Preparing for Landing: NASA’s S-MODE Wraps up Last Week of Experiments

By Dragana Perkovic-Martin, Principal Investigator for DopplerScatt at NASA’s Jet Propulsion Laboratory // SOUTHERN CALIFORNIA //


Yesterday was a hard down day for the team – everyone needed a rest after a very active week before. The hard down days are in NASA airborne rules and ensure that fatigue does not set in and keep everyone’s safety  the top priority.

The NASA King Air B200 and the early morning fog at NASA Ames Research Center.
Spooky! NASA King Air B200 and the early morning fog at NASA Ames Research Center. Photo credit: Alex Wineteer / NASA JPL

To fly or not to fly … Today is supposed to be a good day for optical measurements but the pesky fog is really not willing to leave the area of S-MODE operations. We sit and wait for updates from the ship, satellite imagery and forecasts. In the meantime, we are using the Saildrone measurements of wind speed in the area of interest to determine if it’s worthwhile to operate DopplerScatt. The winds are very low. The hourly reports are telling us that the winds have been below DopplerScatt’s threshold for the whole morning, reporting wind speeds of one meter per second. At this wind speed the ocean surface is very still, so still that it may look like a mirror. This is bad news for radar signals bouncing off the surface as their strength depends on the surface roughness. No dice for DopplerScatt today, and the same decision was made for the MOSES and MASS instruments on the Twin Otter. 


Remember that pesky problem with the monitor from last week? I overnighted a replacement monitor for the DopplerScatt team since yesterday was a doozy with no flights, they decided to swap out the monitor and keyboard on the plane. Trouble is they did not test that it worked. We just thought, “well what could go wrong, it’s the same model.” What do you know, it did go wrong! I’ll spare you the details and the frantic messaging between myself and the operators, but after some time they realized that the power cable was not plugged in and the monitor was not getting power. All in a day of DopplerScatt deployments!

Crew in front of the NASA King Air B200.
Crew of the day from left to right: Karthik Srinivasan (JPL DopplerScatt operator), Hernan Posada (AFRC pilot), Jeroen Molemaker (UCLA MOSES operator), James Less (AFRC pilot). Photo credit: Alex Wineteer / NASA JPL


Today is a science extravaganza! We have a big day ahead of us with two NASA King Air B200 flights planned and all of the in-water assets sampling data throughout the day. The weather is finally cooperating and we have a clear yet windy day ahead of us. The plan today is to fly a morning flight – which just took off at 8am – and then another one leaving approximately 6 hours later and flying the exact same pattern. The comparison of data between the two will tell us about the daily variability of the ocean processes. 

“This is one of the reasons why I am so excited about S-MODE,” said Hector Torres, DopplerScatt team member, operator and one of the main people responsible for simulating ocean processes. “The results based on theory and numerical simulations produced in the last five years are about to get confirmed or debunked today. Either way it will be a breakthrough!”

Flight one is now done! There were some pesky low clouds right in the area of collection that prevented MOSES from collecting quality data for half of the flight, but the second half was great. DopplerScatt data collection went as planned and data are churning already! We are seeing the first quick look data products trickle in as we watch the afternoon flight take off.

While the first flight was a bit difficult for our optical colleague running the MOSES system, Jeroen Molemaker from the University of California, Los Angeles, the afternoon was gloriously clear and provided a great opportunity for all airborne instruments to collect data at the same time. 

Quick look composite image of the sea surface temperature as observed by the MOSES instrument on the November 4, 2021 afternoon flight. The tracks are overlaid on DopplerScatt derived surface current velocities from the morning flight, showing the spatial relationship between currents and density fields. The color scale blue to red has a range of 2°C. Credit: NASA’s S-MODE team / Jeroen Molemaker

Today the S-MODE pilot experiment operated as we envisioned many months ago, with all platforms sampling data throughout the day over the area of interest. The field experiment crew is  tired but happy and the team is excited about the science that we will extract from this data set.

Goodnight moon. NASA King Air B200 on arrival at Moffett Field, California after a long day of flights. Photo credit: Alex Wineteer / NASA Jet Propulsion Laboratory


Today is the final day of the S-MODE pilot campaign. It’s a bittersweet feeling for me as it was so much fun to collaborate and coordinate daily activities with so many people. I will miss that, but I certainly will not miss the hectic calls of “we have a problem with …”

The NASA King Air B200 will fly in the afternoon collecting data in the western region of the S-MODE study area  together with the Twin Otter aircraft. Meanwhile, our friends on the ship will start recovering the autonomous assets and make their way toward Newport, Oregon.

Trouble struck again as our GPS unit could not get itself aligned and produce a good navigation solution, requiring a power reset and making S-turns i.e. banking the aircraft left and right in succession. After this excitement things went smoothly for the rest of the flight. You never know what will go wrong during a field deployment, you just know that something will and you need to be prepared to react and fix things without letting the panic set in! Thankfully that is what happened today thanks to Alex Winteer, a DopplerScatt operator from NASA JPL. He performed a cool and collected power reset while in air!

Happy crew on their last flight of the S-MODE pilot campaign. On the left is Jeroen Molemaker (UCLA MOSES operator) and on the right is Alex Wineteer (JPL DopplerScatt operator). Photo credit: Karthik Srinivasan / NASA JPL

Now it is time to work on our post-deployment to do list and eagerly await results of data processing.

I will leave you with two short blurbs from DopplerScatt team members Alex and Karthik about their impressions of the pilot campaign. 

“On most days, you don’t wake up looking forward to a boring day. As an instrument operator, a boring day during a deployment, however, is a different story. You look forward to sitting in a small round aluminum tube for 4.5 hours with nothing to do. That is a perfect day – a day when the radar just works. No last minute excitement of monitors not turning on (because someone unplugged it and forgot to plug it back in!) or the satellite phone connection not working. While the entire science team is excited about an action-packed day of coincident data collection, all the instrument operators look forward to is a day where everything just works as it should! Of course, sitting in an aluminum tube for many hours, staring out at the ocean with nothing to do makes you yearn for some excitement, but that is a fleeting thought until you get a text message via satellite link asking you to pay attention to the speed of the aircraft!” 

– Karthik Srinivasan, NASA JPL DopplerScatt operator


“I’ve been on quite a few field deployments with DopplerScatt, but none quite as exciting – or as important—as this one. Indeed, such a coordinated effort consisting of multiple aircraft and many assets in the water has never been attempted, and the resulting science will lead to new understanding of our ocean, atmosphere and the climate system as a whole. On Thursday, we attempted two flights for the first time. I operated the first flight: crew brief at 6:30 AM with a takeoff time of 8 AM. Thankfully, our instrument operated normally, and we were able to fly a bit lower –under the clouds – to ensure MOSES could see the ocean surface with its infrared camera. We landed five hours later, at around 1 PM, and I immediately took our data back to our field processing center in the aircraft hangar to start crunching. In the meantime, Karthik took off for our second flight of the day. By the time I finished the first round of processing, it was 5 PM and Karthik was almost back from the second flight, so I went downstairs to welcome him back (and grab the data!). A few hours later, we had both flights processed to quick look data products and I was exhausted. Being just one person, a small part of a much larger mission, it can be easy to lose sight of why we do this, especially when the hours are long. But when the data started pouring in, my exhaustion was quickly replaced by excitement. We were seeing a dataset no one had ever seen before. With these two flights, we are able to not just see the sub-mesoscale structure of the ocean surface over a large area, but we could also see its evolution over time and how the atmosphere interacts with that evolution! There is much work to go in analyzing these data, especially in comparing the many other instruments to our DopplerScatt measurements, but I am grateful to play a part in that analysis, discovery and understanding.”

