast for Kulusuk and the probe-drop areas, and Principal Investigator Josh Willis comes up with science priorities to match the weather. Both may end up revising their plans multiple times before the next morning’s fly/no fly decision.
Add to this list trying to stay in touch with family at home, answering a few pressing emails, eating, showering and so on. No wonder that some days, the team gets no more than a few glimpses of the incredible landscape out of plane and hotel windows.
“It’s more of an adventure in retrospect,” Josh summarized. “While you’re there, you have your head down and you’re working as hard as you can. When you get a day off, you sleep.”
The team has already had the one mandatory day off that it will get in Kulusuk. As far as I could tell, everyone filled it almost as full as the work days. At dinner, several team members did mention a nap, but they also spent some of their precious free time out in the Arctic landscape. Jakob Ipsen, manager of the Hotel Kulusuk, found a villager to take senior pilot Andy Ferguson fishing and another who took four of us to see a nearby glacier. Later, Jakob drove a few team members to the highest point on the island to watch the sunset.
The next morning, it was back to business. Steve gave a favorable weather forecast at 7 a.m., and the team took off for another eight-hour research flight about an hour later. They flew north to Scoresby Sund and dropped another 10 probes in key fjords, for a total of 99 drops in five days. Only 150 more to go.
After years of intensive research on Greenland’s glaciers, Josh Willis is standing next to one for the first time in his life. Apusiaajik isn’t one of Greenland’s giants — in fact, its name means “little glacier.” But its marbled blue-and-white wall of ice is tall, long and, as Willis says, majestic.
It’s also melting. From time to time there’s a loud cracking noise, and seconds later, a few refrigerator-sized chunks of ice drop into the ocean. You can’t help wondering when a larger chunk will fall, and how much icy water will hit you when it does. It’s natural for glaciers to lose ice this way, though disconcerting when you’re in the neighborhood. But Apusiaajik is like most of Greenland’s glaciers, it’s out of balance — melting faster than it can be replenished by winter snowfall.
We’re visiting the little glacier on a down day for NASA’s Oceans Melting Greenland (OMG) campaign. It’s close to Kulusuk, a tiny village on Greenland’s east coast that happens to have an airport with a 4,000-foot-long gravel runway. That’s too short for a big jet to take off and land. But for OMG’s converted DC-3, the Kulusuk airport is perfectly located for the mission’s survey flights around southeastern Greenland, studying how ocean water is affecting glaciers like Apusiaajik.
OMG is on its third annual campaign out of a planned five. The goal each year is to blanket Greenland’s continental shelf with probes measuring the seawater’s temperature and salinity. This year, the team has already dropped 89 out of 250 probes, starting at the southern tip of Greenland and working up the east coast. Soon it’ll be time to move north to the next base.
Halfway through OMG’s expected lifespan, what have scientists learned, and what do they still hope to find out?
“We’re beginning to see the signs of long-term changes on Greenland’s continental shelf — changes that take years to happen,” Willis says. “We’ve never seen that before.” Daily changes in water temperature come and go, but the OMG scientists are finding that glaciers react more strongly to slow changes in water temperature far below the ocean surface.
Greenland’s continental shelf is shallow, averaging about 1,600 feet (500 meters) deep. But it’s gashed by troughs carved by ancient glaciers, which can be two times deeper than that. These troughs are natural conduits for deep water to get up on the shelf, but it’s not an easy passage. Sills and underwater mountains within the troughs impede the flow and create basins.
Willis gestures at the ice-flecked channel flowing past Apusiaajik. “In a couple of weeks, all this water will be way downstream,” he says. “In the troughs and basins on the shelf, that’s not true. They’re almost like tide pools — the water comes in at high tide and stays there till the tide comes back. In those deep basins, instead of twice per day like the tide, it’s more like once per year and sometimes less. And when warm or cold water gets in, it stays for years.” There’s not always enough variation in the seawater from winter or summer for water to get into the basins each year; it may take a change in a large-scale ocean climate pattern, similar to an El Niño event in the Pacific Ocean, to trigger the change.
