Notes from the Field

So Long, and Thanks for All the Leaves

February 18th, 2025 by Shawn Serbin, NASA’s Goddard Space Flight Center


It’s really hard to believe, but I will already be departing Panama tomorrow.  When I arrived a week ago, on February 5, I had a hunch but didn’t fully appreciate just how busy our AVUELO ground and airborne teams would be keeping up with our ambitious sampling and data collection plans and schedule. For me personally, getting to participate in the campaign was exciting because it meant a continuation of my past tropical forest research in Panama, which included similar sampling and objectives at the Smithsonian Tropical Research Institute’s (STRI) crane sites and on Barro Colorado Island.

I had some expectation of how long and challenging the field days would be, especially when they are repeated for multiple days in a row. Yet for AVUELO, the sheer scale and scope of logistical coordination across multiple teams and locations, instrumentation, and lab analyses have been impressive to witness, including how well the whole team has stepped up to meet the challenges and the correspondingly long days in the field and lab. The whole team has come together to support the goals and interests of everyone involved, and it’s been humbling to witness how quickly the team gelled and really became a “well-oiled” machine.  I will surely miss helping with sample processing after I depart!

Thinking back, our first field day at the Smithsonian Parque Natural Metropolitano canopy crane resulted in far more samples to process in the lab than we expected. Despite some remaining uncertainty and a late start on our first sampling day, the team quickly found their sample collection groove and continued the same basic approach until our final sampling day on February 11. Over our time here, the incredibly skilled STRI crane operators, Edwin Andrade and Oscar Saldaña, made sure we could access and collect the samples we needed with ease in order to link with the remote sensing data. We even had some extra help from the forest locals.


In the STRI labs in Gamboa, folks have been busily processing the samples coming in from multiple sites across Panama to try and keep up with field teams. As is common at this point in a campaign, the lab mimics an assembly line, with samples rapidly moving between stations to measure leaf area, leaf water content, and leaf optical properties, as well as prepare samples for other analytical measurements to happen at a later time. Given AVUELO is a hyperspectral remote sensing campaign, we had to have our spectrometers in the lab to measure leaf-level reflectance and transmittance (photos below). With these data, we are building a very comprehensive spectral library that we will use to estimate foliar functional traits and to inform tropical scaling and spectral modeling research.


AVUELO also represents a multi-year dream of mine to be able to link years of field campaigns in Panama to AVIRIS imagery.  It has been incredible to finally see NASA AVIRIS imagery over these sites in Panama, where scientists have already been building a data record for more than a century.


We have been lucky enough to have multiple flight days already, and I am hopeful there will be more, but the data already collected will provide incredible new research opportunities. I am looking forward to working together to develop the products and datasets the community can use to conduct novel science and make new discoveries!

Despite just how busy we all have been, we also had time for other activities. On February 7, Natalia L Quinteros Casaverde, a postdoctoral research associate at NASA Goddard, provided a seminar in Spanish during the STRI seminar series.


Those in attendance had many great questions, and it’s clear this campaign is generating a lot of interest from the community, and our team is eager to help support the use of the data! We also had time to visit Casco Viejo (photo below), though I never did have a chance to jump in the hotel pool. It’s bittersweet to head home, but I look forward to working with the team on data analysis and maybe even coming back to Panama soon to visit, conduct science, and continue to contribute to the rich history of tropical forest research. So long, and thanks for all the leaves!

Day One: AVUELO’S First Tropical Survey

February 11th, 2025 by Dave Schimel, NASA's Jet Propulsion Laboratory

On February 6, 2025, after years of preparation and four months of intense planning, an aircraft with an advanced NASA instrument took off for the AVUELO campaign’s first survey in the tropics, while teams on the ground spread out to collect ground-truth data. The Airborne Validation Unified Experiment: Land to Ocean (AVUELO) is a partnership between NASA, the Smithsonian Institution’s Tropical Research Institute, and the Costa Rican Fisheries Federation, as well as universities and institutes in the United States and Panama. 

AVUELO’s goal is to calibrate a new class of space-borne imagers for tropical vegetation and oceans research. These data will eventually help us understand how the thousands of tree species and marine organisms create unique ecosystems.

Day one, though, was a nail-biting, adrenaline-fueled day as we waited to see if plans for aircraft flights and the coordinated fieldwork would come together or whether the team would go back to the drawing board. Many members of the team had done similar projects in many regions, but each airborne project has its own unique features.

The weekend before, the teams had been thrilled to watch maps on the flight tracker as the twin-engine turboprop aircraft left California for Texas, then stopped in Mexico for fuel, and ultimately arrived in Panama. 