– Alex Wineteer, NASA JPL DopplerScatt operator

The (Virtual) Room Where it Happens: Inside NASA S-MODE’s Control Center


NASA’s Sub-Mesoscale Ocean Dynamics Experiment (S-MODE) relies on two aircraft, 17 remote-controlled vehicles, a ship and dozens of drifting instruments to make its detailed study of ocean eddies, currents and whirlpools. The researchers aim to assess how these small, high-energy ocean events contribute to circulation and heat exchange in the upper ocean, and how oceans affect climate change. The tools are stationed in a 7,800 square mile (roughly 20,200 square km) area west of San Francisco Bay, which the researchers call the “S-MODE Polygon.”

But one of the mission’s most critical tools, its control center, is not on site. The control center is a virtual daily meeting where up to 40 scientists gather to share new data, check in on the mission’s assets and plan where to maneuver their instruments and vehicles to capture the most useful measurements.

Map of the S-MODE study area, or "S-MODE polygon",  off the coast of San Francisco.
The S-MODE Polygon, where the mission’s instruments are stationed, is located off the coast of San Francisco. Credit: Cesar Rocha / University of Connecticut

The S-MODE researchers are studying sub-mesoscale ocean processes like eddies – swirling pockets of ocean water that stretch about 6.2 miles or 10 kilometers in distance and often last for only a few days. Because eddies are relatively small and quick-fading, they can be challenging to study. Opportunities to study these processes often spring up with little warning. To study these events, the S-MODE team needs to be able to move their vehicles around quickly and strategically within the polygon.

For instance, one of the airborne instruments may spot an eddie or whirlpool developing. The scientists may then decide which water measurements they would like to gather, and agree to send the appropriate mission vehicles out to the location of interest. The scientists discuss such decisions at control center meetings.

During the call, representatives for each of the assets begin by providing their status updates.

“First, we review the data our assets are seeing in the field that day or the day before, and then decide what is the interesting feature that we want to study,” said Dragana Perkovic-Martin, principal investigator for DopplerScatt, one of S-MODE’s airborne instruments, at NASA’s Jet Propulsion Laboratory. “Based on that decision, we determine which assets we need in that spot and position them in the right area.” 

A screengrab of scientists during a virtual control center meeting.
Scientists participate in a control center meeting on October 22.

The control center was originally going to be hosted in-person at the NASA Ames Research Center in Silicon Valley, California.

“The idea was for a group of us to work together there to examine the conditions and the data and to update the plan as things unfolded,” said Tom Farrar, S-MODE Principal Investigator and a scientist at Woods Hole Oceanographic Institution in Falmouth, Massachusetts. As COVID-19 cases surged in late summer 2021, the team decided to shift to a virtual format. Now, the only people who are in the field are those who cannot complete their work remotely, like those flying the planes or collecting measurements aboard the ship.

All of the scientists involved in S-MODE have done traditional field deployments before, Perkovic-Martin said. But few have had experience coordinating an expedition from a virtual control center. The group has adapted quickly with the help of online platforms including Slack, WebEx, email, and Zoom.

“The control center works in much the same way as originally envisioned, with a group of people trying to take in as much information about what is happening to make decisions about the plan,” Farrar said. 

One of the S-MODE Deputy Principal Investigators, Professor Eric D’Asaro of the University of Washington, leads control center meetings, with the goal of ending each meeting with an updated plan for the next few days.

“We have benefitted a lot from Eric’s enthusiasm, and his experience in other large field campaigns,” Farrar said. “We have a great team of experts and specialists, and I’m really excited about the coordinated dataset the team is collecting.”




On the Edge of Something New: Studying the Sea with a Fleet of Technologies


The October deployment of NASA’s Sub-Mesoscale Ocean Dynamics Experiment (S-MODE) mission is underway and a current of excitement has filled the halls of our virtual meetings. Over the past two years, more than 50 members of the S-MODE project have been meeting virtually to prepare for this moment. Our campaign has begun and we are testing our instruments, optimizing our sampling patterns and comparing our measurements between various instruments over a nearly three-week pilot experiment. The mission for S-MODE is ambitious: we seek to better measure, understand and ultimately model submesoscale currents, which are ocean fronts, narrow currents called jets, and filaments that are about 300 feet (100 meters) to 6.2 miles (10 kilometers). These are elusive targets for oceanographers as they are difficult to measure: too big for a ship-based study alone, too quick for ship surveys, and too small for remote sensing. Therefore, these currents must be examined using a combination of different approaches and novel technologies, as is being done in our experiment. 

View of the R/V Oceanus ship taken from the Twin Otter aircraft.
View of R/V Oceanus from the Twin Otter aircraft with the SIO MASS package on board. Credit: Nick Statom / Scripps Institution of Oceanography

To researchers with the NASA S-MODE mission, it feels like we are near the edge of something new – that it is a time of rapid change in our understanding of the ocean. Sub-mesoscale currents pull apart and push together water at the ocean surface, and this leads to water flowing up and down, respectively. This up and down motion is important for a number of Earth science processes, including interactions of the air and sea that impact weather and processes that affect the distribution of nutrients that are important for plankton productivity. 

Autonomous vehicles called Wave Gliders on the deck of the R/V Oceanus ship.
Wave Gliders on the deck of the R/V Oceanus being prepared for deployment. Credit: Courtesy of Ben Hodges / Woods Hole Oceanographic Institution(WHOI)

I am part of a team that is deploying Wave Gliders, a small uncrewed vessel that has a set of fins on a submersible platform tethered to a surface float, which it uses to kick its way around the upper ocean. These platforms are decked out with instruments and are not limited by interference from the ship. They also do not have the same risk as putting humans out in the middle of large storms (like ones we have experienced during S-MODE!). 

On the transit from Newport, Oregon to the experiment site off the coast of San Francisco, large waves (some reaching around 23 feet or 7 meters tall) rolled over the deck of the research vessel Oceanus and three of the four Wave Gliders were damaged in the process. Researchers in the Air-Sea Interaction Laboratory at Scripps Institution of Oceanography and a team at Woods Hole Oceanographic Institution began to problem solve issues with the Wave Gliders by inspecting extra platforms that were on land here in San Diego, California and diagnosing the issues based on pictures provided by the team on the R/V Oceanus. Scientists from across the country then assembled to repair the Wave gliders in San Francisco harbor.