For the last two years, the North Atlantic has been moving into a naturally cooler climate phase. Willis is eager to see when and how far the cooler water will move up the West Greenland coast, and how long it will last.
Answering those questions will chip away at the big remaining goal of OMG: quantifying how much glacial ice melt will result from any given change in ocean temperature. If water comes onto the continental shelf that’s a degree Celsius warmer than now, how much will the melt rate increase? What about three degrees?
“One of the advantages of watching a glacier change year after year after year is that you begin to get an idea of what’s driving the change. If it’s the ocean, I think we’ll be able to quantify that with two more years of OMG data,” Willis says.
“That’s what we set out to do. What I’m really excited about is that it’s beginning to happen.”
"There is a fifth dimension beyond that which is known to man. It is the middle ground between light and shadow. It is an area, which we call, the Twilight Zone."
Like many kids growing up in the 1960s, I eagerly anticipated every episode of a black-and-white TV series by Rod Serling, expecting to be surprised, maybe even a little scared, of the mysteries of that fifth dimension he called “The Twilight Zone.” Little did I know that decades later as an oceanographer, I’d find myself at sea with over 60 like-minded scientists on a program specifically targeting the mysteries of another twilight zone—the one in the ocean that lies just below the sunlit surface.
What motivates us is the need to learn more about the role of the twilight zone and the animals that live there in regulating Earth’s climate. The story of how they do this actually starts at the surface, where microscopic marine algae, or phytoplankton, turn carbon dioxide in the water into organic matter via photosynthesis, much like plants on land.
This organic matter forms the base of the marine food web, which basically means that these microscopic plants serve as food for tiny marine animals called zooplankton, which are eaten by larger marine organisms and so on up to larger animals, like the fish that humans consume. Many of these animals come up from the twilight zone at night, using the cover of darkness to feed in surface waters and then disappear come daybreak. This is, in fact, the largest animal migration on Earth and happens around the globe every day, and we barely know it happens.
But I am getting ahead of myself, because despite how appropriate Rod Serling’s description of the mysteries of “the middle ground between light and shadow” fits with what we are doing out here, peering with our instruments into the dimly lit depths, his TV show is not the origin of the name of a twilight zone in ocean sciences. In fact, at least as far back as 1915, textbooks included discussion of the “decrease in the abundance of life from the sunlit surface layers, through the twilight zone, to the zone of darkness,” as was written in College Physiography.
Getting back to this cruise, most of the carbon either sinks out of the surface ocean directly or is carried by animals back down to the twilight zone in their guts and gets excreted. All of this sinking carbon becomes food for other twilight zone animals, with less and less remaining as you go deeper. This constant rain of organic carbon is known as “marine snow,” which drifts through the twilight zone and into the deep ocean.
Who cares how much organic matter or carbon goes through the twilight zone? Well, if you are an animal living in the twilight zone, that’s your main food supply. As a human concerned with the potential for rising carbon dioxide levels in the atmosphere to disrupt our climate, it’s the quickest way you can get organic carbon to the deep ocean, effectively removing it from contact with the surface ocean and atmosphere for hundreds or thousands of years.
Simply put, without the ocean storing carbon in the deep sea, the levels of carbon dioxide in the atmosphere would be much higher than they are today. And the last time they were this high, Earth was a much different place.
The tools I used to measure this cascade of particles carrying organic carbon to depth on this voyage include sediment traps—something like a rain gauge that captures in a tube the sinking particles that are slowly settling through the water. A second method my group uses to measure sinking particles takes advantage of a naturally occurring element called thorium-234, which is slightly radioactive and decays with a precise 24.1-day half-life. This clock allows me to calculate very precisely how much carbon is being carried from the surface through the twilight zone.