On January 6, after the teams arrived for the fieldwork, we had a preflight phone call and agreed on a plan. About 20 scientists collected and measured leaves, while other crews analyzed samples in the laboratory. The aircraft took off and began methodically collecting data over the core study area, a 25- by 50-mile block along the Panama Canal basin, which has dense rainforests, coastal mangroves, rivers, and lakes.


We watched on the flight tracker as the plane perfectly executed the planned flight, hoping for the weather we needed. We were thrilled as field teams returned with numerous successfully and arduously collected leaf samples. An hour or so after the aircraft landed, the team looked at previews of the imagery collected. Despite some clouds in the scenes, most of the key sites were clear, and with this data, the project was off to a successful start. The fieldwork will continue for another month as teams work to fully achieve AVUELO’s scientific objectives.


The day’s accomplishments were satisfying in a cool, calm scientific way, knowing we had started collecting the data that could transform our understanding of tropical forests, while knowing the road to get here was long. It was viscerally thrilling to have a successful first day after months of intense planning and challenges to overcome, which included coordinating arrivals from multiple universities and centers and organizing housing, safety plans, and communications between the aircraft aloft, crews on the ground, and boats in the ocean.

When the previews of the data appeared and we knew we had a successful first day, it was like a weight was being removed. It was time for a celebration!

Validating PACE and Inspiring Future Scientists

October 31st, 2024 by Brenna Biggs, NASA Airborne Science Program

At a weekend science camp in the remote village of Bautista, Philippines, the faces of students at Coloscaoyan National High School quickly changed from skepticism to excitement when they realized that the NASA scientist speaking to them on Zoom was in fact not artificial intelligence. According to the Deputy Executive Director of the Department of Science and Technology of the Philippine Science High School System, “Many of them expressed disbelief that an actual NASA scientist would have time for them or engage with them… We can’t express enough how thankful we are for your time and for the impact you have on those students… Truly, you have left an indelible mark on each of those students and inspired many of them to become future scientists.”

Students and faculty at Coloscaoyan National High School in the Philippines during a PACE-PAX outreach event. Photo by Brenna Biggs.

This story is from one of 63 virtual student engagement events held for NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem Postlaunch Airborne Experiment (PACE-PAX). The mission used aircraft (the NASA ER-2 and CIRPAS Twin Otter) and waterborne research vessels (R/V Blissfully,R/V Shearwater, and R/V Fish) to calibrate and validate the data from the PACE satellite, which was launched in February 2024. California was the main hub for the mission, with most of the airborne and waterborne activities occurring in Edwards, Marina, Long Beach, and Santa Barbara.

NASA Earth science missions are not only an opportunity to conduct great science but also to involve students and the general public in the scientific process. As the NASA Airborne Science Program (ASP) science communication lead, I host outreach events for students worldwide. For PACE-PAX, I reached over 2,600 students from transitional kindergarten through 12th grade from 25 schools in three countries (the United States, Philippines, and South Africa) and six states (California, Illinois, Ohio, Maryland, New Hampshire, and Texas). Over 50 percent of these schools were located in California to highlight the state as the mission’s hub.

Students at Empangeni High School in South Africa during a PACE-PAX outreach event. Photo by Brenna Biggs.

Students at Philippine Science High School Eastern Visayas Campus pose for a picture after a PACE-PAX outreach event. Photo by Brenna Biggs.

Each outreach event consisted of a customized presentation with a duration ranging from 10 minutes to an hour based on grade level and class availability, followed by a question-and-answer (Q&A) session for students to ask about PACE-PAX, NASA, or whatever they wanted. On some occasions, special guests from PACE-PAX were included in content creation, Q&A, or presentations: Ivona Cetinić (NASA GSFC), Bridget Seegers (NASA GSFC), Rachel Smith (University of Maryland, Baltimore County), Norm Nelson (University of California, Santa Barbara), or Brent McBride (University of Maryland, Baltimore County). 

Nelson and Cetinić gave virtual tours of Nelson’s lab at UC Santa Barbara for 15 fifth-grade students at Washington Elementary School, also located in Santa Barbara, California. Additionally, Seegers gave virtual tours of her workspace, water filtration system, and other instruments onboard the R/V Blissfully for a total of 65 students from grades three, five, and six at schools located in Ohio, Illinois, and Texas. Our volunteers greatly enhanced the students’ experiences.

