Data from NASA’s newest Earth-observing satellite, which will provide insight into ocean health, air quality, and the effects of a changing climate, are now available. The Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite launched on February 8, and after several subsequent weeks of testing of the spacecraft and instruments, the mission is gathering data that the public can access.
PACE includes three instruments: The Ocean Color Instrument (OCI), built at NASA Goddard Space Flight Center, observes the ocean, land, and atmosphere across more than 200 unique wavelengths spanning ultraviolet, visible, and near infrared light. It is particularly suited to identifying phytoplankton communities in the ocean.
HARP2, designed and built by UMBC scientists and engineers, and SPEXOne, built at the Netherlands Institute for Space Research (SRON) and Airbus Netherlands B.V., are both polarimeters, which measure light that has reflected off clouds and particles in the atmosphere. These particles, known as aerosols, can range from dust to smoke to sea spray and more.
“First light,” as the first data received from satellites in orbit is known, is a key milestone in the progression of any scientific instrument destined for space.
““When I look at the first light PACE images, I feel like I have put on magical eye glasses and am seeing the true characteristics of aerosol plumes from a satellite for the first time.”
“To me, first light means the conclusion of all the engineering work to develop HARP2 and the beginning of our science quest exploring and understanding the data from PACE,” shares Vanderlei Martins, professor of physics at UMBC and lead of the HARP2 team. “First light means ‘It is working!’ and the question right after first light is, ‘What does it mean?’”
Answering big questions about Earth’s interrelated systems
With data from PACE’s polarimeters, scientists will be able to measure cloud properties and monitor, analyze, and identify atmospheric aerosols to better inform the public about air quality. Scientists will also be able to learn how aerosols interact with clouds and impact cloud formation, which is essential to creating accurate climate models.
The HARP2 team will focus on air pollution, the effect of aerosols produced by humans on cloud formation, and the energy balance of the planet, Martins says. “We will learn about the type of aerosols in Earth’s atmosphere: What they look like in terms of size and shape matters in terms of their health effects,” he says. “The way they absorb and scatter light affects how they interact with solar radiation and influence the energy balance of the planet: Do they produce heating or cooling of the planet, and in which circumstances?”
“I have plans to use PACE aerosol and ocean products to better understand how nutrient-rich aerosols are deposited into the global ocean and how ocean plankton communities respond to this nutrient source,” adds Lorraine Remer, a UMBC climate researcher affiliated with the Goddard Earth Science Technology and Research Center II, one of UMBC’s NASA-partnered research centers.
First, though, “We will spend the next weeks and months tuning our parameters to coax out the most and best possible information on aerosols and clouds,” Remer says. “Then, the next step is to compare PACE’s output with established sensors on the ground.” A validation experiment in September 2024 called PACE-PAX will enable and encourage those comparisons.
PACE lets scientists put on “magical eye glasses”
Because of the power and unique capabilities of the instruments on PACE, “We see confident atmospheric parameters that have never been seen from any previous NASA mission,” Remer says. And because the data will be completely public, the benefits will go far beyond work that current PACE scientists will do.
“PACE data will be free for everyone around the globe and will be useful for decades to come,” Martins says. “Events on Earth will come and go, and they will be recorded forever by the PACE sensors. Beyond our own science studying aerosols, clouds, and the energy balance of the planet, this data will be explored by students and scientists for all sorts of applications that I can’t even imagine.”
Martins expects UMBC scientists to write proposals to analyze PACE data for many years, and many of these projects will involve opportunities for students at all levels to gain experience with research. For now, PACE scientists are still relishing the successful launch and return of first light from the PACE instruments.
“When I look at the first light PACE images,” Remer says, “I feel like I have put on magical eye glasses and am seeing the true characteristics of aerosol plumes from a satellite for the first time.”
Jeremy Werdell, PACE project scientist, shepherded the project from start to finish, beginning when Martins pitched him the idea of including a HARP2-like instrument on board. “We’ve been dreaming of PACE-like imagery for over two decades. It’s surreal to finally see the real thing,” he says. “The data from all three instruments is of such high quality that we can start distributing it publicly less than two months from launch, and I’m proud of our team for making that happen.”
Tags: CNMS, ESI, gestar2, Physics, Research
