NASA Curious Universe Explores Oceanography with PACE and SWOT

Podcast at a glance

NASA's Curious Universe dives into the oceans, highlighting two flagship missions that examine how the planet's oceans function both biologically and physically. The first mission, PACE, maps ocean color to identify phytoplankton communities and their role in Earth’s carbon cycle. The second mission, SWOT, measures surface water and sea level from space to illuminate ocean circulation and its planetary impact. The episode weaves expert insights with personal perspectives from the scientists, including Cody (Cecile) Rousseau and Josh Willis, as well as Climate Elvis, a playful alias used to engage audiences on climate communication.

• PACE enables color-based identification of phytoplankton diversity from space, advancing our view of the ocean’s biological health.
• SWOT creates high-resolution sea level maps, improving understanding of how water moves and heat is distributed globally.
• The data from these missions informs fisheries, coastal management, and climate science.
• Personal storytelling and creative science communication help bridge complex topics to the public.

Overview

The podcast episode centers on two NASA missions that together provide a more complete picture of how Earth’s oceans work. The program explains that Earth is an ocean planet, with currents influencing regional climates and phytoplankton driving oxygen production and carbon sequestration. The conversation introduces the Plankton Aerosol Cloud and Ocean Ecosystem Satellite, abbreviated as PACE, and the Surface Water and Ocean Topography mission, abbreviated as SWOT. Through interviews and expert commentary, the hosts explore how observing oceans from space, using color as a diagnostic tool, offers a unique window into ocean biology and biogeochemistry.

PACE: Color as a Scientific Lens

Cecile Rousseau, a scientist at NASA Goddard Space Flight Center, explains that color is a critical lens for studying oceans. Phytoplankton are tiny aquatic plants whose pigments absorb and reflect light in ways that color the ocean. PACE uses the Ocean Color Instrument to capture subtle color variations across ultraviolet to near infrared wavelengths, enabling researchers to discern phytoplankton communities and pigment composition. This level of spectral detail moves beyond simple blue-green-blue imagery, revealing shifts in phytoplankton species and the related ecological consequences.

PACE’s data are already informing practical outcomes, such as aiding fisheries and coastal managers in forecasting blooms and tracking aerosols, smoke, dust, and sea salt in the atmosphere. The program emphasizes that phytoplankton play a major role in regulating Earth’s climate by absorbing carbon dioxide and supporting the marine food web, ultimately driving oxygen production that sustains life on Earth.

SWOT: Mapping Sea Level and Surface Water

Josh Willis, an oceanographer at NASA's Jet Propulsion Laboratory, introduces SWOT as a mission designed to map surface water and topography with unprecedented resolution. SWOT employs two radars that bounce signals between the spacecraft and the ocean surface, enabling the determination of water elevation and angle. This technique produces a two-dimensional swath of sea level, effectively turning the ocean into a high-resolution map rather than a single data point. The resulting data illuminate how sea level rises in different regions due to thermal expansion and mass loss from ice sheets, as well as how ocean currents tilt the sea surface, shaping global and coastal dynamics.

Willis discusses the broader context of sea level rise, noting that two centuries of warming are driving ongoing changes that are unlikely to reverse in our lifetimes. He also explains the gravity-related effects of melting ice sheets, how changes in ocean heat content accelerate sea level rise, and why space-based measurements provide the most comprehensive view of the world’s oceans.

Intersections and Implications

The episode emphasizes the synergy between PACE and SWOT. While PACE deciphers the ocean color signals to understand phytoplankton ecology and the carbon cycle, SWOT maps the water surface and topography to reveal how ocean circulation and water distribution respond to climate forcing. Together, these missions help fisheries, coastal managers, and scientists develop more accurate models of ocean dynamics, climate feedbacks, and ecosystem health. Beyond science, the hosts highlight the human dimension by discussing how scientists translate complex data into accessible narratives, including the Climate Elvis persona used to engage audiences around climate communication.

Guest Perspectives and Takeaways

Climate Elvis, a persona adopted by Josh Willis in public outreach, illustrates the importance of storytelling in science. The episode also includes reflections on career paths into oceanography and how scientists balance the weight of climate information with effective communication. The dialogue demonstrates how cutting-edge satellite instruments enable a renaissance in ocean science, offering both depth and accessibility in understanding the Earth system.