The Research Vessel Endeavor is the floating
laboratory that scientists will use for the ocean-going portion of the SABOR
field campaign this summer.
Image Credit:
Tom Glennon/University of Rhode
Island
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.
Technician Richard Hare installs instruments on
NASA's UC-12 aircraft at NASA’s Langley Research Center in preparation for the
airborne portion of the SABOR field campaign.
Image Credit:
David C. Bowman/NASA Langley
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.
Knowledge of the vertical distribution of phytoplankton is needed to
understand their productivity, which largely drives the functioning of ocean
ecosystems. These data will allow NASA scientists to improve satellite-based
estimates of how much atmospheric carbon dioxide is absorbed by the ocean.
Simultaneous measurements from the ship will provide a close-up perspective,
as well as validate measurements from the aircraft. Alex Gilerson of the City
College of New York will lead a group on the ship operating an array of
instruments including an underwater video camera equipped with polarization
vision, which can accurately and continuously measure key characteristics of the
sky and the water while underway.
A team led by Ivona Cetinic, of the University of Maine in Walpole, will
analyze water samples for carbon, as well as pump seawater continuously through
various on-board instruments to measure how ocean particles, including
phytoplankton, interact with light. And a group led by Mike Behrenfeld of Oregon
State University in Corvallis will employ a new technique to directly measure
phytoplankton biomass along with photosynthesis.
"The goal is to develop mathematical relationships that allow scientists to
calculate the biomass of the phytoplankton from optical signals measured from
space, and thus to be able to monitor how ocean phytoplankton change from year
to year and figure out what causes these changes," Behrenfeld said.
NASA satellites contributing to SABOR include the Cloud-Aerosol Lidar and
Infrared Pathfinder Satellite Observation (CALIPSO), which observes clouds and
tiny particles in Earth's atmosphere, as well as the Terra and Aqua satellites,
which measure atmospheric, land and marine processes.
Analysis of the combined data from ship, aircraft and satellites is expected
to help guide preparation for a new advanced ocean satellite mission called the
Pre-Aerosol, Clouds, and ocean Ecosystem (PACE) mission. PACE will extend
observations of ocean ecology, biogeochemical cycling and ocean productivity
begun by NASA in the late 1970s with the Coastal Zone Color Scanner and
continued with the Sea-viewing Wide Field-of-view-Sensor (SeaWiFS) and the
Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on Terra and
Aqua.
SABOR is funded by the Earth Science Division in the Science Mission
Directorate at NASA Headquarters. Project management and support will be
provided by the Earth Science Project Office at NASA's Ames Research Center in
Moffett Field, California. Other mission scientists include researchers at the
Naval Research Laboratory and WET Labs, Inc., in Narragansett, Rhode Island.
For more information on the SABOR field campaign, visit:
NASA monitors Earth's vital signs from land, air and space with a fleet of
satellites and ambitious airborne and ground-based observation campaigns. NASA
develops new ways to observe and study Earth's interconnected natural systems
with long-term data records and computer analysis tools to better see how our
planet is changing. The agency shares this unique knowledge with the global
community and works with institutions in the United States and around the world
that contribute to understanding and protecting our home planet.
For more information about NASA's Earth science activities in 2014,
visit:
NASA
Guillermo Gonzalo Sánchez Achutegui
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