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.
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.
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.
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.
Meanwhile on the stern, Gordon is measuring ocean light with an instrument called a HyperPro—he’s a real pro with the HyperPro.
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.
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.
Thursday August 12, 2024: PACE-PAX Day 10 of 28
We are in the field supporting PACE-PAX (Plankton, Aerosol, Cloud, ocean Ecosystem Postlaunch Airborne eXperiment), a multi-disciplinary mission that involves two aircraft—the NASA ER-2 and CIRPAS Twin Otter—and several mobile ocean assets, all helping to validate observations and data products from NASA’s new satellite observation platform, PACE. Our days typically start with an initial look at the weather in the area of operations and airport conditions during takeoff and landing. Both the ER-2 and Twin Otter will fly today since the weather is acceptable for launch, science, and landing.
After breakfast at the hotel, our small team with a big name (LARGE, or the Langley Aerosol Research Group) heads to a semi-abandoned former control tower at the Marina Municipal Airport to check on a set of instrumentation operating 24/7 on the 7th floor. LARGE measures the properties of ambient aerosols, which are small particles in the atmosphere that can affect climate, seed clouds, and degrade air quality. Satellite observations quantify the sunlight scattered by particles to retrieve more complex properties like the particle concentration, size, and composition. For PACE-PAX, we are most interested in how those particles scatter and absorb light, making direct measurements—from the tower and on the Twin Otter aircraft—to provide a ground-truth for both the PACE satellite and for the satellite-proxy instrumentation on the ER-2.
Three hours prior to takeoff, the science team meets with the two pilots for the CIRPAS (Center for Interdisciplinary Remotely Piloted Aircraft Studies) Twin Otter aircraft to discuss the day’s flight plan. The Twin Otter is operated by the Office of Naval Research and has been flying missions like PACE-PAX since 1998. Today’s plan will focus on satellite retrievals of aerosol properties over turbid, complex surface waters. The Sacramento-San Joaquin River delta and San Francisco Bay area will be our areas of operation due to their close proximity to Marina and their biologically active and heterogenous waterways. During this meeting, we describe our goals for the flight, the route, and key decision points to enable a successful mission. Our plan today will have three spiral maneuvers between an altitude of 10,000 feet (the functional ceiling for the Twin Otter during PACE-PAX) and our minimum safe flying altitude, a low-altitude transect of the San Francisco Bay, and a low approach at Moffett Field at NASA Ames Research Center.
Following the pilot briefing, the team goes out to the aircraft to start up instrumentation and replace consumables for flight. The current instrument suite is specifically designed for PACE-PAX, with contributions from NASA, NOAA, and NPS. We sample aerosols by bringing air into the cabin via an inlet referred to on the Twin Otter as the “snorkel,” which looks a little like a large black football on a stick that protrudes just past the nose of the aircraft. We then route the air through a series of tubes towards each of the nine instruments in the cabin. Measurements are made in real-time, so the flight scientist on the plane can monitor each instrument during flight and use the measurements to inform decisions about the location and altitude of the aircraft. It takes us approximately 30 minutes to prepare for the flight and make any necessary last-minute trips to the bathroom (no lavatory is available on the aircraft during the three- to four-hour flight!)
With an on-time departure from Marina, we did a counterclockwise circuit: 1) through the Central Valley of California and spiraling over a ground station at California State University Stanislaus; 2) spiraling over a site at the Sacramento-San Joaquin River delta; 3) spiraling over the San Pablo Bay just north of San Francisco; 4) flying at altitudes of 1,000 to 2,500 feet over the San Francisco Bay; and finally 5) completing a low approach at Moffett Field before returning to base. Just before landing, the Twin Otter did two more low-level passes over the runaway at Marina Municipal Airport at an altitude of 70 feet to confirm consistency with the ground-based tower measurements and to evaluate the transmission of the snorkel inlet.
We observed generally clean conditions throughout the flight, since most of the wildfire smoke emissions in the region were being transported to the east and outside our flight domain. Those conditions will be perfect, though, for testing satellite retrieval algorithms under the most difficult conditions when there is low aerosol ‘signal’ in the atmosphere. As a bonus, we got to view the Golden Gate Bridge and San Francisco skyline from a vantage point not often possible in airspace that is so congested with commercial traffic.
After accomplishing our objectives in flight, our day concludes by downloading all of the data collected on that flight and summarizing the science highlights with project management during a post-flight briefing. These meetings are used to track mission progress and to communicate objectives and flight plans for the following day. A typical airborne mission will have two to six flights per week with a flight window of up to six weeks. During today’s meeting, we were briefed on a plan to fly to Southern California to test the other end of the aerosol ‘signal’ spectrum by sampling wildfire smoke from the Bridge, Line, and Airport fires. We were back at the hotel in plenty of time to enjoy a Buffalo Bills blowout win over their division-rival Miami Dolphins, and back on the aircraft the following day.
Our next steps are to process the data and share it with the rest of the science team. This helps other instrument teams analyze their own data and the project leadership evaluate how successfully we completed our objectives for the flight. Once we complete our calibrations during and after the mission, we can perform one last set of quality checks, and then the data will be shared with the public as well.
Hello from sunny Santa Barbara, California, where the ship operations for the PACE-PAX campaign are underway!
The PACE satellite went into orbit in February 2024. Its mission is to help us better understand how the ocean and atmosphere exchange carbon dioxide, as well as how aerosols can fuel phytoplankton blooms and help us track harmful algal blooms around the planet.
PACE-PAX stands for Plankton, Aerosol, Cloud, ocean Ecosystem – Postlaunch Airborne eXperiment (see why we made it shorter?) We are using two airplanes and three ships, among other free-sailing instruments, to gather data that will tell us how well our shiny new satellite, PACE, is doing. We compare our planet-side data with the space-side data so we can make sure we are providing the very best information about the health of the world’s oceans.
Our planes are the ER-2, which is a super high-flying plane that hangs out right near the edge of space, and the Twin Otter, which holds a variety of instruments that are vital to the aerosols part of the mission.
Our ships are the R/V Shearwater, the R/V Blissfully, and the small fleet of R/V Fish boats. The R/V Shearwater is the main ship for this campaign. She holds a science team from multiple organizations and a wide variety of instruments. These include some that stare at the Sun, some that go in the water, and some that stay on deck.
The R/V Blissfully is a sailboat located in Long Beach, California, that is taking an important subset of measurements to complement the Shearwater. She has a crew of just two people, so they are extra busy!
Finally, the R/V Fish are our rapid response vessels. They can move around much faster than the other two and can get to specific locations quickly to take critical measurements.
My job is to collect water samples and filter or store them for analysis back in the lab, all the way back in Maryland. The samples I collect will be analyzed with at least five different instruments, which cannot be brought out to sea. There’s not enough space, and some of the instruments have dangerous elements that are not worth the risk of using while on a boat. There is also the issue of space. You can only bring so much to sea, so we take and preserve samples that can wait for analysis.
PACE-PAX is unique in that our cruises are day cruises. Usually, we get on a boat and don’t get off until the campaign is over. That can be days to weeks to even months living on a ship! This time we get to go back to a hotel in the evenings, which feels very odd in comparison. It can be hard to get your sea legs when you aren’t given time to get used to the motion. I have been relying on medication, ginger, and very salty snacks to get me used to the motion in the ocean.
I hope you enjoy learning more about this campaign in future Notes!