It’s far too early to share my results from this cruise, but the importance and complexity of these links between twilight zone organisms and climate should not be underestimated. Like snowfall on land, organic carbon transport to the depths varies with the seasons and locations in the oceans, but in ways we cannot predict. And it is important for us in our efforts to better understand how quickly climate will change as we keep adding more carbon dioxide to the atmosphere. This job is so complex that it takes a village out here aboard two research ships, with autonomous vehicles in the water and support teams on land and satellites above. We work together to study these carbon flows and the living organisms in the twilight zone that create what marine biologist and conservationist Rachel Carson called the “most stupendous snowfall on earth.”
I don’t know if there are any episodes of The Twilight Zone to watch out here, but I do know there are many deeper mysteries we hope to unravel about the ocean’s twilight zone.
Ken Buesseler is a senior scientist at the Woods Hole Oceanographic Institution. He has been working for decades on the ocean twilight zone and its impact on Earth’s carbon cycle. He is currently on the R/V Roger Revelle as part of the Export Processes in the Ocean from Remote Sensing (EXPORTS) field campaign.
This piece was originally published on the NASA Earth Expeditions blog.
I am Dave Siegel, a professor of marine science at the University of California, Santa Barbara. I have been working for many years to implement the Export Processes in the Ocean from Remote Sensing (EXPORTS) oceanographic campaign: a coordinated field effort to understand the interactions between life in the sea and Earth’s carbon cycle.
Last Thursday night, I watched “my baby” of a campaign sail away, as the Research Vessel Sally Ride left Pier 91 in Seattle for the northeastern Pacific Ocean.
While I am the science lead for EXPORTS, it’s not just my baby—it is truly a group effort. Two teams of scientists created the EXPORTS science and implementation plans, with a lot of input from the greater oceanographic community. The result is a campaign comprising more than 50 funded NASA and NSF investigators from nearly 30 institutions and many graduate students, postdocs and technicians, all excellently supported by the masters and crews of two Scripps Institution of Oceanography’s research vessels: the R/V Roger Revelle and the R/V Sally Ride.
EXPORTS aims to develop a predictive understanding of the interactions of life in the sea and Earth’s carbon cycle, which is critical for quantifying the carbon storage capacity of the global ocean. The oceans are Earth’s largest active reservoir, or storage, of carbon and carbon dioxide concentrations in the atmosphere and thus helps regulate our planet’s climate. This predictive understanding of the interactions of ocean life and the carbon cycle is especially important as we are seeing that our ocean ecosystems are changing in response to changes in Earth’s physical climate. To do this we need data to test and validate these satellite-based assessments and numerical model predictions.
We are trying to tackle a super hard problem—one I believe to be a true grand challenge in Earth System Science. Our approach is simply to follow the money. For ocean ecosystems, that currency is the energy stored in phytoplankton carbon from photosynthesis. The production of phytoplankton carbon is nearly balanced by its consumption by animals called zooplankton, which in turn provide the energy for the higher trophic levels of the sea, such as fisheries and charismatic megafauna (whales, seals, sharks, and the like).
The slight imbalance—roughly 10 percent of phytoplankton production globally—drives an export of organic carbon from the well-lit surface ocean into the dimly-lit twilight zone beneath. Within the twilight zone, microbes and animals of all description consume this exported organic carbon, utilizing their energy for metabolism. This export of organic carbon from the upper ocean and their consumption within the twilight zone, along with ocean circulation, shape the carbon storage capacity of the global ocean and frame the two major research questions for EXPORTS.
Constructing a field campaign to identify and quantify the flows of organic carbon through the ocean is, of course, a major challenge. Phytoplankton physiologists need to assess phytoplankton growth rates and responses to perturbations in their required nutrients (nitrogen, phosphate, silica & iron). Zooplankton grazing and the carbon cycle impacts of their daily vertical migration to the sunlit layer of the ocean from the twilight zone need to be assessed.