The schools included for PACE-PAX outreach represented a wide variety of students from different socioeconomic backgrounds, academic levels, and demographics. Out of the 25 schools reached, 17 were American public schools, 2 were American private schools, and 6 were international schools. Notably, we reached 50 at-risk and 41 special education fifth-grade students at a school in a disadvantaged community in Corpus Christi, Texas; we hosted three bilingually interpreted events (two English/Spanish and one English/Tagalog); we reached 381 high schoolers in middle- or low-income municipalities in the Philippines. Finally, 30 presentations were delivered to students at schools that are part of the NASA-sponsored Global Learning and Observation to Benefit the Environment (GLOBE) program.

Bridget Seegers (NASA GSFC) answers a 6th grader’s question after a virtual R/V Blissfully tour during a presentation for Wheaton Christian Grammar School in Winfield, Illinois. Photo by Brenna Biggs.

These events were very well received. A group of transitional kindergarten students from Felton, California, even sent handmade cards to express their gratitude! As teachers noted, “This activity fueled the love for science in our students,” and “The class and I learned a lot and really enjoyed you and the presentation,” and “NASA truly rocks!” And as students noted, “Thank you for teaching us about PACE-PAX and what the satellites exploring Earth do. I learned that NASA doesn’t only explore outer space, but Earth too,” and that “Learning about the different types of plankton and aerosols was so much fun!”

I look forward to reconnecting with these students for the next NASA mission!

Photos published with permission via student photo releases from Coloscaoyan National High School, Empangeni High School, Philippine Science High School, and Wheaton Christian Grammar School.

Last Stop: Tundra and Peatland Fires in the Northwest Territories

October 2nd, 2024 by Lucas R. Diaz (Vrije Universiteit Amsterdam) and Sonja Granqvist (University of Helsinki)

After our adventures in Quebec and Greenland, it was now time for our last stop in this intense season of fieldwork. This time we were heading to the Canadian Northwest Territories (NWT). Extraordinary wildfire seasons have become a regular occurrence in the NWT. The territory’s 10-year average for the total number of fires was exceeded in 2022, with nearly 600,000 hectares burned in 256 fires. At the time, that was more than any year since the outlier season of 2014. This may seem like a lot, but 2023 was brutal and far more exceptional.

The 2023 record fire season totaled around 3.6 million hectares burned by 303 fires. About 70 percent of the territory’s population, including the capital Yellowknife, was evacuated in the summer of 2023. The current Canadian fire season is also shaping up to be one of the most extreme in the last two decades. These extreme fire seasons have a significant impact on carbon emissions into the atmosphere. In response, our goal for this campaign was to obtain critical field observations to better estimate these emissions, so we packed our bags one last time for this summer and traveled as far north as Inuvik to begin our final data collections.

Our team in the NWT expedition (from left to right): Lucas Diaz (Vrije Universiteit Amsterdam), Atte Korhola, Jan Weckström, Sonja Granqvist (University of Helsinki).

Despite the significant advances in understanding carbon emissions from boreal forest fires in recent years, there are still substantial gaps in our knowledge when it comes to high-latitude tundra fires. Field-based carbon combustion measurements from tundra fires are scarce, and although these fires have historically been less frequent than those in boreal forests, they can be substantial due to the availability of carbon-rich organic soils in these regions. Part of our team on this expedition has previous field experience with tundra fires, and we know that tussocks can be used as reference points to estimate how much of the soil organic layer was lost due to fire.

Tussocks as reference points: the difference between unburned (left) and burned (right) tussock dominant tundra landscapes. Tussock-forming sedge species tend to survive and resprout after fire, so measurements of the tussock crown height and soil organic layer can be used to estimate the burn depth. Photos by Lucas Diaz.

In 2023, a large tundra fire broke out near the town of Inuvik. North of the Arctic Circle, the fire is in a fairly remote area with no road or river access. So, we sampled this fire by helicopter in an effort to estimate and date carbon stocks and calculate the amount of carbon released into the atmosphere. Along the fire perimeter, we found different types of dominant vegetation in the tundra, ranging from the tussocks to shrublands and even sparsely treed areas.

The view of the northern landscape was mesmerizing from above! The rolling hills stretched endlessly across the horizon, while the striking polygonal soil patterns and distinctive pingos added to the captivating view. The tundra was dotted with lakes of various sizes and ancient riverbeds. With paleo specialists Atte Korhola and Jan Weckström accompanying us, we couldn’t resist the opportunity to sample a lake and study the historical fire record preserved in its sediments. We are grateful to the Aurora Research Institute and the local community for welcoming us.

Working in the tundra: Sonja Granqvist measuring a tall shrub for aboveground carbon stocks estimation; lake sediment core collected inside the fire perimeter; the edge of the fire scar spotted from the helicopter. Photos by Lucas Diaz and Jan Weckström.