Scientists perform emergency repairs on the Wave Gliders.
Ben Hodges, Emerson Hasbrouck, Luc Lenain and Laurent Grare (not shown) perform emergency repairs to the Wave Gliders! Credit: Courtesy of Laurent Grare / Scripps Institute of Oceanography

With the Wave Gliders repaired and deployed, we could again pursue our mission objectives. There was still considerable swell in the water from a historically large storm that had just passed through the region (which was accompanied by the well-publicized atmospheric river that brought so much rain and snow to northern California). In fact, the Saildrones in our campaign measured large significant wave heights during this storm! After the major storms passed, the Wave Gliders were deployed, and they are currently operating in unison with the other instruments in the campaign. The data has started to roll in!

I and several others in the campaign am interested in how surface waves interact with sub-mesoscale current features. For example, as waves turn as they approach the beach to be parallel to shore, sub-mesoscale currents steer the waves, sometimes leading to wave breaking in localized regions. These breaking waves are important for upper ocean dynamics and air-sea interactions: they generate spray and bubbles that are important for gas transfer between the atmosphere and ocean.  Historically, wave data has been viewed as measurement noise. But, with the emerging technologies being employed in S-MODE, scientists are excited about the possibility that wave information can tell us about the underlying currents.


Figure showing measurements from the Sail Drones of the significant wave heights.
Measurements from the Sail Drones of the significant wave heights. Figure courtesy of Bia Villas Boas / Caltech / Colorado School of Mines

For many of us, this experiment has been invigorating, bringing us back in touch with the excitement and discovery that comes with oceanographic field campaigns. There have been many excited conversations around a monitor, examining the data as it comes into our stations on shore. As an early career scientist, I feel as if I am taking part in a historical campaign. This is truly an exciting time to be an oceanographer.  

Researchers Kayli Matsuyoshi, Luke Colosi and Luc Lenain in the Air-Sea Interaction Laboratory at SIO discussing the latest S-MODE findings.
Researchers Kayli Matsuyoshi, Luke Colosi and Luc Lenain in the Air-Sea Interaction Laboratory at SIO discussing the latest S-MODE findings. Credit: Courtesy of Nick Pizzo




Unexpected Turbulence for the S-MODE Airborne Instruments

By Dragana Perkovic-Martin, Principal Investigator for DopplerScatt at NASA’s Jet Propulsion Laboratory // SOUTHERN CALIFORNIA //

Flight crew for October 25, 2021. From left to right: Delphine Hypolite (UCLA MOSES operator), Michael Stewart (Ames Research Center pilot), Tracy Phelps (Armstrong Flight Research Center – Armstrong Flight Research Center pilot) and Federica Polverari (JPL DopplerScatt operator). Photo credit: Hector Torres Guiterrez / NASA JPL


The first message I read this morning is that Ernesto, one of the deputy Principal Investigators on the S-MODE project and our project scientist for DopplerScatt, has succumbed to food poisoning. So, I am going to be making all of the decisions today. I guess I am ready…

We proceeded with our DopplerScatt morning meeting and made some tentative decisions about the flights this week and then went to the flight briefing to stress the importance of flight tracks today and what to nix in case of low fuel. As I was updating the S-MODE control center briefing package about the week’s forecast, Ernesto came back into play. One thing I can say is that we anticipated very well in the decisions we made in the early morning, so I guess I know how to impersonate!

Today’s flight plan focuses on the same area of the S-MODE polygon as last week – the  north-western boundary where the cold filament is collapsing under the warm water.

Underlying VIIRS sea surface temperature from Monday October 25th overlaid by NASA King Air B200 tracks in pink, Twin Otter tracks in black, and Saildrone region of operation (green and yellow rectangles). Red is warm water, green and blue are cooler water.
Credit: NASA S-MODE with Google Earth imagery

The flight is another combination of the King Air B200 and Twin Otter, with the Saildrones down below. All of our assets are active at this time! The first reports from the King Air B200 show the weather is favorable for another excellent day of data collection. 

But…  we had an unexpected power shutdown on board the aircraft for all instruments. While the power was restored immediately and the MOSES camera came back online quite quickly, the DopplerScatt instrument was slow to get out of bed. Typically, the instrument is powered before takeoff and we only enable radar signal transmission through the antenna once we are at safe altitude, which takes seconds. After about 20 minutes DopplerScatt was restored to its previous state and continued to collect data. We were thrilled on the ground and up in the air! Alas, that was not the end of our troubles… 

DopplerScatt requires precise knowledge of its position and orientation so that its radar data that it collects can be processed on board and on the ground. These data are what we call navigation data and they come from a Global Positioning System/Inertial Motion Unit (basically a GPS) instrument aboard the DopplerScatt instrument. After the power on, DopplerScatt was unable to process data onboard. Post landing data were transferred to a ground server where they will be evaluated for usability. 

Looking at the glass half full, the King Air B200 completed all of its planned flight tracks, and MOSES recovered from the power down and collected data almost uninterrupted. DopplerScatt at most lost 25% of its collection – which is not too shabby. We are hoping the planned flight for tomorrow will be less eventful than the one we had today. We like excitement, but not of this kind.

Hector Torres (JPL DopplerScatt operator) ready for the flight on October 26. Photo credit: Federica Polverari / NASA JPL


We are back at it and preparing for the new flight. Today’s plan was for DopplerScatt to survey a wider area to try and see which new feature the S-MODE experiment should focus on. After lots of discussion of how to manage a sudden shutdown onboard, Hector Torres is back at the DopplerScatt “driver seat” – this time on his own with the pilots because the weather is poor for optical measurements, so we decided not to use MOSES today.

DopplerScatt was reported as good to go and the aircraft took off. The next message was something that none really wanted to receive…. The aircraft was reporting a bleed air flow – essentially reporting that they would have pressurization issues. Rather serious stuff. We anxiously watched the aircraft descend and come back to Moffett Field, thankfully landing safely and Hector reported all was well with him and instrument. 

The next day we are in much better shape than yesterday! The aircraft has been repaired and is ready to go for the next flight. We have also recovered the navigation data from the flight on October 25, so now we know that we will be able to process all of the radar data from this flight. 


Federica Polverari (JPL DopplerScatt operator) waiting to board the NASA B200 King Air prior to flight on October 28th. Photo credit: Hector Torres Guieterrez / NASA JPL

At 1pm today we’re cleared for takeoff. Today’s data collection is at full strength, with all S-MODE assets collecting data. This is the first time during the campaign that we’re using all of the assets at once, so it is a big day. Of course – we are just learning how difficult it is to forecast fog…. While DopplerScatt and our in-water assets are fine, our optical remote sensing instruments MASS and MOSES are having a hard time today trying to find a place with good visibility. 