Sediment traps that catch the rain of sinking particles measure the flux of sinking carbon as well as make detailed geochemical measurements that test how well our measurements of the individual pathways reflect the large-scale mass budgets needed to build and test satellite and computational models. Optical oceanographers make ocean color measurements that link the EXPORTS datasets to NASA satellite data products. And I feel bad that I left out so many other individual research activities going on, but mentioning each of them would take up another two paragraphs!
The measurements needed to constrain the various food web and export pathways as well as adequately sample the highly variable ocean environment requires technologists that can overcome these challenges. For example, the EXPORTS team includes robotics experts who build, deploy, and analyze data from an array of autonomous underwater vehicles (AUV) that sample ocean properties on time scales ranging from minute to years.
EXPORTS has also taken advantage of recent technological advances such as novel high-throughput microscopes and in situ imaging devices that take individual images of billions of phytoplankton cells as well as zooplankton and other various organic matter. These images are then analyzed using advanced machine learning techniques to provide unique views of the structure of plankton communities.
Advancements are also available from the biomolecular sciences where metagenomic and bioinformatics approaches provide complementary ways to characterize plankton communities and their metabolism. Lastly, several projects include numerical modelers who will use computational approaches to help answer EXPORTS science questions.
The first EXPORTS field deployment will be to Station P (50N 145W) in the Northeast Subarctic Pacific Ocean. Station P (or PAPA) has been sampled and resampled over many decades—from as far back as 1949, when it served as an ocean weather station. Presently, Station P is the terminus of the Canadian Line P transect ocean research program and is an area of focus for the National Science Foundation’s Ocean Observatories Initiative project.
Last week, the R/V Roger Revelle and the R/V Sally Ride sailed to Station P. Both are floating laboratories that enable our research, but they will have different missions. The R/V Roger Revelle will make detailed rate measurements and conduct a wide variety of experiments while the R/V Sally Ridewill make spatial surveys around its partner ship to assess the three-dimensionality of these processes. These ship-based measurements will be supplemented by the array of AUVs. Both ships and robots will make ocean optical measurements linking the EXPORTS field data to present and future NASA ocean color satellite missions.
EXPORTS is also planning a second field deployment in the North Atlantic Ocean in the spring of 2020 to provide contrasting data. Furthermore, NASA has supported a group of Pre-EXPORTS projects aimed at mining available, relevant data sources for use in EXPORTS synthesis analyses and to conduct modeling experiments to help plan this and the North Atlantic expeditions.
So I’m the science lead but I’m not sailing. Seems weird, but early in our planning we were worried about the coordination between all of the things going on. My job back home now is to help coordinate activities on the two ships and assist the four co-chief scientists in fouling off whatever curveballs that may come. I’m sure they will provide blog posts soon introducing themselves.
It is been a long time coming and I realized that as the R/V Sally Ride was sailing away. I have been there from the start pushing this along, so I suppose it is “my baby.” I do want to thank all involved in the planning and implementation, including the program officers at NASA and NSF.
This piece was originally published on the NASA Earth Expeditions blog.
My name is Arie and I am a 21-year-old student at the University of Denver studying environmental science. I am one of 28 students selected to participate in NASA’s Student Airborne Research Program, or SARP, an eight-week summer internship program that exposes undergraduate students to all aspects of airborne science campaigns, including data collection techniques and data analysis. Students from diverse STEM backgrounds were placed into four research groups—atmospheric chemistry, ocean remote sensing, land remote sensing, and whole air sampling—and they must complete and present a research project by the end of the summer.
I grew up in Lincolnshire, Illinois, and since a young age I have been fascinated by the scientific processes that influence our planet. I believe that every human has the right to live a meaningful and purposeful life predicated on the existence of certain universal guarantees, such as clean air to breathe, safe food and water to eat and drink, and preserved natural areas. Those values align with SARP and almost all other NASA Earth Science campaigns, as their main objective is to collect accurate and high-quality data about the land, ocean, and atmospheric properties of Earth to understand how our world is changing.