After an intense week in Inuvik, our team hit the road again, this time heading south to the Scotty Creek Research Station, about 50 kilometers from Fort Simpson. We began our journey from Yellowknife to Fort Simpson, uncertain whether the ongoing fires would allow us to travel. The smell of smoke was overwhelming, and the sight of the recently burned forest along the road was stark. Along the gravel road to Fort Simpson, we encountered bison, sampled some peatlands, and spent an hour waiting for a ferry. In the evening, we watched as the moon took on an intense red hue, tinted by the smoke particles in the air.

The next morning, we boarded a floatplane from the Mackenzie River to the Scotty Creek Research Station, where a friendly crew gave us a warm welcome. The research station is so isolated that it’s only accessible by plane. The creek, where the station is located, drains a 152-square-kilometer area of boreal forested peatland. Due to the permafrost in the region, significant thawing has transformed parts of the landscape from forested permafrost to treeless wetlands. In October 2022, the station suffered massive damage from an extraordinary late-season wildfire that raged for nearly 100 days before finally reaching the camp. The research station had just reopened during our stay there. This is good news for the entire scientific community, given the importance of this unique site in the heart of the boreal forest.

On the way to Scotty Creek: a bison along the road (left); the smoky sky due to the active fires in the region (middle); and the floatplane that took us to the research station (right). Photos by Lucas Diaz.

The goal of our Scotty Creek campaign was to sample the effects of fires on peatland ecosystems, aiming to better understand the climate change implications of wildfire in this fire-sensitive landscape. We spent three days in the field, sampling key ecosystems from sunrise until sunset.

A special shoutout goes to the station crew, whose professionalism made everything run smoothly. After long days of work, returning to camp was a treat, especially with our hosts preparing dinner for us. We’ll never forget their hospitality—thank you, Scotty Creek team!

A remote research station with critical importance: Scotty Creek view from the plane (left), where it is possible to see both the marks left by the fire and the new firebreak system built around the camp; and the team happy with the work accomplished at the station (right). Photos by Lucas Diaz and Mason Dominico.

And so, our journey comes to an end. It was a summer to remember, one filled with hard work but also moments of joy and discovery. People will read this post, and in the near future, others will study the findings of our field research. Our results may be cited and applied by fellow scientists. Yet, no data or paper can truly capture what this season of fieldwork was like. Only we hold those memories. The months of preparation that preceded the trip: developing research protocols, selecting sites, navigating logistics, and endless paperwork. The long hours driving both paved and dirt roads. Fieldwork under the scorching sun, and other days when cold rain chilled us to the bone. The relentless mosquitoes. Simple lunches in the field contrasted with the risotto made from mushrooms foraged at burned sites. The flat tire. The cracked car window. Lost pens. Inventorying more than 400 trees in a single plot. Charcoal covering our hands and faces day after day. Setting up camp in incredible, remote places. The joy of plunging into a cold lake after a hard day of work. Spontaneously stopping the car on our day off because the excitement of sampling two more sites was too hard to resist. Unexpectedly gaining four extra days in Greenland due to a canceled flight. Swimming in the frigid waters of a fjord. Climbing to the summit of a mountain.

We have had the privilege of visiting places most people will never see, and for that, we are deeply grateful. This chapter of fieldwork for our Ph.D. research is over, but the Arctic continues to warm, and intense fire seasons in these regions are here to stay. We are eager to better understand the complex interactions between these changes and Arctic-boreal fires. As we return home, our suitcases packed with data, the time for  analyses begins—now from our offices, but with this field season always on our minds.

Photos from the field: a collection of some of our field plots with different ecosystems we sampled during this fieldwork season. Photos by Lucas Diaz.

The NWT fires expedition was organized within the Research Council of Finland Academy Research Fellow project “Fire in the Arctic,” led by Meri Ruppel, and the Kone Foundation project FLARE. The fieldwork was also part of FireIce (Fire in the land of ice: climatic drivers & feedbacks), a Consolidator project led by Sander Veraverbeke and funded by the European Research Council. FireIce is affiliated with NASA’s Arctic-Boreal Vulnerability Experiment (ABoVE).

This blog post was co-written by Lucas R. Diaz, a Ph.D. student at Vrije Universiteit Amsterdam, and Sonja Granqvist, a Ph.D. student at the University of Helsinki, both studying Arctic-boreal fires.

Lucas and Sonja at the bottom of the Kangerluarsuk Tulleq fjord, Greenland. Photo by Sander Veraverbeke.