While the fog did create issues for the MOSES camera, DopplerScatt had a stellar day! The flight was centered on the new area of the S-MODE study area and we collected some very exciting data. DopplerScatt seems to have captured a cold front of water where we expected, but we need to upload the data into our computer to process it before we can tell if what we’re seeing is real, or if the DopplerScatt team has an overly active imagination.

Here is the happy crew and a few additional folks who joined the post-flight festivities!

Federica Polverari taking a selfie with the NASA B200 King Air crew for the day. From left to right: Jeff Borton (AFRC pilot), Alex Wineteer (JPL DopplerScatt operator and winds processing guru), Delphine Hypolite (UCLA MOSES operator), Tracy Phelps (AFRC pilot), Hector Torres (JPL DopplerScatt operator), Sommer Nichols (ARC Deputy Project Manager). Photo credit: Federica Polverari / NASA JPL


Talk about last minute changes….. Folks aboard the Twin Otter aircraft reported that they found an area with no fog, however that area was the one that the B200 King Air would visit last in today’s flight. If we wait  too long then the area may get covered by fog and clouds and MOSES would not be able to see through them. Thanks to our newly-installed satellite communication link on the B200 King Air, we messaged the pilots and asked that they change the order of the flight tracks today. Just after takeoff they confirmed this would be possible, and the science team went wild. The images we received from the flight tell us that we were correct to change this order – so phew! We are now glued to our screens following the flights as well as in-water measurements. Today we have the full set of gizmos in the field!

Delphine Hypolite (UCLA MOSES operator) and Karthik Srinivasan (JPL DopplerScatt operator) in flight on October 29. Photo credit: Karthik Srinivasan / NASA JPL

While flight planning and execution was very dynamic and fun, there was another great accomplishment today. We produced our “quick look” data images overnight! What we call quick look images are data products that we crunch as soon as possible after the flight, using the on-board processed data as a starting point. These results have not been through the full calibration and quality check rigor that we usually apply, so they are preliminary. However, they are very important so that the team gets an idea of what is happening, and the products are used for planning activities the next day. 

DopplerScatt preliminary “quick look” results for the October 28, 2021 data collection show estimated wind vectors over the study area. This wind field shows the wind stress is affected by the thermal feedback of the sea surface front shown by VIIRS, where winds slow down as they move across cooler water. Wind stress is also affected by kinematic feedback from the underlying surface currents. The near-instantaneous response of these scatterometer measured winds to the ocean implies a much stronger coupling between atmosphere and ocean than has previously been observed by lower resolution measurements. Credit: NASA S-MODE with imagery from Google Earth
DopplerScatt preliminary “quick look” results for October 28, 2021 showing estimated surface current vectors over the study area. A complex circulation established by the cold front was observed by DopplerScatt: southward flow in the north-western part, eastward flow in the eastern part, and zones of convergence in the center. Credit: NASA S-MODE with imagery from Google Earth


The hinge between the monitor and keyboard failed us today. Nothing that cannot be fixed, thankfully. It just seems that we need to give our DopplerScatt instrument some TLC when we are back in our lab. 

Today was another super successful collection at full S-MODE strength. The research vessel, Oceanus, made planned measurements while the Wave Gliders and Saildrones fought the currents and winds to make transects through the area of interest. The Twin Otter aircraft flew in concert with the B200 King Air and collected data spaced very close in time with DopplerScatt. The MOSES instrument managed some measurements in gaps between the clouds and fog. But the highlights of the day were the quick look products from DopplerScatt within an hour and a half from the collection – all hail our data processing gurus Alex and Ernesto!


While many were out trick-or-treating for Hallowen, the B200 King Air gave us several tricks. Several issues sprung up, however, due to some rather swift actions of the ground crew the takeoff delay amounted to only a half hour. DopplerScatt collected data at the same time as the Twin Otter flights and MASS instrument collections, so we have lots of intercomparisons to look forward to. 

Tomorrow is a down day for the crew to rest. There will be no flight so we can ensure that we can fly every day for the rest of the campaign.

NASA B200 King Air ground and air crew from left to right: Sam Habbal (AFRC ground crew), Karthik Srinivasan (JPL DopplerScatt operator), Alex Wineteer (JPL DopplerScatt operator), Tracy Phelps (AFRC pilot), Delphine Hypolite (UCLA MOSES operator), David Carbajal (AFRC ground crew), Leroy Marsh (AFRC Inspector) and Tom Lynn (ARC ground crew). Photo credit: Erin Czech / NASA Ames Research Center

Liftoff! Aircraft Experiments Take Flight for NASA’s S-MODE Mission

By Dragana Perkovic-Martin, Principal Investigator for DopplerScatt at NASA’s Jet Propulsion Laboratory // SOUTHERN CALIFORNIA //

The first of three aircraft participating in the S-MODE campaign has arrived at Moffett Field in California. The NASA King Air B200 aircraft, carrying two science instruments – DopplerScatt and MOSES – landed on October 18th and is preparing for its first flight early in the morning on October 19th. The weather conditions have been changing and incoming storms in northern California are throwing a wrench into our planning for the airborne part of the campaign. 

NASA King Air B200 aircraft on arrival at Ames Research Center carrying DopplerScatt and MOSES instruments. Credit: Erin Czech / NASA Ames Research Center.
NASA King Air B200 aircraft on arrival at Ames Research Center carrying DopplerScatt and MOSES instruments. Credit: Erin Czech / NASA Ames Research Center.

My name is Dragana Perkovic-Martin and I am the Principal Investigator for DopplerScatt, an instrument that simultaneously measures ocean vector winds and surface currents. DopplerScatt is a key part of the S-MODE Earth Ventures Suborbital Project. The instrument is currently aboard NASA’s King Air B200 aircraft  to collect data for the S-MODE mission. Meanwhile, I am at my pseudo control center at home,  following every minute of the deployment, acting as a point of contact for aircraft communications, and jumping in when things go south with DopplerScatt.

DopplerScatt is a radar and as such it is perfectly happy operating in cloudy conditions since its signals can penetrate the clouds, but it needs the wind to roughen the ocean surface for good data quality. Unlike DopplerScatt, the other instrument aboard this aircraft – MOSES – is an optical instrument (infrared camera to be more precise). That means MOSES can only collect data in clear weather, so no clouds. While high winds and no clouds are not mutually exclusive, the current weather outlook for the week is not great. The science team will have to closely follow forecasts and models and decide at the last moment whether the aircraft should take off. It will be a week at the edge of our seats! 

Ready for flight! Hector Torres Gutierrez (JPL) and Delphine Hypolite (UCLA), DopplerScatt and MOSES operators, ready to board the King Air B200 for the first S-MODE pilot campaign flight. Note just left of the aircraft stairs is the DopplerScatt white cone radome (radar signal transparent material).
Ready for flight! Hector Torres Gutierrez (JPL) and Delphine Hypolite (UCLA), DopplerScatt and MOSES operators, ready to board the King Air B200 for the first S-MODE pilot campaign flight. Note just left of the aircraft stairs is the DopplerScatt white cone radome (radar signal transparent material). Credit: NASA

On Tuesday morning, the King Air B200 took off at 8:20 am for a reconnaissance flight of the S-MODE area. The weather front was coming in and so it was a race between the aircraft and the clouds. The first reports from the aircraft operators were good: the winds were high enough for DopplerScatt to get good data and MOSES was managing to capture data through gaps in the cloud cover.