For this campaign, we were seated in NASA’s DC-8 flying laboratory, a unique plane with scientific instruments protruding from the windows. NASA’s DC-8 is not like any traditional commercial airline flight. It was once a commercial airliner but was repurposed by NASA’s Earth Science Division and is now one of the best research aircraft in the world for conducting airborne science. Prior to my flight, the aircraft completed flights for NASA’s Atmospheric Tomography Mission (ATom), an around-the-world airborne science campaign dedicated to studying the impact of human-produced air pollution on greenhouse gases and on chemically reactive gases in the atmosphere.
On this particular flight, we had instruments that measured the presence and relative concentrations of important atmospheric gases over regions in southern and central California, including the San Joaquin Valley. I could hear the faint crescendo of the aircraft’s engine and full-blast air conditioning system through my noise-canceling headphones. The scientists, flight engineers, and pilot talked over the on-board communication system. I listened intently to the scientists as they updated the crew on their instruments.
The aircraft flight path and maneuvers depend on the goals of a particular scientific mission. On this six-hour flight, we undertook spirals, loops, and Meteorological Measurement System (MMS) maneuvers, which are important for understanding the aerodynamics of the aircraft and its effects on measurements such as pressure, winds, and air flow. We also flew in turbulent conditions at various elevations and over diverse environmental gradients.
That being said, it may come as no surprise that my DC-8 flight was as turbulent as it was long; I actually ended up getting pretty motion sick on the mission. Getting sick is a sacrifice some make to collect the necessary data. Despite not feeling well, I was surrounded by passionate students, scientists, engineers, and flight specialists all cumulatively working to advance one of NASA’s core missions: to understand and protect our home planet.
I am excited to see all of the diverse and interesting projects that SARP 2018 will embark and present on at the end of the summer. I couldn’t ask to be in a better place or time here at NASA working with and be mentored by some of the best minds in the field.
This piece was originally published on NASA's Earth Expeditions blog.
Earlier this month, we showed a space-based view of a glory—a colorful, circular optical phenomenon caused by water droplets scattering light. The Moderate Resolution Imaging Spectroradiometer on the Terra and Aqua satellites can see only a cross section of the glory, making it appear in satellite imagery as two elongated bands parallel to the path of the satellite.
To the Earth-bound observer, however, glories take on a circular shape. You might have seen one while on an aircraft. From this perspective, passengers on the side of the plane directly opposite the Sun can sometimes see the plane’s shadow on the clouds below. This position is also where glories can be observed as the cloud’s water droplets scatter sunlight back toward a source of light.
Before aviation, the phenomenon was often seen by mountain climbers; the glory encircling the climber’s shadow on the clouds below. Today, pilots and passengers have a good chance of seeing them, earning the phenomenon the name “glory of the pilot” or “pilot’s halo.”
But you still have to be flying close enough to the cloud deck for the phenomenon to be visible, which is one of the reasons why they are frequently spotted by scientists and crew with NASA’s Operation IceBridge mission. The mission makes annual flights over Earth’s poles to map the ice; flights are relatively low, long, and frequent. Glories are not part of the mission’s science goals—in fact, clouds can interfere with the collection of science data. But they are on the list of natural wonders that IceBridge scientists witness in the field.
Jeremy Harbeck, a sea ice scientist at NASA’s Goddard Space Flight Center, snapped the top photograph of a glory on April 18, 2018, during an IceBridge science flight over the Chukchi Sea. (See the full image and other photographs shot by Harbeck during the Arctic 2018 IceBridge campaign here.)
“I remember having taken more images of glories, especially down over Antarctica, as we see them quite often down there,” Harbeck said. “From what I remember, they’re not outside the window all the time, but you can catch them here and there on flights when conditions are right.”
One such Antarctic glory is visible in the image above, snapped by Michael Studinger during an IceBridge flight on October 26, 2010. Read more about that image here.
This piece was originally published on the NASA Earth Observatory Earth Matters blog.