Twenty-one Hours a Day on a 30-Foot Floating Science Lab

September 24th, 2024 by Bridget Seegers, Morgan State University

Research Vessel (RV) Blissfully is a 30-foot sailboat that is the science lab and home for two sailing scientists, Captain Gordon Ackland and myself, Dr. Bridget Seegers. The RV Blissfully is a recent addition to the fleet of research vessels. Previously, Blissfully’s days were primarily spent peacefully floating snug in a San Diego boat slip with an occasional day sail. However, Blissfully was volunteered to support the PACE-PAX campaign and therefore transitioned a month ago into RV Blissfully.

RV Blissfully at the dock before heading out for a day of sampling. Photo by Bridget Seegers.

In five slightly stress-filled days, research gear was loaded, Blissfully’s sitting area became a lab, and cables and instruments ready for deployment were hung from the stern. The goal is to gather ocean data for the validation of data from the exciting new PACE satellite. Now, RV Blissfully spends eight to 10 hours a day sailing for science.

Days on RV Blissfully begin in harbor with an alarm waking our sleeping research team. A thermos is quickly filled with coffee and poured into RV Blissfully crew mugs. Some mornings before departing, Bridget does video visits with classrooms of 4th and 6th graders, answering their questions about the ocean and life as a scientist.

Then, the dock lines are tossed, and a 2.5-hour morning commute begins. Leaping dolphins are frequently spotted along the way, and once a pair of fascinating mola molas were observed “swimming” along the surface. 

The commute is also breakfast time, typically with yogurt, granola, and fruit.

Breakfast is served during the morning commute on RV Blissfully. Photo by Bridget Seegers.

A crew of two means everyone onboard fills many roles, including galley chef along with scientist, mechanic, and captain. The destination, 12 miles (20 kilometers) south, is an oil rig that is home to additional research instruments whose data will be combined with RV Blissfully’s data for a more complete picture of conditions in the atmosphere and ocean. The location is also a flyover target for the ER-2 and Twin Otter research planes, allowing for even more data sets for PACE validation. 

The Twin Otter research plane flies past RV Blissfully on sampling station. RV Blissfully’s surface light sensor is seen in the foreground. Photo by Bridget Seegers.

Once on station, a bucket is tossed and 10-liters of water is gathered for a variety of samples, which are processed below deck. These water samples are filtered and frozen at -320ºF (196ºC) in liquid nitrogen or preserved in jars for further analysis when shipped back to the Ocean Ecology Lab at NASA’s Goddard Space Flight Center. The analysis will produce data about the community of microscopic ocean organisms like phytoplankton and bacteria that are critical to understanding our ocean. Bridget takes the lead on the water filtering, and because the lab bench used to be a couch, it is literally at knee-height, and therefore she spends much time working on her knees.

Bridget Seegers is filtering sea water samples in the cabin at the knee-high research bench. Photo by Gordon Ackland.

Meanwhile on the stern, Gordon is measuring ocean light with an instrument called a HyperPro—he’s a real pro with the HyperPro.

Gordon Ackland on RV Blissfully holding the HyperPro instrument on station in front of the oil rig that has additional research instruments providing data for PACE-PAX. Photo by Bridget Seegers.

Once logging begins, he lets the instrument fall to a depth of 20 meters before hauling it up to the surface and letting it descend again to 20 meters. This is repeated 15 times at each station, and the final cast goes to 60 meters to explore the ocean light further below.  The HyperPro is critical for PACE validation because it measures light like the PACE Ocean Color Instrument, so it allows scientists to compare measurements from the ocean with light measured all the way in space.

The routine of collecting water samples and HyperPro profiles keeps the crew busy station after station. 

RV Blissfully’s crew. Gordon Ackland completing HyperPro profiles while Bridget Seegers takes a break from filtering seawater samples below deck. Photo by Bridget Seegers.

Occasionally, the routine is broken by the spotting of wildlife or a wave through a porthole. The shifting waves and weather keep it interesting. The days are beautiful, exhausting, a bit tedious, and inspiring. All emotions fit onto RV Blissfully’s 30 feet out at sea. The winds pick up through the afternoon, so when the final station is done for the day, a sail is frequently raised for the return to harbor.

A sailboat significantly reduces the fuel used for research. RV Blissfully used 14 gallons of diesel over nine days of sampling, covering roughly 230 miles and providing data from 19 research stations. Eventually, RV Blissfully is docked, the instruments are rinsed, the crew wanders to shore for dinner as the sun sets, and after dinner they wander back to RV Blissfully for sleep—resting up to be ready for the rinse and repeat research routine to begin again.

This was the crew’s first sailing field campaign, and both Gordon and Bridget would like to do it again. They are grateful for all the friends, family, and colleagues whose support made it possible. Accomplishing PACE-PAX research on RV Blissfully made the sailing for science dream a reality.