A little over four hours later, the King Air B200 landed, delivering the precious data “cargo” to the hangar at NASA Ames, where the DopplerScatt processing machine is housed. The images from the real-time processor aboard the aircraft promise a really good data set.  The satellite data obtained by the science team is capturing a very interesting ocean circulation feature within the S-MODE sampling area and the science team is abuzz trying to reposition the autonomous marine robots to capture the feature. 

Sea surface temperature images from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument show a warm water intrusion propagating into the S-MODE area (black polygon) from the western boundary and a cold water filament propagating into the S-MODE area from the northwestern boundary.  Left image obtained on October 18th 2021, right image corresponding to October 19th 2021. Credit: NASA
Sea surface temperature images from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument show a warm water intrusion propagating into the S-MODE area (black polygon) from the western boundary and a cold water filament propagating into the S-MODE area from the northwestern boundary. Left image obtained on October 18th 2021, right image corresponding to October 19th 2021. Credit: NASA

While we prepare for the second flight of the NASA King Air B200 this afternoon, the media is having a field day – coming along to watch, photograph and film our experiments. Today’s flight is aimed at mapping the ocean feature that has formed in the past few days in the northern end of the S-MODE sampling area. The winds are forecast to be just high enough for DopplerScatt to perform its measurements. 

Federica Polverari (JPL DopplerScatt operator) in action during S-MODE media day. Credit: NASA
Federica Polverari (JPL DopplerScatt operator) in action during S-MODE media day. Credit: NASA

Meanwhile, back at my home control center, I’m using a software called FlightAware to track the aircraft while in flight. The display can include weather, and today this shows a patchwork of rain and clouds out there. Fingers crossed that it is not raining at the collection site, as DopplerScatt’s signal is attenuated in rain.

After the plane took off and arrived at the data collection area, we lost communication as the satellite connection must have been affected by weather in the area. 

We get one more good flight for the DopplerScatt instrument, but it’s bad luck for MOSES. The cloud cover was thick and extended from approximately 5,000 to 24,000 feet, making it impossible for the camera to image the ocean surface. Perhaps we’ll have better luck Friday when cloud conditions appear to be favorable for an early morning flight. 

NASA’s King Air B200 aircraft fueling pre-flight on a rainy morning at Moffett Field in California. Credit: NASA
NASA’s King Air B200 aircraft fueling pre-flight on a rainy morning at Moffett Field in California. Credit: NASA

There was lots of excitement in the pre-flight instrument power on, as one of the DopplerScatt servers had trouble booting. The DopplerScatt team mobilized over the phone and resolved the issue – sigh of relief! The whole team is glued to their cell phones in the morning, and we may have to investigate the issue upon landing. 

Today’s flight is the first combo experiment of the campaign. The NASA King Air B200 and the Twin Otter  aircraft will be flying, carrying the MASS instrument operated by the Scripps Institute of Oceanography (SIO), in addition to autonomous Saildrones and recently ship-deployed drifters. The Saildrones have been sampling the area overnight and are reporting a disappearance of the cold filament. The science folks suspect that the warmer water has pushed the cold filament deeper because it’s not as visible from overhead. 

October 22nd 2021 flight tracks by the Twin Otter (red lines) and King Air B200 (blue lines) superimposed on the sea surface temperature map, ship, and saildrone data collected overnight.
October 22nd 2021 flight tracks by the Twin Otter (red lines) and King Air B200 (blue lines) superimposed on the sea surface temperature map, ship, and Saildrone data collected overnight.

After a frantic back and forth during the flight to identify the source of monitor malfunction on DopplerScatt, things have settled back to normal. The flight was executed successfully and we will perform some more ground trouble-shooting to make sure that DopplerScatt is ready for the next flight, which will probably be on Monday October 25th.

Hector and Delphine, the instrument operators flying aboard the King Air B200, shared their impressions of the flights from their high-altitude view: 

“The plane flew offshore West of San Francisco and after a cloudy and turbulent takeoff, the ocean appeared perfectly clear at the altitude of 26,000 ft. Operating smoothly thanks to both skills and practice, in coordination with the pilots, we traced an array over the ocean and collected great quality data. When we saw oceanic structures with clean, sharp gradients appearing on our screens we were overjoyed!  The months of preparations were starting to pay off. These structures are exactly what we have come to measure. The other aircraft, the Twin Otter, has also joined the data collection and will provide a very useful data comparison. The plane tracks were successfully changed to optimize the overlap of the two data sets. What a great day for S-MODE,” they told me.

Now quiet resumes while the data are being processed by our teammates. That’s a wrap for the first week of the S-MODE pilot campaign airborne activities!

Landsat Launch Brings City of Lompoc Together

Landsat team members from NASA, partner agencies and companies, and the city of Lompoc cut the ceremonial ribbon to dedicate the Landsat mural in downtown Lompoc, California on September 26. Credit: NASA / Jessica Evans

By Jessica Merzdorf Evans //LOMPOC, CALIFORNIA//

In early 2021, local artist (and Lompoc Mural Society curator) Ann Thompson competed in and won the call for artists to commemorate Landsat 9’s launch and the Landsat program’s 50th anniversary. Along with representatives from NASA, the U.S. Geological Survey, United Launch Alliance, and the city of Lompoc, Thompson helped dedicate the mural for its official opening on September 26, 2021, one day before Landsat 9’s launch.

Artist Ann Thompson poses with her newly-dedicated “50th Anniversary of Landsat” mural in downtown Lompoc, California. Credit: NASA / Jessica Evans

Lompoc, California, has a lot of murals — 40 and counting, according to the city’s website. Some depict local flora and fauna, some show important events and people in the city’s history. The new mural depicts a stylized Landsat 9 orbiting Earth, with colorful pull-out frames showing Landsat images of changing glaciers, bright landscapes, and Santa Barbara County, California – home of Lompoc and Vandenberg Space Force Base. Another pull-out in the corner shows the timeline of the Landsat program, from Landsat 1’s launch in 1972 through Landsat 9.

This image shows the timeline of Landsat launches, from Landsat 1 in 1972 through Landsat 9 in 2021. Credit: NASA / Matthew Radcliff

The city of Lompoc sponsored or highlighted a number of events in the week leading up to launch, including workshops, educational events, talks, and art exhibits. 

At the Lompoc Aquatic Center across town, educators from the Landsat and ICESat-2 teams (Ice, Cloud and Land Elevation Satellite-2) demonstrated how their two missions track land and sea ice around the world. 

