NASA embarks this week on a coordinated ship and aircraft observation campaign off the Atlantic coast of the United States, an effort to advance space-based capabilities for monitoring microscopic plants that form the base of the marine food chain.
Phytoplankton, tiny ocean plants that absorb carbon dioxide and deliver oxygen to Earth’s atmosphere, play a major role in the global cycling of atmospheric carbon between the ocean and the atmosphere. NASA has long used satellites to make observations of the concentration of phytoplankton worldwide, but new types of tools are needed if scientists are to understand how and why different species and concentrations of phytoplankton change from year to year.
For three weeks, NASA’s Ship-Aircraft Bio-Optical Research (SABOR) experiment will bring together marine and atmospheric scientists to tackle the optical issues associated with satellite observations of phytoplankton.
On Friday, July 18, researchers aboard the National Science Foundation’s Research Vessel Endeavor, operated by the University of Rhode Island, will depart from Narragansett, Rhode Island, to study ocean ecosystems from the Gulf of Maine to the Bahamas. NASA’s UC-12 airborne laboratory, based at NASA’s Langley Research Center in Hampton, Virginia, will make coordinated science flights beginning Sunday, July 20.
“By improving our in-water and aircraft-based measurements of particles and material in the ocean, including phytoplankton, SABOR will advance understanding of marine ecology and the carbon cycle,” said Paula Bontempi, ocean biology and biogeochemistry program manager at NASA Headquarters in Washington.
One obstacle in observing marine ecosystems from space is that atmospheric particles interfere with the measurement. Brian Cairns of NASA’s Goddard Institute for Space Studies (GISS) in New York will lead a team flying a polarimeter instrument to address this issue. From an altitude of about 30,000 feet, the instrument will measure properties of reflected light, such as brightness and the magnitude of polarization. These measurements define the concentration, size, shape, and composition of particles in the atmosphere.
These polarimeter measurements of reflected light provide valuable context for data from another instrument on the UC-12 designed to reveal how plankton and optical properties vary with depth in the water.
Chris Hostetler of Langley is leading a group to test a prototype lidar (light detection and ranging) system, the High Spectral Resolution Lidar-1 (HSRL-1), which uses a laser to probe the ocean to a depth of about 160 feet. These data will reveal how phytoplankton concentrations change with depth along with the amount of light available for photosynthesis.