Landsat education outreach coordinator Allison Nussbaum shares Landsat materials and information with a family at the Lompoc Aquatic Center on September 26. Credit: NASA / Jessica Evans
ICESat-2 outreach lead Valerie Casasanto places an inflatable penguin into the pool at the Lompoc Aquatic Center on September 26th. Casasanto and her Landsat colleagues ran demonstrations on land and sea ice at the aquatic center as part of the outreach events surrounding Landsat 9’s launch. Credit: NASA / Jessica Evans

Launching a new satellite to space is often more than just a scientific achievement – it can be a community-wide event that gives educators, artists, and local citizens a chance to be part of the celebration. This week, the city of Lompoc is helping to paint a picture of the Landsat program’s future.

‘The most exciting beep I’ll ever hear’

Mechanical and electrical support equipment for NASA’s Landsat 9 observatory being processed inside the Integrated Processing Facility at Vandenberg Space Force Base in California, on June 24, 2021. The equipment includes a secondary payload adapter and flight system for a group of microsat payloads, called CubeSats, that will launch with Landsat 9 as secondary payloads.
Mechanical and electrical support equipment for NASA’s Landsat 9 observatory being processed inside the Integrated Processing Facility at Vandenberg Space Force Base in California, on June 24, 2021. The equipment includes a secondary payload adapter and flight system for a group of microsat payloads, called CubeSats, that will launch with Landsat 9 as secondary payloads. Credit: NASA / Jerry Nagy


When the Landsat 9 satellite launches to space next week, it won’t be going alone. NASA is partnering with the U.S. Space Force to launch four CubeSats — miniature satellites — on the same Atlas V rocket that’s taking Landsat 9 to its orbit 438 miles above Earth.

While some of the missions sport adorable names — they’re dubbed CUTE (Colorado Ultraviolet Transit Experiment), CuPID (Cusp Plasma Imaging Detector), and Cesium Satellites 1 and 2 — these little satellites are pioneering some serious science and technology.

The four CubeSats are mounted on a ring-shaped frame, called the ESPA, or the “Evolved Expendable Launch Vehicle Secondary Payload Adapter.” (The program’s name, EFS, stands for ESPA Flight Systems.) The ESPA will ride with Landsat 9 inside the top section of the rocket, the payload fairing. After the rocket’s second stage, called the Centaur, safely boosts Landsat 9 to its orbit, it will drop to a lower orbit and send the CubeSats on their way.

“This is a pathfinder mission for NASA, so the process for doing it was undefined,” said Theo Muench, a NASA engineer and the partnership’s program manager. “NASA has never flown an ESPA ring with secondary payloads inside the fairing before, so we had to work with all our stakeholders to invent a plan to fly.”

Rideshare programs aren’t new — programs like NASA’s CubeSat Launch Initiative (CSLI) regularly coordinate rides for small satellites with larger missions. The Air Force, Space Force and commercial launch providers like SpaceX have let satellites tag along on their missions too. But the new EFS partnership provides access to more missions between NASA and the Space Force, increasing the number of options available to mission designers.

“This program is a big cost-saver, because a lot of times you can buy an ESPA ring for a fraction of what it would take to buy a small launch vehicle,” said Maj. Julius Williams, chief of the U.S. Space Force’s Mission Manifest Office, or MMO. The MMO’s goal is to seek out launch partnerships with other agencies. “If someone were to procure a satellite launch vehicle on their own, they wouldn’t use as much of the vehicle capability, on top of the fact that they’re using those funds themselves. This partnership saves taxpayer dollars for other programs.”

Two of the hitchhikers, CUTE and CuPID, are science satellites. CUTE is funded by NASA and managed by the University of Colorado’s Laboratory for Atmospheric and Space Physics (LASP) in Boulder, Colorado. The little satellite will carry a space telescope and a spectroscope, measuring near-ultraviolet light to learn about the atmospheres of planets outside our solar system. Specifically, they’ll be looking at escaping gases from “hot Jupiters” – large planets that orbit close to their parent stars. The team will study how these planets lose atmosphere in their suns’ heat, to better understand how likely atmospheres are to survive on all types of planets.

University of Colorado graduate student Arika Egan leads installation of the CUTE CubeSat into the EFS dispenser system at Vandenberg Space Force Base on July 23, 2021. Credit: NASA / WFF
University of Colorado graduate student Arika Egan leads installation of the CUTE CubeSat into the EFS dispenser system at Vandenberg Space Force Base on July 23, 2021. Credit: NASA / WFF

CUTE is smaller than the average space telescope, and the team is excited to push the envelope technologically as well as scientifically. “The cool story of CUTE is how all the ambitions we packed in at the beginning came together in the end,” said project scientist Brian Fleming, a researcher at the University of Colorado-Boulder. “In the early days, it was a big challenge to get the science performance we needed from this little ‘cereal box.’ We approached it with a little bit of fun—every time we came up with a new crazy idea, we said ‘okay, let’s try that too.’ That approach really paid off, and CUTE can do some amazing things for its size.”

The second science CubeSat, CuPID, will take measurements closer to home — this mission will study the interactions between the Sun’s plasma and Earth’s magnetosphere, or the protective “bubble” formed by Earth’s magnetic field that keeps harmful solar radiation away from the surface.

(To learn more about CuPID, check out their spotlight here.)

Cesium Satellites 1 and 2 are experimental satellites owned by CesiumAstro, an aerospace company that specializes in space communications. These CubeSats will test an antenna technology called an active phased array, which uses electromagnetic interference to move a signal beam without moving the physical antenna. This technology could make future satellites easier to use and repair, with fewer moving parts to break down. “Riding along with Landsat 9 provides Cesium Mission 1 with the opportunity to test their products in space before selling them to consumers,” said Scott Carnahan, Cesium Mission 1 manager.

Delivering the CUTE satellite marked a bittersweet moment, since it’s been “this presence with us for almost four years,” said CUTE lead investigator Kevin France, an associate professor at the University of Colorado.

“Right now, I’m most excited to hear the first beep back from the satellite on launch day,” Carnahan said. “When you go through all the tribulations to get a satellite up to orbit, you want it to get up there and be safe. That will be the most exciting beep I think I’ll ever hear.”

Landsat 9 is a partnership between NASA and the U.S. Geological Survey.

NASA Sends Robots to Study Climate Change in the Arctic

By Emily Fischer, NASA’s Earth Science News Team /GREENBELT, MARYLAND/

On July 7, 2021, NASA sent two robotic explorers to the Arctic to collect sea surface temperature data and improve estimates of ocean temperatures in that region. Pairing up with Saildrone, a designer and manufacturer of non-crewed surface vehicles or USVs, researchers hope to use the results to better understand the impacts of climate change in the Arctic.

Two saildrones awaiting deployment.
Two saildrones awaiting deployment from Dutch Harbor, AK. Credit: Courtesy of Saildrone

“The Arctic is one of those regions that’s being very rapidly impacted by climate change,” said principal investigator Chelle Gentemann, a senior scientist at Farallon Institute in Petaluma, California. “We’re all connected, so what happens in Siberia is going to affect what happens in California. And one of the keys to understanding and mitigating climate change is understanding what’s going on in the Arctic, how fast it’s changing, and how it’s going to affect future weather.”

Acting like Earth’s refrigerator, Arctic climate and weather interact with the rest of the world. Over the past 30 years, the Arctic has warmed about twice as fast as the rest of the Earth. This type of warming can influence sea level rise, global ocean currents, and natural hazards like hurricanes. Researchers in the Arctic are investigating recent and past changes and how they influence other parts of the planet.

Springtime sea ice off of the coast of the Svalbard archipelago. Filmed during the 2017 Operation IceBridge Arctic campaign. Credit: NASA

The Arctic is challenging to study because of its frigid tundra and sea ice dynamics. For years, climate researchers have relied on satellite remote sensing to measure key ocean properties, including ocean salinity, ocean temperature and air-sea interactions (for example, hurricanes). Satellite measurements are validated by collecting field data using buoys and research vessels. Yet in the Arctic, buoys are often destroyed by shifting ice and research vessels are expensive to operate.

“The problem is that almost all of our buoys are located along the coasts of the United States, Europe, near India and Asia and along the tropics. We aren’t able to deploy and maintain buoys in the Arctic,” Gentemann said. “We have to rely on satellite data to understand Arctic ocean temperatures and how they’re changing with climate change.”

Saildrone USVs, are autonomous sailboat-like vehicles powered by green technology; they are propelled by wind and use solar-powered sensors. These autonomous vehicles can be steered from computers hundreds of miles away, allowing them to access severe ocean environments, like the centers of hurricanes and shifting packs of sea ice in the Arctic. They provide a resilient and affordable means to validate satellite data and develop and improve algorithms that model changing temperatures.

The 2021 NASA Arctic Cruise is ongoing; the Saildrone USVs passed through the Bering Strait and are headed into the Chukchi Sea. In previous Saildrone missions, NASA researchers found close correlation between satellite remote sensing measurements of sea surface salinity and data collected by Saildrone.

The path taken by the saildrones during the first 2.5 months of the mission, from June 5 to August 30, 2021. Credit: Courtesy of Saildrone

“We have confidence in satellite information because we are also seeing similar things in the on-site measurements collected by Saildrone. This is encouraging. This tells you that we can use the satellite data to monitor what’s happening over these long periods of time,” said Jorge Vazquez, a scientist for NASA’s Physical Oceanography Distributed Active Archive Center, or PO.DAAC. PO.DAAC is one of several NASA Distributed Active Archive Centers, which process, archive and distribute data collected from NASA projects.

The primary focus of the 2021 NASA Arctic Cruise is to validate sea surface temperature data from satellites, but scientists have also collected information on air-sea interactions, ocean stratification (different layers of water), ocean currents, sea surface salinity and the marginal ice zone (an area where ice forms seasonally and varies over an area) to answer other scientific questions.

The 2021 NASA Arctic Cruise is part the Multi-Sensor Improved Sea Surface Temperature project, or MISST. This is an international and inter-agency collaboration aimed at improving weather and climate research and prediction by providing better-quality ocean temperature measurements from satellites. NASA satellites aid in this effort, and projects like the 2021 NASA Arctic Cruise validate NASA satellite measurements to further MISST’s mission.

“What we’re finding is that we live on a planet where you have to have a multidisciplinary and international approach to understand how this planet works. It’s a team effort,” Vazquez said.

A fjord in western Greenland, filmed during the 2019 Operation IceBridge Arctic campaign. Credit: NASA

NASA has an open data policy, and the 2021 NASA Arctic Cruise takes this one step further. The project has an open invitation for other researchers from around the world to be an observer on the mission, have access to near-real time data and participate in the conversation about the mission and science objectives. The Saildrone Arctic deployments are available through the PO.DAAC at

Roaming the Depths: The Role of Autonomous Assets in the EXPORTS Campaign

By Shawnee Traylor, PhD student in the joint Massachusetts Institute of Technology and Woods Hole Oceanographic Institution program in Chemical Oceanography / NORTHERN ATLANTIC OCEAN /

Satellites have undoubtedly opened up new ways for scientists to study the ocean, giving us global coverage of the surface of the ocean without ever having to step foot on a ship. But how can we learn what lies beneath the surface?

The classic way oceanographers study the ocean is, of course, going there. But putting together a cruise is no easy feat. They take years of planning, preparation, and enormous teams of scientists, mariners, and logistics personnel to bring to fruition. Once aboard, teams must adapt to perform delicate tasks under the demanding conditions of working at sea. Some cruises (such as this one!) run into storm after storm, which limits the ability to conduct our ship-based scientific missions.

One of the seagliders deployed on DY130, the cruise immediately prior to ours, which helped us scout features ahead of the ship and make informed decisions about where to sample.
One of the seagliders deployed on DY130, the cruise immediately prior to ours, which helped us scout features ahead of the ship and make informed decisions about where to sample. Credit: Filipa Carvalho, National Oceanography Centre

The difficulty of science at sea has been one driving factor in the development of autonomous platforms for use in scientific research. The wide range of platforms allow us to study places and timescales that are inaccessible to ships–such as the physics of water under ice sheets, or the interannual variability of biogeochemical cycles now and into the future.

The EXPORTS campaign utilizes a range of autonomous assets to collect data over time and space, and at different depths. Gliders silently soar through the water to waypoints provided by pilots on land, collecting measurements down to 3,281 feet (1000 meters) several times a day. Autonomous floats such as the Biogeochemical Argo float shown in the photo below remain in the ocean for up to five years, gathering critical data as they drift in the ocean’s currents. Drifters deployed at the surface give insight to the upper ocean currents. Like satellite imagery, these assets allow us to make informed decisions while at sea by scouting out the biology, chemistry, and physics of a region without having to move the ship. The assets that remain in the water after the cruise continue our study and give further context to our ship-based measurements.

Shawnee with a BioArgo float on the back deck, immediately prior to deployment. Credit: Leah Johnson, Brown University
Shawnee with a BioArgo float on the back deck, immediately prior to deployment. Credit: Leah Johnson, Brown University

Each type of platform carries a unique sensor package, though most of them measure temperature, salinity, and depth. The floats and gliders utilized in the EXPORTS cruise also include a suite of biogeochemical sensors that measure oxygen, bio-optics, and nitrate. The bio-optical package measures things like chlorophyll, a proxy for the abundance of phytoplankton, and backscatter, which is used to study particles in the water that may be important to carbon export.

On this cruise, I was tasked with deploying two BiogeochemicalArgo floats, to both inform our mission while at sea and enable us to continue our study of the region after we return home. Similar to gliders, these floats move through the water column by finely tuning their buoyancy by moving mineral oil between internal and external bladders. When it is time to take measurements, they sink down to 6,561 feet (2,000 meters) and begin gathering data on their way to the surface, constructing a profile of the water’s properties. Once at the surface, they transmit this data back to servers on land via satellite, who process and send it back to the team on the ship.

Two BioArgo floats running through post-shipment checks on the deck of the RRS Discovery. Credit: Shawnee Traylor, MIT/Woods Hole Oceanographic Institution
Two BioArgo floats running through post-shipment checks on the deck of the RRS Discovery. Credit: Shawnee Traylor, MIT/Woods Hole Oceanographic Institution

We deployed the floats in the first few days of the cruise, transiting over the first drop point at 4:30 AM. The brisk early morning air stole any lasting grogginess from my eyes as I grabbed a drill and opened their wooden crates. I hooked two alligator clips onto the head of the float and successfully made communication, waking it from its slumber. After a few final pre-deployment checks, it was the moment of truth. My fingers hovered above the keyboard, ripe with the responsibility of ensuring a successful deployment. One final keystroke activated the float, and it was time to release it into the vast black waves. How I wished for a blinking light, the purr of a motor, or any sign of life. But it stood silent. I had to trust that once we released it overboard, it would rise once again.

Imaging the Ocean

By Laetitia Drago, PhD student at Sorbonne Université / NORTHERN ATLANTIC OCEAN /

As a child, I used to spend my summers on the rocks near the water in Villefranche-sur-mer, France, my hands busy with a bucket and a small net. I was fascinated by the organisms surrounding me both on the rocks and in the water. Little did I know that I would have the chance to explore the open ocean with a bigger hand net, and multiple imaging instruments on a 231 foot (70.5 meter) long vessel.

Plankton net with 20 meter mesh size on the deck of the Sarmiento de Gamboa ship.
Plankton net with 20 meter mesh size on the deck of the Sarmiento de Gamboa ship (left) and the ship itself (right). Credit: Laetitia Drago

I started my PhD in October at IMEV in Villefranche-sur-mer, France, on the impact of zooplankton on the biological carbon pump through an in-situ imaging approach. It’s in this context that I had the privilege to join this impressive EXPORTS campaign onboard the Sarmiento de Gamboa research vessel. This vessel’s scientific team consisted mostly of people coming from the Woods Hole Oceanographic Institute, researching the ocean twilight zone, the layer of water between 656 and 3,280 feet (200 and 1,000 meters) below the surface of the global ocean. It is a very important layer of the ocean for the biological carbon pump, the process which is at the core of my PhD.

 The biological carbon pump moves carbon from the surface to the intermediate and deep oceans. This process starts at the surface of the water where small plantlike organisms called phytoplankton do photosynthesis, the process of using light to transform carbon dioxide into organic matter. This phytoplankton is then eaten by zooplankton, which transfer the carbon from the surface to the intermediate and deep oceans through multiple processes such as producing fecal pellets and daily migration up and down throughout the ocean. These organisms constitute an important source of food for fish, making them an important link in the food webs supporting fisheries all around the world.

 To look more closely at the ocean twilight zone, I brought imaging instruments to observe which organisms live in this layer. These included Underwater Vision Profilers (UVP). These instruments were developed in my lab in order to study large particles and zooplankton up to nearly 20,000 feet (6000 meters) in depth! The instrument counts and measures particles greater than 0.1 millimeters and saves images of the ones greater than 0.6 millimeters because those are the ones with a clear enough resolution to determine which taxonomic group we’re looking at. To do that, it uses a camera and a dedicated red light flashing system. On the image of the UVP6 you can see that there is a light. It can flash every few  seconds depending on how you program the instrument. For the UVP6 for example, it was programmed to flash once every two seconds. This way, it illuminated a volume of water every two seconds below the camera, which can then take a picture of the illuminated field of view.

The UVP5 has already performed more than 10,000 profiles in the ocean throughout the 10 years since its creation. It has been used in all the oceans fixed on CTD rosettes like the one used during this cruise. CTD rosettes are submerged in the ocean to measure temperature, depth and salinity in the ocean.

Deployment of the CTD frame containing the UVP5 and Niskin bottles. Credit: Laetitia Drago
Deployment of the CTD frame containing the UVP5 and Niskin bottles. Credit: Laetitia Drago

I also used two UVP6s, a more versatile, small and powerful version of the instrument. Each one was in a cage, fixed to a drifting line which was deployed at sea. We hope that the images taken by these two instruments will help improve our knowledge of the biological carbon pump.

UVP6 in its cage (left) and during the deployment (right). Credit: Laetitia Drago
UVP6 in its cage (left) and during the deployment (right). Credit: Laetitia Drago

I also brought with me a Planktoscope. This microscope platform was designed at Stanford University by Plankton Planet and the Prakash Lab in the context of frugal science, which aims to bring science to the maximum number of people. It can be customized, redesigned and mounted aboard a ship by anyone in the world at a very affordable price!

Using a net or the water from the Niskin bottles (as seen in the second picture), I imaged the organisms living in the water and watched as the composition of organisms changed between the different parts of the ocean that we sampled.

Planktoscope imaging a sample collected with the net. Credit: Marley Parker and Laetitia Drago
Planktoscope imaging a sample collected with the net. Credit: Marley Parker and Laetitia Drago

Here a few images acquired by these instruments:

From left to right: Copepod (UVP6), Fish (UVP6), Shrimp (UVP5), Radiolarian (UVP5), Copepod nauplii (Planktoscope), Thalassionema diatom chain (Planktoscope). Credits: Laetitia Drago
From left to right: Copepod (UVP6), Fish (UVP6), Shrimp (UVP5), Radiolarian (UVP5), Copepod nauplii (Planktoscope), Thalassionema diatom chain (Planktoscope). Credits: Laetitia Drago

As you might know, this journey was not an easy one. Three storms came our way during our mission at the PAP site. Nevertheless, we managed to do 11 profiles with the UVP5 and get six and a half days of images from each UVP6 with one image every two seconds. This amounts to around 148,500 vignettes for the UVP5, 323,000 vignettes for the UVP6 and 79,200 vignettes for the Planktoscope. 

The storms were unfortunate for our life on board and the conditions which stopped us from sampling during half of our presence at the PAP site. However, it was fortunate in the sense that we have a unique dataset containing data before the first storm as well as data between the three storms. This will hopefully give us an idea on the potential impacts that one or multiple storms can have on zooplankton and particle flux.

Our hard work was of course rewarded by the data acquired but also by a wonderful sunrise at the end of a very long last night of sampling followed by a 15 minute visit from a group of common dolphins on our way back to Vigo.

Sunrise on the Sarmiento de Gamboa.Credit: Laetitia Drago
Sunrise on the Sarmiento de Gamboa.Credit: Laetitia Drago
Common dolphins. Credit: Laetitia Drago
Common dolphins. Credit: Laetitia Drago

Finally, I want to deeply thank the team in Villefranche-sur-mer, France, who trusted me with handling the instruments and supported me from afar as well as the very motivated team of scientists and the ship’s crew support who helped us acquire very important data which will hopefully help us to understand a little bit more the carbon processes at hand in the ocean twilight zone.